Kidney Transplantation: Principles and Practice [8th Edition] 9780323547970, 9780323547963

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Kidney Transplantation: Principles and Practice [8th Edition]
 9780323547970, 9780323547963

Table of contents :
1 - Kidney Transplantation: A History......Page 14
2 - The Immunology of Transplantation......Page 22
3 - Chronic Kidney Failure: Renal Replacement Therapy......Page 49
4 - The Recipient of a Renal Transplant......Page 64
5 - Access for Renal Replacement Therapy......Page 82
6 - Brain Death and Cardiac Death: Donor Criteria and Care of Deceased Donor......Page 103
7 - Medical Evaluation of the Living Donor......Page 117
8 - Donor Nephrectomy......Page 128
9 - Kidney Preservation......Page 141
10 - Histocompatibility in Renal Transplantation......Page 152
11 - Surgical Techniques of Kidney Transplantation......Page 170
12 - Transplantation and the Abnormal Bladder......Page 186
13 - Perioperative Care of Patients Undergoing Kidney Transplantation......Page 197
14 - Early Course of the Patient With a Kidney Transplant......Page 211
15 - Azathioprine and Mycophenolates......Page 225
16 - Steroids......Page 244
17 - Calcineurin Inhibitors......Page 255
18 - mTOR Inhibitors: Sirolimus and Everolimus......Page 274
19 - Antilymphocyte Globulin, Monoclonal Antibodies, and Fusion Proteins......Page 296
20 - Other Forms of Immunosuppression......Page 326
21 - Approaches to the Induction of Tolerance......Page 346
22 - Transplantation in the Sensitized Recipient and Across ABO Blood Groups......Page 368
23 - Paired Exchange Programs for Living Donors......Page 380
24 - Kidney Allocation......Page 384
25 - Pathology of Kidney Transplantation......Page 392
26 - Biomarkers of Kidney Injury and Rejection......Page 431
27 - Chronic Allograft Failure......Page 447
28 - Vascular and Lymphatic Complications After Kidney Transplantation......Page 471
29 - Urologic Complications After Kidney Transplantation......Page 500
30 - Cardiovascular Disease in Renal Transplantation......Page 509
31 - Infection in Kidney Transplant Recipients......Page 530
32 - Liver Disease Among Renal Transplant Recipients......Page 552
33 - Neurologic Complications after Kidney Transplantation......Page 579
34 - Cutaneous Disease in Kidney Transplantation Patients......Page 591
35 - Cancer in Dialysis and Transplant Patients......Page 604
36 - Pancreas and Kidney Transplantation for Diabetic Nephropathy......Page 621
37 - Kidney Transplantation in Children......Page 646
38 - Kidney Transplantation in Developing Countries......Page 683
39 - Results of Renal Transplantation......Page 697
40 - Psychosocial Aspects of Kidney Transplantation and Living Kidney Donation......Page 722
41 - Ethical and Legal Aspects of Kidney Donation......Page 737
42 - Evidence in Transplantation......Page 750
A......Page 759
B......Page 761
C......Page 762
D......Page 764
E......Page 766
G......Page 767
H......Page 768
I......Page 769
K......Page 770
L......Page 771
M......Page 772
O......Page 773
P......Page 774
R......Page 776
S......Page 777
T......Page 778
V......Page 779
Y......Page 780

Citation preview

Kidney Transplantation Principles and Practice EIGHTH EDITION

Stuart J. Knechtle, MD, FACS William R. Kenan, Jr. Professor of Surgery Executive Director, Duke Transplant Center Duke University School of Medicine Durham, North Carolina, USA

Lorna P. Marson, MBBS, MD, FRCSEng, FRCSEd, FRCP(Ed) Professor of Transplant Surgery Clinical Sciences (Surgery) University of Edinburgh Edinburgh, United Kingdom

Sir Peter J. Morris, MD, PhD, FRS, FRCS Emeritus Nuffield Professor of Surgery University of Oxford; Honorary Professor University of London; Nuffield Department of Surgical Sciences University of Oxford Oxford, United Kingdom

1600 John F. Kennedy Blvd. Ste 1800 Philadelphia, PA 19103-2899 KIDNEY TRANSPLANTATION: PRINCIPLES AND PRACTICE, EIGHTH EDITION ISBN: 978-0-323-53186-3 Copyright © 2020 by Elsevier, Inc. All rights reserved. No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher. Details on how to seek permission, further information about the Publisher’s permissions policies and our arrangements with organizations such as the Copyright Clearance Center and the Copyright Licensing Agency, can be found at our website: www.elsevier.com/permissions. This book and the individual contributions contained in it are protected under copyright by the Publisher (other than as may be noted herein).

Notice Practitioners and researchers must always rely on their own experience and knowledge in evaluating and using any information, methods, compounds or experiments described herein. Because of rapid advances in the medical sciences, in particular, independent verification of diagnoses and drug dosages should be made. To the fullest extent of the law, no responsibility is assumed by Elsevier, authors, editors or contributors for any injury and/or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions, or ideas contained in the material herein.

Previous editions copyrighted 2014, 2008, 2001, 1994, 1988, 1984 and 1979. Library of Congress Control Number: 2019948029

Content Strategist: Russell Gabbedy/Jessica L. McCool Content Development Specialist: Meghan Andress Publishing Services Manager: Deepthi Unni Project Manager: Beula Christopher Design Direction: Christian J. Bilbow Printed in China Last digit is the print number: 9 8 7 6 5 4 3 2 1

Video Contents CHAPTER 2

CHAPTER 17

2.1 Introduction

17.1 Calcineurin inhibitor mechanism of action animation

2.2 Formation of an immune synapse DAN DAVIS

2.3 3-D rotational image of immune synapses FIONA J. CULLEY

2.4 An NK cell killing its target DAN DAVIS

CHAPTER 5 5.1 Laparoscopic: peritoneal dialysis - catheter insertion ADAM D. BARLOW, JAMES P. HUNTER, and MICHAEL L. NICHOLSON

CHAPTER 6

MATTHEW L. HOLZNER, VIKRAM WADHERA, AMIT BASU, SANDER FLORMAN, and RON SHAPIRO

CHAPTER 36 36.1 Real-time ultrasound guided pancreas allograft biopsy TALAL M. AL-QAOUD, DIXON B. KAUFMAN, PETER J. FRIEND, and JON S. ­ODORICO

CHAPTER 42 42.1 The transplant library on OvidSP LISET H. M. PENGEL

42.2 The transplant library on Evidentia LISET H. M. PENGEL

6.1 Brain death examination LAURA S. JOHNSON, NICHOLAS BYRON PITTS, and RAM M. SUBRAMANIAN

CHAPTER 8 8.1 Laparoendoscopic single site (LESS) donor nephrectomy: technique and outcomes ROLF N. BARTH

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Preface to the First Edition Renal transplantation is now an accepted treatment of patients in end-stage renal failure. A successful transplant restores not merely life but an acceptable quality of life to such patients. The number of patients in endstage renal failure in the Western World who might be treated by hemodialysis and transplantation is considerable and comprises some 30-50 new patients/million of population. Unfortunately in most, if not all, countries the supply of kidneys for transplantation is insufficient to meet the demand. Furthermore, hemodialysis facilities are usually inadequate to make up this deficit so that many patients are still dying of renal disease who could be restored to a useful and productive life. Nevertheless, few of us would have imagined even 10 years ago that transplantation of the kidney would have become such a relatively common procedure as is the case today, and indeed well over 30,000 kidney transplantations have been performed throughout the world. Transplantation of the kidney for the treatment of renal failure has been an attractive concept for many years. As long ago as 1945, three young surgeons at the Peter Bent Brigham Hospital in Boston, Charles Hufnagel, Ernest Landsteiner and David Hume, joined the vessels of a cadaver kidney to the brachial vessels of a young woman who was comatose from acute renal failure due to septicemia. The kidney functioned for several days before it was removed, and the woman regained consciousness. Shortly afterwards, the woman’s own kidneys began to function and she made a full recovery. The advent of the artificial kidney at that time meant that this approach to the treatment of acute renal failure was no longer necessary, but attention was soon given to the possibility of transplanting kidneys to patients with end-stage renal failure who were requiring dialysis on the newly developed artificial kidney to stay alive. Although the first experimental kidney transplants in animals were reported first in Vienna by Dr. Emerich Ulmann in 1902 and then in 1905 by Dr. Alexis Carrel in the United States, the problem of rejection was not mentioned by either author. Later in 1910, Carrel did discuss the possible differences between an autograft and a homograft. The vascular techniques developed by Carrel for the anastomosis of the renal vessels to the recipient vessels are still used today. But in 1923, Dr. Carl Williamson of the Mayo Clinic clearly defined the difference between an autografted and homografted kidney and even published histological pictures of a rejecting kidney. Furthermore, he predicted the future use of tissue matching in renal transplantation. It is unfortunate that the lower animals, such as the dog, do not possess a blood grouping like that of man. In the future it may be possible to work out a satisfactory way of determining the reaction of the recipient’s blood serum or tissues to those of the donor and the reverse; perhaps in this way we can obtain more light on this as yet relatively dark side of biology. viii

The recognition that allogeneic tissues would be rejected was further established in later years by Drs. Gibson and Medawar, who treated burn patients with homografts in Glasgow during the Second World War. Indeed, it was the crash of a bomber behind the Medawars’ house in Oxford during the early years of the war that first stimulated his interest in transplantation, especially of skin. In his address at the opening of the new Oxford Transplant Unit in 1977, Sir Peter Medawar recounted this event. Early in the war, an R.A.F. Whitley bomber crashed into a house in North Oxford with much serious injury and loss of life. Among the injured was a young man with a third degree burn extending over about 60% of his body. People burned as severely as this never raised a medical problem before: they always died; but the blood transfusion services and the control of infection made possible by the topical use of sulphonamide drugs now made it possible for them to stay alive. Dr. John F. Barnes, a colleague of mine in Professor H. W. Florey’s School of Pathology, asked me to see this patient in the hope that being an experimental biologist I might have some ideas for treatment. With more than half his body surface quite raw, this poor young man was a deeply shocking sight; I thought of and tried out a number of ingenious methods, none of which worked, for ekeing out his own skin for grafting, trying to make one piece of skin do the work of ten or more. The obvious solution was to use skin grafts from a relative or voluntary donor, but this was not possible then and it is not possible now. I believe I saw it as my metier to find out why it was not possible to graft skin from one human being to another, and what could be done about it. I accordingly began research on the subject with the Burns Unit of the Glasgow Royal Infirmary, and subsequently in the Zoology Department in Oxford. If anybody had then told me that one day, in Oxford, kidneys would be transplanted from one human being to another, not as a perilous surgical venture, but as something more in the common run of things, I should have dismissed it as science fiction; yet it is just this that has come about, thanks to the enterprise of Professor Morris and his colleagues. Nevertheless in 1951, David Hume in Boston embarked on a series of cadaver kidney transplants in which the kidney was placed in the thigh of the recipient. All but one of these kidneys were rejected within a matter of days or weeks, the one exception being a patient in whom the kidney functioned for nearly 6 months and enabled the patient to leave the hospital! This event provided hope for the future as no immunosuppressive therapy had been used in this patient. At this time, the problems of rejection of kidney allografts in the dog were being clearly defined by Dr. Morton Simonsen in Copenhagen and Dr. William Dempster in London, but in 1953, a major boost to transplantation research was provided by the demonstration, by Drs. Rupert Billingham, Lesley Brent and Peter Medawar, that tolerance to an allogeneic skin graft in an adult animal could be produced by injecting the fetus with donor strain

Preface to the First Edition

tissue, thus confirming experimentally the clonal selection hypothesis of Burnet and Fenner in the recognition of self and non-self. The induction of specific unresponsiveness of a host to a tissue allograft has remained the ultimate goal of transplant immunologists ever since. Then in 1954, the first kidney transplant between identical twins was carried out successfully at the Peter Bent Brigham Hospital which led to a number of further successful identical twin transplants in Boston and elsewhere in the world over the next few years. There still remained the apparently almost insoluble problem of rejection of any kidney other than an identical-twin kidney. The first attempts to suppress the immune response to a kidney allograft employed total body irradiation of the recipient and were carried out by Dr. Merril’s group in Boston, two groups in Paris under the direction of Drs. Kuss and Hamburger, respectively, and by Professor Shackman’s group in London. Rejection of a graft could be suppressed by irradiation, but the complications of the irradiation were such that this was really an unacceptable approach, although an occasional relatively long-term acceptance of a graft provided encouragement for the future. Then came the discovery by Drs. Schwartz and Dameshek in 1959 that 6-mercaptopurine could suppress the immune response of rabbits to human serum albumin. Shortly afterwards, they showed that the survival of skin allografts in rabbits was significantly prolonged by the same drug. This event ushered in the present era of renal transplantation, for very quickly Roy Calne in London and Charles Zukoski working with David Hume in Virginia showed that this same drug markedly prolonged the survival of kidney allografts in dogs. And indeed,6-mercaptopurine was first used in a patient in Boston in 1960. Elion and Hitchings of the Burroughs Wellcome Research Laboratories in New York State then developed azathioprine, which quickly replaced 6-mercaptopurine in clinical practice as it was less toxic. With the addition of steroids, the standard immunosuppressive therapy of today was introduced to the practice of renal transplantation in the early sixties. Not that this meant the solution of the problems of renal transplantation for this combination of drugs was dangerous and mortality was high in those early years. But there was a significant number of long-term successful transplants, and as experience grew, the results

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of renal transplantation improved. Another major area of endeavor in renal transplantation at that time was directed at the study of methods of matching donor and recipient for histocompatibility antigens with the aim of lessening the immune response to the graft and so perhaps allowing a decrease in the immunosuppressive drug therapy. Although this aim has only been achieved to any great extent in siblings who are HLA identical, tissue typing has made a significant contribution to renal transplantation, perhaps best illustrated by the recognition in the late sixties that the performance of a transplant in the presence of donor-specific presensitization in the recipient leads to hyperacute or accelerated rejection of the graft in most instances. Nevertheless, the more recent description of the Ia-like system in man (HLA-DR) may have an important impact on tissue typing in renal transplantation. The present decade also has seen an enormous effort directed at immunological monitoring in renal transplantation and at attempts to induce experimental specific immunosuppression. We have solved most of the technical problems of renal transplantation; we have been left with the problem of rejection and the complications arising from the drug therapy given to prevent rejection. Although the contributions in this book cover all aspects of renal transplantation, certain subjects, as for example immunological monitoring before transplantation, transplantation in children and cancer after renal transplantation, have received considerable emphasis as they do represent developing areas of great interest, and I must take responsibility for this emphasis. For in the seventies we have seen many of the principles and practice of renal transplantation become established and the areas of future investigation become more clearly defined. With an ever-increasing demand for renal transplantation, more and more people in many different disciplines, doctors (surgeons, physicians, pathologists, virologists, immunologists), nurses, scientists and ancillary staff are becoming involved in renal transplantation either in the clinic or in the laboratory. It is to these people I hope this book will be of value. Sir Peter J. Morris Oxford, UK November 1978

Preface to the Eighth Edition Kidney transplant patients and practitioners benefit from updated knowledge of current and improved practice guidelines and novel techniques, in addition to being familiar with well-established principles. For these reasons we have sought out leading international experts to write the chapters of this 8th edition of the Textbook of Kidney Transplantation. What has not changed over the past 41 years since the first edition is Professor Morris’s dedication to the textbook’s quality and his personal attention to the details that are included. He has been the lead editor since the first edition, indeed the sole editor of the first five editions. Professor Marson and Knechtle are delighted that he has chosen to include us as editors, as this text remains the most widely circulated authoritative book on the subject of kidney transplantation, used internationally to help develop practice guidelines and train specialists. We are furthermore grateful to the authors who have produced the content of this 8th edition, including its up-to-date outcomes data and analysis of the evidence supporting current practice in the field. Finally, we thank the leadership of Elsevier for its excellent communication with the authors and editors and for their technical assistance with all aspects of the production of this complex project. In this 8th edition, we have chosen to combine the chapters on azathioprine and mycophenolate based on the relatedness of these compounds as inhibitors of cell proliferation. We have added two new chapters, one addressing kidney allocation because policy varies in the international community, reflecting the ethical and societal values of different countries and populations. Secondly, we have added a chapter on biomarkers of kidney injury and rejection. The latter is in recognition of the need for better monitoring tools for kidney injury and rejection to guide therapy and patient management. Given the large number of candidate assays for injury and rejection and their relatively nascent status with respect to clinical use, we suspect that this will be a rapidly developing field in coming years and will help guide improvement of long-term kidney transplant outcomes. The chapter in the previous edition on belatacept has merged with the chapter on antibody and fusion

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proteins and includes considerable new data on the clinical use of costimulation blockade. Some areas of renal transplantation remain challenges for the field and this certainly would include the sensitized patient, antibody-mediated rejection, and management of chronic allograft failure. These topics are addressed in detail in associated chapters. Quite a number of chapters have been completely rewritten by new authors compared with the 7th edition, and we believe that these new chapters offer refreshing perspectives on their respective topics. We acknowledge that our field continues to be guided by new basic and clinical research that in many cases is beyond the scope of this text, despite our desire to treat subjects comprehensively. We have sought to include what is most pertinent to current clinical practice in the field. Our hope is that the coming decades will continue to build on the remarkable record of progress in kidney transplantation that we have witnessed since the first successful kidney transplant in 1954 by the late Joseph Murray at Peter Bent Brigham Hospital in Boston. Ours is an exciting field that offers improved and extended life to many persons with severely impaired renal function. It is also our hope that improved immunosuppressive therapy will further prolong graft survival and reduce the side effects of infection and malignancy, ultimately extending patient survival yet further. Improved preservation techniques offer the prospect of increasing the use of kidneys that were previously considered to be of inadequate quality, and thereby increase the supply of donor kidneys. Improved antiviral agents have made possible the use of HIV-positive and hepatitis C-positive donor kidneys. These innovations are described in this updated text, which we expect will inspire further good work. Stuart J. Knechtle Durham, NC, USA Lorna P. Marson Edinburgh, UK Sir Peter J. Morris Oxford, UK

Contributors Gaurav Agarwal, MD

Assistant Professor of Medicine University of Alabama at Birmingham Birmingham, Alabama, USA

Talal M. Al-Qaoud, MD, FRCSC

Assistant Professor of Surgery Department of Surgery, Division of Transplantation University of Maryland Baltimore, Maryland, USA

Barbara D. Alexander, MD, MHS

Department of Medicine, Division of Infectious Diseases Duke University Durham, North Carolina, USA

Richard D.M. Allen, MBBS, FRACS Professor Emeritus University of Sydney Sydney, Australia

Frederike Ambagtsheer, PhD, LL.M.

Doctor Internal Medicine, Transplantation and Nephrology Erasmus MC Rotterdam, Netherlands

Rolf N. Barth, MD

Professor Department of Surgery University of Maryland School of Medicine Baltimore, Maryland, USA

Amit Basu, MD, FACS, FRCS

Attending Surgeon Surgery Jamaica Hospital Medical Center Jamaica, New York, USA

Tomas Castro-Dopico, MBiochem, PhD

Research Associate Molecular Immunity Unit, Department of Medicine University of Cambridge Cambridge, United Kingdom

Jeremy R. Chapman, AC, FRACP, FRCP Clinical Director Division of Medicine and Cancer Westmead Hospital, Westmead Sydney, New South Wales, Australia

Menna R. Clatworthy, BSc, MBBCh, PhD, FRCP

NIHR Research Professor and Reader in Immunity and Inflammation Molecular Immunity Unit, Department of Medicine University of Cambridge Cambridge, United Kingdom

Bradley Henry Collins, MD

Associate Professor Department of Surgery Duke University Medical Center Durham, North Carolina, USA

Robert B. Colvin, MD

Benjamin Castleman Distinguished Professor of Pathology Pathology Harvard Medical School and Massachusetts General Hospital Boston, Massachusetts, USA

Lynn D. Cornell, MD

Consultant, Division of Anatomic Pathology Associate Professor of Laboratory Medicine and Pathology Mayo Clinic Rochester, Minnesota, USA

Sylvia F. Costa, MD

Adjunct Assistant Professor Medicine, Division of Infectious Diseases Duke University Durham, North Carolina, USA

Alice Crane, MD, PhD Doctor Urology Cleveland Clinic Cleveland, Ohio, USA

Eileen T. Chambers, MD

Associate Professor Pediatrics and Surgery Duke University Durham, North Carolina, USA

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Contributors

Andrew Davenport, MD, FRCP

Professor of Dialysis and ICU Nephrology UCL Department for Nephrology Royal Free Hospital University College London London, United Kingdom

Matthew J. Ellis, MD

Medical Director Kidney Transplant Nephrology Duke University Durham, North Carolina, USA

Brian Ezekian, MD

General Surgery Resident Department of Surgery Duke University Medical Center Durham, North Carolina, USA

Casey Victoria Farin, MD

Clinical Fellow Multiple Sclerosis and Neuroimmunology Department of Neurology Duke University Durham, North Carolina, USA

Alton B. Farris III, MD

Associate Professor, and Director Laboratory of Nephropathology and Electron Microscopy Department of Pathology Emory University Atlanta, Georgia, USA

Jay A. Fishman, MD

Professor of Medicine Harvard Medical School; Physician Division of Infectious Disease and Massachusetts General Hospital Transplant Center Boston, Massachusetts, USA

Sander Florman, MD

Professor of Surgery, Director Recanati/Miller Transplantation Institute Icahn School of Medicine at Mount Sinai New York City, New York, USA

John L.R. Forsythe, MD, FRCS Eng, FRCS Ed, FEBS, FRCPEd Honorary Professor Transplant Surgery University of Edinburgh Edinburgh, United Kingdom

Peter J. Friend, MD

Professor of Transplantation Nuffield Department of Surgical Sciences University of Oxford Oxford, United Kingdom

Susan V. Fuggle, DPhil, MSc, BSc

Professor of Transplant Immunology Nuffield Department of Surgical Sciences University of Oxford; Consultant Clinical Scientist Transplant Immunology and Immunogenetics Laboratory, Oxford Transplant Centre Oxford University Hospitals NHS Foundation Trust Oxford, United Kingdom

Rouba Garro, MD

Assistant Professor Pediatrics Emory University Atlanta, Georgia, USA

Robert S. Gaston, MD

Director Comprehensive Transplant Institute; Professor of Medicine and Surgery Robert G. Luke Endowed Chair in Transplant Nephrology University of Alabama at Birmingham Birmingham, Alabama, USA

Edward K. Geissler, PhD

University Hospital Regensburg Department of Surgery Division of Experimental Surgery Regensburg, Germany

Sommer Elizabeth Gentry, PhD

Professor Mathematics United States Naval Academy Annapolis, Maryland, USA; Research Associate Surgery Johns Hopkins University School of Medicine Baltimore, Maryland, USA

James A. Gilbert, BM, BS, MA(Ed), FRCS

Consultant Transplant and Vascular Access Surgeon Renal and Transplant Oxford University Hospitals Oxford, United Kingdom

David Hamilton, MB, ChB, PhD, FRCS Retired Transplant Surgeon Independent Scholar The World of Learning St. Andrews, United Kingdom

Reem E. Hamoda, MPH

Public Health Program Associate Department of Surgery, Division of Transplantation Emory University School of Medicine Atlanta, Georgia, USA

Contributors

Benson M. Hoffman, MA, PhD

Stuart J. Knechtle, MD, FACS

Matthew L. Holzner, MD

Simon R. Knight, MA, MB, MChir, FRCS

Associate Professor Department of Psychiatry and Behavioral Sciences Duke University Medical Center Durham, North Carolina, USA Postdoctoral Fellow Recanati/Miller Transplantation Institute Icahn School of Medicine at Mount Sinai New York City, New York, USA

Joanna Hooten, BS, MD Staff Dermatologist Chelsea Dermatology Chelsea, Michigan, USA

James P. Hunter, BSc (Hons), MBChB, MD, FRCS

Senior Clinical Research Fellow and Consultant Transplant Surgeon University Hospitals Coventry and Warwickshire Coventry, United Kingdom; University of Oxford Oxford, United Kingdom

Alan G. Jardine, BSc, MD, FRCP

Professor of Renal Medicine and Head of the Undergraduate Medical School Institute of Cardiovascular and Medical Sciences University of Glasgow Glasgow, United Kingdom

Laura S. Johnson, MD

Assistant Professor Department of Surgery Georgetown University School of Medicine Washington, District of Columbia, USA

Arman A. Kahokehr, MB, PhD, FRACS Fellow in Reconstructive Urology Duke University Medical Center Durham, North Carolina, USA

Dixon B. Kaufman, MD, PhD

Ray D. Owen Professor of Surgery Department of Surgery, Division of Transplantation University of Wisconsin-Madison School of Medicine and Public Health Madison, Wisconsin, USA

Karen L. Keung, MBBS, FRACP

Nephrologist Centre for Transplant and Renal Research Westmead Institute of Medical Research Westmead, New South Wales, Australia

Allan D. Kirk, MD, PhD

Professor and Chairman Surgery Duke University Durham, North Carolina, USA

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William R. Kenan, Jr. Professor of Surgery Executive Director, Duke Transplant Center Duke University School of Medicine Durham, North Carolina, USA Senior Clinical Research Fellow Centre for Evidence in Transplantation Oxford Transplant Centre Nuffield Department of Surgical Sciences University of Oxford Oxford, United Kingdom

Kate Kronish, MD

Assistant Professor Department of Anesthesia and Perioperative Care University of California San Francisco San Francisco, California, USA

John C. LaMattina, MD

Associate Professor Surgery University of Maryland School of Medicine Baltimore, Maryland, USA

Jennifer S. Lees, BA (Hons), MA (Cantab), MBChB, MRCP Clinical Research Fellow/Specialist Trainee in Nephrology University of Glasgow/NHS Greater Glasgow and Clyde Glasgow, United Kingdom

Henri Leuvenink, PhD

UMCG Surgery University Medical Center Groningen Grorolfningen, Netherlands

Jayme E. Locke, MD, MPH, FACS, FAST

Associate Professor of Surgery Director University of Alabama at Birmingham Comprehensive Transplant Institute Birmingham, Alabama, USA

Michael R. Lucey, MB, BCh, MD

Professor Medicine, Gastroenterology and Hepatology University of Wisconsin School of Medicine and Public Health Madison, Wisconsin, USA

Matthew William Luedke, MD

Assistant Professor Department of Neurology Duke University; Department of Medicine, Division of Neurology Veterans Affairs Medical Center Durham, North Carolina, USA

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Contributors

Anne Louise Marano, BS/BA, MD Assistant Professor Dermatology Duke Univeristy Durham, North Carolina, USA

Lorna P. Marson, MBBS, MD, FRCSEng, FRCSEd, FRCP(Ed) Professor of Transplant Surgery Clinical Sciences (Surgery) University of Edinburgh Edinburgh, United Kingdom

Chantal Mathieu, MD, PhD

Professor of Medicine Faculty of Medicine Katholieke University of Leuven (KU Leuven); Head, Endocrinology University Hospitals Leuven; Laboratory of Clinical and Experimental Endocrinology University of Leuven (KU Leuven) Leuven, Belgium

Madhav C. Menon, MBBS, MD, FACP

Assistant Professor Medicine Nephrology and Recanati-Miller Transplant Institute Icahn School of Medicine at Mount Sinai New York City, New York, USA

Sir Peter J. Morris, MD, PhD, FRS, FRCS Emeritus Nuffield Professor of Surgery University of Oxford; Honorary Professor University of London; Nuffield Department of Surgical Sciences University of Oxford Oxford, United Kingdom

Elmi Muller, MBChB, PhD

Professor Surgery Groote Schuur Hospital University of Cape Town Cape Town, Western Cape, South Africa

Barbara Murphy, MD

Murray M. Rosenberg Professor of Medicine Chair of the Department of Medicine Mount Sinai Health System New York City, New York, USA

Sarah A. Myers, MD

Professor Dermatology Duke University Durham, North Carolina, USA

Brian J. Nankivell, MB, BS, MSc, PhD, MD, MRCP(UK), FRACP Doctor, Renal Medicine Westmead Hospital Westmead, New South Wales, Australia

Claus U. Niemann, MD

Professor Department of Anesthesia and Perioperative Care; Professor Department of Surgery University of California San Francisco San Francisco, California, USA

John O’Callaghan, BSc, MBBS, DPhil Specialty Registrar Transplantation Surgery Oxford University Hospitals Oxford, United Kingdom

Philip John O’Connell, MD, PhD

Director of Transplantation Renal Unit University of Sydney at Westmead Hospital Westmead, New South Wales, Australia

Jon S. Odorico, MD

Professor of Surgery Department of Surgery, Division of Transplantation University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, USA

Andrea Olmos, MD

Assistant Professor Department of Anesthesia and Perioperative Care University of California San Francisco San Francisco, California, USA

Gabriel Oniscu, MD, FRCS

Consultant Transplant Surgeon Transplant Unit Royal Infirmary of Edinburgh; Honorary Clinical Senior Lecturer Clinical Surgery University of Edinburgh Edinburgh, United Kingdom

Rachel E. Patzer, PhD, MPH

Associate Professor Department of Surgery Emory University School of Medicine; Rollins School of Public Health Department of Epidemiology Emory University Atlanta, Georgia, USA

Contributors

Liset H.M. Pengel, PhD

Co-director Peter Morris Centre for Evidence in Transplantation Nuffield Department of Surgical Sciences University of Oxford Oxford, United Kingdom

Andrew C. Peterson, MD, FACS

Professor of Surgery Duke University Medical Center; Urology Residency Program Director Duke University Durham, North Carolina, USA

Jacques Pirenne, MD, MSc, PhD

Professor of Surgery Faculty of Medicine University of Leuven (KU Leuven); Head Abdominal Transplant Surgery University Hospitals Leuven; Director Abdominal Transplant Surgery Laboratory Department of Microbiology and Immunology University of Leuven (KU Leuven) Leuven, Belgium

Rutger J. Ploeg, MD, PhD, FRCS

Professor of Transplant Biology and Consultant Surgeon Nuffield Department of Surgical Sciences University of Oxford Oxford, United Kingdom; Professor of Transplant Biology LUMC Transplant Centre University of Leiden Leiden, Netherlands; Professor of Transplant Surgery Surgery Medical Faculty University of Groningen Groningen, Netherlands

Brenda Maria Rosales, BA, BMS (Honours), MPH Sydney School of Public Health The University of Sydney Sydney, New South Wales, Australia

Nasia Safdar, MD

Professor Medicine, Infectious Diseases University of Wisconsin School of Medicine and Public Health Madison, Wisconsin, USA

Adnan Said, MD, MS

Associate Professor Medicine, Gastroenterology and Hepatology University of Wisconsin School of Medicine and Public Health Madison, Wisconsin, USA

Caroline K. Saulino, PsyD

Medical Instructor Department of Psychiatry and Behavioral Sciences Duke University Durham, North Carolina, USA

Carrie Schinstock, MD

Doctor Nephrology and Hypertension Mayo Clinic Rochester, Minnesota, USA

Paul M. Schroder, MD, PhD

Research Fellow Department of Surgery Duke University School of Medicine Durham, North Carolina, USA

Dorry L. Segev, MD, PhD

Professor of Surgery and Epidemiology Surgery Johns Hopkins University; Associate Vice Chair Surgery Johns Hopkins Hospital Baltimore, Maryland, USA

Ron Shapiro, MD

Professor of Surgery, Surgical Director Kidney/Pancreas Transplantation Recanati/Miller Transplantation Institute Icahn School of Medicine at Mount Sinai New York City, New York, USA

Daniel A. Shoskes, MD, MSc, FRCSC Professor of Urology Urology Cleveland Clinic Cleveland, Ohio, USA

Patrick J. Smith, PhD, MPH

Associate Professor Department of Psychiatry and Behavioral Sciences Department of Medicine, Division of Pulmonary, Allergy, and Critical Care Medicine Department of Population Health Sciences, Center for Health Measurement Duke University Medical Center Durham, North Carolina, USA

Ben Sprangers, MD, PhD, MBA, MPH

Associate Professor of Medicine Faculty of Medicine University of Leuven (KU Leuven); Department of Nephrology University Hospitals Leuven; Laboratory of Molecular Immunology (Rega Institute) Microbiology and Immunology University of Leuven (KU Leuven) Leuven, Belgium

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Contributors

Mark Stegall, MD

Transplant Center Mayo Clinic Rochester, Minnesota, USA

Ram M. Subramanian, MD Associate Professor Medicine and Surgery Emory University Atlanta, Georgia, USA

Craig J. Taylor, PhD, FRCPath

Consultant Clinical Scientist [Retired] Histocompatibility and Immunogenetics (Tissue Typing) Laboratory Cambridge University Hospitals Cambridge, Cambridgeshire, United Kingdom

John F. Thompson, MD

Professor of Melanoma and Surgical Oncology The University of Sydney Melanoma Institute Australia; Professor of Surgery (Melanoma and Surgical Oncology) Sydney Medical School The University of Sydney Sydney, New South Wales, Australia

Vikram Wadhera, MD

Assistant Professor of Surgery Recanati/Miller Transplantation Institute Icahn School of Medicine at Mount Sinai New York City, New York, USA

Mark Waer, MD, PhD

Emeritus Professor of Medicine Faculty of Medicine University of Leuven (KU Leuven); Laboratory of Experimental Transplantation, Microbiology and Immunology University of Leuven (KU Leuven) Leuven, Belgium

Christopher J.E. Watson, MA, MD, BChir Professor of Transplantation Department of Surgery University of Cambridge Cambridge, United Kingdom

Angela Claire Webster, MBBS, MM (Clin Epid), PhD Professor of Clinical Epidemiology School of Public Health University of Sydney Sydney, New South Wales, Australia; Senior Staff Specialist Centre for Transplant and Renal Research Westmead Hospital Westmead, New South Wales, Australia

Willem Weimar, MD, PhD Professor, Doctor Internal Medicine Erasmus MC Rotterdam, Netherlands

Pamela D. Winterberg, MD

Assistant Professor Pediatric Nephrology Emory University School of Medicine; Children’s Healthcare of Atlanta Atlanta, Georgia, USA

Kathryn J. Wood, MD

Transplantation Research Immunology Group Nuffield Department of Surgical Sciences University of Oxford Oxford, United Kingdom

Diana A. Wu, MBChB

Research Fellow Transplant Surgery University of Edinburgh Edinburgh, United Kingdom

1

Kidney Transplantation: A History DAVID HAMILTON

CHAPTER OUTLINE

Early Experiments Human Kidney Transplants The Middle Years Post World War II Immunosuppression and the Modern Era Chemical Immunosuppression

The modern period of transplantation began in the late 1950s, but two earlier periods of interest in clinical and experimental transplantation were the early 1950s and the first two decades of the 20th century. Hamilton1 provides a bibliography of the history of organ transplantation. Table 1.1 summarizes landmarks in kidney transplantation.

Early Experiments Interest in transplantation developed in the early part of the 20th century because experimental and clinical surgical skills were rapidly advancing, and many of the pioneering surgeons took an interest in vascular surgical techniques as part of their broad familiarity with the advance of all aspects of surgery. Payr’s demonstration of the first workable, although cumbersome, stent method of vascular suturing led to widespread interest in organ transplantation in Europe. Many centers were involved, notably Vienna, Bucharest, and Lyon. The first successful experimental organ transplant was reported by Ullmann in 1902. Emerich Ullmann (1861–1937) (Fig. 1.1) had studied under Edward Albert before obtaining a position at the Vienna Medical School, which was then at its height. Ullmann’s article shows that he managed to autotransplant a dog kidney from its normal position to the vessels of the neck, which resulted in some urine flow. The animal was presented to a Vienna medical society on March 1, 1902, and caused considerable comment.2 At this time, Ullmann was chief surgeon to the Spital der Baumhertigen Schwestern, and his experimental work was done in the Vienna Physiology Institute under Hofrath Exner. Exner’s son Alfred had already tried such a transplant without success. In the same year, another Vienna physician, Alfred von Decastello, physician assistant at the Second Medical Clinic, carried out dog-to-dog kidney transplants at the Institute of Experimental Pathology.3 Ullmann and von Decastello had used Payr’s method, and later in 1902 Ullmann demonstrated a dog-to-goat kidney transplant that, to his surprise, passed a little urine

A Time of Optimism Tissue Typing The 1970s Plateau Waiting for Xenografts Conclusion

for a while. Neither Ullmann nor von Decastello continued with this work, although von Decastello was noted for his work on blood groups, and Ullmann published extensively on bowel and biliary surgery. In Lyon, the department headed by Mathieu Jaboulay (1860–1913) had a major influence (Fig. 1.2). In his research laboratories, his assistants Carrel, Briau, and Villard worked on improved methods of vascular suturing, leading to Carrel’s famous article credited with establishing the modern method of suturing.4 Carrel left to work in the United States, and in the next 10 years he published extensively on organ grafting, successfully carrying out autografts of kidneys in cats and dogs and, showing that allografts, contrary to accepted opinion, eventually failed after functioning briefly, established the existence of “rejection” as it was later termed. He made attempts at tissue matching and demonstrated cold-preservation of tissues. He was awarded a Nobel Prize for this work in 1912.5 

Human Kidney Transplants Jaboulay, Carrel’s teacher, had carried out the first recorded human kidney transplant in 1906,6 although Ullmann later claimed an earlier attempt in 1902.7 Jaboulay was later to be better known for his work on thyroid and urologic surgery, but, doubtless encouraged by the success of Carrel and others in his laboratory, he carried out two xenograft kidney transplants using a pig and goat as donors, transplanting the organ to the arm or thigh of patients with chronic renal failure. Each kidney worked for only 1 hour. This choice of an animal donor was acceptable at that time in view of the many claims in the surgical literature for success with xenograft skin, cornea, or bone. More is known of the second and third attempts at human kidney transplantation. Ernst Unger (1875– 1938) (Fig. 1.3) had a thorough training in experimental work and set up his own clinic in 1905 in Berlin, being joined there by distinguished colleagues. He continued with experimental work and by 1909 reported successful 1

2

Kidney Transplantation: Principles and Practice

TABLE 1.1  Landmarks in Kidney Transplantation 1902 1906 1933 1950 1950–1953 1953 1954 1958 1959–1962 1960 1960 1962 1966 1967 1967 1973 1978 1978 1987 1997 2010

First successful experimental kidney transplant2 First human kidney transplant—xenograft6 First human kidney transplant—allograft54 Revival of experimental kidney transplantation4,16,57 Human kidney allografts without immunosuppression, in Paris18,19,56,59 and Boston21 First use of live related donor, Paris20 First transplant between identical twins, Boston22 First description of leukocyte antigen MAC62 Radiation used for immunosuppression, in Boston24 and Paris25,56 Effectiveness of 6-mercaptopurine (6-MP) in dog kidney transplants29,42 Prolonged graft survival in patient given 6-MP after irradiation34 First use of tissue matching to select a donor and recipient44,47,49,56 Recognition that positive crossmatching leads to hyperacute rejection29,50,56 Creation of Eurotransplant46 Development of kidney preservation Description of the transfusion effect57 First clinical use of cyclosporine55 Application of matching for HLA-DR in renal transplantation29 First of new wave of immunosuppressive agents appears (tacrolimus) Transgenic pigs strategy63 Laparoscopic kidney insertion64

Fig. 1.2  Mathieu Jaboulay (1860–1913) and his surgical team at Lyon in 1903. Until his death in a rail accident, Jaboulay made numerous surgical contributions and encouraged Alexis Carrel’s work on vascular anastomosis. In 1906 Jaboulay reported the first attempt at human kidney transplantation.

Fig. 1.3  A contemporary cartoon of Ernst Unger (1875–1938) at work at the Rudolf Virchow Hospital, Berlin. (Courtesy the Rudolf Virchow Hospital.)

Fig. 1.1  Emerich Ullmann (1861–1937) carried out the first experimental kidney transplants in dogs in 1902. (Courtesy the Vienna University, Institute for the History of Medicine.)

transplantation of the kidneys en masse from a fox terrier to a boxer dog. The urine output continued for 14 days, and the animal was presented to two medical societies. By 1910, Unger had performed more than 100 experimental kidney transplants. On December 10, 1909, Unger attempted a transplant using a stillborn child’s kidney grafted to a baboon. No urine was produced. The animal died shortly after the operation, but postmortem examination showed that the vascular anastomosis had been successful. This success and the new knowledge that monkeys and humans were serologically similar led Unger to attempt, later in the same month, a monkey-to-human transplant.8 The patient was a young girl dying of renal

1 • Kidney Transplantation: A History

failure, and the kidney from an ape was sutured to the thigh vessels. No urine was produced. Unger’s report concluded that there was a biochemical barrier to transplantation, a view mistakenly advocated by the basic science of the day; his main contributions thereafter were in esophageal surgery. (For a biography of Unger, see Winkler.9) These early experiments established that kidney transplants were technically possible. Methods of study of renal function were primitive then; without routine measurement of blood urea and without any radiologic methods, subtle studies of transplant function were impossible. This impossibility plus the uncertainty of the mechanism of allograft rejection led to a diminished interest in organ transplantation after about 10 years of activity. By the start of World War I, interest in organ transplantation had almost ceased and was not resumed in the European departments of surgery after the war. Carrel had switched his attention to studies of tissue culture. Interest elsewhere also was low; in Britain and the United States, scarce research funds were being applied to fundamental biochemistry and physiology, rather than applied projects of clinical relevance. Transplantation immunology faded away after the bright start in the capable surgical hands of Carrel, Murphy’s sound grasp of immunosuppression, and Landsteiner’s awareness of the serologic detection of human antigens. Carrel, Murphy, and Landsteiner all worked at the Rockefeller Institute in New York. In 1914, in a remarkable lecture to the International Surgical Society, Carrel did anticipate the future development of transplantation. His colleague at the Rockefeller Institute, J. B. Murphy, had found that radiation or benzol treatment would increase the “take” of tumor grafts in rats, and Carrel realized the potential of these findings: It is too soon to draw any definite conclusions from these experiments. Nevertheless it is certain that a very important point has been acquired with Dr. Murphy’s discovery that the power of the organism to eliminate foreign tissue was due to organs such as the spleen or bone marrow, and that when the action of these organs is less active a foreign tissue can develop rapidly after it has been grafted. It is not possible to foresee whether or not the present experiments of Dr. Murphy will lead directly to the practical solution of the problem in which we are interested. The surgical side of the transplantation of organs is now completed, as we are now able to perform transplantations of organs with perfect ease and with excellent results from an anatomical standpoint. But as yet the methods cannot be applied to human surgery, for the reason that homoplastic transplantations are almost always unsuccessful from the standpoint of the functioning of the organs. All our efforts must now be directed toward the biological methods which will prevent the reaction of the organism against foreign tissue and allow the adapting of homoplastic grafts to their hosts.10 

The Middle Years Until the revival of interest in transplantation in the 1950s, the 1930s and 1940s were a stagnant period in clinical science. The great European surgical centers had declined; in North America, only at the Mayo Clinic was there a cautious program of experimental transplantation without building on Carrel’s work, notably failing to make attempts

3

Fig. 1.4  Yu Yu Voronoy (1895–1961) had experience with dog allografts before carrying out the first human kidney allograft in 1933 at Kherson in the Ukraine. His experimental animal model is shown here.

at immunosuppression. In transplantation circles, such as they were, there was not even the confidence to counter the vivid claims of Voronoff to rejuvenate human patients via monkey gland grafts, and the endless reports of successful human skin homografts were not examined critically. The main event of this period was an isolated and littleknown event—the first human kidney allograft. It was performed in the Ukraine by the Soviet surgeon Yu Yu Voronoy.11 Voronoy was an experienced investigator, and he eventually performed six such transplants up to 1949. Voronoy (1895–1961) trained in surgery at Kiev under Professor V.N. Shamov and obtained experience there with serologic methods of blood transfusion, then in their developmental stage. He used these methods to detect complement-fixing antibodies after testis slice transplants, and later he had some success with the same methods applied to kidney grafts (Fig. 1.4). In 1933 Voronoy transplanted a human kidney of blood group B to a patient of blood group O with acute renal failure as a result of mercuric chloride poisoning. The donor kidney was obtained from a patient dying as a result of a head injury and was transplanted to the thigh vessels under local anesthetic; the warm time for the kidney was about 6 hours. There was a major mismatch for blood groups, and despite a modest exchange transfusion, the kidney never worked. The patient died 2 days later; at postmortem, the donor vessels were patent. By 1949, Voronoy reported six such transplants, although no substantial function had occurred in any. (For a biography of Voronoy, see Hamilton and Reid12 and Matevossian and colleagues.13) 

Post World War II The sounder basis of transplantation immunology, which followed Medawar’s pioneer studies during World War II, led to a new interest in human transplantation. In 1946 a human allograft kidney transplant to arm vessels under local anesthetic was attempted by Hufnagel, Hume, and Landsteiner at the Peter Bent Brigham Hospital in Boston. The brief period of function of the kidney may have helped the patient’s recovery from acute renal failure; it marked the beginning of that hospital’s major interest in transplantation and dialysis.14 In the early 1950s, interest in experimental and clinical kidney transplantation increased. With a growing certainty

4

Kidney Transplantation: Principles and Practice

Fig. 1.5  David M. Hume (1917–1973) pioneered human kidney transplantation at the Peter Bent Brigham Hospital, Boston, and the Medical College of Virginia. He died in an air crash at the age of 55.

that immunologic mechanisms were involved, the destruction of kidney allografts could be reinvestigated. Simonsen, then an intern in Ålborg in Denmark, persuaded his surgical seniors to teach him some vascular surgery; using dog kidney transplants, he reported on the mechanism of kidney rejection.15 Dempster in London also reexamined this question.16 Both workers found, like Küss in Paris, that the pelvic position of the kidney was preferable to a superficial site, and both concluded that an immunologic mechanism was responsible for failure. Dempster found that radiation, but not cortisone, delayed rejection. Both workers considered that a humoral mechanism of rejection was likely. In the early 1950s, two groups simultaneously started human kidney transplantation. In Paris, with encouragement from the nephrologist Jean Hamburger, the surgeons Küss (five cases),17 Servelle (one case),18 and Dubost (one case)19 reported on kidney allografts without immunosuppression in human patients, placing the graft in the nowfamiliar pelvic position. The Paris series included a case reported by Hamburger of the first live-related kidney transplant, the donor being the mother of a boy whose solitary kidney had been damaged in a fall from a height. The kidney functioned immediately, but was rejected abruptly on the 22nd day.20 In the United States, the Chicago surgeon Lawler had been the first to attempt such an intraabdominal kidney allograft in 1950; it was met with the intense public interest and professional skepticism that were to characterize innovative transplantation thereafter. A series of nine cases, closely studied, was recorded from Boston, using the thigh position of the graft, and for the first time hemodialysis had been used in preparing the patients, employing Merrill’s skill with the early Kolff/ Brigham machine. David Hume (Fig. 1.5) reported on this Boston experience in 1953. Modest unexpected survival of the kidney was obtained in some of these cases and served

to encourage future careful empirical surgical adventures, despite advice from scientists to wait for elegant immunologic solutions. Although small doses of adrenocorticotropic hormone or cortisone were used, it was thought that the endogenous immunosuppression of uremia was responsible for these results, rather than the drug regimen. Many of Hume’s tentative conclusions from this short series were confirmed later, notably that prior blood transfusion might be beneficial, that blood group matching of graft and donor might be necessary, and that host bilateral nephrectomy was necessary for control of posttransplant blood pressure.21 The first observation of recurrent disease in a graft was made, and accelerated arteriosclerosis in the graft vessels was noted at postmortem. Other cases were reported from Chicago, Toronto, and Cleveland in the early 1950s, but because no sustained function was achieved, interest in clinical and experimental renal allograft transplantation waned, despite increasing knowledge of basic immunologic mechanisms in the laboratory. The technical lessons learned from the human allograft attempts of the early 1950s allowed confidence in the surgical methods, and in Boston, on December 23, 1954, the first transplant of a kidney from one identical twin to another with renal failure was performed. From then on, many such transplantations were performed successfully in Boston.22 Although sometimes seen now merely as a technical triumph, valuable new findings emerged from this series. Some workers had predicted that, in the short term, the activity of the inactive bladder could not be restored, and that in the long term, human kidney grafts would decline in vitality as a result of denervation or ureteric reflux. Other workers were convinced that a single kidney graft could not restore biochemical normality to an adult, and that in any case the existing changes caused by chronic renal failure were irreversible. All of these gloomy predictions were neutralized by the success of the twin kidney transplants, and the greatest triumph came when one such recipient became pregnant and had a normal infant, delivered cautiously by cesarean section, with the anxious transplanters in attendance. Many of the twin recipients are still alive today, although the good results were tempered by failures caused by the prompt return of glomerulonephritis in some transplanted kidneys. This complication was later much reduced by immunosuppression. Other lessons learned were that the hazard of multiple donor renal arteries provided a need for pretransplant angiography of the kidneys in living donors, although it still was not thought necessary to perfuse or cool the donor organ. Lastly, there was the first airing of the legal aspects of organ donation, particularly the problem of consent in young, highly motivated related donors. (For an account of this period, see Murray and colleagues.23) 

Immunosuppression and the Modern Era In 1948, the first patients crippled with rheumatoid arthritis were given the Merck Company’s Cortone (cortisone) at the Mayo Clinic, and intense worldwide interest in the pharmacologic actions of adrenal cortical hormones followed. Careful studies by Medawar’s group in the early 1950s suggested a modest immunosuppressive effect of cortisone,

1 • Kidney Transplantation: A History

but when Medawar shortly afterward showed profound, specific, and long-lasting graft acceptance via the induction of tolerance, the weak steroid effect was understandably sidelined and thought to be of no clinical interest. Induction of tolerance in adult animals (rather than newborns) was accomplished by lethal irradiation and bone marrow infusion, and with this strong lead from the laboratory, it was natural that the first attempts at human immunosuppression for organ transplants were with preliminary totalbody irradiation and allograft bone marrow rescue. These procedures were carried out in Paris, Boston, and elsewhere in the late 1950s. This regimen was too difficult to control, and graft-versus-host disease was inevitable. It was found unexpectedly that sublethal irradiation alone in human patients was quite immunosuppressive, however, and this approach was used until 1962, the year of the first general availability of azathioprine (Imuran). In Boston, 12 patients were treated in this way, but with only one long-term survival in a man receiving his transplant from his nonidentical twin.24 In Paris, similar success was obtained with sibling grafts.25,26 These isolated kidney survivals after a single dose of radiation gave further hope and showed again that the immunology of humans, dogs, and mice is different. These cases also showed that if a human organ could survive the initial crucial rejection period, it could be protected or adapted to the host in some way, possibly shielded by new endothelium, by enhancement, or, as suggested later, by microchimeric tolerance induced by mobile cells in the graft. 

Chemical Immunosuppression In 1958, at the New England Medical Center, attempts were made at human bone marrow transplantation for aplastic anemia and leukemia. To enable the marrow grafts to succeed, irradiation of the recipient was used. Results were poor, and mortality was high. Schwartz and Dameshek27 looked for alternatives to irradiation and reasoned that an anticancer drug, such as 6-mercaptopurine (6-MP) or methotrexate, might be of use for immunosuppression in their patients. (For an account of this period, see Schwartz.28) Their important paper in 1959, showing a poor immune response to foreign protein in rabbits treated with 6-MP,27 was noticed by Roy Calne, then a surgeon in training at the Royal Free Hospital, London, and David Hume, new Chairman of Surgery at the Medical College of Virginia. Calne had been disappointed at the failure of irradiation to prolong kidney allograft survival in dogs and, like others looking for an alternative, he found that 6-MP was successful.29 Zukoski and colleagues30 in Richmond found the same effect. In 1960 Calne visited Boston for a period of research with Murray, and Hitchings and Elion of Burroughs Wellcome, then at Tuckahoe, provided him with new derivatives of 6-MP.31 Of these, BW57-322 (later known as azathioprine [Imuran]) proved to be more successful in dog kidney transplants and less toxic than 6-MP.32 From 1960 to 1961, 6-MP was used in many human kidney transplants. In London at the Royal Free Hospital, three cases were managed in this way, but without success, although one patient receiving a live related transplant died of tuberculosis rather than rejection.33 In Boston, no lasting

5

Fig. 1.6  R. Küss (right) and M. Legrain (center) in 1960 with their first long-term kidney transplant survivor. The patient and her brotherin-law donor (center right) are shown with the staff of the unit at the Hôpital Foch. Immunosuppression with irradiation and mercaptopurine was used. (Courtesy Prof. M. Legrain.)

human kidney function was obtained, but in Paris, Küss and associates34 reported one prolonged survival of a kidney from a nonrelated donor when 6-MP was used with intermittent prednisone in a recipient who also had received irradiation as the main immunosuppressive agent (Fig. 1.6). This case was the first success for chemical immunosuppression. This change in approach, giving lifelong, risky medication with toxic drugs, although an obvious development in retrospect, was accepted with reluctance because it meant leaving aside, at least in the short term, the hopes from the work of the transplantation immunologists for the elegant, specific, one-shot, nontoxic tolerance regimen. Many workers thought that entry into this new paradigm was only a temporary diversion. In 1961 azathioprine became available for human use; the dosage was difficult to judge at first. The first two Boston cases using the drug did not show prolonged survival of the grafts, but in April 1962 the first extended successes with human kidney allografts were obtained.35 Shortly afterward, at the bedside rather than in the laboratory, it was discovered that steroids, notably prednisolone, when given with azathioprine had a powerful synergistic effect. The regular use of both together became a standard regimen after reports by Starzl and colleagues36 and Goodwin and coworkers,37 and this combined therapy continued to be the routine immunosuppressive method despite many other suggested alternatives, until azathioprine was displaced by cyclosporine much later. Use of the combined immunosuppression and the increasing use of live related donors (rather than occasional twin or free or cadaver kidneys), along with the remarkably good results reported in 1963 from Denver36 and Richmond,38 greatly encouraged the practice of transplantation. (For an account of this period, see Starzl.39) 

A Time of Optimism The mid-1960s was a period of great optimism. The rapid improvement in results seemed to indicate that routine success was at hand. Looking to the future, calculations were

6

Kidney Transplantation: Principles and Practice

Medawar produced a powerful immunosuppressive antilymphocyte serum, and production of versions suitable for human use started.42 Initial results were favorable, but the whole antilymphocyte serum had an unspectacular role thereafter, added to from 1975 onward by the use of monoclonal antibody versions. Hopes for another biological solution to transplantation were raised in 1969 when French and Batchelor43 found an enhancing serum effect in the new experimental model of rat kidney transplantation made possible by the development of microsurgical methods, but it proved impossible to mimic the effect in humans. 

Tissue Typing Fig. 1.7  Jean Dausset first described an antigen MAC, later known as HLA-2, defined by numerous antisera from multitransfused patients, and which later was shown to be part of the major histocompatibility complex in humans (HLA).

made that suggested that enough donor organs would be available in the future if all large hospitals cooperated, and such donations did start to come from outside the transplantation pioneer hospitals. Transplantation societies were set up, and specialist journals were started. The improvements in regular dialysis treatment meant an increasing pool of patients in good health suitable for transplantation, and this allowed for better and planned preparation for transplantation. With a return to dialysis being possible, heroic efforts to save a rejected kidney were no longer necessary. Management of patients improved in many aspects, and the expected steroid long-term effects were met and managed (primarily by the demonstration that low-dose steroids were as effective as high-dose steroids). The need for cooling of donor organs was belatedly recognized, many tests of viability were announced, and transport of organs between centers began. Bone disease and exotic infections were encountered and treated, but the kidney units were affected by a hepatitis B epidemic in the mid-1960s, which affected morale and status. The narrow age limit for transplantation was widened, and in Richmond the first experience with kidney grafts in children was obtained. Recipients of kidney transplants reentered the normal business of life and became politicians, professors, pilots, and fathers and mothers of normal children. Other good news in the United States came when the federal government accepted the costs of regular dialysis and transplantation in 1968. There were always unexpected findings, usually reported from the pioneer units with the longest survivors. Cautiously, second kidney transplants were performed at Richmond when a first had failed; these did well, and the matter became routine. Chronic rejection and malignancy first were reported in kidney transplant recipients from Denver. As a result of the optimism, experimental heart transplantation started, the first human livers were grafted, and there was a revival of interest in xenotransplantation. Although the attempts of Reemtsma and coworkers,40 Hume,41 and Starzl39 at transplantation with chimpanzee or baboon kidneys ultimately failed, rejection did not occur immediately, and the cases were studied closely and described. In the search for better immunosuppression, there was great excitement when laboratory studies by Woodruff and

The greatest hopes resided in the evolution of tissue-typing methods, which entered routine use in 1962 (Fig. 1.7).44,45 The increasing identification of the antigens of the human leukocyte antigen (HLA) system seemed to promise excellent clinical results in the future from close matching made possible when choosing from a large pool of patients. Sharing of kidneys in Europe started in 1967 at van Rood’s suggestion,46 and in North America, Amos and Terasaki set up similar sharing schemes on both coasts of the United States. Others followed throughout the world, and these organizations not only improved the service but also soon gathered excellent data on kidney transplant survival. The need to transport kidneys within these schemes encouraged construction of perfusion pumps designed to increase the survival of organs and the distance they could be transported.47 Much work on perfusion fluids was done until the intracellular type of fluid devised by Collins et al. in 1969 allowed a simple flush and chill to suffice for prolonged storage.48 Although the hopes for typing were not fully realized, such schemes had other benefits in obtaining kidneys when urgently required for patients with rarer blood groups, for children, or for highly sensitized patients. Such patients had been recognized by the new lymphocytotoxicity testing using a crossmatch between donor cells and recipient serum. First noted by Terasaki and associates49 and described in more detail by Kissmeyer-Nielsen and colleagues50 in 1966 and Williams and colleagues,51 such pretransplant testing explained cases of sudden failure and led to a marked diminution in hyperacute rejection. 

The 1970s Plateau The 1970s was a period of consolidation, of improvements in data collection such as the valuable European Dialysis and Transplant Association surveys, and increased sophistication in HLA typing methods and organ-sharing schemes. Cadaver organ procurement generally increased as a result of wider involvement of the public and medical profession, although the number of patients waiting for transplantation persistently exceeded the organs available, and donation declined transiently during times of public concern over transplantation issues. Governments took initiatives to increase donations; in the United Kingdom, the Kidney Donor Card was introduced in 1971, becoming a multidonor card 10 years later. In hospital practice, methods of resuscitation and intensive care improved, and the concept of brain death was established to prevent prolonged,

1 • Kidney Transplantation: A History

pointless ventilation, although its immediate application to transplantation provoked controversy. Despite many new claims for successful methods of immunosuppression, such as trials of splenectomy, thymectomy, thoracic duct drainage, and a new look at cyclophosphamide, no agent except antithymocyte globulin became established in routine use. Although patient survival after kidney transplantation continued to increase, the 1970s did not show the expected increase in cadaver graft survival. Some groups reported decreased survival figures; this paradox was solved partly by the demonstration that blood transfusion during regular dialysis, which had been discouraged because of the risk of sensitization, was beneficial to the outcome of kidney transplantation,52 an observation made some years earlier by Morris and coworkers.53 The 1970s ended with two innovations that revived hopes of reaching the goal of routine, safe, and successful kidney transplantation. Ting and Morris54 reported the successful clinical application of HLA-DR matching, and Calne and associates55 revived memories of the excitement of the early days of the use of azathioprine by introducing into clinical practice the first serious rival to it in 20 years, cyclosporine, which had been discovered to be a powerful immunosuppressive agent by Borel.56 Cyclosporine replaced the earlier drug regimens and was the dominant agent in use until the 1990s. Transplantation had grown to a sufficiently large clinical service that it was worth the attention of the pharmaceutical companies, and in the 1990s steady production of new agents occurred—tacrolimus, mycophenolate mofetil, rapamycin, FTY720, brequinar, and others. Any drug with promise was marketed aggressively, and sponsored trials became a routine part of clinical life. The improved results of transplantation meant that the shortage and procurement of organs became a more dominant issue. Living donors were encouraged, to which were added occasional altruistic donations, with use later of “kidney chains” to pass on locally incompatible organs. There was a return to using possibly damaged “marginal” kidneys and organs removed rapidly after cardiac death (DCD). Comparisons of transplantation practice throughout the world showed remarkable differences in attitudes to use of live related donors and cadaver organs, depending on religion and cultural traditions. Kidney transplantation had started as a difficult surgical and scientific challenge confined to a few academic centers in the developed world, but its success had led to the technique becoming a routine service in all parts of the world.57 In some nations not sharing Western attitudes, the donor shortage meant the appearance of undesirable commercial developments in renal transplantation, such as the purchase of kidneys from living unrelated donors (discussed in more detail in Chapter 41).58 

Waiting for Xenografts As the demand for kidney transplants continued to exceed supply, other initiatives appeared and included study of nations and areas with high donation rates (e.g., Spain). As all attempts to increase donor supply fell short of the everrising target, the radical alternative of the use of animal organs was examined afresh. Profound immunosuppression alone was ineffective and, at first, methods of removing

7

natural antibody from recipient plasma were tried to deal with the hyperacute phase of xenograft organ rejection. Although the traditional hopes for xenografting of human patients had assumed that “concordant” species such as the monkey would be used, a new strategy using genetic engineering methods first used a line of transgenic pigs, a distant species discordant with humans, with a modified endothelium that reduced the complement-mediated immediate reaction.59 Hopes continue that these early developments will evolve into a sophisticated successful routine.60 Meanwhile, the kidney transplanters can only watch, with detached interest, the emergence of stem cell use in cellular transplantation. These new hopes for xenografts raised old fears among the public and legislators, notably regarding disease transmission. Although this had been a familiar problem in human-to-human transplantation and had been met regularly and dealt with, governments required reassurances about xenotransplantation with the added threat of retrovirus transmission. 

Conclusion Kidney transplantation was the first of the organ transplant procedures to develop because cadaveric donor kidneys revived with time, the availability of live donors increased, and the crucial backup of dialysis was implemented. When radical new ideas are to be tested, pioneers still turn to kidney transplantation. Kidney transplantation is where it all started, with good reason, and it will always be a test bed for major innovation, including laparoscopic and robotic surgery. Nowhere is the excitement of the early days reflected better than in the recollections of 35 of the pioneers of transplantation gathered together by Terasaki.61

References 1. Hamilton D. Organ transplantation: a history. Pittsburgh: Pittsburgh University Press; 2012. 2. Ullmann E. Experimentelle nierentransplantation. Wien Klin Woche­n­ schr 1902;15:281. [For a biography of Ullmann, see Lesky E. Die erste Nierentransplantation: Emerich Ullmann (1861–1937). Munch Med Wochenschr 1974;116:1081.] 3. von Decastello A. Experimentelle nierentransplantation. Wien Klin Wochenschr 1902;15:317. 4. Carrel A. La technique operatoire des anastomoses vasculaires et la transplantation des viscères. Lyon Med 1902;98:859. 5. Hamilton D. The first transplant surgeon: the flawed genius of nobel prize winner, Alexis Carrel. Singapore: World Scientific; 2017. 6. Jaboulay M. Greffe de reins au pli du coude par soudure arte. Bull Lyon Med 1906;107:575. [For a biography of Jaboulay, see Biogr Med Paris 1936;10:257.] 7. Ullmann E. Tissue and organ transplantation. Ann Surg 1914;60:195. 8. Unger E. Nierentransplantation. Berl Klin Wochenschr 1909;1:1057. 9. Winkler FA. Ernst Unger: a pioneer in modern surgery. J Hist Med Allied Sci 1982;37:269. 10. Carrel A. The transplantation of organs. New York Times 1914. 11. Voronoy YY. Sobre el bloqueo del aparato reticulo-endothelial. Siglo Med 1936;97:296. 12. Hamilton D, Reid WA. Yu Yu Voronoy and the first human kidney allograft. Surg Gynecol Obstet 1984;159:289. 13. Matevossian E, Kern H, Hüser N, et al. Surgeon Yurii Voronoy (1895– 1961) — a pioneer in the history of clinical transplantation. Transpl Int 2009;22:1132. 14. Moore FD. Give and take: the development of tissue transplantation. Philadelphia: WB Saunders; 1964.

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Kidney Transplantation: Principles and Practice

15. Simonsen M. Biological incompatibility in kidney transplantation in dogs: serological investigations. Acta Pathol Microbiol Scand 1953;32:1. 16. Dempster WJ. The homotransplantation of kidneys in dogs. Br J Surg 1953;40:447. 17. Küss R, Teinturier J, Milliez P. Quelques essais de greffe du rein chez l’homme. Mem Acad Chir 1951;77:755. 18. Servelle M, Soulié P, Rougeulle J, et al. Greffe d’une reine de supplicie à une malade avec rein unique congénital, atteinte de nephrite chronique hypertensive azotémique. Bull Soc Med Hop Paris 1951;67:99. 19. Dubost C, Oeconomos N, Vaysse J, et al. Resultats d’une tentative de greffe rénale. Bull Soc Med Hop Paris 1951;67:1372. 20. Michon L, Hamburger J, Oeconomos N, et al. Une tentative de transplantation rénale chez l’homme. Presse Med 1953;61:1419. 21. Hume DM, Merrill JP, Miller BF, et al. Experiences with renal homotransplantation in the human: report of nine cases. J Clin Invest 1955;34:327. 22. Murray JE, Merrill JP, Harrison JH. Kidney transplantation between seven pairs of identical twins. Ann Surg 1958;148:343. 23. Murray JE, Tilney NL, Wilson RE. Renal transplantation: a twenty-five year experience. Ann Surg 1976;184:565. 24. Murray JE, Merrill JP, Dammin GJ, et  al. Study of transplantation immunity after total body irradiation: clinical and experimental investigation. Surgery 1960;48:272. 25. Hamburger J, Vaysse J, Crosnier J, et al. Transplantation of a kidney between non-monozygotic twins after irradiation of the receiver: good function at the fourth month. Presse Med 1959;67:1771. 26. Küss R, Legraine M, Mathe G, et al. Prémices d’une homotransplantation rénale de soeur à frère non jumeaux. Presse Med 1960;68:755. 27. Schwartz R, Dameshek W. Drug-induced immunological tolerance. Nature 1959;183:1682. 28. Schwartz RS. Perspectives on immunosuppression. In: Hitchings GH, editor. Design and achievements in chemotherapy. Durham, NC: Burroughs Wellcome; 1976. p. 39–41. 29. Calne RY. The rejection of renal homografts: inhibition in dogs by 6-mercaptopurine. Lancet 1960;1:417. 30. Zukoski CF, Lee HM, Hume DM. The effect of 6-mercaptopurine on renal homograft survival in the dog. Surg Forum 1960;11:47. 31. Calne RY. The development of immunosuppressive therapy. Transplant Proc 1981;13:44. 32. Calne RY, Alexandre GPJ, Murray JE. The development of immunosuppressive therapy. Ann NY Acad Sci 1962;99:743. 33. Hopewell J, Calne RY, Beswick I. Three clinical cases of renal transplantation. BMJ 1964;1:411. 34. Küss R, Legraine M, Mathe G, et al. Homologous human kidney transplantation. Postgrad Med J 1962;38:528. 35. Murray JE, Merrill JP, Harrison JH, et al. Prolonged survival of human kidney homografts by immunosuppressive drug therapy. N Engl J Med 1963;268:1315. 36. Starzl TE, Marchioro TL, Waddell WR. The reversal of rejection in human renal homografts with subsequent development of homograft tolerance. Surg Gynecol Obstet 1963;117:385. 37. Goodwin WE, Mims MM, Kaufman JJ. Human renal transplant, III: technical problems encountered in six cases of kidney homotransplantation. Trans Am Assoc Genitourin Surg 1962;54:116. 38. Hume DM, Magee JH, Kauffman HM, et al. Renal homotransplantation in man in modified recipients. Ann Surg 1963;158:608.

39. Starzl TE. Personal reflections in transplantation. Surg Clin North Am 1978;58:879. 40. Reemtsma K, McCracken BH, Schlegel JU, et  al. Renal heterotransplantation in man. Ann Surg 1964;160:384. 41. Hume DM. Discussion. Ann Surg 1964;160:409. 42. Wolstenholme GEW, O’Connor M, editors. Antilymphocytic serum. London: J&A Churchill; 1967. 43. French ME, Batchelor JR. Immunological enhancement of rat kidney grafts. Lancet 1969;2:1103. 44. Dausset J. The challenge of the early days of human histocompatibility. Immunogenetics 1980;10:1. 45. Hamburger J, Vaysse J, Crosnier J, et al. Renal homotransplantation in man after radiation of the recipient. Am J Med 1962;32:854. 46. van Rood JJ. Histocompatibility testing. Copenhagen: Munkgaard; 1967. 47. Belzer FO, Ashby BS, Dunphy JS. 24-Hour and 72-hour preservation of canine kidneys. Lancet 1967;2:536. 48. Collins GM, Bravo-Shugarman M, Terasaki PI. Kidney preservation for transportation: initial perfusion and 30 hours’ ice storage. Lancet 1969;2:1219. 49. Terasaki PI, Marchioro TL, Starzl TE. In: Amos DB, van Rood JJ, editors. Histocompatibility testing. Washington, DC: National Academy of Sciences; 1965:83. 50. Kissmeyer-Nielsen F, Olsen S, Peterson VP, et al. Hyperacute rejection of kidney allografts. Lancet 1966;2:662. 51. Williams GM, Hume DM, Hudson RP, et  al. Hyperacute renalhomograft rejection in man. N Engl J Med 1968;279:611. 52. Opelz G, Sengar DPS, Mickey MR, et al. Effect of blood transfusions on subsequent kidney transplants. Transplant Proc 1973;5:253. 53. Morris PJ, Ting A, Stocker J. Leucocyte antigens in renal transplantation, I: the paradox of blood transfusions in renal transplantation. Med J Aust 1968;2:1088. 54. Ting A, Morris PJ. Matching for B-cell antigens of the HLADR (D-related) series in cadaver renal transplantation. Lancet 1978;1:575. 55. Calne RY, White DJG, Thiru S, et al. Cyclosporin A in patients receiving renal allografts from cadaver donors. Lancet 1978;2:1323. 56. Borel JF. Comparative study of in vitro and in vivo drug effects on cell mediated cytotoxicity. Immunology 1976;31:631. 57. Burdick JF, DeMeester J, Koyama I. Understanding organ procurement and the transplant bureaucracy. In: Ginns LC, Cosimi AB, Morris PJ, editors. Transplantation. Boston: Blackwell; 1999. p. 875–94. 58. Morris PJ. Problems facing the society today. Transplant Proc 1987;19:16. 59. van den Bogaerde J, White DJG. Xenogeneic transplantation. Br Med Bull 1997;53:904. 60. D’Apice A, Cowan PJ. Gene-modified pigs. Xenotransplantation 2008;15:87. 61. Terasaki PI. History of transplantation: thirty-five recollections. Los Angeles: UCLA Tissue Typing Laboratory; 1991. 62. Dausset J. Iso-leuco-anticorps. Acta Haematol (Basel) 1958;20:156. 63. Oriol R, Ye Y, Koren E, Cooper DK. Carbohydrate antigens of pig tissues reacting with human natural antibodies as potential targets for hyperacute vascular rejection in pig-to-man organ xenotransplantation. Transplantation 1993;56:1433–42. 64. Rosales A, Salvador JT, Urdaneta G, Patiño D, Montlleó M, Esquena S, et al. Laparoscopic kidney transplantation. Eur Urol 2010;57:164–7.

2

The Immunology of Transplantation TOMAS CASTRO-DOPICO and MENNA R. CLATWORTHY

CHAPTER OUTLINE

Introduction Activation of the Immune System Peritransplant Damage Signals and Their Receptors Soluble Innate Immunity – Complement Innate Immunity – Cellular Components Neutrophils Macrophages NK Cells and Innate Lymphoid Cells Cells at the Interface Between Innate and Adaptive Immunity Stimulation of Adaptive Alloimmunity ABO Blood Group Antigens HLA Molecules Major Histocompatibility Antigens Minor Histocompatibility Antigens Antigen Presentation Dendritic Cells Direct, Indirect, and Semidirect Antigen Presentation T Cell Activation Signal 1—TCR Activation Signal 2—Costimulation Signal 3—Cytokines

Introduction Solid organ transplant requires the removal of an organ from one individual, the donor, and its placement in the recipient. Whether the donor is living or deceased, this process inevitably requires a temporary cessation of circulation and hence oxygenation, with attendant cellular dysfunction and damage. Thus when the blood supply is restored to the allograft in the recipient, and the recipient’s immune system can access the transplant, there are broadly two main stimuli that may be recognized: damage-associated signals that activate the innate immune system, and differences in cell surface molecules (such as human leukocyte antigens [HLA] or blood group antigens) between donor and recipient that can activate the adaptive immune system. In the past 50 years, the increased understanding of cellular adaptive immunity has transformed our ability to suppress this arm of the immune system, such that T cell-mediated rejection (TCMR) is now uncommon, occurring in less than 20% of kidney transplant recipients, for example. However, the control of innate and humoral adaptive immunity remains challenging, and efforts to achieve this will need to be

T Cell-Mediated Rejection Migration of Activated Cells Into the Graft Mechanisms of Cytotoxicity Complement and TCMR B Cell Activation and Antibody-Mediated Rejection B Cell Activation B Cell Function Alloantibodies Antigen Presentation to CD4 T Cells Formation and Maintenance of Secondary Lymphoid Tissue Production of Proinflammatory Cytokines B Cells as Regulators of the Immune Response Antibody-Effector Function in ABMR Direct Stimulation of Endothelial MHC Complement Activation FcγR Activation Transplant Tolerance Factors Influencing Rejection Beyond the Graft—The Microbiome Conclusion

underpinned by a greater understanding of the basic biology of these important systems. Of note, attempts to understand the immune response to an allograft have historically relied on rodent and nonhuman primate models. Although useful, such studies do not always accurately reflect the alloimmune response in humans, and there is an increasing emphasis on the need for experimental medicine studies in transplantation to enable advances in genomic, transcriptomic, and proteomic technologies to be harnessed toward this goal.1 In this chapter, we will provide a description of the various arms of the immune system and consider how they contribute to the immune response to transplanted organs (Fig. 2.1). 

Activation of the Immune System Peritransplant During the process of organ retrieval and reimplantation, there is an inevitable period of ischemia. The cessation of oxygen supply renders the cells unable to generate sufficient energy to continue homeostatic processes that maintain cellular 9

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Kidney Transplantation: Principles and Practice

Allograft rejection timeline

1 year

Pathology

IRI

TCMR

aABMR

20+ years

cABMR

Innate

Immune response

Complement

integrity, leading to damage or even death of some cells. This cellular damage or death is associated with the release of molecules that can be detected by both the innate and adaptive immune system. During organ reperfusion, it is the innate immune system that is principally activated. This ancient system includes a soluble arm—the complement system and a variety of opsonins that have evolved to facilitate pathogen recognition, for example, C-reactive protein (CRP), complement activation products (C3b), natural immunoglobulin (Ig) M antibody, and a cellular arm, composed of phagocytes and innate lymphoid cells, including natural killer (NK) cells.

Phagocytes NK cells

DAMAGE SIGNALS AND THEIR RECEPTORS

Adaptive CD4 T cells CD8 T cells B cells (non-antibody) IgG

Fig. 2.1  Timeline of allograft rejection.  During transplantation and beyond, allografts are subjected to a variety of stresses that cause graft damage and destruction. Indicated in the schematic shown here is a timeline of the pathologic insults potentially experienced by a transplanted organ and the types of immune cells that contribute to each pathology, stratified based on innate and adaptive immunity. aABMR, Acute antibody-mediated rejection; cABMR, chronic antibody-mediated rejection; IgG, immunoglobulin G; IRI, isch­emia reperfusion injury; NK, natural killer; TCMR, T cell-mediated rejection.

The innate immune system has evolved to recognize molecules expressed by pathogens, known as pathogen-associated molecular patterns (PAMPs), including specific carbohydrates, lipopolysaccharide (LPS), flagellin, lipoteichoic acid, and doublestranded ribonucleic acid (RNA). This is achieved by an array of receptors, so-called pattern recognition receptors (PRRs), some of which are surface bound and survey the extracellular environment, and some of which are located within the cell, in the cytoplasm or endosomal compartments (Fig. 2.2). PRRs include cell-associated receptors, such as toll-like receptors (TLRs),2 retinoic acid inducible gene-1–like receptors,3 and nucleotidebinding oligomerization domain (NOD)-like receptors,4 and soluble molecules, including CRP, ficolins, and mannan-binding

PAMP DAMP (HMGB1...)

DAMPs (ATP...) Extracellular Cytoplasm

TLR1/2/4/5/6

Endosome

PHAGOCYTE Receptors (P2RX7...)

Cytosolic DNA sensors RIG-I-like receptors NOD-like receptors

TLR3/7-8/9

Inflammasome NLRP3

IL-1β, TNF, CXCL8...

ASC CASP1

Pro-IL-1β

Active caspase

IL-1β

TNF CXCL8... Fig. 2.2  Mechanisms of immune sensing and inflammatory cytokine production during sterile inflammation.  Schematic of the different classes of pattern recognition receptors and their potential to response to danger-associated molecular patterns (DAMPs) released during sterile inflammation and ongoing allograft destruction. For example, high mobility group box 1 (HMGB1) binds to toll-like receptors (TLRs) to induce expression of inflammatory mediators, while extracellular adenosine triphosphate (ATP) can engage cell surface receptors, such as P2RX7, leading to inflammasome assembly (e.g., the nucleotide-binding domain leucine-rich repeat contain­ing protein 3 (NLRP3) inflammasome), caspase activation, and mature interleukin (IL)-1β and IL-18 production. These mechanisms are particularly important in innate immune cells, such as macrophages and neutrophils.

2 • The Immunology of Transplantation

lectin (MBL).5 Matzinger first proposed that the immune system may have the capacity to respond to damage signals, even in the absence of microbes—the danger hypothesis—and may have even evolved in response to these stimuli.6 It is now clear that many cell-damage or death-associated signals (termed danger-associated molecular patterns [DAMPs]) are recognized by the same PRRs that mediate responses to PAMPs.7 These DAMPs include extracellular adenosine triphosphate (ATP),8 hyaluronan,9 uric acid, heat-shock proteins (HSPs), and high-mobility group box 1 (HMGB1).10 These molecules are normally hidden from the immune system or are derived from degradation products of extracellular matrix components generated during ischemia reperfusion injury (IRI) and inflammation.11 Similarly, falling intracellular potassium and oxidative stress can act as intracellular danger signals.12–14 

SOLUBLE INNATE IMMUNITY—COMPLEMENT The complement system is a series of protein kinases that are sequentially activated and culminate in the formation of the membrane attack complex (MAC).15,16 The MAC comprises complement components C5 to C9, which are inserted into the cell membrane (pathogen or host), disrupting integrity and causing cell lysis (Fig. 2.3). In addition, many proximal complement components may augment the immune response to the allograft. The complement system may be activated by three pathways: the classical pathway, the alternative pathway, and the MBL pathway. IgM or IgG immune complexes activate the classical pathway, and hence this pathway may become activated during antibody-mediated rejection (see section on B Cell Activation). The alternative pathway is constitutively active and must be controlled by a series of regulatory proteins. The PATHWAY ACTIVATION

Classical Alloantibody

11

mannose-binding pathway is activated by carbohydrates present on pathogens or by damaged endothelium. The net result of activating any of the three pathways is the formation of a C3 convertase (either C4bC2a or C3bBb), which cleaves C3. The resulting C3b cleaves C5 and activates a final common pathway resulting in MAC formation. Complement activation also leads to the formation of anaphylatoxins (C3a and C5a), which activate neutrophils and mast cells, promoting inflammation. In addition, C3b can opsonize pathogens for uptake by complement receptors CR1 and CR3 on phagocytes and can activate B cells; the latter may promote B cell activation in transplantation. Because the alternative pathway is continuously activated, effective regulation is critical to prevent inappropriate activation. Regulatory proteins may be circulating or membrane-bound. Circulating inhibitors include C1 esterase inhibitor and factors H and I. Membrane-bound regulatory proteins include membrane cofactor protein (MCP), CD55 (decay accelerating factor [DAF]), and CD59 (protectin). Defects or mutations in complement regulatory proteins can result in severe renal pathology, for example, atypical hemolytic uremic syndrome (HUS), which can recur in the transplanted allograft.17,18 The C3 glomerulopathies, including dense deposit disease and type I and III mesangiocapillary glomerulonephritides, are also underpinned by complement mutations.19,20 Small case series suggest a recurrence rate of around 60% in the transplanted organ.21 The C5 inhibitor eculizumab may well have efficacy in both primary and recurrent forms of these diseases.22 The endothelial cell damage associated with ischemiareperfusion injury during transplantation leads to MBL and alternative complement pathway activation.23 Histologic evidence of complement activation (C3d deposition) is present in animal models and in human kidneys with

MBL Endothelial damage (ischemia)

Alternative Endothelial damage (ischemia)

C1 MBL-MASP1-MASP2 C3 C4, C2

C4bC2a

Factor D C3bBb

CR1-4

C3a C3b C5b

C5 C3aR/C5aR TCMR

APC maturation T cell activation

C5a

Factor B

B cell activation

MAC Neutrophil recruitment and degranulation

ABMR IRI

Fig. 2.3  The complement cascade.  Activation of the complement cascade can contribute to tissue destruction directly via formation of the membrane attack complex (MAC) and through complement receptor engagement and subsequent immune cell activation. This includes the maturation of antigen-presenting cells and neutrophil activation. Three pathways are possible for complement activation and each may contribute to tissue destruction in rejection. The classical pathway is mediated by antibodies and may be driven by donor-specific IgG and IgM immune complexes during ABMR, whereas activation of the alternative and MBL pathways results from damage to allograft endothelial cells as a result of IRI. All pathways converge on the cleavage of C3 and the generation of the C5-cleaving fragment C3b and the anaphylatoxin C3a. Subsequently, C5a and C5b act as an anaphylatoxin that binds to C5aR and a component of the MAC, respectively, leading to cell death.

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Kidney Transplantation: Principles and Practice

acute tubular necrosis (ATN).24 Factor B-deficiency and a factor B-blocking antibody are protective in a murine model of IRI,24,25 suggesting alternative pathway involvement. Biopsies in murine and human kidneys with ATN also demonstrate MBL deposition,26 likely triggered by endogenous ligands expressed by dying cells, and MBL-deficient mice are protected from IRI.27 Transplantation of a kidney from a C3-deficient mouse into a C3-sufficient recipient results in significant attenuation of IRI, in contrast to the reciprocal transplant, suggesting that local C3 production in the kidney rather than circulating C3 is the major player in IRI.28 In human kidneys, cold ischemia may alter the methylation state of the C3 promoter, resulting in increased local expression of C3 after reperfusion,29 which is associated with a diminished graft survival.30 Silencing of the gene encoding C3 using small interfering RNA (siRNA) has been shown to reduce C3 expression, histologic and biochemical parameters of kidney injury, and mortality in an animal model of IRI.31 The terminal pathway products C5a and C5b–C9 appear to be critical in mediating cellular injury.32–34 A C5-blocking antibody and C5a receptor antagonist have both been shown to abrogate IRI35 and gene silencing of the C5a receptor also protects mice from IRI.36 Gene silencing may provide a promising tool in renal transplantation, because siRNA-to-complement components might be applied to the allograft during cold storage, before implantation.37 Similarly, other strategies to inhibit local complement activation may have utility in limiting allograft IRI.38,39 Ongoing clinical trial in renal transplantation to prevent IRI and delayed graft function include the use of C1 esterase inhibitors (https://clinicaltrials.gov/ct2/show/NCT02134314) and the C5 inhibitor eculizumab (https://clinicaltrials.gov/ct2/ show/NCT02145182). However, although there was a reduced rate of delayed graft function in a small pediatric trial (n = 57) using eculizumab in kidney transplantation, there was an unexpectedly high rate of graft loss because of thrombosis in eculizumab-treated subjects,40 necessitating caution in its future use in this context. 

INNATE IMMUNITY—CELLULAR COMPONENTS Cellular innate immunity comprises a variety of hematopoietic myeloid and lymphoid cells, often poised within tissues for the rapid nonspecific detection of invading microorganisms and transformed cells. However, innate immunity also encompasses various nonhematopoietic cells, such as the gastrointestinal, respiratory, and urogenital epithelium, which, in addition to forming a physical barrier, also express PRRs and orchestrate local immunity (Fig. 2.4).

Neutrophils Although often viewed as nonspecific effector cells, granulocytes, such as neutrophils and eosinophils, are likely to play a significant role in transplant pathology through their potent effector functions and rapid recruitment to sites of inflammation during IRI and rejection. It is also increasingly appreciated that there may be tissue-resident populations within a variety of organs. Neutrophils are the dominant circulating phagocyte in humans, and their recruitment into the graft involves a

complex multistep process requiring a series of interactions between the surface of the leukocyte and the endothelial cell or its extracellular matrix.41,42 The proteins involved fall into three groups: the selectins, and members of the integrin and Ig superfamilies. Initial interaction and rolling of neutrophils along the endothelium allow the leukocyte to sample the endothelial environment, while maintaining its ability to detach and travel elsewhere. This step is largely controlled by the selectins, although α4 integrins may also play a role. Endothelial cells express interleukin (IL)-8 and platelet-activating factor, which induces strong neutrophil adhesion. This interaction leads to signaling to the neutrophil, slowing and arresting the rolling process. Shedding of L-selectin by leukocytes allows their detachment and extravasation.43 The latter stages of leukocyte transmigration are regulated mainly by the β2 integrins and adhesion proteins of the immunoglobulin superfamily. The expression of adhesion proteins involved in these interactions is upregulated by proinflammatory cytokines. Ischemic damage alone results in increased expression of several cytokines that upregulate the expression of selectins.44,45 Other adhesion proteins, such as intercellular adhesion molecule (ICAM)-1 and vascular cell adhesion molecule (VCAM)-1 of the immunoglobulin superfamily and E-selectin (endothelial-specific selectin), are upregulated by cytokines induced by donor brain death46 and implantation. After exit from the vasculature, neutrophil PRR engagement by DAMPs can induce the production of reactive oxygen species, hydrolytic enzymes, and cytokines,47,48 with graft neutrophilia linked to alloreactive T cell responses and disease activity in mouse models.49–51 Neutrophils can also undergo a form of programmed cell death known as NETosis, whereby activated neutrophils form so-called extracellular traps (NETs).52 These have been observed in human lung transplant recipients and in mouse models of allograft IRI, although how they contribute to inflammation remains controversial.53 Perhaps less appreciated is the potential role of neutrophils in the resolution of inflammation in alloimmunity: efferocytosis of apoptotic neutrophils leads to the production of antiinflammatory mediators, such as IL-10, while proresolving factors, including lipoxins and resolvins, are important in wound healing and may suppress ongoing rejection.54 

Macrophages Tissue-resident macrophages represent the major innate leukocyte population in most tissues.55 Through their widespread expression of PRRs, these sentinel cells are specialized in antigen phagocytosis and cytokine production, being key drivers of inflammation in numerous settings. During inflammatory conditions, the macrophage pool is further reinforced by recruited monocytes from the bloodstream, with several macrophage- and monocytederived cytokines capable of contributing to tissue damage.56 For example, tumor necrosis factor (TNF)α can drive cellular necroptosis and the concomitant release of intracellular contents and DAMPs,57,58 in addition to augmenting angiogenesis, matrix metalloprotease (MMP) production, immune cell activation, and germinal center formation, all with particular importance in the context of transplantation.59 Furthermore, via production of IL-1β

2 • The Immunology of Transplantation

Epithelium

13

Mononuclear phagocytes Tissue dendritic cells

Physical barrier Antimicrobial peptides Cytokine production Mucus

Granulocytes Blood Tissue granulocytes neutrophils (e.g., eosinophils)

Phagocytosis Microbicidal molecules Cytokines/chemokines Histamine and eicosanoids

Tissue macrophages

Blood monocyte

Phagocytosis Cytokine production Antigen presentation

Lymphocytes NK cells (CD56bright and CD56lo)

Helper ILCs (ILC1–3)

Cytotoxicity Cytokine production Antigen presentation

Fig. 2.4  The innate immune system.  A schematic of the major components of the innate immune system and a brief summary of their respective functions in inflammation and homeostasis. Epithelial cells form the physical barriers of mucosal gastrointestinal, respiratory, and urogenital tracts, and play a critical role in host-microbe interactions at these environmental interfaces. Mononuclear phagocytes represent tissue-resident dendritic cells and macrophages in addition to those recruited to tissues during inflammation. In most circumstances, these cells play essential roles in tissue homeostasis, but can also prime alloreactive adaptive immune responses, are major sources of inflammatory mediators, and participate directly in tissue destruction. Granulocytes include neutrophils, normally circulating in the blood but rapidly recruited to sites of inflammation, and tissue-resident cells, such as eosinophils. The workhorses of innate immunity, they are increasingly appreciated for their roles in influencing adaptive immunity within tissues and lymphoid organs. Innate lymphocytes encompass the well-characterized NK cells, which participate in receptor-mediated cell lysis and IFNγ production, and the recently discovered class of helper innate lymphoid cells. Helper ILCs are enriched at mucosal surfaces and are potent sources of T cell-associated cytokines, and also serve as APCs through expression of MHC class II molecules.

and IL-8, macrophages play a strategic role in the recruitment of neutrophils to inflamed sites through the induction of adhesion molecules on endothelial cells and direct chemotactic activity, respectively.60 Endogenous ligands with the capacity to engage macrophage PRRs are generated during transplantation, either through IRI or as a consequence of ongoing rejection.61 Detection of DAMPs leads to the association of nucleotide-binding domain leucine-rich repeat containing protein (NLRP)3 with apoptosis-associated speck-like protein (ASC), and recruitment of procaspase-1, forming a complex known as the NLRP3 inflammasome48,62,63 (Fig. 2.3). Inflammasome activation results in the cleavage of procaspase-1 to caspase-1, which subsequently cleaves IL-1β and IL-18 from their precursors. Of note, in  vitro data suggests that in macrophages, inflammasome activation is a two-step process. First, macrophages must be “primed” by TLR stimuli, resulting in NFγB-dependent pro-IL-1β production and upregulation of NLRP3 expression. A number of DAMPs are thought to signal via TLRs; for example, HMGB1 activates TLR4.64 The second signal

is provided by DAMP receptors, for example the ATP receptor, P2X7R. IL-1 plays a pivotal role in initiating and amplifying sterile inflammation, as evidenced by experiments showing that mice deficient in the IL-1 receptor (IL-1R) or in the adaptor protein MyD88 (which is required for IL-1R signaling), demonstrate minimal neutrophilic inflammation after challenge with necrotic cells.62 IL-1β has multiple actions, including stimulation of nonhematopoietic cells to produce the neutrophil chemoattractants chemokine (C-X-C motif) ligand (CXCL)2 (also known as macrophage inflammatory protein [MIP]-2) and CXCL1 (also known as keratinocyte chemoattractant [KC]).65 DAMPs may also act directly as chemotactic agents for neutrophils.47,66 IL-1β also increases the expression of cell adhesion molecules (e.g., ICAM-1 [CD54]) on endothelial cells.67 ICAM-1 interacts with integrins (CD11 and CD18) on neutrophils and monocytes to promote endothelial adherence and subsequent entry into tissues. There is a significant body of evidence that suggests that sterile inflammation contributes to the severity of IRI;

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Kidney Transplantation: Principles and Practice

neutralization of the DAMP HMGB1 with a monoclonal antibody attenuates renal injury after IRI, whereas recombinant HMGB1 exacerbates it.68 Some DAMPs stimulate TLRs, and mice deficient in TLR-2 and TLR-4 are protected from IRI with a reduction in neutrophil and macrophage infiltration.69,70 Furthermore, NLRP3, ASC, and caspase-1 deficient mice are protected from renal ischemic injury.71–73 Pharmacologic inhibition of caspase-1 has been shown to reduce renal IRI74 and may therefore be a viable therapeutic strategy in transplantation. In rodent models, treatment with monoclonal antibodies directed against ICAM-1, CD11a, or CD11b also protect against IRI.75–77 In a human phase I trial, ICAM blockade using a murine antibody BIRR1 was associated with a reduction in delayed graft function in renal transplant recipients.78 However, a randomized controlled trial of anti-ICAM-1 antibody in renal transplantation failed to demonstrate any significant improvement in delayed graft function.79 Blockade of another adhesion molecule, P-selectin, also attenuates leukocyte recruitment and IRI in rodent models80,81 and in humans.82 Innate cells may also drive an adaptive alloimmune response. In TCMR, macrophages may act as antigen-presenting cells (APCs), and the IRI-associated inflammation may induce upregulation of major histocompatibility complex (MHC) class II (MHC-II) on resident cells, augmenting their antigen-presenting functions. In antibody-mediated rejection (ABMR), IgG and complement are deposited in peritubular capillaries, facilitating monocyte, macrophage, and neutrophil activation via their Fcγ receptors (FcγR) and complement receptors. Indeed, the presence of neutrophils within peritubular capillaries is one of the diagnostic features of ABMR,83 and increased numbers of intraglomerular monocytes and macrophages have been observed in C4d+ ABMR.84 Macrophages may also contribute to chronic ABMR; early macrophage infiltration is predictive of chronic allograft nephropathy and long-term graft survival.85 

NK Cells and Innate Lymphoid Cells In the context of organ transplantation, it is increasingly clear that NK cells play a significant role.86–88 NK cells are a distinct class of cytotoxic lymphocyte characterized by the production of perforin, granzymes, and IFNγ that play a role as effector cells, lysing sensitive targets according to the presence or absence of specific target antigens. Two subsets of NK cells exist in humans, CD56bright cells and CD56dim cells, with CD56dim NK cells comprising approximately 90% of blood and spleen NK cells. This subset expresses FcγRIIIA (CD16) and undergoes antibodydependent cell-mediated cytotoxicity (ADCC), the targeted release of cytotoxic molecules in response to FcγR ligation by IgG-opsonized cells. The relevance of ADCC to organ rejection will be discussed in more detail when discussing mechanisms of ABMR. NK cells also express an array of other activating and inhibitory cell surface receptors that dictate cellular activation depending on the microenvironment encountered by the cell. Although the importance of NK cells in bone marrow transplantation has been long established,89,90 their role in solid organ transplantation has taken longer to be recognized. Several laboratories using different experimental models found that grafts survive indefinitely in the presence of demonstrable

NK effector activity,91,92 although more recently CD28independent rejection in mouse models of transplantation has been shown to be NK dependent and sensitive to blockade of NKG2D.93 The activating receptor NKG2D is engaged by MHC class I polypeptide-related sequence (MIC) A (MICA) and MICB, that are induced in allografts during acute and chronic rejection.94 The binding of these ligands to NKG2D activates NK cells to enhance effector functions, whereas the engagement of killer immunoglobulin-like receptors (KIRs) by KIR ligands such as HLA-C (KIR2DL1 and KIR2DL2) and HLA Bw4 (KIR3DL1) generally inhibit function. Genetic studies of donor and recipient HLA-C type (grouped as C1 and C2 depending on polymorphisms at position 77 and 80 and which seem to exhibit differential NK cell inhibition) suggest that longterm outcomes may be influenced by donor or recipient interaction with KIRs.86,87 This has also been observed when KIR HLA mismatches are analyzed in HLA-compatible transplantation.95 Inhibitory receptor function underlies the phenomenon of responses to “missing self,”96,97 which contributes to tumor immunity,98 the killing of stem cells,99 and hybrid resistance in experimental models of transplantation.88 Beyond NK cells, another class of innate lymphocyte are the recently described “helper” innate lymphoid cells (ILCs). The subject of intense research in the last decade, ILCs are characterized by their similarity to helper T (Th) cell subsets, with the notable absence of somatically recombined antigen-specific receptors or classical lineage markers.100 ILCs can subdivided into ILC1s, ILC2s, and ILC3s, which mirror Th1, Th2, and Th17 subsets in terms of transcription factor dependency and effector cytokine profile. The phenotype and dynamics of donor and recipient helper ILCs after transplantation remains poorly understood. However, it is likely that the nature of the transplanted organ dictates the relative contribution of ILCs to transplant phenomena: ILCs may be expected to have significant influence on transplanted mucosal tissues, because they are particularly enriched at these sites. For example, the production of homeostatic IL-22 and amphiregulin by ILC3s and ILC2s, respectively, may limit detrimental tissue destruction and reinforce antimicrobial defense at the mucosal epithelium in the gut and lung.101–103 Indeed, ILC3-derived IL-22 production has been implicated in reduced disease progression and intestinal tissue damage in murine models of graft-versus-host disease.104,105 Conversely, the transition to ILC1like phenotypes is associated with increased inflammation and may promote early graft dysfunction.106 Curiously, the absence of ILC reconstitution in severe combined immunodeficiency (SCID) patients after hematopoietic stem cell (HSC) transplantation, including NK cells, was not associated with any overt susceptibility to disease.107 Therefore more investigation into the precise nature of ILCs within allografts is needed. 

CELLS AT THE INTERFACE BETWEEN INNATE AND ADAPTIVE IMMUNITY Although sufficient for initial protection against most microorganisms and sterile insults, innate immunity plays a crucial role in shaping adaptive immune responses according to the context in which antigen is encountered. Indeed,

2 • The Immunology of Transplantation

complex mechanisms have evolved to ensure optimal targeting of different effector mechanisms against viruses, bacteria, fungi, protozoa, and multicellular parasites, while maintaining immunologic tolerance toward innocuous self and foreign antigens.108 A critical class of innate immune cell mediating this cross-talk between innate and adaptive immunity is the dendritic cell (DC). DCs pick up antigen within tissues and migrate to local draining lymph nodes for MHC-mediated presentation to antigen-specific T cells and the initiation of adaptive immunity.109 Furthermore, DCs integrate a variety of secondary cues, such as PRR or cytokine stimulation, to dictate the fate of T cell activation. For example, it is not surprising that mucosal-resident DCs are locally primed for the homeostatic induction of peripheral regulatory T cells (Tregs) via production of TGFβ and retinoic acid,110–112 whereas those DCs elicited in the context of infection can skew T cell activation toward inflammatory Th1, Th2, or Th17 subsets, depending on the nature of the pathogen.113,114 A similar set of considerations can be applied to monocytes and tissue-resident macrophages. Although less efficient at antigen presentation than DCs, several macrophage-derived cytokines can influence T cell polarization and activation, including IL-1β, IL-23, IL-12, and TNFα.115–117 This communication with T and B cells is bidirectional. T cell-derived IFNγ and IL-4 or IL-10 are classically associated with the differentiation of monocytes and macrophages to so-called M1 and M2 phenotypes, respectively.118 M1 macrophages produce high levels of reactive oxygen species and proinflammatory cytokines and chemokines, whereas M2 macrophages produce high levels of IL-10 and tissue-remodeling factors. However, this remains an oversimplification of the complex macrophage phenotypes in  vivo. Similarly, macrophages express high levels of FcγRs, cell surface receptors that bind to the Fc portion of IgG antibodies, and mediated potent cellular responses to opsonized microbes, immune complexes, or deposited IgG.119 In recent years, there has been increasing appreciation for the role of certain subsets of granulocytes in the activation of adaptive immunity, particularly with regard to B cell activation and maintenance. Neutrophils have been described to promote antibody production by splenic marginal zone B cells via their production of B cell activating cytokines and costimulatory molecules, such as IL-21 and CD40L, respectively.120 Furthermore, these cells express FcγRs, with the potential for IgG-mediated feedback. There is also evidence that neutrophils can traffic to lymph nodes (LNs) for presentation of antigen to T cells121 or licensing DCs for T cell activation by TNFα-mediated maturation.51 Eosinophils have also been demonstrated to be a major determinant of B cell maintenance within the bone marrow and mucosal tissues via similar mechanisms.122–124 Given their residency and recruitment to numerous tissues, it is likely that these cells can influence the induction or progression of alloimmunity. ILCs are critically dependent on, and influence the activity of, neighboring immune cells, including those of the adaptive immune system. Indeed, seminal work by Sonnenberg and colleagues has demonstrated that ILC3s are capable of MHC class II-mediated antigen presentation and the suppression of antigen-specific T cells within the

15

gut.125,126 Similarly, others groups have shown that lungresident and systemic ILC2s and ILC3s are capable of driving T cell activation in a MHC-II-dependent manner.127,128 Furthermore, human splenic ILCs support B cell antibody production through the production of B cell activating molecules, including a proliferation-inducing ligand (APRIL) and B cell activating factor (BAFF), and maintenance of B cell-helper neutrophils.129 

Stimulation of Adaptive Alloimmunity The antigen-specific or adaptive immune response to a graft occurs in two main stages. In the afferent arm, donor antigens stimulate recipient lymphocytes, which become activated, proliferate, and differentiate while sending signals for growth and differentiation to a variety of other cell types. In the efferent arm, effector leukocytes migrate into the organ and donor-specific alloantibodies are synthesized, both of which cause tissue damage. To initiate adaptive immunity, the graft must express antigens that are recognized by the recipient as foreign, and these include ABO antigens, HLA, and non-HLA “auto-antigens” that are polymorphic.

ABO BLOOD GROUP ANTIGENS When allocating an organ to a potential recipient the first consideration is to ensure that it is compatible for the ABO blood group antigens. ABO antigens are expressed by most cell types in organ allografts and, were an ABO incompatible transplant to be performed, the presence of naturally occurring anti-A and anti-B antibodies in recipients will likely cause antibody-mediated hyperacute rejection and rapid graft loss. Organs from blood group O donors may be safely given to recipients of any blood groups (“universal donor”) and recipients who are blood group AB may safely receive organs from donors of any blood group (“universal recipient”). In practice recipients of organs from deceased donors receive ABO blood group identical organs to avoid inequity of access to organs, although recipients of kidneys from living donors often receive an ABO compatible but non-ABO identical kidney. 

HLA MOLECULES Histocompatibility antigens differ between members of the same species and are therefore targets of the immune response in allogeneic transplantation. In all vertebrate species, histocompatibility antigens can be divided into a single, albeit multigenic, MHC and numerous minor histocompatibility (miH) systems. Incompatibility between donor and recipient for either MHC or miH leads to an immune response against the graft, more vigorous for MHC than miH. Indeed rejection of MHC-compatible organ grafts is often delayed, sometimes indefinitely, although in some mouse strain and organ combinations miH differences alone can result in acute rejection similar to that observed across full MHC mismatch.130 On the other hand, the outcomes of allogeneic stem cell transplantation between HLA-identical siblings can be significantly affected by miH mismatches causing graft-versus-host disease.131

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Kidney Transplantation: Principles and Practice

Major Histocompatibility Antigens MHC class I proteins are cell surface glycoproteins composed of two chains—the alpha chain, which is highly polymorphic and encoded by a class I gene, and a nonvariable β2-microglobulin chain (molecular weight approximately 12 kD). MHC class I proteins are expressed on most nucleated cells, albeit at variable levels, and they are generally responsible for activating cytotoxic CD8 T cells. MHC class II proteins are encoded entirely within the MHC and are composed of two membrane-anchored glycoproteins, an alpha and a beta chain. MHC class II molecules present peptides and activate CD4-expressing helper T cells. The tissue distribution of MHC class II proteins is far more restricted than that of class I, being expressed constitutively only by B lymphocytes, DCs, and some endothelial cells (particularly in humans). During an immune or inflammatory response, many other cell types may be induced to express MHC class II proteins.132–136 Both MHC class I and MHC class II molecules have the capacity to present peptides but the origin of these peptides differs between the two. In the case of MHC-I, they are largely acquired from the intracellular environment, whereas MHC-II largely present peptides acquired from the extracellular environment. Nevertheless, so called “crosspresentation” between these pathways may occur, particularly in the context of specialized antigen presentation by DCs.137,138 A combination of MHC and peptide forms a compound epitope that is engaged by the antigen-specific T cell receptor (TCR). The peptide-binding groove is usually occupied by many different peptides, derived from self-proteins (often those from the MHC) which, during infection, are replaced by those derived from pathogens.139 The TCR repertoire is subject to negative thymic selection so that autoreactive cells are purged and positive thymic selection for TCRs that engage with peptides presented by autologous MHC occurs. When a pathogen invades, MHC proteins become loaded with foreign peptides that are engaged by TCR in a selfrestricted immune response. In humans, the HLA class I molecules are HLA-A, -B, and -C; MHC class II molecules are HLA-DR, -DP, and -DQ. Their role in presenting antigenic peptide to the TCR has led to the evolution of a high level of genetic diversity such that there are thousands of variants of both MHC class I and class II genes in the human population. This is likely to have evolved in response to their role as restriction elements in the response to pathogen-derived peptides. Certain cohorts of animals within species that have limited polymorphism at MHC loci have been devastated by infections that are cleared without difficulty in closely related species with polymorphic MHC.140 This genetic diversity in the MHC loci is an important driver of alloimmune sensitization stimulated by pregnancy, blood transfusion, and prior transplantation. The immune mechanisms involved in these responses are not fundamentally different from those involved with any other antigen. The cellular immune response to alloantigen is, however, fundamentally different at least in magnitude, because MHC molecules bind a diverse range of endogenous peptides, which are therefore normally presented at the cell surface. Allogeneic MHC generate a correspondingly wide range of compound epitopes distinct from the repertoire generated by syngeneic MHC. These are therefore recognized

as foreign and engaged by the TCR in the so-called “direct alloimmune response.” The cellular immune response to MHC alloantigens is consequently unique in its diversity and therefore the number of T cells that can be recruited to an immune response.141,142 Clinically, we currently assess and attempt to optimally match transplant donors and recipients according to the number of HLA-A, -B, and -DR mismatches, with a minimum of 0 mismatches (0-0-0) and a maximum of 6 mismatches (2-2-2) considered in the algorithm. In general, a greater emphasis is placed on matching at DR loci because of the capacity of MHC-II mismatches to activate CD4 T cells. 

Minor Histocompatibility Antigens Several genes within the class I and class II regions do not encode classical MHC proteins. In addition to those involved in antigen processing, others encode nonclassical MHC proteins that are similar in structure to classical MHC proteins but are nonpolymorphic. These may have antigenpresenting capacity for specialized antigens, such as lipids (e.g., mycolic acid and lipoarabinomannan from Mycobacterium) or peptides of different sequence but with common characteristics (e.g., with N-formylated amino termini). Others such as HLA-G play a role in immune regulation143 particularly at the feto-maternal barrier.144 The class III region of the MHC is large and contains genes encoding proteins with a wide range of functions including many with roles in the immune system, including TNFα and TNFβ.145 Polymorphisms that determine the production of such cytokines have also been linked to certain immune responses, including transplant rejection.146 Although the highest degree of genetic polymorphism within a species lies within the MHC, many other loci encode proteins with a lower degree of variability. It is clear from genetic studies that these proteins can act as transplantation antigens; they are miH antigens. Their structure and distribution were for many years elusive. Although T cells could recognize and respond to cells from MHC-identical individuals, it was almost impossible to raise antibodies against the antigens involved, making biochemical characterization difficult. The knowledge that T cells recognize small peptides, together with the application of molecular genetic techniques, allowed the characterization of the prototypic miH antigen, the male antigen or H-Y.147,148 From such work, it is clear that miH antigens generally represent peptides from low-polymorphic proteins presented in the MHC groove, in the same way as a conventional antigen derived from infectious agents. The so-called H-Y antigen is actually derived from a group of such proteins encoded on the Y chromosome.147–150 The first observation explains why it has been difficult to raise antibodies to miH antigens: because the combination of autologous MHC with allogeneic peptide constitutes a relatively poor conformational determinant for antibody binding, despite being an adequate determinant for TCR engagement. MiH antigens can play a prominent role in rejection in a recipient who is given an MHC-compatible graft but in whom preexisting sensitization to miH antigens exists. This situation can be shown in the rat and mouse151,152 and probably explains the occurrence of rejection episodes (which rarely result in graft loss) in renal transplants performed between HLA-identical siblings. Multiple miH

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differences have been shown to represent an immunogenic stimulus equivalent to that of the MHC in a nonsensitized recipient of a cardiac allograft in the mouse151 but it is difficult to gather similar data in clinical transplantation. Tissue-specific polymorphic protein antigens have also been described, for example, in mouse skin153 and rat kidney.154 An endothelial-monocyte antigenic system has been shown in humans, and it has been suggested that cells sensitized to these antigens can cause graft damage. This area has been reviewed by other authors.155–157 

Donor leukocytes and shed antigens

ANTIGEN PRESENTATION

Direct, Indirect, and Semidirect Antigen Presentation Allogeneic MHC on DCs derived from the graft can present a wide range of endogenous peptides derived from donor tissue, both from nonpolymorphic proteins174 but also from MHC proteins themselves.175,176 These combinations

DIRECT

Allo-MHC/ peptide

Donor DC/APC

T cell receptor

Recipient T cell

Self-MHC + shed donor antigen

INDIRECT 1

Dendritic Cells DCs are present in all organs, including those that are routinely transplanted, and in secondary lymphoid org­ ans.162–164 Much of the work on DC function has emerged from murine studies, with more limited data from human tissues, because of the challenge of obtaining fresh clinical samples for in-depth analysis. However, expression of CD11c and MHC-II are useful markers to identify classical DCs (cDC) in human tissues. cDC can be further subdivided into the cDC1 subset that are CD141 (THBD) and XCR1+, the cDC2 subset that express CD1c+, and a further CD1c/ CD141− subset. All three subsets have recently been isolated in the human kidney using flow cytometric analysis.165 After transplantation, these cells migrate out of the transplanted organ, into the bloodstream, and will subsequently encounter the recipient lymphoid system, where they are able to interact with and stimulate the host immune response.166,167 Tissue-resident DCs have an immature phenotype,168 but activation with PAMPs or DAMPs results in their rapid maturation into potently immunogenic APCs169–172 with high expression of MHC class I and class II antigens together with a range of costimulatory molecules and cytokines (see section on Direct, Indirect, and Semidirect Antigen Presentation). DCs with an immature or partly mature phenotype deliver tolerogenic rather than activating signals and play a crucial role in the induction of Tregs, T cell anergy, and deletion.171,173 These effects are mediated by secretion of cytokines such as IL-10 and TGFβ, which promote the emergence of Treg cells and through the expression of “negative costimulatory molecules” such as programmed deathligand (PD-L)1/2, inducible T cell costimulatory (ICOS) ligand, Ig-like transcript (ILT)3/4, and Fas ligand. 

Allograft-draining lymph node

Recipient DC/APC

SEMI-DIRECT

As discussed, donor antigens are presented to T cells in the context of MHC. Activation of CD4 T cells is of particular importance, given their ability to promote both cellular and humoral adaptive responses, and has been demonstrated in a number of experimental transplant systems.132,158–161 CD4 T cell activation requires the presentation of antigen in the context of MHC-II and is carried out by professional APCs, namely DCs, B cells, and some macrophages. DCs in particular, have received great attention in this context.

17

T cell receptor

Recipient T cell

Shed allo-MHC/ peptide exosomes

Recipient DC/APC

T cell receptor

Recipient T cell

Fig. 2.5  Mechanisms of antigen presentation by dendritic cells in alloimmunity.  Donor tissue-resident DCs and shed antigens derived from transplanted allografts can activate recipient T cells for alloreactive immunity. Direct antigen presentation is mediated by migrating donor-derived DCs within local lymphoid tissue. Indirect antigen presentation arises from recipient DCs acquiring shed antigens from damaged tissue. Semidirect antigen presentation results from shed allo-MHC/peptide exosomes being acquired by recipient DCs for presentation to recipient T cells.

of peptide and MHC can be engaged by recipient TCR, in a process termed direct antigen presentation (Fig. 2.5). The T cell response to allogeneic MHC occurs at a remarkably high frequency—in the order of 1 in 100. This relates in part to the wide range of endogenous peptides that occupy the MHC groove, generating an equivalent number of compound epitopes. It is also dependent on the capacity of the TCR to recognize multiple distinct ligands, that is to say polyspecificity is a feature of TCR engagement.141,177 Alloantigens can also be processed and presented conventionally by recipient antigen-presenting cells. This is termed indirect antigen presentation (see Fig. 2.5). The indirect pathway accounts for the fact that, in animal models, elimination of passenger leukocytes from the graft does not

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Kidney Transplantation: Principles and Practice

abolish although it may alleviate rejection. Indeed, skin grafts from class II−/− mice transplanted onto normal mice were rejected in a CD4+ T cell dependent manner.178 These and other experiments demonstrated the potential role of self MHC class II restricted presentation of exogenous alloantigen to stimulate T cell responses through the indirect pathway.179–181 In clinical transplantation, and in particular in the context of chronic allograft dysfunction, evidence for the role of indirect allorecognition has been presented in various reports using peptides derived from polymorphic regions of MHC antigens182,183 or cytoplasmic membrane protein preparations.184,185 These studies need careful interpretation, however, because such assays present particular difficulties for reproducibility and standardization in an outbred population.186,187 It has been proposed that the direct allogeneic response dominates acute rejection and indirect allogeneic response allows for ongoing class II restricted responses after the loss of donor DCs.188–190 This is almost certainly an oversimplification,191,192 because there are significant differences between the expression of MHC molecules on the endothelium of mouse versus human, with long-term tonic expression of MHC-II on human endothelium even in the absence of inflammation. Therefore mouse transplant experiments may not reflect the response in humans. Nevertheless, these models have implicated indirect allorecognition in providing cognate help for B cell alloantibody formation,193,194 and are supported by the observation of an increased risk for graft loss associated with nondonor-specific and donorspecific antibody.195,196 In addition to direct and indirect antigen presentation, there is evidence that intact proteins can be exchanged between cells in cell culture systems, that MHC proteins transfer in  vivo197 and that transferred MHC stimulates allogeneic responses in vitro.197–200 The importance of this semidirect pathway of antigen presentation to transplant outcomes remains to be clearly established. 

T CELL ACTIVATION T cell activation requires not only engagement of the TCR by a peptide:MHC complex (signal 1), but also engagement of cell surface costimulatory molecules present on APC (signal 2) and T cell stimulation by cytokines (signal 3) (Fig. 2.6).

Signal 1—TCR Activation The T cell receptor comprises an alpha and a beta chain that recognize and bind to peptide:MHC complexes. The TCR has no catalytic activity of its own, but forms a complex with six CD3 subunits (γδɛ2ζ2) that contain cytoplasmic immunoreceptor tyrosine-based activation motifs (ITAMs).201 Lymphocyte-specific protein tyrosine kinase (LCK) phosphorylates these ITAMs after TCR ligation resulting in association with the ζ-chain-associated protein kinase: zetachain-associated protein kinase 70 (ZAP70).202 ZAP70 recruitment results in phosphorylation of the adapter proteins SH2 domain-containing leukocyte protein of 76 kD (SLP76) and linker of activated T cells (LAT). LAT facilitates the formation of multiprotein complexes that drive multiple activation pathways203 leading to de novo expression of a

wide range of genes encoding cytokines and cell surface proteins. These signaling pathways are the targets of a number of immunosuppressive medications, including calcineurin inhibitors, and are described in detail elsewhere.201–206 

Signal 2—Costimulation To generate sustained T cell activation, engagement of surface costimulatory molecules is required in addition to signal 1 (see Fig. 2.6). These costimulatory molecules determine and mediate short-term function and long-term fate during priming, expansion, and death of T cells. There are many families of costimulatory molecules including those of the immunoglobulin superfamily (e.g., B7), tumor necrosis factor family (e.g., CD154), G protein-coupled receptors (e.g., C3a and C5a receptors), and lectin receptors (e.g., DC-SIGN). As increasing numbers of molecules have been described it has become evident that these interactions are highly complex, involving paracrine and cell contact dependent mechanisms. In the absence of costimulatory signals, T cells may become anergic, that is they are unresponsive even if they subsequently receive an adequate second signal.207–211 Anergic cells can also inhibit the activation of neighboring T cells.212–215 The molecular basis for the costimulatory or second signal for naive T cell activation was defined as that between CD28 and the B7 family molecule now known as CD80.216 These costimulatory interactions were not only the first to be described but also the first to be manipulated in the setting of clinical transplantation.217,218 The cell surface protein CD28 is now known to be a member of a family of similar proteins.219–221 Activation of downstream signaling via CD28 results from ligation with B7 family proteins, CD80 or CD86. These proteins are expressed by APCs such as DCs and engage CD28 during antigen presentation. Signaling through CD28 in the context of TCR ligation results in an increase in glucose metabolism and high levels of cytokine and chemokine expression, particularly IL-2, a cytokine that promotes T cell proliferation and survival. CD28-deficient mice have impaired immune responses but can reject skin grafts, albeit in a delayed fashion222; this is likely because of other costimulatory proteins that can substitute the action of CD28.219,221,223 Blocking the CD28 pathway in normal animals inhibits the alloimmune response and results in prolonged graft survival or tolerance.224–226 The most widely used reagent for this purpose has been cytotoxic T lymphocyte-associated protein 4 (CTLA-4)-Ig. This blocks B7 engagement of both CD28 and CTLA-4, the latter of which could be counterproductive because CTLA-4 acts primarily as a coinhibitory molecule, counterbalancing the effects of CD28. This is evident in the severe phenotype of CTLA-4−/− mice, in which animals die of lymphoproliferative disorder within a few weeks of birth. Similar in structure to CD28, CTLA-4 inhibits the earliest events in T cell activation. CTLA-4 has a higher affinity for CD80 and CD86 than does CD28227,228 and its engagement with CD80 induces a lattice structure at the cell surface consisting of alternating CTLA-4 and CD80 homodimers. These properties of CTLA-4 may limit the ability of CD80 to interact with and cluster CD28 at the immune synapse, potentially explaining the finding that low levels of CTLA-4 can be effective at inhibiting immune responses. CTLA-4 may

2 • The Immunology of Transplantation

19

Allograft-draining lymph node

Signal 1

Dendritic cell

MHC-II CD80/ CD86

TCR

Recipient CD4+ T cell

Signal 2 CD28

CD40

CD40L

Signal 3

IL-2

Th-polarizing cytokines

Granzymes Perforin pore Fas

Allograft destruction

FasL

CD8+ T cell activation and expansion

Fig. 2.6  Molecular mechanisms of T cell activation.  Within local draining lymph nodes, DC-T cell interaction in the presence of alloantigen results in recipient T cell activation through a variety of molecular mechanisms. Signal 1 is provided by antigen-loaded MHC class II molecules interacting with an antigen-specific TCR. Signal 2 is mediated by costimulatory molecules on antigen-presenting cells, such as CD80/CD86 and CD40, which engage the corresponding receptors on T cells, in this case CD28 and CD40L, respectively. Signal 3 is mediated by APC-derived cytokines, which skew T cells into specific subsets, such as Th1, Th2, or Th17 cells. Activated T cells also secrete IL-2, resulting in autocrine signaling and T cell expansion and survival, and paracrine activation of local T cells, such as CD8+ effector T cells. CD8+ T cell activation can then induce tissue destruction through FasL and perforin/ granzyme-mediated mechanisms.

also deliver a negative intracellular signal229 independent of its effect on CD28 that halts cell cycle progression and IL-2 production230 or affects TCR engagement.231 The actions of CTLA-4 may be even more complex at a polyclonal level because CTLA-4 engagement may promote Treg function in vivo.232,233 A modified CTLA4-Ig fusion protein, belatacept, has undergone robust assessment in two large clinical trials, BENEFIT and BENEFIT-EXT, and these demonstrate that it is as effective as calcineurin-inhibitors (CNIs) in preventing acute TCMR in humans, but avoids CNI-associated nephrotoxicity resulting in better allograft function.234–236 Belatacept-treated subjects also had a significantly lower rate of development of de novo donor-specific antibody (DSA), and nonhuman primate studies suggest this may be because of inhibition of B cell-T follicular helper (Tfh) cell interactions.237 Since the role of CD28 engagement was defined other members of this family of molecules have been identified; bound by various ligands, they generate effects that can broadly be termed costimulatory ICOS, DNAX accessory

molecule 1 (DNAM-1) and cytotoxic and regulatory T-cell molecule (CRTAM) or coinhibitory CTLA-4, programmed cell death protein 1 (PD-1), B- and T-lymphocyte attenuator (BTLA), lymphocyte-activation gene 3 (LAG-3), T cell Ig and mucin-domain containing-3 (TIM-3), T cell immunoreceptor with Ig and ITIM domains (TIGIT), and leukocyte-associated Ig-like receptor 1 (LAIR-1). A second major family of costimulatory molecules on the T cell surface is the TNF superfamily including CD27, CD134 (OX40), and CD137 (4-1BB), which interact with a range of TNFreceptor family members.223,238,239 On the T cell surface the TNF receptor family member CD154 (CD40 ligand, gp39) itself interacts with CD40 on B cells, DCs, and monocytes. Larsen and coworkers showed that blocking this interaction could prolong graft survival in a mouse cardiac transplant model.240 Even more impressive, however, were data that combined CD28 and CD40 blockade induced permanent survival of allogeneic skin grafts in mice with no long-term deterioration of graft integrity.241 Tolerance to graft antigens could not be shown in these mice, despite the excellent

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Kidney Transplantation: Principles and Practice

survival of the transplant itself. In a large animal setting, kidney graft rejection in monkeys can be prevented completely with antibodies to CD154242; however, its clinical application is limited by thromboembolic events associated with its expression on platelets. Alternative approaches using nondepleting antibodies to CD40 are therefore now being explored.243 An understanding that memory T cells are an important barrier to successful engraftment in the presence of immunosuppression and to tolerance induction, combined with the fact that they may be relatively resistant to CD28 inhibition, has directed interest toward identifying molecular targets in T memory cells. The expression of CD2 on T effector memory cells,244,245 of and lymphocyte function-associated antigen (LFA)-1 on T memory cells,246 and even expression of a specific potassium channel on T effector memory cells247 have been investigated. These approaches require further assessment and are not without potential competing risks.248,249 

Signal 3—Cytokines The consequences of TCR engagement and costimulation are proliferation and differentiation of the T cells into effector phenotypes and the concomitant production of cytokines required to stimulate themselves, and other immune cell types, including CD8 T cells, macrophages, DCs, and B cells. IL-2 is a potent activator and proproliferative cytokine for T cells. Its effects are dependent on binding to its cell surface receptor, which has three subunits, α (CD25), β, and γ. During T cell activation the α subunit becomes associated with the other subunits to form a high affinity receptor. Blockade of the IL-2 receptor by targeting the α-chain profoundly inhibits T cell proliferation. CD25 blockade with basiliximab or daclizumab have proven efficacy as induction agents in renal transplantation.250,251 A number of other cytokines act to polarize CD4 T cells toward different fates, where they promote different types of immune responses. Th1 polarized cells mainly produce IFNγ and drive cell-mediated inflammation and immunoglobulin class switching to IgG antibodies. Th2 cells produce IL-4, IL-5, and IL-13, and are involved in IgE class switching and eosinophil recruitment. Th17 cells produce IL-17 and IL-22 and play an important role in the clearance of extracellular pathogens and in autoimmune pathology. The role of different cytokines in allograft rejection has been approached using neutralizing antibodies and mice deficient in specific cytokines. However, interpretation of these experiments is complex, because the absence of the cytokines can influence immune system development, there is redundancy in the action of cytokines, and cytokines may have opposing actions depending on the context. This is illustrated by studies of IL-2−/− or IFNγ−/− mice, which demonstrated that neither were required for rejection.252,253 IL-15 can for example substitute many of the actions of IL-2, and IL-15 transcripts are found in grafts placed in IL-2−/− mice. Subsequent studies demonstrated that whereas neither IL-2 or IFNγ were required for rejection, both were required for tolerance induction.254 This suggested nonredundant functions for both IL-2255,256 and IFNγ257–259 in the function of regulatory T cells (see section on Transplant Tolerance). 

T Cell-Mediated Rejection TCMR, previously known as acute cellular rejection, is the most common type of rejection observed in the current era. TCMR occurs in around 20% of kidney transplant recipients and most frequently occurs in the first 6 months posttransplant (see Fig. 2.1). TCMR is characterized by immune cell infiltration into the graft and may involve epithelial cells, for example a tubulitis in kidney transplants, or in more severe cases, an arteritis. This infiltrate is composed of CD8 T cells, CD4 T cells, monocytes, macrophages, and B cells. The sequence of events that culminate in TCMR include the migration of immune cells into the graft, which is dependent on the production of chemokines by graft-resident cells and on the interaction of adhesion molecules on endothelial cell and immune cells. Once in the graft, cellular effector functions are activated causing damage to the transplant, and the cytotoxic functions of CD8 T cells in particular play a key role in this process.

MIGRATION OF ACTIVATED CELLS INTO THE GRAFT To enter a site of inflammation, leukocytes must migrate across the vascular endothelium. This migration process is controlled by chemokines, and by cell-cell interactions between the leukocyte and the endothelium.42 Activated and memory cells bear adhesion proteins, chemokine receptors, and addressins, which allow homing to and migration into peripheral tissues.260,261 In transplantation, this activation is thought to predominantly take place in secondary lymphoid organs, because aly mice lacking lymphoid organs have reduced graft rejection262,263 as do splenectomized mice deficient in LTα or LTβ (and therefore lacking in lymph nodes and Peyer’s patches).264 In small bowel transplantation, recipient-derived leukocytes migrate in large numbers into the mesenteric lymph nodes and Peyer’s patches of the graft.265–268 This likely results from normal homing of immune cells to the large volume of lymphoid tissue within the graft. During chronic rejection, lymphoid neogenesis or ectopic accumulations of lymphoid cells may develop within transplants in mouse models and in humans, enabling local activation of immune cells within the organ.269 The movement of lymphocytes out of secondary lymphoid organs requires sphenogosine1-phosphate receptor, a G protein‐coupled protein, and this has been targeted using FTY720 (fingolimod). FTY720 acts as a high-affinity agonist for S1P1R, inducing internalization of the receptor. This renders the cells unresponsive to the S1P1, depriving them of an obligatory signal required for egress from lymphoid organs. Lymphocytes are therefore unable to access the peripheral circulation and allograft. Although FTY720 was used in a number of clinical trials in transplantation, its use was associated with macula edema and bradycardia, and therefore it has not entered routine clinical use.270–272 The processes underpinning the movement of lymphocytes into the graft are similar to those described for neutrophils in the section on Activation of the Immune System Peritransplant. Of note, antigen-activated lymphocytes migrate into nonlymphoid tissues260,273,274 and may show

2 • The Immunology of Transplantation

tissue-selective homing and preference for sites where they are most likely to reencounter their specific antigen.275 This process may be facilitated further by cognate recognition by the T cell of MHC class II/peptide complexes on the vascular endothelium.276 Blocking adhesion molecule interactions has been attempted in experimental and clinical transplantation.78,277–279 In general, cocktails of antibodies blocking multiple adhesion molecules are more potent than single antibodies280 but the results vary. Indeed, in one study a combination of antibodies blocking both ICAM-1 and LFA-1 led to accelerated rejection of rat cardiac allografts.281 Antisense oligonucleotides have also been used to prevent the expression of ICAM-1 and were effective in prolonging graft survival in experimental models.282 Small molecule inhibitors also may effectively interrupt the interactions required for leukocyte adhesion and extravasation,283 and these reagents may simultaneously be effective in blocking IRI and rejection.284 Chemokines play a crucial role in leukocyte trafficking under both normal conditions and in the setting of sterile inflammation and rejection. There are more than 40 different chemokines belonging to two major structural families that are recognized by a range of chemokine receptors expressed on immune cells: CC or β chemokines (e.g., MIP-1α/β, [CCL3/4] regulated on activation, normal T cell expressed and secreted [RANTES; also known as CCL5], and monocyte chemoattractant protein [MCP1; also known as CCL2]) which attract T cells, monocyte/macrophages, DCs, NK cells, and some polymorphs and CXC or α chemokines (e.g., IL-8 [CXCL8] and IFNγinducible protein) which primarily attract neutrophils and T cells.285–289 A number of experimental transplant models have demonstrated the importance of chemokines in mediating immune cell infiltration in IRI and in acute and chronic rejection.285,286,290–293 For example, CCR1-deficient mice accept MHC class II mismatched grafts without immunosuppression and MHC class I and II mismatched grafts with only low-dose immunosuppression.294 CXCL10−/− recipients show normal rejection kinetics of a wildtype graft, but CXCL10−/− grafts placed into wildtype recipients show prolonged survival.295 These murine studies have sparked interest in therapeutic targeting of chemokine networks in human transplantation, but as yet, no agents are currently used in clinical practice.296 

MECHANISMS OF CYTOTOXICITY CD8 cytotoxic T cells damage and destroy target cells by the production of lytic molecules such as perforin and granzyme, and through the induction of Fas-Fas-Ligandmediated apoptosis (Fig. 2.6). In cell culture systems, MHCmismatched lymphocytes proliferate and produce cytokines in response to one another in the mixed lymphocyte reaction. This results in the differentiation of CD8 T cells into effectors that lyse target cells bearing the mismatched MHC antigens.297,298 There is considerable evidence that CD8 T cells are involved in TCMR. First, they make up a significant proportion of infiltrating leukocytes in rejection allografts, in contrast to the low number observed in grafts of animals treated with cyclosporine to prevent rejection.92,299 Second, cloned populations of CD8 T cells are capable of

21

causing the type of tissue damage associated with rejection. Third, graft rejection may be delayed by CD8 T cell depletion.130,160,300–302 The importance of the individual effector mechanisms of CD8 T cells in mediating rejection is debated. Mice deficient in perforin are still able to reject skin303 and organ grafts,304 even when the grafts are resistant to Fas-mediated and TNFα-mediated killing,305 but grafts mismatched only at the MHC class I were found to be rejected more slowly in perforin knockout mice.304 A number of elegant experiments in animal transplant models demonstrate that both antigen-specific and nonantigen-specific effector mechanisms because of collateral damage of bystander cells may be involved in graft destruction.306–310 

COMPLEMENT AND TCMR Murine models suggest that complement may play a role in acute TCMR. In a fully MHC-mismatched model (C57BL/6 to B10.BR), kidneys from C3-deficient donors survived for long periods without immunosuppressive treatment, in contrast to wildtype C57BL/6 donor grafts that were rejected within 2 weeks. Recipient C3 had only a minor effect in this model.311 Similarly, in a cardiac allograft model, deficiency of the complement regulator CD55 (DAF) in transplanted hearts resulted in aggressive TCMR.312 The mechanism by which complement augments TCMR may be a result of the effects of C3a and C5a on antigen-presenting cells313 or a result of a direct effect on T cells via ligation of C3aR and C5aR.314 

B Cell Activation and AntibodyMediated Rejection B CELL ACTIVATION B cells are immune cells of the lymphoid lineage that develop in the bone marrow (Fig. 2.7). They are characterized by the expression of antibody as their surface antigen receptor, the B cell receptor (BCR), and other markers such as CD20 and CD19. Antibodies comprise two heavy and two light chains, and are classified according to the heavy chain they express; IgM antibodies have a μ heavy chain, IgG antibodies a γ heavy chain, etc. When B cells emerge from bone marrow, they express an IgM antibody and pass through a transitional phase (expressing high levels of CD24 and CD38 on their surface) before becoming follicular B cells that reside within secondary lymphoid organs (the lymph node and spleen). When B cells encounter an antigen that binds their surface BCR they may either develop into short-lived plasmablasts that produce early, germ-line encoded antibody315 or alternatively, become a germinal center B cell. Here, they divide and mutate their variable region genes (somatic hypermutation) in an attempt to produce antibody with a higher affinity for antigen.316 They also undergo class switching, so that the heavy chain present in antibody changes from μ to one of the other isotypes. During many rounds of division and hypermutation, B cells with a high affinity BCR are positively selected and differentiate into

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Kidney Transplantation: Principles and Practice

B2 CELLS SECONDARY LYMPHOID ORGAN Memory B cell

Follicular B cell

CSR SHM

Transitional B cell

Germinal center

Immature B cell

i. ii. iii. Marginal zone B cell

T follicular helper cell

High-affinity plasmablast

B cell follicle

Long-lived BM plasmablast

Short-lived plasmablast

i. MHC-II presentation ii. Co-stimulation (CD40L) iii. IL-21 and IL-4

B1 CELLS

REGULATORY B CELLS

PLEURAL/PERITONEAL CAVITY

CD5+

Natural IgM

HUMAN

CD24+ CD27+ CD5+ CD38+ CD1d+

IL-10

Fig. 2.7  Molecular mechanisms of B cell activation.  B cells can be divided into two major populations: B1 and B2. B2 cells contribute to the follicular B cell population within lymphoid organs and to marginal zone B cells in the spleen. After stimulation of the BCR, follicular B cells receive help signals at the interface of the T cell zone through antigen presentation to T follicular helper cells and CD40- and cytokine-mediated signals. Activated follicular B cells undergo rounds to somatic hypermutation (SHM) and class-switch recombination (CSR), resulting in the generation of short-lived plasmablasts, high-affinity long-lived plasma cells, and memory B cells that contribute to the high-affinity class-switched antibody pool. B1 cells are enriched in the pleural and peritoneal cavities and are a major source of natural polyreactive IgM. Regulatory B cells also exist with the capacity to secrete antiinflammatory molecules, such as IL-10, that are essential for the suppression of damaging allo- and autoimmunity.

either memory B cells or plasma cells.317 A subset of CD4 T cells, known as Tfh cells, are engaged by germinal center (GC) B cells presenting antigen to them. This Tfh-B cell interaction is essential for the progress of the GC reaction and for the development of memory B cells (that express CD27) and plasma cells.318,319 Only a small proportion of plasma cells arising from the GC become established as long-lived plasma cells in the bone marrow. They reside within a number of limited niches, do not proliferate, but act as long-term antibody factories, producing IgG.320 Plasma cells have also been described in inflamed tissues in autoimmunity and within allografts.321–324 

B CELL FUNCTION B lymphocytes are best known for their ability to produce antibodies—the soluble (humoral) mediators of an adaptive immune response. In addition, B cells can act as important antigen-presenting cells for CD4 T cells, thereby initiating cellular immunity, and may produce cytokines that can both activate and regulate a range of other immune cells. B cells also contribute to the development of secondary

lymphoid organs (lymph node and spleen), and can therefore have broad effects on immune responses far beyond their most obvious function of antibody generation.

Alloantibodies Antibodies are the only soluble components of the adaptive immune system and have wider tissue distribution than their cellular immune counterparts. Alloantibodies, particularly those that recognize donor HLA, can mediate hyperacute rejection, acute ABMR, and chronic ABMR. Early efforts to assess whether recipient antibodies could potentially recognize donor cells were based on the cytotoxic crossmatch assay, incubating recipient serum with donor cells in the presence of complement.325 Currently, HLA genotyping of the donor and recipient and the use of single HLA antigen beads (SAB) allow a more precise assessment of the titer of DSA, assisting in the assessment of pretransplant immunologic risk.326,327 Currently, around 30% of patients on the kidney transplant waiting list are sensitized and have varying levels of HLA antibodies that may preclude transplantation or require an antibody-reduction strategy to allow transplantation to proceed.328 A meta-analysis of published

2 • The Immunology of Transplantation

data suggests that even low titers of pretransplant DSA (detectable by SAB but with a negative flow cytometric crossmatch), doubles the risk of ABMR and increases the risk of graft failure by 76%.329 In addition, the development of de novo DSA posttransplant in nonsensitized transplant recipients is associated with an increased frequency of acute ABMR and worse graft survival.330 The pathogenicity of HLA DSA also varies according to its specificity, with MHC class II DSA having a worse effect on the allograft than class I DSA.330,331 In addition, non-HLA antibodies such as those binding MICA or angiotensin II type 1 receptors may also have a deleterious effect on grafts.332–334 Sigdel and colleagues used high-density protein arrays to analyze serum samples obtained from 172 renal transplant recipients and identified 38 de novo non-HLA antibodies that significantly associated with the development of chronic allograft injury on protocol biopsies.335 Other non-HLA binding antibodies that may negatively affect the allograft include antibodies binding apoptotic cells.336,337 

Antigen Presentation to CD4 T Cells In order for CD4 T cells to orchestrate adaptive immune responses, they must be activated by antigen presented to them in the context of an MHC class II molecule, together with costimulatory signals. B cells are very effective APCs and have several advantages over DCs, traditionally considered to be the principle APC. First, they may have a high-affinity, specific receptor for antigen (the BCR), and can therefore efficiently and rapidly acquire large amounts of antigen for presentation.338,339 Second, they can clonally proliferate, and therefore may rapidly become the numerically dominant APC. Murine models have shown the importance of B cells for T cell activation in vivo,340,341 including in the context of autoimmunity342 and alloimmunity.343 In human kidney transplant recipients, transcriptomic analysis of kidney biopsies with TCMR supports the notion that B cells contribute to worse outcomes in TCMR. Sarwal and colleagues identified a B cell transcriptomic signature (CD20, CD74, immunoglobulin heavy and light chains) in allografts with steroid-resistant TCMR and a poorer outcome.344 Furthermore, the 11 genes found to comprise a “common rejection module,” present in samples obtained from a variety of organs during rejection, include the chemokines CXCL9 and CXCL10345 that are produced by B cells after interactions with cytotoxic T cells.346 Two B cell genes (CD72 and BTLA) are also among those most differentially expressed in biopsies with TCMR.347 Together, these data emphasize the potential importance of B cells as APCs in transplantation, and in this context, it is notable that B cell depletion has proven to be an effective treatment for autoimmune diseases considered to be mediated by T cells, including rheumatoid arthritis, multiple sclerosis, and type 1 diabetes mellitus.348–350  Formation and Maintenance of Secondary Lymphoid Tissue B cells produce lymphotoxins (LTs) and thereby initiate the formation and shape the architecture of lymph nodes and spleen.351–353 Their ongoing production of LTα1β2 is also required for the maintenance and integrity of subcapsular sinus macrophages that form a protective screen around the perimeter of lymph nodes.354 B cell production of VEGF-A

23

may also promote intranodal lymphangiogenesis, increasing antigen and DC distribution in the lymph nodes.355 They also may be involved in the generation of tertiary lymphoid structures that emerge in inflamed organs affected by autoimmunity, for example in Sjogren disease, rheumatoid arthritis, or type 1 diabetes mellitus,356,357 that may be the source of some autoantibodies.321,358 

Production of Proinflammatory Cytokines B cells have the capacity to produce a number of cytokines after stimulation and can thereby affect a variety of immune cells.359 IL6 is a cytokine required for T-dependent antibody responses,360 but B cells can themselves produce this cytokine,361 and this may contribute to autoimmune pathology, for example, via Th17 cell activation leading to exacerbation of experimental autoimmune encephalomyelitis.362 Indeed, B cells from patients with multiple sclerosis also demonstrate increased IL-6 production compared with healthy controls.362 B cell production of TNFα and IFNγ can also promote Th1 T cells361,363 and macrophage activation.364 Recently so-called innate response activator (IRA) B cells have been described. These splenic IgM+ B cells can produce granulocyte macrophage-colony stimulating factor (GM-CSF) in response to LPS, a TLR4 ligand, facilitating the mobilization of neutrophils.365 This makes an important contribution to pathogen containment in mouse models of gram-negative sepsis and in pleural responses to grampositive bacteria366 but may exacerbate atherosclerosis via Th1 cell activation.367 These B cells are thought to originate from B1 B cells, a subset enriched in the peritoneal and pleural cavities.368,369  B Cells as Regulators of the Immune Response There is increasing evidence that B cells can not only act as effectors of the immune response but can also play an immunoregulatory role, particularly via the production of IL-10370 but also by contact-dependent mechanisms (e.g., via PD-L1 expression371) and perhaps by direct granzymeB-dependent cytotoxicity.372 IL-10-producing B cells have been shown to be important in limiting autoimmunity in mouse models. In mice, several groups have identified IL-10-producing B cells within a number of B cell populations including B1, transitional, and marginal zone subsets.373–375 IL-10-producing B cells have also been identified in humans and comprise around 5% of circulating B cells, although cells with the potential to produce IL-10 may be found at higher frequencies. As in mice, human IL-10-producing B cells are present within different subsets, including transitional B cells. Several markers, such as CD5, CD1d, Tim-1, CD9, and CD80, have also been reported to localize to these “regulatory cells.”376–381 Unlike regulatory T cells that can be identified by expression of Foxp3, a subset-specific transcription factor has not been identified in regulatory B cells. Some recent data suggest that plasma cells may be the main source of IL-10 in vivo.382 The potential importance of B cells with a regulatory capacity has now been identified in a number of disease contexts, including systemic lupus erythematosus (SLE),376,377 allergy,379,383 transplant tolerance,384,385 and protection from allograft rejection.386 In particular, the balance

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Kidney Transplantation: Principles and Practice

between the production of IL-10 and proinflammatory cytokines such as IL-6 and TNFα may be important in regulating immune responses. For example, a lower number of CD24/CD38high transitional B cells that produce high levels of IL-10 versus TNFα is associated with worse allograft outcome in renal transplant recipients.387 In contrast, in patients with drug-free long-term graft function that are deemed “operationally tolerant” there is a significant increase in the number of total B cells, particularly memory B cells and B cells expressing CD1d and CD5. In vitro, B cells purified from these subjects had a relative increase in FcγRIIB expression and an increase in B cell scaffold protein with ankyrin repeats 1 (BANK1), a negative regulator of CD40 signaling.388 Other studies show a higher proportion of CD24/CD38high transitional B cells associated with longterm transplant tolerance and B cells from tolerant subjects produce more IL-10 after in vitro stimulation.384,385 

ANTIBODY-EFFECTOR FUNCTION IN ABMR Acute ABMR is uncommon in nonsensitized transplant recipients and is difficult to treat. The diagnosis of ABMR has been facilitated by more sensitive methods of alloantibody detection and by the identification of complement activation in allograft biopsies via C4d staining. Clinical features of ABMR include a decline in allograft function, the presence of donor-specific HLA antibodies, C4d deposition in peritubular capillaries, and evidence of acute vascular injury (e.g., capillaritis, with neutrophils in capillaries). ABMR, particularly in its chronic form, may occur in the absence of C4d deposition on biopsy.83,389,390 Analysis of transcripts may also assist in making a more accurate assessment of the type of rejection, particularly in diagnosing antibody-mediated rejection, compared with standard histopathological analysis, even in the absence of C4d staining.391,392 A gradual decline in allograft function with time is almost universally observed. This was previously termed chronic allograft nephropathy but the more recent Banff Classifications have sought to distinguish nonimmunologic insults, for example, CNI toxicity, from chronic rejection, particularly chronic ABMR. Chronic ABMR is characterized by vasculopathy and in the kidney is evidenced by glomerulopathy (double contouring in peripheral capillary loops) and peritubular capillary basement. There may also be peritubular capillary C4d staining, although this is not universal. Clinically, this usually occurs in patients with detectable HLA DSA, often in the context of noncompliance. The histologic features of ABMR result from well-established pathways of alloantibody effector function, namely direct activation of endothelial cells via binding to MHC393 complement activation (via the classical pathway) or recruitment and activation of immune cells that express receptors for the Fc portion of IgG or complement receptors (including neutrophils, macrophages, monocytes, DCs, and NK cells394; Fig. 2.8).

Direct Stimulation of Endothelial MHC Independently of FcγR engagement, IgG can directly activate allograft endothelium. Binding of DSA to HLA induced intracellular signaling and endothelial cell survival and proliferation, mediated by upregulation of the fibroblast

growth factor (FGF) receptor and increased FGF ligand binding. Furthermore, DSA deposition could induce expression of endothelial P-selectin for adherence of monocytes. Reed and colleagues have produced an elegant body of work demonstrating that HLA antibodies can have direct effects on allograft endothelial cells via variable region binding.393 

Complement Activation IgG immune complexes can activate complement via the classical pathway and this process is evident in ABMR by the detection of C4d on peritubular capillaries.83 Further evidence that complement fixation may contribute to the pathogenicity of alloantibodies is provided by the studies investigating C1q or C3d binding. Loupy et al. investigated 1016 antibody-compatible renal transplant recipients and demonstrated that patients that developed C1q-binding DSA after transplantation had the lowest 5-year rate of graft survival (54%), compared with those with noncomplement-DSA (93%).395 A more recent study suggests that the detection of HLA antibodies that bind to C3d may have an even greater prognostic significance in patients with acute ABMR.396 A number of complement inhibitors, including eculizumab and C1 esterase inhibitors, are currently being trialed for both the prevention of ABMR in antibody-incompatible transplant recipients,397 and for the treatment of ABMR.398,399  FcγR Activation The absence of C4d staining in more than half of biopsies with late ABMR highlights the importance of complementindependent mechanisms in mediating the deleterious effects of DSAs.83,391 Furthermore, some IgG isotypes (IgG4) cannot fix complement, whereas IgG2 has a limited complement-activating capacity compared with IgG1 and IgG3.400 FcγRs bind to the Fc portion of IgG and mediate activation of the immune cells that express them (Fig. 2.8). In humans, there are several activating receptors (FcγRIIA, FcγRIIC, FcγRIIIA, and FcγRIIIB) and a single inhibitory receptor, FcγRIIB, which plays a critical role in suppressing IgGmediated inflammation.401,402 FcγRs are widely expressed on immune cells, including neutrophils, monocytes, macrophages, DCs, mast cells, NK cells, and B cells but the effect of FcγR ligation varies between cells. For example, neutrophils express FcγRIIA and FcγRIIIB, and cross-linking leading to phagocytosis, cytokine and superoxide production, neutrophil adhesion, and extracellular trap formation (NETosis),403–410 whereas on macrophages and dendritic cells, FcγR ligation induces proinflammatory cytokine production, including TNFα and IL-1β, phagocytosis, CCR7dependent migration, and antigen presentation.411–414 There are several lines of evidence implicating FcγR activity in rejection severity and graft survival in ABMR. NK cells, in particular, have received significant attention as an immune cell subset mediating FcγR-dependent inflammation in AMBR. Hirohashi et al. demonstrated that chronic allograft vasculopathy in murine heat allografts was NK cell and FcγR dependent, inflammation being attenuated after anti-NK1.1 IgG-treatment or in the presence of F(ab′)2 fragments of IgG2a DSA.415 Consistent with a role in human ABMR, FCGR3A and other NK cell-associated transcripts correlate with the presence of DSA and ABMR.416,417 Furthermore, several groups have examined

2 • The Immunology of Transplantation

25

NK cell/neutrophil/ monocyte iii. Complement activation

i. FcγR ligation on immune cells ii. Direct activation of endothelium

Allograft endothelium Key C1q

C4d

FcγR

DSA

Donor HLA

A A=I

IgG glycosylation

AI

SA

B Fig. 2.8  Mechanisms of antibody-mediated rejection.  (A) Donor-specific antibody (DSA) binding to allograft endothelium can activate a variety of inflammatory mechanisms: (i) engagement of FcγRs on local and circulating immune cells, such as NK cells; (ii) direct activation of allograft endothelium through cross-linking of endothelial cell surface molecules; (iii) activation complement via the classical pathway. (B) Numerous factors influence the ability of IgG-FcγR engagement to direct inflammation and tissue damage. FcγR cellular expression levels are controlled by the cytokine milieu: inflammatory mediators, such as IFNγ and TNFα increase expression levels of activating FcγR, increasing the activating-to-inhibitory (A:I) ratio. FcγR polymorphisms can influence FcγR expression level or signaling capacity. Finally, the IgG glycosylation state alters the capacity of antibodies to interact with different FcγRs: sialylated IgG exhibits reduced binding to activating type I FcγRs, whereas defucosylated IgG increases FcγRIIIA binding affinity. Fuc, ucose; SA, sialic acid. Green receptor, activating FcγR (A). Red receptor, inhibitory FcγR (I).

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Kidney Transplantation: Principles and Practice

activating FcγR single nucleotide polymorphisms (SNPs) in kidney transplant recipients. A recent study of a cohort of 85 DSA-positive kidney allograft recipients by Arnold et al. demonstrated that individuals with the high-affinity FcγRIIIA-V158 variant showed higher rate of peritubular capillaritis, an effect independent of C1q-binding or capillary C4d.418 Functionally, a model NK cell line expressing FcγRIIIA-V158 produced over two fold more IFNγ upon incubation with HLA antibody-coated cells compared with those expressing low-affinity FcγRIIIA-F158, consistent with the potential role of NK cells in driving ABMR. FcγR associations have also been identified independently of NK cells and FcγRIIIA. Whereas allograft survival was increased in patients with the FcγRIIA-R/R131 genotype in one study,419 in subsequent studies the same genotype was associated with acute rejection.420 The FcγRIIA-R131 variant exhibits reduced binding affinity for IgG1 and IgG2 subclasses and has been postulated to contribute to pathology through inefficient clearance of deposited IgG within allografts.421,422 This is consistent with the high levels FcγRIIA expression on professional phagocytes. Indeed, monocytes expressing the high-affinity FcγRIIA-H/H131 variant were found to adhere more strongly to HLA antibody-activated endothelium.423 In a larger study of 200 kidney transplant recipients who had lost their grafts, the FcγRIIA-R/R131 genotype was associated with early graft loss, particularly in those patients who were DSA positive.424 In mouse models, FcγRIIB-deficient mice develop alloantibody-driven chronic vasculopathy analogous to human chronic rejection in a cardiac allograft model (BM12 organs into C57BL/6 mice).425 This study is consistent with the known role of FcγRIIB in suppressing humoral immunity, although the exact mechanism of IgG-mediated pathology was not dissected. Indeed, in a model of antibody-mediated nephritis, myeloid-specific FcγRIIB deficiency is sufficient to exacerbate tissue inflammation.426 A number of nonsynonymous SNPs have been identified in the FCGR2B gene in humans, with one occurring at a notable frequency (rs1050501). This SNP encodes an isoleucine-to-threonine substitution at position 232, located within the transmembrane domain.402 This substitution results in receptor loss of function as a result on impaired lateral mobility and recruitment to signaling domains.427–429 Surprisingly, despite being a major risk factor in SLE and the heightened inflammatory responses of monocytes from FcγRIIB-T232 individuals to IgG, no association was observed between FcγRIIB-T232 and graft or patient survival in a large study of more than 2800 renal transplant recipients.430 However, patients were not stratified, for example based on DSA or ABMR status, possibly masking effects. Curiously, human cultured aortic endothelial cells also express FcγRI and FcγRII and mediated IgG internalization, cytokine production, and the upregulation of adhesion molecules directly.431,432 This expression can be further enhanced with IFNγ and TNFα in vitro. However, whether this occurs in  vivo and whether it contributes to IgGmediated phenomena in allografts remains to be addressed. 

Transplant Tolerance Given the adverse effect of long-term immunosuppression, one of the key goals in transplantation is the generation of immunologic nonresponsiveness (tolerance) to the

allograft. Animal models have suggested that costimulatory blockade may provide, in theory, a mechanism of achieving this (as discussed in the section on T Cell-Mediated Rejection), although this has not directly translated to clinical practice in humans. A number of immune cell subsets have immunoregulatory capacity, and may therefore contribute to tolerance induction in transplantation, including CD4 T cells, B cells, DCs, and macrophages. These cells broadly act via the production of antiinflammatory cytokines such as IL-10 and TGFβ, and contact-dependent inhibition. The best-characterized regulatory cell subset are CD4+CD25+ Tregs cells that modulate immune responses via IL-10, TGFβ, and IL-35,433 adenosine production,434 down-regulation of DC costimulation, and up-regulation of indoleamine-pyrrole 2,3-dioxygenase (IDO).215 Tregs also may have more direct actions on effector cell viability through mechanisms that involve granzyme B.435 The phenotype of CD4+CD25+ Tregs cells is highly dependent on the expression of the transcription factor Foxp3, which is required to mediate regulatory activity including suppression of IL-2 and IFNγ production, and expression of CTLA-4 and glucocorticoidinduced TNFR-related protein (GITR). Foxp3 is therefore an important marker of Treg activity, although the phenotype of peripherally generated Tregs may not be stable in all circumstances.436 CTLA-4 appears to play an important role in Treg function,233,437 engaging CD80/86 on DCs and inducing IDO expression.215,438 There is ample evidence for the importance of Tregs in many models of experimental transplantation tolerance,439–441 well-illustrated in models using donor-specific transfusion, and nondepleting anti-CD4 antibody in which Treg function seems to play a crucial mechanistic role.442 Perhaps more importantly, recent evidence in humanized animal models suggests that the infusion of nonspecifically expanded Tregs can abrogate the acquisition of transplant arteriosclerosis, opening potential translation into the clinical setting.443–446 In this context, a clinical trial in kidney transplant is underway, the ONE Study, which expands regulatory cells ex  vivo (including Tregs) and aims to initially assess safety (https:// clinicaltrials.gov/ct2/show/NCT02129881). Perhaps one of the most surprising findings on the nature of allograft tolerance in humans has been gained by studying the handful of human subjects who fail to reject their allografts in spite of little or no immunosuppression. These observations have arisen in a tiny fraction of noncompliant patients or in cases where immunosuppression has been stopped in the context of malignancy. Analysis of the peripheral blood mononuclear cell (PBMC) transcriptome in these tolerant transplant recipients identified an excess of B cell gene transcripts and an increase in CD20 mRNA in the urine of tolerant subjects.388,447 In addition, a significant increase in the number of total B cells, particularly memory B cells and B cells expressing CD1d and CD5, has been observed in these subjects,388 whereas other groups have shown a higher proportion of IL-10-producing CD24/ CD38high transitional B cells.384,385 In contrast, a lower number of IL-10-producing CD24/CD38high transitional B cells has been associated with worse allograft outcome in renal transplant recipients.387 Together, these data suggest that manipulation of the regulatory fraction of the B cell compartment may also hold utility in efforts to induce transplant tolerance. 

2 • The Immunology of Transplantation

Factors Influencing Rejection Beyond the Graft—The Microbiome The human body is a complex ecosystem of host cells and commensal microorganisms and it is increasingly appreciated that the composition of the microbiome has significant consequences for host homeostasis and inflammation. Indeed, it is clear that the microbiome has a significant influence on the activity of host immune cells, not only within mucosal barrier sites, such as the gastrointestinal tract, but also systemically.448–450 With respect to transplant rejection, environmentinterfacing organs, such as the gut, are the most likely to be influenced by the composition of the microbiome. For example, monocolonization of germ-free mice with segmented filamentous bacteria is sufficient to induce local Th17 cells that contribute to intestinal inflammation.451 Conversely, tolerogenic DCs and microbiota-derived short-chain fatty acids have direct roles in the priming of local Treg responses to suppress damaging inflammatory responses.452 Therefore it is possible that a transplanted organ’s microbial flora may dictate subsequent alloimmunity and rejection, opening the way for targeted manipulation of the microbiome in these individuals.453 In addition to the importance of the donor organ microbiome, organ failure and transplantation have secondary effects on the recipient microbiome, characterized by a loss of diversity and species richness. Ongoing immunosuppression, prophylactic antibiotic administration, dietary restrictions, and IRI have effects on commensal dysbiosis and the emergence of pathobionts, increasing the risk of enteric infections and inflammation.454 For example, advanced renal failure is associated with urea and uric acid influx into the gastrointestinal tract and alterations in the intestinal microbiota and increases in microbial families, such as Proteobacteria. A similar dysbiosis is observed in individuals with acute and chronic liver disease and in patients with small bowel transplant rejection. In renal allografts, the magnitude of IR-induced acute kidney injury may be influenced by the gut microbiota, via the production of short-chain fatty acids.455 In a mouse model of minor antigen-mismatched skin grafts, pretreatment of donor and recipient mice with broad-spectrum antibiotics or the use of germ-free mice significantly prolonged the survival of allografts, attributed to a reduction in the ability of antigen-presenting cells to induce alloreactive T cells.456 In renal transplant recipients, changes in the urine microbiome have been associated with adverse features on biopsy, including interstitial fibrosis and tubular atrophy.457 Therefore further research is required to delineate the contribution of the microbiota to allograft rejection. 

knowledge of the detail and complexity of both innate and adaptive immune systems has been transformed by basic research. After the initial intense focus on T cell response that has been accompanied by increasing success in targeting this pathway to prevent TCMR, attention has now turned to innate and humoral immunity. Innate immune responses mediate sterile inflammation in IRI and compromise immediate and long-term graft function. Organ shortage has necessitated the use of allografts from suboptimal donors that are more susceptible to the effects of IRI. Therefore developing treatments that can ameliorate IRI is of significant clinical interest. With prolonged patient and allograft survival and an increasing number of patients being listed for retransplantation, the issue of allosensitization is also a major problem. The presence of DSA is still a significant barrier to transplantation, and there is need for an increased understanding of the mechanisms of B cell and antibody effector function to identify immunosuppressants that can deal with this arm of the immune system. These studies will need to move away from the historical reliance on mouse models, in part because of significant differences in HLA expression between mouse and human endothelium, and because our increasing genomic and informatic capabilities will enable experimental medicine studies using human subjects, with all their complexity and diversity.

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Conclusion The immunologic basis of transplant rejection was proposed by Gorer458 and defined by Medawar, who demonstrated an immune response that is specific for donor tissue, is consequent upon infiltration by leukocytes, and displays memory.459–462 In the 70 years since these discoveries, our

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2 • The Immunology of Transplantation 408. Sur Chowdhury C, et al. Enhanced neutrophil extracellular trap generation in rheumatoid arthritis: analysis of underlying signal transduction pathways and potential diagnostic utility. Arth Res Ther 2014;16(3):R122. 409. Kessenbrock K, et  al. Netting neutrophils in autoimmune smallvessel vasculitis. Nat Med 2009;15(6):623–5. 410. Sadik CD, et  al. Neutrophils orchestrate their own recruitment in murine arthritis through C5aR and FcgammaR signaling. Proc Natl Acad Sci USA 2012;109(46):E3177–85. 411. Clatworthy MR, et al. Immune complexes stimulate CCR7-dependent dendritic cell migration to lymph nodes. Nat Med 2014;20(12):1458– 63. 412. Guilliams M, et al. The function of Fcγ receptors in dendritic cells and macrophages. Nature reviews. Immunology 2014;14(2):94–108. 413. Boruchov AM, et  al. Activating and inhibitory IgG Fc receptors on human DCs mediate opposing functions. J Clin Invest 2005;115(10):2914–23. 414. Vogelpoel LT, et  al. Fc gamma receptor-TLR cross-talk elicits proinflammatory cytokine production by human M2 macrophages. Nat Commun 2014;5:5444. 415. Hirohashi T, et  al. A novel pathway of chronic allograft rejection mediated by NK cells and alloantibody. Am J Transplant 2012;12(2):313–21. 416. Hidalgo LG, et al. Interpreting NK cell transcripts versus T cell transcripts in renal transplant biopsies. Am J Transplant 2012;12(5):1180–91. 417. Venner JM, et  al. The molecular landscape of antibody-mediated kidney transplant rejection: evidence for NK involvement through CD16a Fc receptors. Am J Transplant 2015;15(5):1336–48. 418. Arnold ML, et  al. Functional Fc gamma receptor gene polymorphisms and donor-specific antibody-triggered microcirculation inflammation. Am J Transplant 2018;1–13. 419. Pawlik A, et  al. The correlation between FcgammaRIIA polymorphism and renal allograft survival. Transplant Proc 2002;34(8):3138–9. 420. Ozkayin N, Mir S, Afig B. The role of Fcgamma receptor gene polymorphism in pediatric renal transplant rejections. Transplant Proc 2008;40(10):3367–74. 421. Bruhns P, et  al. Specificity and affinity of human Fcgamma receptors and their polymorphic variants for human IgG subclasses. Blood 2009;113(16):3716–25. 422. Gillis C, et  al. Contribution of human FcgammaRs to disease with evidence from human polymorphisms and transgenic animal studies. Front Immunol 2014;5:254. 423. Valenzuela NM, et al. Monocyte recruitment by HLA IgG-activated endothelium: the relationship between IgG subclass and FcgammaRIIa polymorphisms. Am J Transplant 2015;15(6):1502–18. 424. Arnold ML, et al. Association of a coding polymorphism in Fc gamma receptor 2A and graft survival in re-transplant candidates. Hum Immunol 2015;76(10):759–64. 425. Callaghan CJ, et  al. Regulation of allograft survival by inhibitory FcgammaRIIb signaling. J Immunol 2012;189(12):5694–702. 426. Sharp PE, et  al. FcgammaRIIb on myeloid cells and intrinsic renal cells rather than B cells protects from nephrotoxic nephritis. J Immunol 2013;190(1):340–8. 427. Floto RA, et  al. Loss of function of a lupus-associated FcgammaRIIb polymorphism through exclusion from lipid rafts. Nat Med 2005;11(10):1056–8. 428. Kono H, et  al. FcgammaRIIB Ile232Thr transmembrane polymorphism associated with human systemic lupus erythematosus decreases affinity to lipid rafts and attenuates inhibitory effects on B cell receptor signaling. Hum Mol Genet 2005;14(19):2881–92. 429. Xu L, et al. Impairment on the lateral mobility induced by structural changes underlies the functional deficiency of the lupus-associated polymorphism Fc γ RIIB-T232. J Exp Med 2016;213(12):2707. 430. Clatworthy MR, et  al. Defunctioning polymorphism in the immunoglobulin G inhibitory receptor (FcγRIIB-T/T232) does not impact on kidney transplant or recipient survival. Transplantation 2014;98(3):285–91. 431. Devaraj S, Du Clos TW, Jialal I. Binding and internalization of C-reactive protein by Fcgamma receptors on human aortic endothelial cells mediates biological effects. Arterioscler Thromb Vasc Biol 2005;25(7):1359–63. 432. Pan LF, Kreisle Ra, Shi YD. Detection of Fcgamma receptors on human endothelial cells stimulated with cytokines tumour necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma). Clin Exper Immunol 1998;112(3):533–8.

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433. Akdis M, et  al. Interleukins, from 1 to 37, and interferon-gamma: receptors, functions, and roles in diseases. J Allergy Clin Immunol 2011;127(3):701–21. e1-70. 434. Deaglio S, et al. Adenosine generation catalyzed by CD39 and CD73 expressed on regulatory T cells mediates immune suppression. J Exp Med 2007;204(6):1257–65. 435. Gondek DC, et  al. Cutting edge: contact-mediated suppression by CD4+CD25+ regulatory cells involves a granzyme B-dependent, perforin-independent mechanism. J Immunol 2005;174(4):1783–6. 436. Zhou X, et  al. Instability of the transcription factor Foxp3 leads to the generation of pathogenic memory T cells in vivo. Nat Immunol 2009;10(9):1000–7. 437. Tivol EA, et al. Loss of CTLA-4 leads to massive lymphoproliferation and fatal multiorgan tissue destruction, revealing a critical negative regulatory role of CTLA-4. Immunity 1995;3:541–7. 438. Grohmann U, et  al. CTLA-4-Ig regulates tryptophan catabolism in vivo. Nat Immunol 2002;3(11):1097–101. 439. Schliesser U, Streitz M, Sawitzki B. Tregs: application for solid-organ transplantation. Curr Opin Organ Transplant 2012;17(1):34–41. 440. Lechler RI, Garden OA, Turka LA. The complementary roles of deletion and regulation in transplantation tolerance. Nat Rev Immunol 2003;3(2):147–58. 441. Jiang S, Lechler RI. Regulatory T cells in the control of transplantation tolerance and autoimmunity. Am J Transplant 2003;3(5):516–24. 442. Bushell A, et al. The generation of CD25+ CD4+ regulatory T cells that prevent allograft rejection does not compromise immunity to a viral pathogen. J Immunol 2005;174(6):3290–7. 443. Nadig SN, et al. In vivo prevention of transplant arteriosclerosis by ex vivo-expanded human regulatory T cells. Nat Med 2010;16(7): 809–13. 444. Edinger M, Hoffmann P. Regulatory T cells in stem cell transplantation: strategies and first clinical experiences. Curr Opin Immunol 2011;23(5):679–84. 445. Hoffmann P, Eder R, Edinger M. Polyclonal expansion of human CD4(+)CD25(+) regulatory T cells. Methods Mol Biol 2011;677:5–30. 446. Tang Q, Bluestone JA, Kang SM. CD4(+)Foxp3(+) regulatory T cell therapy in transplantation. J Mol Cell Biol 2012;4(1):11–21. 447. Newell KA, et  al. Identification of a B cell signature associated with renal transplant tolerance in humans. J Clin Invest 2010;120(6):1836–47. 448. Turnbaugh PJ, et al. A core gut microbiome in obese and lean twins. Nature 2009;457(7228):480–4. 449. Qin N, et al. Alterations of the human gut microbiome in liver cirrhosis. Nature 2014;513(7516):59–64. 450. Le Chatelier E, et al. Richness of human gut microbiome correlates with metabolic markers. Nature 2013;500(7464):541–6. 451. Ivanov II , et al. Induction of intestinal Th17 cells by segmented filamentous bacteria. Cell 2009;139(3):485–98. 452. Furusawa Y, et  al. Commensal microbe-derived butyrate induces the differentiation of colonic regulatory T cells. Nature 2013;504(7480):446–50. 453. Vindigni SM, Surawicz CM. The gut microbiome: a clinically significant player in transplantation? Expert Rev Clin Immunol 2015;11(7):781–3. 454. Bromberg JS, et al. Microbiota-implications for immunity and transplantation. Nat Rev Nephrol 2015;11(6):342–53. 455. Andrade-Oliveira V, et  al. Gut bacteria products prevent AKI induced by ischemia-reperfusion. J Am Soc Nephrol 2015;26(8): 1877–88. 456. Lei YM, et al. The composition of the microbiota modulates allograft rejection. J Clin Invest 2016;126(7):2736–44. 457. Modena BD, et  al. Changes in urinary microbiome populations correlate in kidney transplants with interstitial fibrosis and tubular atrophy documented in early surveillance biopsies. Am J Transplant 2017;17(3):712–23. 458. Gorer PA. The antigenic basis of tumour transplantation. J Pathol Bacteriol 1938;47:231–52. 459. Gibson JM, Medawar PB. The fate of skin homografts in man. J Anat 1943;77:299–310. 460. Medawar PB. Behaviour and fate of skin autografts and skin homografts in rabbits. J Anat 1944;78:176–99. 461. Medawar PB. A second study of the behaviour and fate of skin homografts in rabbits. J Anat 1945;79:157–76. 462. Medawar PB. Immunity to homologous grafted skin. III. The fate of skin homografts transplanted to the brain, to subcutaneous tissue and to the anterior chamber of the eye. Brit J Exp Path 1948;29:58–69.

3

Chronic Kidney Failure: Renal Replacement Therapy ANDREW DAVENPORT

CHAPTER OUTLINE

Introduction Definition and Timing Referral Prevalence and Incidence Etiology Treatment of CKD5 Dialysis General Aspects Hypertension and Fluid and Electrolyte Balance Hematopoiesis and Immunity Calcium, Phosphate, and the Skeleton Nutrition and Metabolism Hemostasis Skin Neurologic and Musculoskeletal Manifestations Endocrine Abnormalities Psychological Problems Initiation of Dialysis Hemodialysis Complications Peritoneal Dialysis Dialysis Adequacy

Introduction Renal replacement therapy (RRT) is a general term encompassing a range of different treatment modalities for patients with what was formally termed acute renal failure and endstage kidney disease, which are now called acute kidney injury stage 3 (AKI-3)1 and chronic kidney disease stage 5 dialysis (CKD5d),2 respectively (Table 3.1A and B). RRT includes various forms of dialysis (hemodialysis, hemodiafiltration, and peritoneal dialysis), hemofiltration, and renal transplantation. Dialysis has rapidly expanded from a treatment restricted to AKI in teaching hospitals in the 1960s to what is now a routine treatment for around 3 million patients with CKD worldwide. However, all types of RRT are incomplete solutions for CKD, with a 5-year life expectancy for a dialysis patient in the United Kingdom (UK) of around 60%, somewhere between that of patients with ovarian and bowel cancer (www.renalreg.com).3 The management of patients with CKD centers on trying to slow down the progression of underlying kidney disease 36

Dialysis Transport Automated Peritoneal Dialysis Continuous Ambulatory Peritoneal Dialysis Practical Considerations Indications for and Advantages of Peritoneal Dialysis Posttransplantation Complications Loss of Ultrafiltration Peritonitis Exit Site and Tunnel Infection Anatomic Complications Encapsulating Peritoneal Sclerosis Metabolic Complications Choice and Planning for the Individual Patient Dialysis Posttransplant Hemodialysis Continuous Ambulatory Peritoneal Dialysis Return to Dialysis After Transplant Failure RRT Modality and Survival Quality of Life

and reducing cardiovascular risk factors, because many more patients will die of cardiovascular disease compared with those who progress to dialysis (CKD5d).4 Uncontrolled hypertension is the major risk factor for progression followed by proteinuria. Angiotensin-converting enzyme inhibitors and angiotensin receptor blockers are the preferred antihypertensives, aiming for blood pressure targets of 130 to 140/80 to 90 mmHg, depending on the age of the patient. In a minority of cases specific management strategies may be appropriate to halt progression, such as immunosuppression for patients with renal vasculitis or lupus nephritis. Thereafter management is directed to control the complications of progressive kidney disease, hypervolemia, anemia, acidosis, and renal bone disease.5 In progressive CKD patient education is vital, so that patients can make an informed decision about whether to have RRT or opt for a conservative nondialysis approach, accepting that they will die of azotemia. For those patients opting for RRT, it is important to plan ahead, asking about potential live organ donors, creating vascular access for those choosing

3 • Chronic Kidney Failure: Renal Replacement Therapy

TABLE 3.1A  Staging for Chronic Kidney Diseasea CKD Stage

eGFR (mL/min/1.73 m2)

Stage 1 Stage 2 Stage 3a Stage 3b Stage 4 Stage 5 Stage 5d

>90 60–90 45–60 30–44 15–29 50 mmol/L not due to hypovolemia Refractory metabolic acidosis pH ≤7.1 End organ damage: pericarditis, encephalopathy, neuropathy, myopathy, uremic bleeding, weight loss Refractory volume overload

42

Kidney Transplantation: Principles and Practice

HEMODIALYSIS During hemodialysis, water-soluble solutes that are small enough to pass through the pores of a semipermeable dialyzer membrane diffuse and move down a concentration gradient. In addition, the application of a pressure gradient across the semipermeable membrane drives ultrafiltration or convection because of a bulk water movement across the membrane; this leads not only to water loss, but also to a convective loss of those water-soluble solutes that are able to pass through the membrane pores. Whereas diffusion is effective for clearing small solutes, this convective clearance increases middle-sized solute clearances. In routine practice, this requires a dialysis membrane with a surface area of 1.0 to 2.3 m2 (now conveniently packaged as single-use sterilized hollow-fiber dialyzers), a blood flow of 250 to 400 mL/min, and a countercurrent flow of dialysate, generated by a proportioning machine, of 500 to 800 mL/min. The dialysate can be made in a batch and pumped to the dialysis machine, or made by the dialysis machine by adding concentrated electrolytes and sodium bicarbonate to the dialysis water, warming it, checking conductivity, and pumping it through the dialyzer and then to waste. The dialysis machine pumps the blood from the patient through the dialyzer and returns it via a venous air detector, which is alarmed to prevent air embolism. Anticoagulation can be achieved by a single bolus of lowmolecular-weight heparin or by a bolus of unfractionated heparin followed by a continuous infusion. Modern dialysis machines can be programmed to remove fluid gained in the interdialytic interval, and by altering the dialysate sodium concentration, temperature, and the rate of ultrafiltration, reduce the risk of intradialytic hypotension. Dialysis prescription can be altered by choice of dialyzer membrane, surface area, blood and dialysate flow rates, dialysate composition and temperature, and frequency and duration of the dialysis sessions. Hemodialysis treatments traditionally used low-flux dialyzers, which effectively cleared small-sized solutes, such as urea, but were not effective in clearing middle-sized solutes such as β2-microglobulin. As such dialyzer membranes were developed with larger pore sizes designed to remove more middle-sized solutes, termed high-flux, or expanded hemodialysis, and studies have suggested a survival advantage for high-flux dialysis.24 Hemodiafiltration, which involves the ultrafiltration of fluid across a high-flux dialyzer with compensatory reinfusion of ultrapure dialysate, increases middle-sized molecule clearances further. This approach is often tolerated better by patients with unstable cardiovascular systems, with less frequent intradialytic hypotension.25 In addition to achieving larger convective exchange, hemodiafiltration has been reported to improve patient survival compared with high-flux hemodialysis.26 The key to adequate hemodialysis is reliable vascular access (see Chapter 5). Poorly functioning access inevitably leads to poor dialysis and increases morbidity. Reliance on central venous catheter access exposes patients to increased risk of bacterial infection, venous thrombosis, and stenoses. The organization and management of hemodialysis units are major exercises. The aim is to use the capital equipment and staff in the most economical way. Dialysis units generally should have no fewer than 10 stations running two,

preferably three, shifts per day, 6 days per week, with one nurse or dialysis technician being responsible for 4 to 6 dialysis patients at a time. An important consideration is the production of large volumes of water in the generation of dialysate. Tap water is purified by filtration to remove bacteria, softened to remove calcium, carbon filtered to remove small organic compounds such as chloramines, and reverse osmosis treated to remove other contaminating substances, including metals and nitrites. The water system should run 24 hours per day to prevent stagnation and biofilm deposition, with ideally multiple passes through the reverse osmosis system to improve final water quality to achieve ultrapure water, which is essential if high-flux and hemodiafiltration treatments are used. Water ring-mains require regular cleaning and disinfection. Patients who are hepatitis B antigen–positive should be dialyzed in isolation and on dedicated dialysis machines. Hepatitis B vaccinations are recommended and are most effective if administered before CKD5 develops. Universal precautions are considered sufficient to prevent spread of human immunodeficiency virus and hepatitis C, but many centers cohort these patients to prevent nosocomial transmission.

Complications Hypotension occurs in up to 30% of dialysis sessions and most commonly is secondary to intravascular hypovolemia. It is more common when large volumes of fluid have to be removed during a short hemodialysis session after excessive gains between dialyses. Eating meals during dialysis increases the risk of hypotension. Hypotension usually responds to laying the patient flat or head-down, stopping ultrafiltration, or giving a volume of normal saline or hypertonic glucose. Muscle cramps (approximately 5%–20% of dialyses) often accompany hypotension, an excessively low target weight, or the use of a low-sodium dialysate. Occasionally cramps may be caused by carnitine deficiency. Correction of these or the administration of a hypertonic solution (saline or glucose) usually is effective treatment. Regular sufferers may be helped by prophylactic quinine sulfate. Nausea, vomiting, and headache also are fairly common during hemodialysis. Mild chest and back pains may be related to complement activation by the dialysis membrane and are less common with biocompatible membranes. Some patients may have allergic reactions to heparins, or some of the organic chemicals that are released from the glues in the dialyzer cap, or from the plastic polymers used in the blood lines, particularly if there has been minimal rinsing of the dialysis circuit. Pyrogen or microbial contamination of the dialysate occasionally may occur. Patients developing fever and/or rigors on dialysis must be examined carefully for evidence of infection of dialysis access; blood cultures should be taken and patients empirically treated with broad-spectrum antibiotics while awaiting cultures. 

PERITONEAL DIALYSIS Peritoneal dialysis is the process by which solutes, buffer, waste products, and fluid are exchanged between the blood in the peritoneal capillaries and the dialysate instilled into the peritoneal cavity. This exchange takes place across

A

1.2 1

1.03

0.8

0.68

0.6

0.61 0.47

0.4

Fast average Slow average

0.34 Slow

0.2 0

Fast

0

1

2

3

D4h/D0 glucose ratio

Creatinine dialysate to plasma ratio

3 • Chronic Kidney Failure: Renal Replacement Therapy

4

Dwell time (hours)

B

1 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0

0.64 0.5 0.38 0.26 0.11 0

1

2

3

43

Slow Slow average Fast average Fast

4

Time (hours)

Fig. 3.1  Changes in creatinine (A) and glucose (B) during a standard 2-L peritoneal dialysis exchange during a 4-hour dwell are used to categorize patients in terms of transporter status. Although fast transporters have higher creatinine clearances, as the glucose gradient falls quicker, they are prone to sodium retention due to reduced osmotically driven ultrafiltration. D0 refers to the initial glucose concentration; otherwise dialysate concentrations refer to 4-hour drain.

the peritoneal barrier, which comprises the capillary wall, interstitial matrix, the visceral mesothelial cells, and overlying glycocalyx. The efficiency of solutes cleared depends on the vascularity and surface area of the peritoneum, the blood flow, the permeability of the capillary-matrix barrier, the volume and frequency of the dialysate instilled, and the osmotic or oncotic gradient generated by glucose, glucose polymer, or amino acid content of the dialysate. In addition, there will be a variable lymphatic absorption of glucose and glucose polymer from the dialysate.

Dialysis Adequacy The efficacy of peritoneal dialysis can be altered only by changes in the volume and frequency of exchanges. Weekly creatinine clearance and urea clearance (measured using the weekly Kt/V) are used to assess adequacy of peritoneal dialysis.16 The CANUSA study prospectively followed 680 patients after starting continuous ambulatory peritoneal dialysis (CAPD).27 Although patient survival was related to Kt/Vurea (5% increase in relative risk of death for every 0.1 decrease in Kt/Vurea), this reduced over time as a result of the loss of residual renal function with no change in peritoneal dialysis clearance. A larger study also found a correlation with residual function but not peritoneal dialysis clearance, and currently there is no evidence that increasing peritoneal dialysis dose reduces morbidity or mortality.28 Most circumstantial data suggest that more dialysis is better, and the current consensus is that the target should be above a combined Kt/Vurea (dialysis and residual renal function) of 1.7 per week. V is estimated from height, weight, age, and sex, but the ideal body weight should be used to avoid inaccuracies in obese or fluid-overloaded patients. Similarly, a combined urinary and peritoneal creatinine clearance of 50 L/1.73 m2 also has been suggested as a target.16 As residual renal function reduces, it may become impossible to achieve target clearance, even with larger and more frequent exchanges, especially for larger patients, and transfer to hemodialysis is necessary.  Dialysis Transport After infections, the next common cause of peritoneal dialysis treatment failure is loss of ultrafiltration. Transport status should be assessed by a standard 4-hour dwell with a 2.0-L exchange, and ultrafiltration failure defined as 50 leukocytes/μL) and abdominal pain, but the latter may precede the former by one exchange or 1 to 2 days. There may be fever (more common in children), nausea and vomiting (approximately 30%) and, when severe, hypotension. Abdominal tenderness with peritonism is the major clinical finding. The effluent peritoneal fluid after a 4-hour dwell contains greater than 100 leukocytes (>50% neutrophils) per μL (normally 2 years >2 years >2 years >2 years >2 years (Local treatment) (Local treatment) >2 years >2 years >2 years >2 years >2 years >2 years >2 years >2 years >2 years (Contraindicated without liver Tx) >2 years >2 years >2 years >2 years >5 years—assess risk of metastasis >2 years >2 years—use TORi immunosuppression >2 years >5 years >2 years >2 years >2 years >2 years >2 years >2 years >2 years >2 years >2 years >2 years >5 years >5 years >5 years

Duration before considering transplantation = The period after apparent successful cure of the individual cancer when transplantation may be considered if investigations substantiate cure of the cancer. Note also comments for individual cancers. Recurrence of cancer has been recorded despite disease-free periods exceeding those suggested here. Each individual patient must be assessed individually and these intervals may be too long or too short for individual circumstances. Multiple myeloma needs specific consideration of prior bone marrow transplantation. Data from Martín-Dávila P, Fortún J, López-Vélez R, et al. Transmission of tropical and geographically restricted infections during solid-organ transplantation. Clin Microbiol Rev. 2008;21(1):60–96.

GASTROINTESTINAL TRACT Perforation of a peptic ulcer has led to many transplant recipient deaths in the era of high corticosteroid use and before routine introduction of H2 receptor blockers and then proton pump inhibitors after transplantation. The incidence of untreated Helicobacter pylori/peptic ulcer disease is now quite low and many units use either low dose or complete

avoidance of steroids combined with a proton pump inhibitor to prevent peptic ulceration, despite the potential for interaction with immunosuppressant drug absorption.82 Gastroesophageal reflux, malabsorption syndromes, celiac disease, diverticulosis, and cholelithiasis may all present issues for specific consideration in individual patients. 

4 • The Recipient of a Renal Transplant Adjusted for recipient age and gender

Adjusted for recipient age and gender

1.00

1.00

0.75

0.75

0.50

0.50

0.25

0.25

0

A

61

No DM, DD, K only No DM, LD, K only DM1, DD, K only DM1, LD, SPK only

DM1, LD, K only DM2, DD, K only DM2, LD, K only

0 0

2

4

6

8

10

Years

B

0

2

4

6

8

10

Years

Fig. 4.4  The outcome of renal transplantation based on diabetes status, type of kidney, and presence of a simultaneous pancreas transplant. (A) Kidney graft survival. (B) Patient survival. DM1, type 1 diabetes mellitus; DM2, type 2 diabetes mellitus; LD, living donor transplant; DD, deceased donor transplant; K, kidney alone; SPK, simultaneous pancreas kidney. (Data courtesy Australian National Pancreas Transplant and ANZDATA Registries.)

DIABETES Recipients with both type 1 and 2 diabetes require special consideration. Transplantation rates of diabetic patients fluctuate markedly by era and by the approach of the transplant program to this large group of high-risk patients83 and the development and availability of simultaneous pancreas and kidney transplantation (SPK).84

Type 1 Diabetes Mellitus The first decision for patients with type 1 diabetes is whether or not to seek a simultaneous kidney and pancreas (SPK) transplant. In countries where this expertise is available the two options that provide the best patient survival are preemptive living related renal transplantation and SPK transplantation (Fig. 4.4). Acceptance criteria for SPK transplantation usually include a rather stricter age cut-off than for kidney transplants and almost all units use routine cardiac catheterization for cardiac screening. Approximately half of the type 1 recipients with end-stage renal failure prove suitable for SPK, which compares favorably with living donor kidney transplantation for both patient and kidney outcomes in the first 10 years.84 Selection of patients for SPK transplants is focused even more on vascular and cardiac operative risks, but is otherwise similar to selection for kidney transplantation. The procedure is more demanding on both surgeon and patient, it takes longer, and involves the additional risk of pancreas exocrine drainage either into the bladder or, more commonly, into the bowel. Postoperative recovery takes longer because of the ileus induced by the bowel surgery and immunosuppression is on the whole more intense than for a simple kidney transplant. Against these issues, the patient must set the benefits of good glucose control without exogenous insulin administration, reduced long-term complications of diabetes, and improved survival compared with a deceased donor kidney alone.85 Detailed consideration of SPK transplantation is beyond the scope of this chapter, but it is undoubtedly a good solution for type 1 diabetics without severe cardiac disease and suitable for kidney transplantation (see Chapter 36). The role of islet transplantation is still evolving such that

consideration of islet transplantation, before, after, or with a simultaneous kidney, remains the subject of formal clinical trials in a limited number of centers globally. Although the results in those specialized centers are encouraging there is still insufficient evidence to lead to widespread adoption of islet transplants outside of clinical trials.86 

Type 2 Diabetes Mellitus Transplantation of the majority of patients with end-stage renal failure resulting from type 2 diabetes represents a challenge to both surgical and medical expertise. The epidemic of type 2 diabetes that is sweeping both the developed and developing world has led to more than threefold increases in the number of people commencing renal replacement therapy.87 The disease is treacherous for both patients and physicians especially because of the effect of ischemic heart disease, and to exacerbation of the clinical effect of comorbid peripheral vascular disease.88 Only a small proportion of type 2 diabetics are suitable for transplantation because of the effect of age, obesity, and these comorbid conditions, and transplant units need to have specific policies for evaluation of cardiac and vascular disease of those deemed suitable otherwise. Obesity is being tackled in some centers by pretransplant bariatric surgery, with some success in motivated patients.89 A small minority of type 2 diabetics may be helped by SPK transplantation, but this is not widely adopted as a therapy.90 

RENAL DISEASE The range of underlying renal diseases of patients on dialysis and those accepted for transplant waiting lists are similar, because few diseases actually prevent successful renal transplantation. The exceptions to this rule are from recurrent disease in primary oxalosis and in the presence of antiglomerular basement membrane antibodies in Goodpasture syndrome. The causes of renal failure in Australian patients commencing dialysis and those receiving a renal transplant are shown in Table 4.3. These data demonstrate the skewed distribution of proportions of each type of disease in the

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Kidney Transplantation: Principles and Practice

TABLE 4.3  Causes of Renal Failure in Patients Commencing End-Stage Renal Disease Therapy and Receiving a Renal Transplant in Australia, 2010 Diagnosis

Dialysis Patients (%)

Transplant Recipients (%)

Glomerulonephritis Analgesic nephropathy Polycystic kidney Reflux nephropathy Hypertensive nephropathy Diabetes mellitus Miscellaneous Unknown

20 1 6 2 14 37 13 7

42.5 0.3 12.5 7.4 7.3 13 13 4

Data courtesy ANZDATA Registry, Adelaide, SA, Australia.

transplant population, especially noting the underrepresentation of type 2 diabetes.

Recurrent Renal Disease Glomerulonephritis. Recurrence of glomerulonephritis (GN) in the renal transplant is an issue that needs routine discussion with patients who have a diagnosis of focal and segmental glomerular sclerosis, IgA nephropathy, and to a lesser extent, other immune-mediated glomerular diseases. It is important to distinguish between the risk of recurrence and the prognosis of the graft with recurrence. A seminal analysis of the ANZDATA database demonstrated GN recurrence that is a significant cause of late graft loss, causing twice as many losses over a 10-year period as acute rejection, but half as many as chronic allograft nephropathy or death with a functioning graft.91 There have been many attempts, over the years, to summarize the risks for different diseases,92 and a further attempt is shown in Table 4.4 in which the risks of disease recurrence and graft failure are presented from general literature review.  Focal Segmental Glomerulosclerosis. Recurrence of primary focal segmental glomerulosclerosis (FSGS) is one of the more difficult issues that must be addressed by transplant units. Risk factors for recurrence include young age of the recipient, the duration of native disease from onset to development of end-stage renal failure, mesangial proliferative pathology, and the possibility that the risk is higher in related donor grafts.93,94 There is a very high risk of recurrence in a second graft after loss of the first graft from FSGS, questioning the wisdom of retransplantation under those circumstances. The disease may result from a circulating glomerular permeability factor, encouraging use of plasma exchange to control disease.95 A number of interventions have been designed using various combinations of steroids, plasma exchange, cyclosporin, intravenous immunoglobulin, and rituximab.92 Therapy is certainly justified despite the absence of results from well powered randomized clinical trials.92,96  IgA Nephropathy. IgA GN is a common disease in most countries, accounting for a relatively high proportion of end-stage renal failure. Recurrence rates are high, especially if sought in renal biopsies after transplantation using specific identification of IgA deposits in the glomeruli. IgA is thus

TABLE 4.4  The Risks of Recurrence of Renal Disease after Transplantation and the Risks of Graft Loss as a Result of Recurrence, Derived from Literature Review

Disease

10-Year Risk of Risk of Recur- Graft Loss From rence (%) Recurrence (%)

GLOMERULONEPHRITIS Focal segmental sclerosis IgA nephropathy Henoch-Schoenlien purpura Mesangiocapillary type I Mesangiocapillary type II Membranous Hemolytic uremic syndrome ANCA +ve vasculitis Pauci-immune Goodpasture syndrome (Ab +ve) Systemic lupus erythematosus

20–30 40–50 10–20 20–30 80–90 10–20 10–30 10–15 10–20 100 1

8–15 5–15 5–10 10–15 5–10 10–25 10–15 5 5–10 80 1

METABOLIC AND OTHER DISEASES Diabetic nephropathy Amyloidosis Oxalosis Cystinosis Fabry disease Alport syndromea Light chain nephropathy Mixed essential cryoglobulinemia Scleroderma

100 30 90–100 0 100 3–4 10–25 50 20

Low Low 80 0 0 2 10–30 40 5–10

aThe

risk of de novo antiglomerular basement membrane antibody-mediated Goodpasture syndrome. ANCA, antineutrophil cytoplasmic antibodies.

among the commonest of recurrent diseases, but is generally slow to cause renal impairment and graft loss.93 It is more common after living related donor grafts, but recurrence does not seem to affect early or medium term graft survival, though use of steroid-free regimens may increase recurrence rates.97 Assessment of the family donor, however, needs to include consideration of the possibility that IgA may be familial disease and thus also affect the potential donor.  Thrombotic Microangiopathies. There have been substantial advances in the understanding of a range of diseases that produce hemolytic uremic syndromes.98 Definition of typical and atypical syndromes and assessment of the genetic complement defects that lead to the latter disease have been transformative. The option of posttransplant treatment of such patients with eculizumab has released these patients from a life of failed transplants and dialysis.99  Membranous Nephropathy. Membranous GN may occur as either de novo or recurrent disease after transplantation. It is becoming clear that de novo appearance of membranous histology is related to chronic alloimmune antibodymediated rejection, but that autoantibodies specific for the phospholipase A2 receptor are present in the majority of patients with recurrent membranous GN.100  Mesangiocapillary Glomerulonephritis. Type I, II, and III mesangiocapillary GN are all uncommon diseases with high recurrence rates after transplantation.94,101 Evidence that recurrence of type III—dense deposit disease—may be treated by eculizumab offers hope for what is otherwise a disease conferring a high risk of graft failure.102 

4 • The Recipient of a Renal Transplant

Anti–Glomerular Basement Membrane (GBM) Disease. There is very little recent experience of recurrence of Goodpasture syndrome after transplantation because of the early and convincing reports of recurrence in the presence of circulating antibody and advice to await clearance before transplantation.103 It is thus essential to ensure a negative anti-GBM antibody test before transplantation. Patients with Alport syndrome have abnormal basement membrane antigens and they have been reported to develop antibody to the normal basement membrane of a transplanted kidney, mimicking anti–glomerular basement membrane (anti-GBM) disease in a small percentage of patients but without the same level of destructive glomerular disease.104  Recurrent Vasculitis. Antineutrophil cytoplasmic antibodies (ANCA) were discounted as a cause of recurrent crescentic GN in 127 patients in whom the incidence of recurrence was 17%, but with no association with presence of ANCA.105 Current data support transplantation of this group of patients without the need to resolve circulating antibody levels, but most will delay transplantation until vasculitis is quiescent. Recurrence is possibly more frequent with proteinase 3 (PR3) ANCA than with mycloperoxidase (MPO) ANCA and while treated traditionally with cyclophosphamide, intensification of immunosuppression with or without rituximab is generally advised.106,107  Hereditary Metabolic Disorders. Primary oxalosis has a high recurrence rate after transplantation and is now best treated by combined kidney and liver transplantation, correcting the metabolic abnormality simultaneously. Crystal nephropathy also occurs after long-term high-dose vitamin C administration in a dialysis dependent patient and in the inherited disorder adenine phosphoribosyl transferase (APRT) deficiency, which can be treated successfully with lifelong allopurinol.108 Fabry disease and cystinosis are both inherited enzyme deficiencies that cause renal disease through accumulated glycosphingolipid and cystine, respectively. The former leads to recurrent disease in the transplant but the latter only to extrarenal deposition of cystine. Both are, to a certain extent, treatable and recurrent diseases that should be preventable with recombinant alpha-galactosidase A enzyme replacement and oral analogs of cysteamine, respectively.109,110 Tuberous sclerosis, although not leading to recurrent disease, deserves special consideration because of the high lifetime risk of developing renal cell carcinoma in the native kidneys. The risk of tumor can be managed either by bilateral nephrectomy or through regular screening by CT. The known responsiveness of the angiomyolipomata of tuberous sclerosis to the mammalian target of rapamycin (mTOR) inhibitors is significant and warrants selection of one or other of these agents in the immunosuppression protocol.111 

Urogenital Tract Abnormalities Bladder. Pretransplant recognition of the patient with bladder dysfunction is important to avoid immediate problems during and after surgery. Patients with the triad syndrome or other congenital obstructive uropathy, spina bifida, and diabetes are at easily recognizable risk of poor

63

bladder function based on careful history taking and investigation with urodynamic studies. More subtle problems that may be encountered include asymptomatic prostatic enlargement in an anuric dialysis dependent patient and the very small capacity bladder that will be encountered in long-term dialysis patients who have been anuric for many years. Creation of alternative bladder conduits is less popular than in the past because of the morbidity of the surgical procedures required. Indwelling or suprapubic catheters followed by prostatectomy or self-catheterization are the standard approaches today for the majority of patients with bladder dysfunction.112  Reflux Nephropathy. Recurrent urinary tract infection and reflux nephropathy seldom lead to life-threatening septicemia before transplantation, but when the pretransplant experience of an individual demonstrates otherwise, bilateral nephrectomy can be justified if antibiotic prophylaxis fails to ameliorate the risk. Recurrent urinary sepsis is much more common after transplantation despite prophylactic measures and may threaten both the graft and the patient. Bilateral native nephrectomy thus becomes the lesser risk in a few patients after transplantation.  Polycystic Kidney Disease. The size of polycystic kidneys must be evaluated before transplant surgery, preferably by the surgeon who will be implanting the new kidney. CT provides an excellent view of the anatomic challenge that will face the surgeon when the patient is horizontal on the operating table, but will underestimate the space available for the transplant when the patient stands up. Unilateral nephrectomy may be needed between the onset of dialysis therapy and a renal transplant, precluding preemptive transplantation, though concurrent transplant and nephrectomy is also advocated.113 

Coagulation Disorders Hemorrhage during the transplant and coagulation of the graft or other vital vascular conduit after the operation require careful prediction and management. Coagulation disorders and the risk of thrombosis are much more predictable today through screening tests (Box 4.2). Use of heparin starting soon after transplantation in those identified as having a possible thrombotic tendency seems to reduce the risk of thrombosis.89 The risk of hemorrhage is usually easily identified from the medical history and from a careful review of the medication list. Iatrogenic hemorrhage is much more common than inherited disorder such as hemophilia, especially with the widespread use of anticoagulation for atrial fibrillation and after vascular stenting. Each transplant unit thus requires a protocol for the rapid reversal of anticoagulation, usually involving small doses of vitamin K, together with fresh frozen plasma replacement (Box 4.3). Double antiplatelet anticoagulation for patients with cardiac or dialysis fistula stents has led to substantial postoperative bleeding problems and most transplant units regard this combination as a contraindication to listing. The advent of new direct oral anticoagulants has complicated the situation considerably. Because of the renal clearance of these agents (dabigatran, rivaroxaban, apixaban, and edoxaban) their use in dialysis dependent patients and those suitable

64

Kidney Transplantation: Principles and Practice

BOX 4.2  Risks of Thrombosis and Coagulation Disorder Medication Dual antiplatelet therapy Aspirin Warfarin Heparin Low molecular weight heparins  Coagulation Medical history of thromboses Coagulation tests: prothrombin time, activated partial thromboplastin time Factor V Leiden, protein C, protein S, antithrombin III deficiency Antiphospholipid antibodies Full blood count: polycythemia  Hemostasis Medication history (warfarin, aspirin, clopidogrel, dipyridamole) Medical history of bleeding Medical history of liver disease Coagulation tests: skin bleeding time, activated partial thromboplastin time, and congenital factor deficiencies

BOX 4.3  Anticoagulant Reversal Protocol Before Transplant Surgery A patient on warfarin who requires surgery within the next 8 hours should receive: . 1 unit of fresh frozen plasma (FFP) 1 2. 5 mg intravenous vitamin K 3. Prothrombinex (Human Prothrombin Complex)—dose adjusted for International Normalized Ratio (INR) and patient weight □ if INR 2–3.9: 25 units/kg □ 4–5.9: 35 units/kg □ >6.0: 50 units/kg □ Prothrombinex (1000 unit/vial)—calculate to the nearest 1000 units 4. Check prothrombin time (PT)/activated partial thromboplastin time (APTT) before surgery and 4 to 8 hours later if surgery delayed. 5. If surgery is to occur >8 hours from reversal, FFP is not required but PT/APTT needs to be rechecked before surgery to confirm adequate reversal.

for kidney transplantation is rare. Only dabigatran has a method for rapid though incomplete reversal, using the expensive monoclonal antibody fragment idarucizumab. Experience with this agent before transplantation is currently very limited and not recommended.114 

Obesity Increasing BMI is not associated with increased risks of death or graft loss but is associated with new onset posttransplant diabetes mellitus and in obese children is associated with graft failure.115–117 The depth of abdominal fat certainly challenges the surgeon and without careful management can lead to increased risk of wound infection

and other problems. The data now suggest that low BMI is the greater concern, with malnourished patients having higher mortality rates. The problem that both physician and patient face is the task of reducing weight in the very obese and increasing weight in the malnourished before transplantation. In patients treated by peritoneal dialysis it is especially hard to change the body habitus derived from the high carbohydrate intake from peritoneal dialysis fluids, such that a switch to hemodialysis may be the only option. Lifestyle changes are sometimes achievable when renal transplantation is the goal but bariatric surgery in a determined individual provides the best chance of weight loss.89 

Psychosocial Factors Smoking provides serious cardiovascular and pulmonary risks before, during, and after transplant surgery and is heavily discouraged by all programs.118 The unanswered question remains whether or not it is appropriate to transplant patients who continue to smoke. Many in both the lay and professional communities argue that it is not appropriate for the community to provide access to the scarce resource of a donated kidney if the patient continues to self harm through smoking. Recreational drug and alcohol abuse require careful evaluation.119 It is important to wean patients from drug dependency, testing compliance and assessing the possibility of recent hepatitis or HIV infection before activating them on the transplant waiting list. Psychiatric evaluation and treatment are often essential components of preparation for transplantation in drug dependency, but may be rejected or unsuccessful. Families may be the harshest critics of such individuals and thus not offer living kidney donation, leaving transplant programs with the decision of whether or not it is appropriate to provide access to a deceased donor kidney. Documented abstinence for 6 months and determination of likely compliance after transplantation provide a nonjudgmental approach to resolving this dilemma but are in themselves complex assessments. Alcoholism may be well hidden and needs an enquiring and suspicious clinical evaluation including an understanding of the effect on the liver and the psychological state of the patient. Compliance and reliability for follow-up after transplantation are important factors that will influence patient and graft outcomes. Mental illness requires formal evaluation and treatment, with the important additional need to determine the patient’s ability to understand and consent to renal transplantation. There is no substitute for an independent psychiatric evaluation of fitness to consent and ensure optimal pre- and postoperative psychiatric treatment.120  Sensitization and Transfusion Status Good knowledge of the anti–human leukocyte antigen (HLA) antibody status and both the patient and donor’s HLA type is critical to success but outside the scope of this chapter (see Chapter 22).  Previous Transplantation Previous renal transplants provide both visible and invisible barriers to the next transplant, both of which need to be considered carefully. Retransplantation is usually even less

4 • The Recipient of a Renal Transplant

successful than the first transplant procedure and requires careful assessment of the patient’s immunologic reactivity. The total number of individuals with chronic graft loss is increasing in most countries, as is the number of patients with nonrenal organ transplants requiring a renal transplant as a result of nephrotoxicity or other cause of chronic renal failure.121 The clinician’s decision to offer retransplantation is sometimes hard. Should a patient who has lost their first graft because of noncompliance with medication be offered the chance to destroy another priceless donation in the same way? Perhaps the older, wiser, and now experienced individual will be a model of compliance the second time around? Assessment of the medical suitability for transplantation needs to be just as rigorous the second time as it was the first time, noting especially that infective, malignant, and cardiovascular diseases are all more common in the previously transplanted than in the dialysis patient. Opinion and practices have varied with respect to the management of a failed graft,122 but many units favor early graft nephrectomy.123 Transplant nephrectomy is a reasonably low-risk procedure that removes an ongoing source of foreign antigenic stimulation and allows for discontinuation of immunosuppression without risk of incurring a debilitating response. Nephrectomy is always sensible in cases of early acute graft failure from whatever cause. 

Preparation for Transplantation TO JOIN AND REMAIN ON THE DECEASED DONOR WAITING LIST The majority of this chapter has defined the issues of importance for assessment, selection, and preparation of candidates for the transplant waiting lists. Acceptance should then lead to histocompatibility testing and entry on to the transplant waiting list. The initial evaluation may be performed many years before the kidney becomes available and thus repeated reassessment is also required over the years that a patient may be on the waiting list. Compliance with the needs of the transplant waiting list and, in particular, providing a current blood sample for crossmatching may sort out the willing and motivated patients from the noncompliant. Most programs maintain serum screening protocols to identify patients who are sensitized, both to predict the chances of receiving a transplant and to better evaluate donor T and B cell crossmatch results obtained after working hours. Maintaining a current record of clinical events and relevant serology for infectious disease (HIV, hepatitis B, and hepatitis C especially) should be the province of the dialysis unit responsible for the patient’s treatment. Ensuring that this data is available to the transplant program in the middle of the night remains challenging and is likely to fail without a good information system. In the final analysis there is little alternative but to ensure that those who are managing the patient on a daily basis are always contacted when a kidney offer is made. An additional issue that has been raised by the dearth of donors and the burgeoning waiting lists has been prior

65

consent to receive offers for donors outside of the standard donor criteria. It is unreasonable to expect the patient to consent meaningfully in the middle of the night to a complex offer of an older donor kidney or one potentially infected with hepatitis B or C. Thus many programs have special categories of prior consent, which permit individuals to choose to receive a kidney from an extended criteria donor,124 an old donor,125 or one infected with the same virus that they carry—be it hepatitis B or C, or HIV126 with realistic options for posttransplant treatment of hepatitis C now available.58 

TO UNDERGO ELECTIVE LIVING DONOR TRANSPLANTATION The assessment of the recipient of a living donor graft is, by contrast to the deceased donor recipient, a more orderly and planned affair. Despite this the focus is often more on the suitability of the donor and less on the recipient. Ensuring that the donor and recipient are assessed by different nephrologists and different surgeons brings attention back to the recipient. Providing that there is good communication between the two teams, it is possible to manage the interface between donor and recipient issues smoothly and effectively. It is just as important for the donor to understand the risks of a poor outcome in the recipient as it is for the recipient to understand them. A donor unaware of the possibility of recurrent disease in a patient with FSGS, for example, will reasonably ask why he or she was not informed before the donation. The risk of death at operation for a particular recipient may be acceptable to them, but not to the donor who may be unprepared for that possibility. The opposite situation may also occur. A donor may undertake risky behavior, such as intravenous drug use or unprotected high-risk intercourse, which the recipient may know more about than either the donor or recipient’s medical teams. Understanding the level and nature of the risk is paramount for the recipient. 

TO UNDERGO DECEASED DONOR TRANSPLANTATION A transplant team will receive the news that a kidney is available for a particular patient only a few hours before the operation needs to be performed. All too often, the allocation takes place in the middle of the night and the news is passed through a transplant coordinator and junior doctors. The patient and their family will probably not be in contact with the individuals who have assessed them and who care for their dialysis. Their questions and uncertainties will be carried away in a rush of investigations including a chest x-ray, an electrocardiogram, routine blood tests, bowel preparation, shower, anesthetic evaluation, immunosuppressive medication, and perhaps also preoperative hemodialysis. Despite this rush of activity, the pressure to reduce cold ischemia time for the kidney and to meet the deadlines and timetables of operating suites tend to overshadow the needs for discussion and informed consent. This emphasizes the need for full education and information during the workup for acceptance onto the transplant waiting list.

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Kidney Transplantation: Principles and Practice

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1. Cosio FG, Alamir A, Yim S, et  al. Patient survival after renal transplantation: I. The impact of dialysis pre-transplant. Kid Int 1998;53:767. 2. Ashby VB, Leichtman AB, Rees MA, et  al. A kidney graft survival calculator that accounts for mismatches in age, sex, HLA, and body size. Clin J Am Soc Nephrol 2017;12(7):1148–60. 3. Grace BS, Clayton PA, Cass A, McDonald SP. Transplantation rates for living-but not deceased-donor kidneys vary with socioeconomic status in Australia. Kidney Int 2012;15:336–41. 4. World Health Organization. http://www.who.int/transplantation/ knowledgebase/en/ [accessed 06.12.17]. 5. Howell M, Wong G, Rose J, Tong A, Craig JC, Howard K. Patient preferences for outcomes after kidney transplantation: a best-worst scaling survey. Transplantation 2017;101(11):2765–73. 6. Rosenberger J, van Dijk JP, Nagyova I, et al. Predictors of perceived health status in patients after kidney transplantation. Transplantation 2006;81(9):1306. 7. Wolfe RA, Ashby VB, Milford EL, et al. Comparison of mortality in all patients on dialysis, patients on dialysis awaiting transplantation and recipients of a first cadaveric transplant. New Engl J Med 1999;341:1725. 8. Merion RM, Ashby VB, Wolfe RA, et  al. Deceased-donor characteristics and the survival benefit of kidney transplantation. JAMA 2005;294(21):2726. 9. Mathes T, Großpietsch K, Neugebauer EAM, Pieper D. Interventions to increase adherence in patients taking immunosuppressive drugs after kidney transplantation: a systematic review of controlled trials. Syst Rev 2017;6(1):236. 10. Pérez-Sáez MJ, Arcos E, Comas J, Crespo M, Lloveras J, Pascual J. Catalan Renal Registry Committee: survival benefit from kidney transplantation using kidneys from deceased donors aged ≥75 years: a time-dependent analysis. Am J Transplant 2016;16(9): 2724–33. 11. Clayton PA, McDonald SP, Snyder JJ, Salkowski N, Chadban SJ. External validation of the estimated posttransplant survival score for allocation of deceased donor kidneys in the United States. Am J Transplant 2014;14(8):1922–6. 12. Meier-Kriesche HU, Cibrik DM, Ojo AO, et  al. Interaction between donor and recipient age in determining the risk of chronic renal allograft failure. J Am Geriatr Soc 2002;50(1):14. 13. Ojo AO. Expanded criteria donors: process and outcomes. Semin Dial 2005;18(6):463. 14. Lim WH, Russ GR, McDonald SP. Comparable transplant outcomes between local and shipped deceased-donor kidneys in Australia: analysis of Australia and New Zealand Dialysis and Transplant Registry 1992–2007. Nephrology (Carlton) 2010;15(1): 124–32. 15. Chapman JR, O’Connell PJ, Nankivell BJ. Chronic renal allograft dysfunction. J Amer Soc Nephrol 2005;16(10):3015. 16. http://www.anzdata.org.au/anzdata/AnzdataReport/39thReport/c 03_deaths_v2.1_20170418.pdf [accessed 06.12.17]. 17. h ttp://www.transplant-observatory.org/data-charts-andtables/chart/ [accessed 06.12.17]. 18. Muralidharan A, White S. The need for kidney transplantation in low- and middle-income countries in 2012: an epidemiological perspective. Transplantation 2015;99(3):476–81. 19. Batabyal P, Chapman JR, Wong G, Craig JC, Tong A. Clinical practice guidelines on wait-listing for kidney transplantation: consistent and equitable? Transplantation 2012;94(7):703–13. 20. McAdams-DeMarco MA, Olorundare IO, Ying H, et  al. Frailty and postkidney transplant health-related quality of life. Transplantation 2018;102(2):291–9. 21. Rao PS, Schaubel DE, Guidinger MK, et  al. A comprehensive risk quantification score for deceased donor kidneys: the Kidney Donor Risk Index. Transplantation 2009;88:231–6. 22. Israni AK, Salkowski N, Gustafson S, et  al. New national allocation policy for deceased donor kidneys in the United States and possible effect on patient outcomes. J Am Soc Nephrol 2014;25(8): 1842–8. 23. Hart A, Gustafson SK, Skeans MA, et al. OPTN/SRTR 2015 Annual Data Report: early effects of the new kidney allocation system. Am J Transplant 2017;17(Suppl. 1):543–64.

24. Kasiske BL, Zeier MG, Chapman JR, et  al. Best practice guidelines KDIGO clinical practice guideline for the care of kidney transplant recipients: a summary. Kidney Int 2010;77(4):299–311. 25. US Department of Health & Human Services. Organ Procurement and Transplantation Network (OPTN): Kidney Donor Profile Index calculator. Available online at: https://optn.transplant.hrsa.gov/re sources/allocation-calculators. 26. Kennedy SE, Mackie FE, Rosenberg AR, et  al. Waiting time and outcome of kidney transplantation in adolescents. Transplantation 2006;82(8):1046. 27. Williams RC, Opelz G, Weil EJ, McGarvey CJ, Chakkera HA. The risk of transplant failure with HLA mismatch in first adult kidney allografts 2: living donors, summary, guide. Transplant Direct 2017;3(5):e152. 28. Delmonico F, Council of the Transplantation Society. A report of the Amsterdam Forum on the care of the live kidney donor: data and medical guidelines. Transplantation 2005;79(Suppl. 6):S53. 29. Rodriguez JR, Cornell DL, Lin JK, et al. Increasing live donor kidney transplantation: a randomized controlled trial of a home-based educational intervention. Am J Transplant 2007;7(2):394. 30. Lentine KL, Costa SP, Weir MR, et al. Cardiac disease evaluation and management among kidney and liver transplantation candidates. Circulation 2012;126:617–63. 31. Abramowicz D, Cochat P, Claas F, et  al. The European Renal Best Practice (ERBP) transplantation guideline. Nephrol Dial Transplant 2013;28(2):ii1–71. 32. Cosio FG, Falkenhain MF, Pesavento TE, et al. Patient survival after renal transplantation II: the impact of smoking. Clin Transplant 1999;13:336. 33. Feringa HH, Bax JJ, Schouten O, et al. Ischemic heart disease in renal transplant candidates: towards non-invasive approaches for preoperative risk stratification. Eur J Echocardiogr 2005;6(5):313. 34. Manske CL, Wang Y, Rector T, et al. Coronary revascularisation in insulin-dependent diabetic patients with chronic renal failure. Lancet 1992;340(8826):998. 35. Sharma R, Pellerin D, Gaze DC, et  al. Dobutamine stress echocardiography and cardiac troponin T for the detection of significant coronary artery disease and predicting outcome in renal transplant candidates. Eur J Echocardiogr 2005;6(5):327. 36. Cortigiani L, Desideri A, Gigli G, et  al. Clinical, resting echo and dipyridamole stress echocardiography findings for the screening of renal transplant candidates. Int J Cardiol 2005;103(2):168. 37. Norby GE, Günther A, Mjøen G, et  al. Prevalence and risk factors for coronary artery calcification following kidney transplantation for systemic lupus erythematosus. Rheumatology (Oxford) 2011;50(9):1659–64. 38. Wang LW, Fahim MA, Hayen A, et al. Cardiac testing for coronary artery disease in potential kidney transplant recipients: a systematic review of test accuracy studies. Am J Kidney Dis 2011;57:476–87. 39. Borentain M, Le Feuvre C, Helft G, et  al. Long-term outcome after coronary angioplasty in renal transplant and hemodialysis patients. J Interv Cardiol 2005;18(5):331. 40. Groetzner J, Kaczmarek I, Mueller M, et al. Freedom from graft vessel disease in heart and combined heart- and kidney-transplanted patients treated with tacrolimus-based immunosuppression. J Heart Lung Transplant 2005;24(11):1787. 41. Nankivell BJ, Lau S-G, Chapman JR, et al. Progression of macrovascular disease after transplantation. Transplantation 2000;69:574. 42. Wong G, Howard K, Chapman JR, et al. Comparative survival and economic benefits of deceased donor kidney transplantation and dialysis in people with varying ages and co-morbidities. PLoS One 2012;7(1):e29591. Epub 2012 Jan 18. 43. Eggers PW, Gohdes D, Pugh J. Nontraumatic lower limb extremity amputations in the Medicare end-stage renal disease population. Kidney Int 1999;56:1524. 44. de Mattos AM, Prather J, Olyaei AJ, et  al. Cardiovascular events following renal transplantation: role of traditional and transplantspecific risk factors. Kidney Int 2006;70(4):757. 45. Hughes PD, Becker GJ. Screening for intracranial aneurysms in autosomal dominant polycystic kidney disease. Nephrology (Carlton) 2003;8(4):163. 46. Sarin Kapoor H, Kaur R, Kaur H. Anaesthesia for renal transplant surgery. Acta Anaesthesiol Scand 2007;51(10):1354–67.

4 • The Recipient of a Renal Transplant 47. Al-Efraij K, Mota L, Lunny C, Schachter M, Cook V, Johnston J. Risk of active tuberculosis in chronic kidney disease: a systematic review and meta-analysis. Int J Tuberc Lung Dis 2015;19(12):1493–9. 48. Ferguson TW, Tangri N, Macdonald K, et  al. The diagnostic accuracy of tests for latent tuberculosis infection in hemodialysis patients: a systematic review and meta-analysis. Transplantation 2015;99(5):1084–91. 49. Al-Mukhaini SM, Al-Eid H, Alduraibi F, et  al. Mycobacterium tuberculosis in solid organ transplantation: incidence before and after expanded isoniazid prophylaxis. Ann Saudi Med 2017;37(2): 138–43. 50. Kasiske BL, Vazquez MA, Harmon WE, et al. Recommendations for the outpatient surveillance of renal transplant recipients: American Society of Transplantation. J Am Soc Nephrol 2000;4:S1. 51. Lee J, Cho J-H, Lee JS, et al. Pretransplant hepatitis B viral infection increases risk of death after kidney transplantation: a multicenter cohort study in Korea. Medicine (Baltimore) 2016;95(21):e3671. 52. David-Neto E, Americo da Fonseca J, Jota de Paula F, et  al. The impact of azathioprine on chronic viral hepatitis in renal transplantation: a long-term single-centre, prospective study on azathioprine withdrawal. Transplantation 1999;68:976. 53. Nadim MK, Sung RS, Davis CL, et  al. Simultaneous liver–kidney transplantation summit: current state and future directions. Am J Transplant 2012;12(11):2901–8. 54. Habib S, Khan K, Chiu-Hsieh H, Meister E, Rana A, Boyer T. Differential simultaneous liver and kidney transplant benefit based on severity of liver damage at the time of transplantation. Gastroenterology Res 2017;10(2):106–15. 55. Lauer GM, Walker BD. Hepatitis C virus infection. N Engl J Med 2001;345:41. 56. Lubetzky M, Chun S, Joelson A, et al. Safety and efficacy of treatment of hepatitis C in kidney transplant recipients with directly acting antiviral agents. Transplantation 2017;101(7):1704–10. 57. Saxena V, Khungar V, Verna EC, et al. Safety and efficacy of current direct-acting antiviral regimens in kidney and liver transplant recipients with hepatitis C: results from the HCV-TARGET study. Hepatology 2017;66(4):1090–101. 58. Heo NY, Mannalithara A, Kim D, Udompap P, Tan JC, Kim WR. Long-term patient and graft survival of kidney transplant recipients with hepatitis C virus infection in the United States. Transplantation 2018;102(3):454–60. Available online at: https://doi. org/10.1097/TP.0000000000001953. 59. Gane E, Lowitz E, Pugateh D, et  al. Glecaprevir and pibrentasvir in patients with HCV and severe renal impairment. N Engl J Med 2017;377:1448–55. 60. Sarkio S, Salmela K, Kyllönen L, Rosliakova M, Honkanen E, Halme L. Complications of gallstone disease in kidney transplantation patients. Nephrol Dial Transplant 2007;22(3):886–90. 61. Genc G, Ozkaya O, Aygun C, Yakupoglu YK, Nalcacioglu H. Vaccination status of children considered for renal transplants: missed opportunities for vaccine preventable diseases. Exp Clin Transplant 2012;10(4):314–8. 62. Prelog M, Pohl M, Ermisch B, et al. Demand for evaluation of vaccination antibody titers in children considered for renal transplantation. Pediatr Transplant 2007;11(1):73–6. 63. Kruger S, Seyfarth M, Sack K, et  al. Defective immune response to tetanus toxoid in haemodialysis patients and its association with diphtheria vaccination. Vaccine 1999;17:1145. 64. h ttps://www.cdc.gov/meningococcal/clinical/eculizumab.html [accessed 06.12.17]. 65. Smith KG, Isbel NM, Catton MG, et al. Suppression of the humoral immune response by mycophenolate mofetil. Nephrol Dial Transplant 1998;13(1):160. 66. Pelletier SJ, Norman SP, Christensen LL, et  al. Review of transplantation of HIV patients during the HAART era. Clin Transpl 2004;63–82. 67. Stock PG, Barin B, Murphy B, et al. Outcomes of kidney transplantation in HIV-infected recipients. N Engl J Med 2010;363(21):2004– 14. 68. Muller E, Barday Z, Mendelson M, Kahn D. Renal transplantation between HIV-positive donors and recipients justified. S Afr Med J 2012;102(6):497–8. 69. Lucas GM, Ross MJ, Stock PG, et  al. Clinical practice guideline for the management of chronic kidney disease in patients infected with HIV: 2014 update by the HIV Medicine Association of the Infec-























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tious Diseases Society of America. Clin Infect Dis 2014;59(9): e96–e138. 70. Avettand-Fenoël V, Rouzioux C, Legendre C, Canaud G. HIV infection in the native and allograft kidney: implications for management, diagnosis, and transplantation. Transplantation 2017;101(9):2003–8. 71. Kotton CN, Kumar D, Caliendo AM, et  al. International consensus guidelines on the management of cytomegalovirus in solid organ transplantation: Transplantation Society International CMV Consensus Group. Transplantation 2010;89(7):779–95. 72. Rodríguez-Romo R, Morales-Buenrostro LE, Reyes PA, et  al. Seroprevalence of Trypanosoma cruzi in kidney transplant donors and recipients in Mexico City. Transpl Infect Dis 2013;15(6): 639–44. 73. Martín-Dávila P, Fortún J, López-Vélez R, et al. Transmission of tropical and geographically restricted infections during solid-organ transplantation. Clin Microbiol Rev 2008;21(1):60–96. 74. Vajdic CM, McDonald SP, McCredie MR, et  al. Cancer incidence before and after kidney transplantation. JAMA 2006;296(23):2823. 75. van Leeuwen MT, Webster AC, McCredie MRE, et al. Effect of reduced immunosuppression after kidney transplant failure on risk of cancer: population based retrospective cohort study. BMJ 2010;340:c570. 76. Rosenberg SA. IL-2: the first effective immunotherapy for human cancer. J Immunol 2014;192(12):5451–8. 77. Johnson DB, Sullivan RJ, Menzies AM. Immune checkpoint inhibitors in challenging populations. Cancer 2017;123(11):1904–11. 78. Williams NC, Tong A, Howard K, Chapman JR, Craig JC, Wong G. Knowledge, beliefs and attitudes of kidney transplant recipients regarding their risk of cancer. Nephrology (Carlton) 2012;17(3): 300–6. 79. Chapman JR. Compliance: the patient, the doctor, and the medication? Transplantation 2004;77(5):782–6. 80. Ong SC, Gaston RS. Medical management of chronic kidney disease in the renal transplant recipient. Curr Opin Nephrol Hypertens 2015;24(6):587–93. 81. Ingulli EG, Mak RH. Growth in children with chronic kidney disease: role of nutrition, growth hormone, dialysis, and steroids. Curr Opin Pediatr 2014;26(2):187–92. 82. Gabardi S, Olyaei A. Evaluation of potential interactions between mycophenolic acid derivatives and proton pump inhibitors. Ann Pharmacother 2012;46(7-8):1054–64. 83. White S, Chadban S. Diabetic kidney disease in Australia: current burden and future projections. Nephrology (Carlton) 2014;19(8):450–8. 84. Young BY, Gill J, Huang E, et al. Living donor kidney versus simultaneous pancreas-kidney transplant in type I diabetics: an analysis of the OPTN/UNOS database. Clin J Am Soc Nephrol 2009;4(4):845– 52. 85. Gruessner AC, Sutherland DE, Gruessner RW. Long-term outcome after pancreas transplantation. Curr Opin Organ Transplant 2012;17(1):100–5. 86. Holmes-Walker DJ, Gunton JE, Hawthorne W, et al. Islet transplantation provides superior glycemic control with less hypoglycemia compared with continuous subcutaneous insulin infusion or multiple daily insulin injections. Transplantation 2017;101(6):1268–75. 87. Grace BS, Clayton P, McDonald SP. Increases in renal replacement therapy in Australia and New Zealand: understanding trends in diabetic nephropathy. Nephrology (Carlton) 2012;17(1):76–84. 88. Lim WH, Johnson DW, Hawley CM, Pascoe E, Wong G. Impact of diabetes mellitus on the association of vascular disease before transplantation with long-term transplant and patient outcomes after kidney transplantation: a population cohort study. Am J Kidney Dis 2018;71(1):102–11. 89. Scalea JR, Cooper M. Surgical strategies for type II diabetes. Transplant Rev (Orlando) 2012;26(3):177–82. 90. Gruessner AC, Laftavi MR, Pankewycz O, Gruessner RWG. Simultaneous pancreas and kidney transplantation: is it a treatment option for patients with type 2 diabetes mellitus? An analysis of the International Pancreas Transplant Registry. Curr Diab Rep 2017;17(6):44. 91. Briganti EM, Russ GR, McNeil JJ, et al. Risk of renal allograft loss from recurrent glomerulonephritis. N Engl J Med 2002;347(2):103. 92. Canaud G, Audard V, Kofman T, Lang P, Legendre C, Grimbert P. Recurrence from primary and secondary glomerulopathy after renal transplant. Transpl Int 2012;25(8):812–24.

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93. McDonald SP, Russ GR. Recurrence of IgA nephropathy among renal allograft recipients from living donors is greater among those with zero HLA mismatches. Transplantation 2006;82(6):759. 94. Allen PJ, Chadban SJ, Craig JC, et al. Recurrent glomerulonephritis after kidney transplantation: risk factors and allograft outcomes. Kidney Int 2017;92(2):461–9. 95. Doublier S, Zennaro C, Musante L, et al. Soluble CD40 ligand directly alters glomerular permeability and may act as a circulating permeability factor in FSGS. PLoS One 2017;12(11):e0188045. 96. Alasfar S, Matar D, Montgomery RA, et  al. Rituximab and therapeutic plasma exchange in recurrent focal segmental glomerulosclerosis postkidney transplantation. Transplantation 2018;102(3): e115–e120. 97. Clayton P, McDonald S, Chadban S. Steroids and recurrent IgA nephropathy after kidney transplantation. Am J Transplant 2011;11(8):1645–9. 98. Rafat C, Coppo P, Fakhouri F, et al. Hemolytic and uremic syndrome and related thrombotic microangiopathies: treatment and prognosis. Rev Med Intern 2017;38(12):833–9. 99. Legendre C, Sberro-Soussan R, Zuber J, et  al. Eculizumab in renal transplantation. Transplant Rev (Orlando) 2013;27(3):90–2. 100. Debiec H, Martin L, Jouanneau C, et al. Autoantibodies specific for the phospholipase A2 receptor in recurrent and de novo membranous nephropathy. Am J Transplant 2011;11(10):2144–52. 101. Andresdottir MB, Assmann KJM, Hoitsma AJ, et al. Renal transplantation in patients with dense deposit disease: morphological characteristics of recurrent disease and clinical outcome. Nephrol Dial Transplant 1999;14:1723. 102. McCaughan JA, O’Rourke DM, Courtney AE. Recurrent dense deposit disease after renal transplantation: an emerging role for complementary therapies. Am J Transplant 2012;12(4):1046–51. 103. Wilson CB, Dixon FJ. Antiglomerular basement membrane antibody induced glomerulonephritis. Kidney Int 1973;3:74. 104. Gobel J, Olbricht CJ, Offner G, et al. Kidney transplantation in Alport’s syndrome: long-term outcome and allograft anti-GBM nephritis. Clin Nephrol 1992;38:299. 105. Nachman PH, Segelmark M, Westman K, et  al. Recurrent ANCAassociated small vessel vasculitis after transplantation: a pooled analysis. Kidney Int 1999;56:1544. 106. Geetha D, Eirin A, True K, et al. Renal transplantation in antineutrophil cytoplasmic antibody-associated vasculitis: a multicenter experience. Transplantation 2011;91(12):1370–5. 107. Geetha D, Lee SM, Shah S, Rahman HM. Relevance of ANCA positivity at the time of renal transplantation in ANCA associated vasculitis. J Nephrol 2017;30(1):147–53. 108. Bollée G, Cochat P, Daudon M. Recurrence of crystalline nephropathy after kidney transplantation in APRT deficiency and primary hyperoxaluria. Can J Kidney Health Dis 2015;2:31. 109. Lidove O, Joly D, Barbey F, et al. Clinical results of enzyme replacement therapy in Fabry disease: a comprehensive review of literature. Int J Clin Pract 2007;61(2):293. 110. Markello TC, Bernardini IM, Gahi WA. Improved renal function in children with cystinosis treated with cysteamine. N Engl J Med 1993;328:1157.

111. Haidinger M, Werzowa J, Weichhart T, Säemann MD. Targeting the dysregulated mammalian target of rapamycin pathway in organ transplantation: killing 2 birds with 1 stone. Transplant Rev (Orlando) 2011;25(4):145–53. 112. Cabello BR, Quicios DC, López ML, Simón RC, Charry GP, González EC. The candidate for renal transplantation work up: medical, urological and oncological evaluation. Arch Esp Urol 2011;64(5):441– 60. 113. Tyson MD, Wisenbaugh ES, Andrews PE, Castle EP, Humphreys MR. Simultaneous kidney transplantation and bilateral native nephrectomy for polycystic kidney disease. J Urol 2013;190(6):2170–4. 114. Salerno DM, Tsapepas D, Papachristos A, et  al. Direct oral anticoagulant considerations in solid organ transplantation: a review. Clin Transplant 2017;31(1):1–13. 115. Strejar E, Molnar MK, Kovesdy CP, et  al. Associations of pretransplant weight and muscle mass with mortality in renal transplant recipients. Clin J Am Soc Nephrol 2011;6(6):1463–73. 116. Chang SH, Coates PT, McDonald SP. Effects of body mass index at transplant on outcomes of kidney transplantation. Transplantation 2007;84(8):981–7. 117. Ladhani M, Lade S, Alexander SI, et al. Obesity in pediatric kidney transplant recipients and the risks of acute rejection, graft loss and death. Pediatr Nephrol 2017;32(8):1443–50. 118. Bluman LG, Mosca L, Newman N, et al. Preoperative smoking habits and postoperative pulmonary complications. Chest 1998;113:883. 119. Parker R, Armstrong MJ, Corbett C, Day EJ, Neuberger JM. Alcohol and substance abuse in solid-organ transplant recipients. Transplantation 2013;96(12):1015–24. 120. DiMartini A, Crone C, Fireman M, Dew MA. Psychiatric aspects of organ transplantation in critical care. Crit Care Clin 2008;24(4):949–53. 121. Srinivas TR, Stephany BR, Budev M, et al. An emerging population: kidney transplant candidates who are placed on the waiting list after liver, heart, and lung transplantation. Clin J Am Soc Nephrol 2010;5(10):1881–6. 122. Bennett WM. The failed renal transplant: in or out? Semin Dial 2005;18(3):188. 123. Ayus JC, Achinger SG, Lee S, Sayegh MH, Go AS. Transplant nephrectomy improves survival following a failed renal allograft. J Am Soc Nephrol 2010;21(2):374–80. 124. Grams ME, Womer KL, Ugarte RM, Desai NM, Montgomery RA, Segev DL. Listing for expanded criteria donor kidneys in older adults and those with predicted benefit. Am J Transplant 2010;10(4): 802–9. 125. Giessing M, Fuller TF, Friedersdorff F, et al. Outcomes of transplanting deceased-donor kidneys between elderly donors and recipients. J Am Soc Nephrol 2009;20(1):37–40. 126. Carbone M, Cockwell P, Neuberger J. Hepatitis C and kidney transplantation. Int J Nephrol 2011;2011:593291.

5

Access for Renal Replacement Therapy JAMES P. HUNTER and JAMES A. GILBERT

CHAPTER OUTLINE

Introduction Vascular Access Catheters Temporary Dialysis Catheters Permanent Dialysis Catheters Complications of Hemodialysis Catheters Catheter Dysfunction Catheter-Related Central Vein Stenosis Central Vein Occlusion Infection Fistulas and Synthetic Grafts Planning and Timing of Vascular Access Preoperative Assessment Anesthesia Autogenous Arteriovenous Fistulas Wrist Fistula Elbow Fistulas Arteriovenous Grafts Complications of Arteriovenous Fistulas and Grafts Hemorrhage Stenosis Thrombosis Infection Aneurysm Formation Arteriovenous Access Ischemic Steal Syndrome

Introduction Worldwide the population of patients with chronic kidney disease (CKD) is expanding, leading to increasing numbers of patients hitting end-stage renal failure (ESRF) and requiring renal replacement therapy (RRT). In the UK the incidence of new dialysis starters increased from 115 per million population (pmp) in 2014 to 120 pmp in 2015, resulting in 7814 new patients initiating RRT.1 The median age of these new dialysis starters was 64.4 years, highlighting the fact that a significant proportion of the UK dialysis population are elderly patients, many of whom have multiple comorbid conditions, such as diabetes, hypertension, ischemic heart disease, and obesity. There has been a paradigm shift

Arteriovenous Fistula Surveillance and Maintenance Advances in Vascular Access HeRO (Hemodialysis Reliable Outflow) Graft Surfacer Inside-Out Catheter System Endovascular Arteriovenous Fistula Peritoneal Dialysis Acute Peritoneal Dialysis Peritoneal Dialysis Delivery Systems and Catheters Catheter Selection Catheter Insertion Complications Associated With Peritoneal Dialysis Catheters Bleeding Pain Cuff Extrusion Catheter Obstruction Pericatheter Leak Hernias Exit-Site and Tunnel Infections Peritoneal Dialysis Peritonitis Encapsulating Peritoneal Sclerosis Renal Transplant Issues With Peritoneal Dialysis Conclusion

in recent years and the leading cause of kidney disease is now diabetes, which accounts for 30% of all cases.1 This is important to recognize, because many of these patients are high-risk surgical candidates and are particularly challenging with regard to creating dialysis access because of small, diseased vessels, a paucity of good-caliber veins, and higher infection rates. Long-term access for RRT through the creation of an arteriovenous fistula (AVF), placement of an arteriovenous graft (AVG), or peritoneal dialysis (PD) catheter requires the input of multiple dedicated access specialists. Over the past decade this has expanded to include nephrologists, surgeons, radiologists, and nurse specialists who work closely as a multidisciplinary team to provide timely access creation 69

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and ongoing access maintenance for each individual renal patient. There is a growing recognition that the approach to access creation should be increasingly bespoke for each individual patient. The historical tradition of starting dialysis via a tunneled dialysis catheter while waiting for a wrist fistula to mature has evolved to a “fistula first,” “line last” strategy. This is employed with the aim of preserving venous real estate and ensuring patients start dialysis using an access that is patient-specific based on comorbidities and needs. Technologic advancements of products specifically for dialysis access have provided an array of options for patients on RRT, particularly when access options have been exhausted. The improved long-term outcomes with newly developed grafts along with increasing armamentarium such as drug-eluting balloons and stents for the maintenance of access or technologies to recanalize occluded central veins are providing renal failure patients with ongoing reliable access and improved life expectancy rates on dialysis. This chapter will explore much of the current modernday practices associated with establishing and maintaining RRT for patients with ESRF.

VASCULAR ACCESS CATHETERS Temporary Dialysis Catheters Central venous catheters (CVCs) are an option in patients with renal failure to provide dialysis. Catheters are either cuffed or uncuffed. Uncuffed CVCs are used as a temporizing measure in patients who require immediate or emergent hemodialysis. About 40% of patients with renal failure present acutely and require short-term vascular access and dialysis. These patients include the “acute presenter” and the “crash lander.” Acute presenters require short-term RRT to allow renal recovery, and crash landers, those who present suddenly with new ESRF, require short-term access during planning for a long-term option. In both instances a temporary uncuffed CVC may be placed to facilitate dialysis. Temporary catheters can be inserted at the bedside and can remain in situ for up to 3 weeks depending on the site of insertion. The three most common locations for temporary vascular access are the internal jugular vein (IJV), subclavian vein (SCV), and common femoral vein (CFV). Upper limb catheters can remain in situ for up to 3 weeks, patients can remain fully ambulatory, infection rates are lowest, and they are therefore preferred to groin CVCs. Currently the favored site for temporary venous access is the right IJV, although some patients find the visibility of the catheter in the neck above the collar unsightly. The advantages of IJV placement are lower risk of infection, higher patency rates, and lower risk of insertion-related complications.  Permanent Dialysis Catheters Patients requiring long-term dialysis and in whom there has not been an opportunity to create a fistula, AVG, or peritoneal dialysis catheter in a timely fashion will require a permanent dialysis catheter. In the US the incidence of patients starting dialysis on a tunneled catheter remains high at around 70%.2 The UK incidence is not much better with 48% of new starters initiating hemodialysis via a CVC.1 The current indications for central

venous catheter insertion are displayed in Box 5.1. Permanent catheters are always tunneled, dual-lumen, large-diameter (14 to 16 French) polyurethane catheters that have an annular fibrous cuff that holds that catheter in place within the tunnel tract.3 CVCs are composed of biologically neutral material that should not induce catheter lumen thrombosis or a perivascular reaction and subsequent venous thrombosis. The catheter should be soft and compliant, easy to insert, durable, and should be coated with an agent that reduces bacterial proliferation and biofilm formation. Furthermore it should be inexpensive and permit blood flow of >350 mL/min to facilitate efficient dialysis. Numerous catheters are available for use, and they can be differentiated by the design of the distal tip and the presence of side holes and flow dividers.3 The hemodynamic effects of these design variations are regularly debated and remain largely unknown and are influenced by numerous factors such as insertion technique, site of insertion, and position of the catheter tip.3 Although interesting, catheter design and insertion principles are less important than providing efficient dialysis. This includes the ability of the catheter to be able to process at least 50 L of fluid during a standard 4-hour dialysis session with favorable arterial and venous pump pressures and minimal recirculation.3–5 The right IJV is the most favored site of placement of a permanent catheter, which is then tunneled to an exit site on the anterior chest wall. Care should always be taken to ensure that the cuff is at least 4 cm from the exit site to minimize the risk of cuff extrusion and minimize infection rates. Internal jugular vein catheter placement can be performed surgically using a cut down at the medial border of sternocleidomastoid. However, the Seldinger technique using ultrasound to guide the needle into the vessel is more frequently performed. It is essential to place catheters under fluoroscopic control, to ensure that the tip of the catheter is placed in the superior vena cava (SVC).6 The malposition rate of catheters when placed without fluoroscopic control has been shown to be as high as 29%.7,8 The tip of the catheter should be at the junction of the SVC and right atrium as this affords the most optimal blood flow through the catheter. A list of complications associated with central venous catheter insertion is displayed in Box 5.2. Tunneled catheters can provide access for months and even years, particularly in those patients in whom all native venous conduits for AVF or AVG formation have been exhausted or where arteriovenous strategies are likely to induce risks of limb loss from steal syndrome or precipitating heart failure from the high volume venous return. Indeed, in such patients who become dependent on a tunneled catheter, placement is becoming more adventurous with reports of transhepatic, translumbar and even transmediastinal approaches being used as last resort procedures.9–11 

COMPLICATIONS OF HEMODIALYSIS CATHETERS Catheter Dysfunction Catheter dysfunction was historically defined as “failure to attain and maintain adequate extracorporeal blood flow

5 • Access for Renal Replacement Therapy

BOX 5.1  Indications for Tunneled Hemodialysis Catheters During maturation of autogenous arteriovenous fistula During maturation of peritoneal dialysis catheter Patients awaiting a living donor transplant Dialysis bridge after failure of current access to permit planning and imaging for long-term access Permanent access—all other sites exhausted, severe cardiac dysfunction or patient choice.

BOX 5.2  Complications of Central Venous Catheter Insertion Arterial puncture Bleeding Pneumothorax Hemothorax Hemomediastinum Atrial perforation Air embolus Arrhythmias Primary failure

sufficient to perform dialysis in a timely fashion.” A recent collaboration of transplant surgeons and physicians, the North American Vascular Access Consortium (NAVAC), introduced a new definition in an attempt to create a uniform standard. Dysfunction was defined as the first occurrence of either (1) peak blood flow of 200 mL ⁄ min or less for 30 minutes during a dialysis treatment, (2) mean blood flow of 250 mL ⁄ min or less during two consecutive dialysis treatments, or (3) inability to initiate dialysis owing to inadequate blood flow, after attempts to restore patency have been attempted. Dysfunction accounts for 17% to 33% of all catheter removals and can be either early or late. Early dysfunction is due to technical error such as kinking of the catheter in the subcutaneous tunnel or catheter malpositioning. Late dysfunction is due to central vein occlusion, catheter thrombosis, and fibrin sheath formation (Fig. 5.1).7 Catheter thrombosis has an estimated frequency of 0.5 to 3 episodes per 1000 days and an incidence of 46% and is the major cause of catheter dysfunction.7,12 Antifibrinolytic therapy introduced via the catheter is the treatment of choice and first-line therapy is usually 5000 IU/mL of urokinase of sufficient volume to fill the lumen. This can be repeated immediately and if bolus dosing fails can be followed by a systemic infusion of 20,000 IU/mL/hr over 6 hours or a continuous infusion during dialysis of 250,000 IU. An RCT of tenecteplase versus placebo in patients with catheter dysfunction demonstrated that patients treated with tenecteplase had significantly increased flow rates (>300 mL/min). Patients within the study with 155 mmol/L, has also been associated with poor outcomes after transplant. Presumably, the hyperosmolar cellular milieu established in hepatocytes while the donor is hypernatremic results in osmotic injury when the liver is transplanted into a nonhypernatremic recipient.13  Endocrine Pituitary failure is the primary source of endocrine abnormalities associated with brain death. However, not all hormones decrease to the same amount. Novitzky et  al. demonstrated in animal studies that, whereas AVP drops to undetectable levels by 6 hours, and free triiodothyronine (T3) concentrations dropped to 50% of baseline within an hour of injury and were undetectable by 9 hours after injury, adrenocorticotropic hormone (ACTH) and thyroid-stimulating hormone (TSH) were not significantly lower when measured at 16 hours after injury.14 Although other animal studies have shown less dramatic thyroid hormone responses, they have nevertheless demonstrated differential responses of other pituitary hormones to brain death.10 Human studies suggest that these differences can be attributed to anatomic differences between the anterior and posterior pituitary: whereas posterior pituitary hormones (antidiuretic hormone, or AVP) decrease rapidly after brain death, anterior pituitary hormone (ACTH, TSH) changes are less predictable. The exact mechanisms for this difference are yet to be fully elucidated. 

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Kidney Transplantation: Principles and Practice

Fig. 6.1  The distribution and pathophysiologic correlation of the rostral–caudal progression of cerebral-spinal ischemia termed coning, which eventuates in herniation and brain death. (Courtesy Kenneth E. Wood, DO.)

Inflammatory There are two triggers of inflammatory response to brain death. The first is direct neural tissue damage, which results in inflammation of the central nervous system. The second is in response to ischemia-reperfusion injury that occurs during the period of supranormal SVR in response to pontine ischemia. Release of inflammatory cytokines has been demonstrated locally in response to brain injury.15 Both cytokine profiles and complement levels have been studied specifically in organ donation, with effect on delayed graft function16,17; however, future work is necessary to identify ways to blunt these responses and improve donor graft function (Fig. 6.1). 

DIAGNOSIS Death by neurologic criteria, or brain death, is a clinical diagnosis based on the presence or absence of a set of responses to neurologic stimuli. In the half century since the Harvard Committee first reported on “irreversible coma” as a new criterion for death, numerous variations on the determination of brain death have been proposed.18 However, after the President’s Commission for the Study of Ethical Problems in Medicine equated cardiac death and brain death in 1981,19 the modern criteria for brain death determination were set. These were then expounded upon by the American Academy of Neurology in 1995,20 and more recently reviewed and revalidated by Wijdicks and colleagues in 2010.21 Ranging from electroencephalograms to neuropathologic examination,22 none of the ancillary tests have proven as consistently reliable as a clinical examination done by a physician experienced in performing these tests. Several prerequisites have to be met before initiation of a brain death examination. First, there needs to be evidence of a catastrophic brain injury that is compatible with a possible diagnosis of brain death. This can be established either clinically (evidence of gross head trauma) or using basic neuroimaging (computed tomography [CT]). However, it is important to remember that CT findings are not themselves

BOX 6.1  Confounding Conditions and Exclusions in the Diagnosis of Brain Death Hypothermia Diagnosis of brain death requires core temperature >32°C Absence of brainstem reflexes when core temperature 32°C before starting the brain death examination. Severe hypothermia, defined as core body temperature 36°C) iii. Euvolemia iv. Eucapnea (Paco2 35–45 mmHg) v. Absence of hypoxia



vi.  No prior history of CO2 retention (no history of chronic obstructive pulmonary disease or obstructive sleep apnea) b. Preparation i. Preoxygenate the patient with 100% O2 before the test; target is a Pao2 >200 mmHg. ii. Reduce the ventilation frequency to 10 to 12 breaths/min to achieve eucapnea. iii. Measure arterial Po2, Pco2, and pH after these preparatory steps before starting the test. c. Testing i. Disconnect the patient from the ventilator. ii. Continue to deliver 100% Fio2 at the level of the carina through a suction catheter or straight nasal cannula placed through the endotracheal tube. iii.  Observe closely for respiratory movements (abdominal, chest, neck) that could produce adequate tidal volumes. iv. Continue the test as long as the patient remains stable. If, at the completion of 8 to 10 minutes, the patient remains stable, another 1 to 2 minutes can be taken before drawing an arterial blood gas. If the patient becomes hypotensive (systolic blood pressure 20 mmHg above baseline normal Paco2, the test is positive and the patient is clinically brain-dead. iii. If respiratory movements are not observed, but the test was halted early for hemodynamic instability and the Paco2 parameters were not met, the test is indeterminate and additional testing should be considered. This test cannot be performed on every patient; approximately 10% of patients will be hemodynamically unstable at the time testing could occur, or before the conclusion of testing, requiring a premature stop.25 In these circumstances, other tests may be utilized.   Additional testing is not required by the American Association of Neurology guidelines, as brain death is a clinical examination. However, in patients for whom a complete examination cannot be performed, ancillary testing can be useful.19,21 Certain hospital or state guidelines on the declaration of brain death may also require an additional test, and therefore the practitioner is encouraged to review hospital and state-specific requirements (Box 6.2). 

Death by Cardiopulmonary Criteria (Cardiac Death) With less than 1% of deaths in the US occurring from brain death, it has become a priority in the transplantation

6 • Brain Death and Cardiac Death: Donor Criteria and Care of Deceased Donor

BOX 6.2  Confirmatory Studies Cerebral angiography Contrast agent injected under high pressure into anterior and posterior circulations Absence of cerebral filling at carotid and vertebral entrance into skull Potential for contrast-induced nephrotoxicity Rarely performed Cerebral scintigraphy (technetium 99mTc-HMPAO) Can be performed at bedside in brief time Good correlation with conventional angiography Isotope angiography Albumin labeled with technetium 99m Can be performed at bedside Delayed filling of sagittal and transverse sinuses Posterior cerebral circulation not visualized Transcranial Doppler ultrasound Middle cerebral artery through temporal bone above zygomatic arch and vertebral or basilar arteries through suboccipital transcranial windows bilaterally Lack of transcranial Doppler signals should not be interpreted as confirmatory because 10% of patients may not have temporal windows May not be diagnostic with intratentorial lesions Electroencephalogram No electrical activity for 30 minutes Complex technical requirements

community to expand available sources for organs to transplant. One way this has been done is to reevaluate donor criteria and designate “expanded criteria” donors based on age and comorbidities. Another way this has been achieved has been to redefine “standard” donor criteria based on scientific evidence; this has been most successful in the arena of lung transplantation.26 Finally, the most recent method has been to revisit donation after circulatory death (DCD). Historically, the first transplants were done using organs from asystolic donors, but with professional acceptance of brain death following the 1968 Ad Hoc Committee of Harvard Medical School review of the issue,18 and evidence of improved outcomes from donors whose hearts continue to beat, DCD faded into obscurity. However, with new evidence that organs can tolerate short periods of warm ischemia with successful outcomes, DCD is being revived by the transplant community.27–30 Often this option is possible for patients who have suffered a significant head injury requiring full cardiopulmonary support, but who are not able to undergo brain death testing.31 Less frequently, patients who have had cardiac arrests or suffer from terminal respiratory diseases may be good candidates for DCD.31

DIAGNOSIS Deceased circulatory death is categorized using the modified Maastricht classification. Although the possibility for acute retrieval from an uncontrolled DCD does exist, for the purposes of this chapter only controlled DCD will be discussed.

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BOX 6.3  Prediction of Death Within 60 Minutes of Withdrawal of Life-Sustaining Treatment UNOS Characteristics For Death within 60 minutes Apnea Respiratory rate 30 breaths/min Dopamine ≥15 μg/kg/min Left or right ventricular assist device Venoarterial or venovenous extracorporeal membrane Oxygenation Positive end-expiratory pressure ≥10 and Sao2 ≥92% Fio2 ≥0.5 and Sao2 ≤92% Norepinephrine or phenylephrine ≥0.2 μg/kg/min Pacemaker unassisted heart rate 60–90 minutes

Procede with procurement

DCD NO LONGER POSSIBLE

Move patient to quiet room for remainder of withdrawal period Fig. 6.3  General approach to the diagnosis of brain death.  OPO, organ procurement organization; DCD, donation after circulatory death; OR, operating room.

ethicists decide otherwise, the most important role the medical team can play in a DCD is to enforce the “dead donor rule,” wherein patients can only become donors after they are dead, and recovery of organs cannot cause a donor’s death. There is some thought that premortem interventions, such as obtaining blood samples and maintaining life-sustaining therapy while organ allocation processes take place, are acceptable, as the overall goal is to respect the patient’s final wish for organ donation.30,36 However, procedures that can cause serious harm, such as systemic heparinization, or cause pain, such as femoral cannulation, are not permitted until the patient has been declared clinically dead.36 It is also important to note that the transplantation team can have absolutely no involvement in patient management until after death has been declared, to avoid a conflict of interest. Critical care

physicians should be familiar with their hospital’s policy on DCD, as they are often the individuals declaring death in these situations. 

Donor Management The management of organ donor candidates falls under the purview of the critical care physician. As such, the same systematic approach employed when managing other patients in the intensive care unit should be used in the management of potential organ donors. Approaches to organ donor management following a protocol continue to show improvement in the overall number of organs transplanted, with beneficial effects on graft function.38–40 As a result, various international groups have

6 • Brain Death and Cardiac Death: Donor Criteria and Care of Deceased Donor

endorsed standardized pathways for the management of potential organ donors.41 Donor management guidelines are constantly undergoing reevaluation and updating as the science of critical care advances; the guidelines laid out in Box 6.4 represent the current recommendations in the management of organ donation. For the context of this section, it is important to remember that the smooth integration of organ donor management techniques within the context of a preexisting systematic approach to critically ill patients will result in the best outcomes for these patients, regardless of whether they proceed to organ donation. In addition, strict attention to donor management guidelines will result in the highest-quality organs for procurement, and ensure the best outcomes for organ donation recipients (see Box 6.4).42

BOX 6.4  Donor Management Guidelines Cardiac □

□ □ □ □ □

Mean arterial pressure 70–100 mmHg □ Treat hypertension with short-acting beta-blocker □ Treat hypotension with volume, followed by vasoactive agents Limit vasoactive agents where possible to ≤1 Heart rate 60–120 beats/min Urine output 0.5–3 mL/kg/h Hemoglobin 8 g/dL Scvo2 >70% EF ≥50% 

Respiratory □ □

Mechanical ventilation goals □ Fraction of inspired oxygen 0.40 □ Normal arterial pH □ Tidal volumes 8–10 mL/kg □ Plateau pressure 4 mL/kg/h, increasingly serum osm, inappropriately dilute urine, or hypernatremia Na >145) □ DDAVP 8 ng/kg loading dose followed by 4 ng/kg/h titrated to urine output 70 mmHg, urine output

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0.5 to 3 mL/kg/h, heart rate of 60 to 120 beats/min, and a hemoglobin >8 g/dL. Acidosis needs to be corrected, targeting a pH 7.40 to 7.45. Volume expansion is the initial therapy of choice, using isotonic fluids or colloids (blood or albumin), with a target of euvolemia at the end of resuscitation. Fluid choice should be tailored depending on potential organs to be harvested, as crystalloid administration in excess can decrease the chances of successful lung harvest. If volume alone is insufficient to attain these goals quickly, as may be the case in up to 80% of donors, vasoactive agent support is required. The use of vasoactive agents has been shown to improve organ viability by stabilizing the donor, though there is still debate about the first-line agent of choice.41 In deciding between dopamine and norepinephrine, it is important to consider the physiologic problem being treated. In the setting of low SVR alone, norepinephrine may offer a more targeted treatment option, whereas if there is cardiac dysfunction separately or in addition, dopamine will provide single-agent treatment for both. AVP (0.04 U/min) may also be an appropriate choice in the early periods of vasodilatory shock.47 Vasopressin has been shown to improve outcomes after kidney and lung transplants,47 a result that is ascribed to a decrease in microvascular thrombotic events after “pretreating” the endothelium. Coupled with effectiveness in treating diabetes insipidus, it is a useful vasoactive agent in the treatment of vasodilatory shock after brain death. If an inotrope is required, it is important to realize that the vasodilatory effects of dobutamine, especially in the setting of hypovolemia, may provoke additional hypotension and tachycardia. However, at low doses (5 μg/kg/min), dobutamine has been shown to have some protective effects in animal models of renal transplant.48 If the donor is tachycardic at baseline, milrinone is a better first-line inotropic agent. Aside from standard physiologic monitoring, invasive markers of volume status can be very useful, especially when donors may have confounding factors affecting their urine output (mannitol, diabetes insipidus). Central venous pressure (CVP) has been the traditional parameter of choice, with a target range of 4 to 12 mmHg. However, in the setting of mechanical ventilation, this measure has significant limitations due to alterations in intrathoracic pressure. CVP monitoring does allow measurement of central venous oxygen saturation (Scvo2), a marker of organ perfusion and delivery. Regardless of whether this parameter is checked intermittently or continuously, the target range is still a Scvo2 > 70%. Despite an absence of data on “normal” ranges for Scvo2 after brain death, this value still represents a useful target for end organ oxygen delivery and consumption. If there is a concern for myocardial depression, either preexisting in the donor or as a result of brain death itself, additional monitoring can be used. Although pulmonary artery catheters have been used to optimize cardiac output in the past, echocardiography is increasingly prevalent in the intensive care unit (ICU), providing equivalent information. In addition, the use of dynamic indices of cardiac function, such as pulse pressure variation and stroke volume variation, has been promoted in the intensive care literature as a more accurate measure of preload than static indices such as CVP or pulmonary capillary wedge pressure,

although this has yet to be borne out in the organ donor management literature.49,50 Regardless of the modality used to evaluate cardiac function, the recommended targets are a cardiac index >2.4 L/min/m2 and a mean arterial pressure of >70 mmHg. It is important to remember that donor management techniques also increase the potential for the heart transplantation as an end in itself. After stabilizing the donor and reaching standard physiologic norms, initial evaluation of the heart should be performed using echocardiography, evaluating for structural heart disease, left ventricular ejection fraction, and gross wall motion abnormalities. However, it should be noted that although singleuse echocardiography is helpful in screening for anatomic abnormalities, it is not sufficient for the evaluation of physiologic suitability. Given evidence that young hearts with left ventricular dysfunction can recover from the initial insult of autonomic storm, serial evaluation of cardiac function after optimizing volume status and repleting hormone deficiencies (discussed later) provides the best data for determining suitability for transplant. Cardiac catheterization is reserved for the assessment of potential donor hearts from patients 45 years of age or older, or at the particular request of the transplant center. 

RESPIRATORY Perhaps nowhere has the adoption of a standardized protocol made as much impact for organ recovery as in the management of potential lung donors. Historically, lung procurement has been as low as 7% from all available organ donors, and hovers optimally around 15% to 25%,41 with multiple factors contributing to this rate.25 These include acute lung injury after brain death, atelectasis, aspiration, and pneumonia. Although previous work demonstrated that a standardized protocol could improve recovery, implementation of the San Antonio lung transplant donor management protocol, developed by Luis Angel and colleagues, has demonstrably doubled their ability to identify and transplant lungs from donors at their institution.51 Following in the footsteps of previous work that suggested marginal lung donor candidates could actually produce adequate lungs for transplant recipients, Angel was able to show not only an increase in the number of “poor” donors optimized to ideal or extended criteria donors with implementation of their protocol, but also that no significant 30-day or 1-year mortality differences were observed between groups.51 Lung-protective ventilation, the strategy to prevent ventilator-associated lung trauma from a combination of overstretch of lung parenchyma and oxygen toxicity (as defined as a delivered Fio2 greater than 0.60 for greater than 48 hours), has been demonstrated to increase the available pool of potential lungs for transplantation.52 Arguably, the study that demonstrated that effect also left patients on continuous positive pressure support during their apnea trials, so it is less clear how much the continuity of a closed circuit affected the ability to keep lungs recruited before transplantation. Regardless, baseline targets of oxygenation and ventilation (Po2 >80 mmHg and Pco2 30–35 mmHg) can be met using this technique and should be even if patients are not candidates for lung donation, to maintain appropriate

6 • Brain Death and Cardiac Death: Donor Criteria and Care of Deceased Donor

oxygen delivery to the other organs. Lung recruitment strategies need to be balanced with appropriate peak and plateau airway pressures to avoid negative effects on patient hemodynamics. Strict monitoring of volume status is the next important component of lung management in the donor population. Cardiac instability during the autonomic storm causes significant shifts in blood pressure, and, without strict parameters, can result in significant volume overload. With direct catecholamine effect on alveolar permeability, fluid can redistribute into the pulmonary interstitium. In addition, an increase in left atrial pressure due to increased SVR can result in functional heart failure and cardiogenic pulmonary edema. Several studies have demonstrated that pulmonary edema decreases the potential for lung transplantation.53,54 Judicious fluid administration and administering diuretics as tolerated are parts of the overall strategy for decreasing pulmonary edema and optimizing oxygenation before donation, without significantly affecting renal graft function.55 Standard ICU management for the prevention of ventilator-associated pneumonia and aspiration pneumonitis should be continued. This includes elevating the head of the bed at least 30 degrees at all times, administration of deep vein thrombosis prophylaxis (mechanical and chemical methods), and administration of a proton pump inhibitor for the prevention of gastritis. If, after lung recruitment measures, infiltrates or contusions persist on chest x-ray, bronchoscopy with bilateral lavage can be performed to evaluate those areas. The most important concept in the management of donors for lung transplantation is to remember that every donor should be considered a potential lung donor, because standardized attention to a few basic management principles can result in optimization of initially poor-quality organs. 

RENAL Most considerations relative to donor renal function have been mentioned already in the section on cardiovascular management. Euvolemia with appropriate end-organ perfusion and oxygen delivery is the goal of intensive donor management. It is important to mention here that, in the process of managing the brain injury before brain death, the donor is likely to have been exposed to a number of agents with diuretic properties (mannitol, hypertonic saline). These agents can complicate both the hemodynamic stability of an already hypovolemic patient, and affect the diagnosis of renal-specific processes associated with brain injury. It is important for these agents to be carefully documented and considered when evaluating urine output. The target for urine output, as previously mentioned, is the same as for any other patient in the ICU—approximately 0.5 to 1 mL/kg/h. However, up to 2.5 to 3 mL/kg/h can be considered normal in donors as they equilibrate from fluid repletion during periods of hemodynamic instability. It is important to avoid an excessively positive fluid balance— there is a significant body of literature in critical care suggesting that this can lead to end-organ dysfunction, and in fact, fluid-restrictive strategies have demonstrated improvement in the numbers of lungs transplanted.55

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If urine output targets exceed 4 mL/kg/h, diabetes insipidus should be suspected. The hypothalamic–posterior pituitary neuronal connections become hypoxic with the progression of brain death, and production of AVP ceases. As a result, despite relative hypotension in the setting of loss of sympathetic tone, the kidneys continue to secrete large volumes of dilute urine until the patient becomes profoundly hypovolemic and oliguric. This is also associated with hypernatremia, which is known to be detrimental for potential liver donors. Treatment is aimed at restoring intravascular volume, at the same time supplementing the loss of AVP. Supplementation can be done either with desmopressin (DDAVP 8 ng/kg loading dose followed by 4 ng/kg/h titrated to urine output), or with continuous infusion of AVP (1 U bolus followed by 0.01–0.04 U/min).56 Desmopressin is a more selective vasopressin receptor agonist, targeting V2 receptors, and therefore has significant antidiuretic properties without the concomitant vasopressor activity of AVP.44,56 It can therefore be used without increasing organ vasoconstriction and causing posttransplant impairment. However, if the patient requires vasopressor support in addition to volume repletion, AVP is a better choice. Hypernatremia, a side effect of diabetes insipidus, has been associated with increased rates of liver graft loss, and possibly renal graft function.57,58,59,60 Serum sodium levels should be kept between 140 and 155 mmol/L, in an effort to decrease osmotic gradients between donor liver and recipient vasculature upon reanastomosis.61 In addition, a balanced nutritional approach using dextrose-based solutions is helpful for maintaining hepatic glycogen stores; however, this cannot be done at the expense of glycemic control.61 

ENDOCRINE Hormonal resuscitation is a concept in organ donor management aimed at addressing the three endocrine deficiencies of brain death that can affect outcomes. The first of these is thyroid hormone (thyroxine [T4] and T3) depletion. The exact mechanism of thyroid hormone function is as yet not fully elucidated, but several studies have implicated low levels of thyroid hormone as a contributory factor to the hemodynamic instability after brain death. Novitzky and colleagues were able to demonstrate in a series of animal and human studies that the administration of T3 improved cardiac function, decreased hemodynamic instability, and transitioned brain-dead donors from anaerobic metabolism to aerobic metabolism.14,62 Additional work by these and other authors has confirmed these findings while using T4 and suggested that the use of thyroid hormone replacement can increase the overall number of organs harvested from a single donor and decrease the incidence of delayed graft function.63–65 Rosendale et  al. looked at recipient outcomes and were able to demonstrate that, for cardiac recipients, 1-month survival was improved, with a 50% decrease in early graft dysfunction, although this improvement occurred in conjunction with the use of steroids.66 Although clinical research has suggested that oral repletion of T4 produces comparable bioavailability at 91% to 93% of the available IV T4 dose in circulation,

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Kidney Transplantation: Principles and Practice

overall, current recommendations call for thyroid hormone supplementation, preferably with T3 due to its more rapid onset and decreased susceptibility to influence by exogenous factors.67 T3 can be dosed at 4 μg bolus followed by 3 μg/h infusion for 10 hours.56 If T3 is unavailable, T4 can be used at 20 μg bolus followed by a 10 μg/h infusion for 10 hours.45 Vasopressin, as mentioned earlier, is a pharmacologic agent in both brain death-related peripheral vasodilatation and diabetes insipidus. Again, treatment is aimed at restoring intravascular volume, while at the same time supplementing the loss of AVP. Corticosteroid administration is the third component of hormone resuscitation, and is based on two possible mechanisms of function. The first is the attenuation of the inflammatory process associated with brain death. Two studies looking at posttransplant liver rejection markers, inflammatory markers, and posttransplant cardiac function demonstrated improvement in both parameters when steroid therapy was given to the donor.66,68 In addition, lung procurement was demonstrated to be directly tied to the administration of steroids, which was related to increased oxygenation.69 However, more recent work has suggested that, although suppression of the inflammatory state does occur, the incidence of rejection in liver and kidney recipients was not improved with steroid pretreatment.70 The second physiologic derangement for which steroid administration has been suggested to help is for adrenal insufficiency. During the CORTICOME trial from France, which randomized steroid supplementation as part of brain death management, testing revealed 78% incidence of adrenal insufficiency in the population. However, significant decreases in vasopressor utilization after steroid administration was not related to preexisting adrenal insufficiency, making it less likely this is the mechanism by which corticosteroid use improved donor physiology.71 Current guidelines still endorse the use of methylprednisolone (15 mg/kg bolus) as part of hormone resuscitation.70 Finally, although not part of hormone resuscitation, glycemic control is an important ongoing component of intensive care management of the donor. Between stress-related insulin resistance after brain injury and the replacement of free water deficits during diabetes insipidus with free water solutions that contain dextrose, donors can become quite hyperglycemic.42 Evidence suggests that renal function over the course of donor management worsens significantly in the setting of persistent hyperglycemia and significant glycemic shifts72; this could reflect both osmotic diuresis affecting donor resuscitation and tissue damage due to protein glycosylation. Management of hyperglycemia (glucose >180 mg/dL) improves the number of organs transplanted per donor and results in higher rates of long term renal graft survival.73 In addition, pancreas function in the recipient is affected by donor glucose levels, with normoglycemia improving outcomes.74 An insulin infusion therapy can be titrated for this effect. 

INFECTIOUS DISEASE Although donor to recipient infection transmission is well documented and can result in serious, and potentially fatal, outcomes, most donor infections independently are

BOX 6.5  Infection Diagnoses That Exclude Transplantation □ □

 ctive fungal, parasitic, or viral meningitis or encephalitis A Bacterial meningitis—conditional—okay if treated for at least 48 hours

Bacterial □ □

Tuberculosis Gangrenous bowel or perforated bowel or intraabdominal sepsis 

Viral □ □ □ □ □ □ □ □ □

 epatitis B surface antigen positivity H Rabies Retroviral infections, including HTLV-I/II Active herpes simplex, EBV, varicella, or CMV viremia, or pneumonia West Nile virus Hep B—HBV core antibody okay Hep C—Hep C positive donor to Hep C positive recipients okay HIV—HIV positive donor to HIV positive recipients okay HIV—HIV seronegative in high risk behaviors conditionally okay with adequate consent 

Fungal □ □

 ctive infection with Cryptococcus, Aspergillus, Histoplasma, CocA cidioides Active candidemia or invasive yeast 

Parasites □

 ctive infection with Trypanosoma cruzi (Chagas), Leishmania, A Strongyloides, or Plasmodium sp. (malaria) 

Prion □

Creutzfeldt–Jakob disease

CMV, cytomegalovirus; EBV, Epstein–Barr virus; HIV, human immunodeficiency virus; HTLV, human T-lymphotropic virus.

not contraindications to transplantation.75 Those that are serious are listed in Box 6.5.76 It is worth noting that several diseases that used to be absolute contraindications are now conditionally so; most notably hepatitis B and C, and human immunodeficiency virus (HIV), but also bacterial meningitis.41,77–79 Recipients of organs from these donors will need posttransplant monitoring, and in some situations additional therapy, but donation from individuals with these diseases is no longer impossible. It is important to pursue accurate testing of these diseases in the donors; nucleicacid amplification testing (NAT) is now the recommended method of testing where appropriate. Effective treatment of preexisting donor infections can result in successful transplantation, as can transplantation of a donor organ exposed to a chronic viral infection to a recipient with the same exposure history.80 It is important to recognize infections in donors and treat them quickly and efficiently to keep the donation process moving forward. Treatment starts with good prevention—standard ICU policies for the prevention of hospital-acquired infections (pneumonias, central lineassociated bloodstream infections, and urinary tract infections) should be maintained even after the focus of care has transitioned.

6 • Brain Death and Cardiac Death: Donor Criteria and Care of Deceased Donor

A high index of suspicion for infection is the next step. There are many reasons why a donor will not mount a standard response to infection: loss of thermoregulation preventing fevers, preexisting leukocytosis secondary to the inciting injury, massive blood transfusions, or use of steroids resulting in immunosuppression. Therefore it is important to pay attention to other clinical markers, including the skin examination, sputum characteristics, chest x-ray findings, and urinalysis results. Choice and interpretation of cultures, as well as guidelines for surveillance cultures when no infection is obvious, are at the discretion of the Organ Procurement Agency; however, it is always useful to obtain a Gram stain of the initial specimen to allow early antibiotic tailoring. Antibiotic choice is also a regional matter, as local sensitivities will change regularly. However, it is important to tailor broad empiric therapy as soon as culture results are available. In the presence of renal or hepatic dysfunction, extended criteria donors (age), and obesity, it is important to adjust antibiotic dosing. 

HEMATOLOGY Anemia should be avoided in organ donors to optimize oxygen delivery to various organs. Interestingly, De la Cruz et al. found a positive association between number of units of blood transfused before transplantation and renal graft function; the more units transfused, the less likely the kidney was to develop delayed graft function.81 Recommendations are currently to target a hemoglobin level of 8 g/ dL, in an effort to balance potential immunosuppressive effects while maximizing hemodynamic stability and oxygen delivery. Coagulopathy can occur for a variety of reasons in the donor. Donors may have preexisting conditions that can result in coagulopathy, including cardiac arrhythmias, for which they are treated with anticoagulants. Iatrogenic causes need to be ruled out, including dilutional coagulopathy, acidosis, and hypothermia. The loss of hypothalamic thermoregulation in the brain-dead donor, in addition to the inability to vasoconstrict or shiver, results in a poikilothermic donor. Close attention needs to be paid to environmental control of temperature and the temperature of infusing fluids to prevent the adverse effects of hypothermia. Core temperature should be maintained above 34°C with the use of warming blankets, fluid warmers, and ventilator heating units for inhaled gases. Additionally, the release of cerebral proteins into the circulation with brain death can trigger a consumptive coagulopathy (disseminated intravascular coagulopathy) or a hypercoagulable state.82 Any evidence of coagulopathy should be identified early and treated based on bleeding risk. Preexisting coagulopathies (secondary to medication) should be identified and reversed if at all possible. Donor acidosis and hypothermia should be corrected, and consideration should be given to a 1:1:1 ratio of packed red blood cells, fresh frozen plasma, and platelet resuscitation model for patients who are bleeding (similar to trauma resuscitation), as this has been shown to decrease both time to hemodynamic stability and coagulopathy. If available, thromboelastography can augment traditional measures of coagulopathy, and potentially indicate patients at risk for

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hypercoagulable states early in their management.83 Standard ICU protocol for the prevention of deep vein thrombosis should be continued. 

Other Topics in Donor Management ETHICS The ethical ramifications of organ transplantation and the responsibilities inherent in maintaining the spirit in which a donation is made are never far from the surface in the management of organ donors. With an increasing focus on the imbalance between support for organ donation and actual registration as a donor, the concept of first-person authorization for donation, wherein the designation as “donor” of a given individual is held as a mandate for the care team to facilitate donation in appropriate circumstances, has been increasingly popular and has been considered for policy implementation.84 However, recent publicity over manipulation of the organ transplant allocation system has again brought to the forefront appropriate allocation of a scarce and precious resource.85,86 It is part of the responsibility of the care team to continue to educate patients, family members, and the community about both the process through which donation happens, and the importance of the act of donation for the donor and the recipient. Only through education and transparency will the transplantation community continue to engender patient support, and ensure an ongoing stream of willing donors. 

FUTURE TECHNOLOGIES With the current shortage of available organs for transplantation, much work is being done to extend the donor pool and to optimize the organs that are available for transplantation. Approaches range from the microcellular— chemical and electrical modulation of the inflammatory cascade brought on by brain death—to the macrocellular, using direct peritoneal resuscitation practices to improve attainment of donor management goals and increase organ transplant rates.14,87,88 There has even been a resurgence of interest in using ex-vivo organ management to optimize extended criteria organs for potential transplantation.89 This is an exciting time to be involved in the field of organ donation, as new technologies bring new possibilities for donor management. 

Conclusion The field of organ donor management continues to evolve. The application of both critical care best practices and organ transplantation research to the clinical management of organ donors has allowed for improvements in both the number and quality of organs recovered. Known as donor management guidelines, these best practices will allow practitioners to continue to provide optimal medical care to both the donor and eventually the recipient.

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28. Bellingham JM, Santhanakrishnan C, Neidlinger N, et  al. Donation after cardiac death: a 29-year experience. Surgery 2011;150: 692–702. 29. Monbaliu D, Pirenne J, Talbot D. Liver transplantation using donation after cardiac death donors. J Hepatol 2012;56:474–85. 30. Oto T. Lung transplantation from donation after cardiac death (nonheart-beating) donors. Gen Thorac Cardiovasc Surg 2008;56:533–8. 31. Manara AR, Murphy PG, O’Callaghan G. Donation after circulatory death. Br J Anaesth 2011;108:i108–21. 32. Suntharalingam C, Sharples L, Dudley C, et al. Time to cardiac death after withdrawal of life-sustaining treatment in potential organ donors. Am J Transplant 2009;9:2157–65. 33. de Groot YJ, Lingsma HF, Bakker J, et al. External validation of a prognostic model predicting time of death after withdrawal of life support in neurocritical patients. Crit Care Med 2012;40:233–8. 34. DeVita MA, Brooks MM, Zawistowski C, Rudich S, Daly B, Chaitin E. Donors after cardiac death: validation of identification criteria (DVIC) study for predictors of rapid death. Am J Transplant 2008;8:432–41. 35. Brieva J, Coleman N, Lacey J, Harrigan P, Lewin TJ, Carter GL. Prediction of death in less than 60 minutes after withdrawal of cardiorespiratory support in potential organ donors after circulatory death. Transplantation 2014;98:1112–8. 36. Reich DJ, Mulligan DC, Abt PL, et  al. ASTS recommended practice guidelines for controlled donation after cardiac death organ procurement and transplantation. Am J Transplant 2009;9:2004–11. 37. Stiegler P, Sereinigg M, Puntschart A, et al. A 10 min “no-touch” time – is it enough in DCD? A DCD animal study. Transpl Int 2012;25:481– 92. 38. Malinoski DJ, Patel MS, Ahmed O, et al. The impact of meeting donor management goals on the development of delayed graft function in kidney transplant recipients. Am J Transplant 2013;13:933–1000. 39. Abuanzeh R, Hashmi F, Dimarakis I, et al. Early donor management increases the retrieval rate of hearts for transplantation in marginal donors. Europ J Cardio-Thorac Surg 2015;47:72–7. 40. Billeter AT, Sklare S, Franklin GA, et  al. Sequential improvements in organ procurement increase the organ donation rate. Injury 2012;43:1805–10. 41. Kotloff RM, Blosser S, Fulda GJ, et  al. Management of the potential organ donor in the ICU: Society of Critical Care Medicine/American College of Chest Physicians/Association of Organ Procurement Organizations consensus statement. Crit Care Med 2015;43:1291–325. 42. Patel MS, De La Cruz S, Sally MB, Groat T, Malinoski DJ. Active donor management during the hospital phase of care is associated with more organs transplanted per donor. J Am Coll Surg 2017;225:525–31. 43. Audibert G, Charpentier C, Seguin-Devaux C, et  al. Improvement of donor myocardial function after treatment of autonomic storm during brain death. Transplantation 2006;82:1031–6. 44. Wood KE, Becker BN, McCartney JG, et al. Care of the potential organ donor. N Engl J Med 2004;351:2730–9. 45. Dosemeci L, Yilmaz M, Cengiz M, et al. Brain death and donor management in the intensive care unit: experiences over the last 3 years. Transplant Proc 2004;36:20–1. 46. West S, Soar J, Callaway CW. The viability of transplanting organs from donors who underwent cardiopulmonary resuscitation: a systematic review. Resuscitation 2016;108:27–33. 47. Plurad DS, Bricker S, Neville A, Bongard F, Putnam B. 2012 Arginine vasopressin significantly increases the rate of successful organ procurement in potential donors. Am J Surg 2012;204:856–61. 48. Gottmann U, Brinkkoetter PT, Bechtler M, et al. Effect of pre-treatment with catecholamines on cold preservation and ischemia/reperfusioninjury in rats. Kidney Int 2006;70:321–8. 49. Al-Khafaji A, Elder M, Lebovitz DJ, et al. Protocolized fluid therapy in brain-dead donors: the multicenter randomized MOnIToR trial. Intensive Care Med 2015;41:418–26. 50. D’Aragon F, Dhanani S, Lamontagne F, et  al. Canada-donate study protocol: a prospective national observational study of the medical management of deceased organ donors. BMJ Open 2017;7. 51. Angel LF. Impact of a lung transplantation donor-management protocol on lung donation and recipient outcomes. Am J Respir Crit Care Med 2006;174:710–6. 52. Mascia L, Pasero D, Slutsky AS, et al. Effect of a lung protective strategy for organ donors on eligibility and availability of lungs for transplantation a randomized controlled trial. JAMA 2010;304(23):2620–7. 53. Reilly PM, Grossman M, Rosengard BR, et al. Lung procurement from solid organ donors: role of fluid resuscitation in procurement failures. Chest 1996;110. 220S-7S.

6 • Brain Death and Cardiac Death: Donor Criteria and Care of Deceased Donor 54. Venkateswaran RV, Patchell VB, Wilson IC, et al. Early donor management increases the retrieval rate of lungs for transplantation. Ann Thorac Surg 2008;85:278–86. 55. Minambres E, Perez-Villares JM, Terceros-Almanza L, et al. An intensive lung donor treatment protocol does not have negative influence on other grafts: a multicentre study. Euro J Cardio-Thorac Surg 2016;49(6):1719-1724. 56. Linos K, Fraser J, Freeman WD, et  al. Care of the brain-dead organ donor. Curr Anaesth Crit Care 2007;18:284–94. 57. Figueras J, Busquets J, Grande L, et al. The deleterious effect of donor high plasma sodium and extended preservation in liver transplantation: a multivariate analysis. Transplantation 1996;61:410–3. 58. Kazemeyni SM, Esfahani F. Influence of hypernatremia and polyuria of brain-dead donors before organ procurement on kidney allograft function. Urol J 2008;5:173–7. 59. Totsuka E, Fung U, Hakamada K, et  al. Analysis of clinical variables of donors and recipients with respect to short-term graft outcome in human liver transplantation. Transplant Proc 2004;36: 2215–8. 60. Totsuka E, Fung JJ, Ishii T, et al. Influence of donor condition on postoperative graft survival and function in human liver transplantation. Transplant Proc 2000;32:322–6. 61. Powner D. Factors during donor care that may impact liver transplant outcomes. Prog Transplant 2004;14:241–9. 62. Novitzky D. Novel actions of thyroid hormone: the role of triiodothyronine in cardiac transplantation. Thyroid 1996;6:531–6. 63. Salim A, Martin M, Brown C, et al. Using thyroid hormone in braindead donors to maximize the number of organs available for transplantation. Clin Transplant 2007;21:405–9. 64. Salim A, Vassiliu P, Velmahos GC, et al. The role of thyroid hormone administration in potential organ donors. Arch Surg 2001;136: 1377–80. 65. Novitsky D, Mi Z, Sun Q, Collins JF, Cooper DKC. thyroid hormone therapy in the management of 63,593 brain-dead organ donors: a retrospective analysis. Transplantation 2014;98:1119. 66. Rosendale JD, Kauffman HM, McBride MA, et al. Hormonal resuscitation yields more transplanted hearts, with improved early function. Transplantation 2003;75:1336–41. 67. Sharpe MD, van Rassel B, Haddara W. Oral and intravenous thyroxine (T4) achieve comparable serum levels for hormonal resuscitation protocol in organ donors: a randomized double-blinded study. Can J Anesth/J Can Anesth. 2013;60:998–1002. 68. Kotsch K, Ulrich F, Reutzel-Selke A, et  al. Methylprednisolone therapy in deceased donors reduces inflammation in the donor liver and improves outcome after liver transplantation: a prospective randomized controlled trial. Ann Surg 2008;248:1042–50. 69. Follette DM, Rudich SM, Babcock WD. Improved oxygenation and increased lung donor recovery with high-dose steroid administration after brain death. J Heart Lung Transplant 1998;17:423–9. 70. D’Aragon F, Belley-Cote E, Agarwal A, et  al. Effect of corticosteroid administration on neurologically deceased organ donors and transplant recipients: a systematic review and meta-analysis. BMJ Open 2017;7. 71. Pinsard M, Ragot S, Mertes PM, et al. Interest of low-dose hydrocortisone therapy during brain-dead organ donor resuscitation: the CORTICOME study. Crit Care 2014;18:R158.

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72. Blasi-Ibanez A, Hirose R, Feiner J, et al. Predictors associated with terminal renal function in deceased organ donors in the intensive care unit. Anesthesiology 2009;110:333–41. 73. Sally MB, Ewing T, Crutchfield M, et al. Determining optimal threshold for glucose control in organ donors after neurologic determination of death: A United Network for Organ Sharing Region 5 Donor Management Goals Workgroup prospective analysis. J Trauma Acute Care Surg 2014;76:62–9. 74. Gores PF, Gillingham KJ, Dunn DL, et al. Donor hyperglycemia as a minor risk factor and immunologic variables as major risk factors for pancreas allograft loss in a multivariate analysis of a single institution’s experience. Ann Surg 1992;215:217–30. 75. Mehta SR, Logan C, Kotton CN, Kumar D, Aslam S. Use of organs from donors with bloodstream infection, pneumonia, and influenza: results of a survey of infectious diseases practitioners. Transpl Infect Dis 2017;19. 76. Domínguez-Gil B, Delmonico FL, Shaheen FAM, et  al. The critical pathway for deceased donation: reportable uniformity in the approach to deceased donation. Transpl Int 2011;24:373–8. 77. Trotter PB, Robb M, Hulme W, et al. Transplantation of organs from deceased donors with meningitis and encephalitis: a UK registry analysis. Transplant Infect Dis 2016;18:862. 78. Coilly A, Samuel D. Pros and cons: usage of organs from donors infected with hepatitis C virus – revision in the direct-acting antiviral era. J Hepatology 2016;64:226. 79. Levitsky J, Formica RN, Bloom RD, et  al. The American society of transplantation consensus conference on the use of hepatitis c viremic donors in solid organ transplantation. Am J Transplantat 2017;17(11): 2790–2802. 80. Lumbreras C, Sanz F, Gonzalez A, et al. Clinical significance of donorunrecognized bacteremia in the outcome of solid-organ transplant recipients. Clin Infect Dis 2001;33:722–6. 81. De la Cruz JS, Sally MB, Zatarain JR, et al. The impact of blood transfusions in deceased organ donors on the outcomes of 1,884 renal grafts from United Network for Organ Sharing Region 5. J Trauma Acute Care Surg 2015;79. 82. Laroche M, Kutcher ME, Huang MC, et al. Coagulopathy after traumatic brain injury. Neurosurgery 2012;70:1334–45. 83. Powner D. Thromboelastography during adult donor care. Prog Transplant 2010;20:163–8. 84.  Human Transplantation (Wales) Act. 2013 (anaw 5). Available online at: http://www.legislation.gov.uk/anaw/2013/5/pdfs/anaw_ 20130005_en.pdf. Accessed April 22, 2019. 85. Shaw D. Lessons from the German organ donation scandal. JICS 2013;14(3):200. 86. Caplan A. Bioethics of organ transplantation. Cold Spring Harb Perspect Med 2014;4. 87. Hoeger S, Bergstraesser C, Selhorst J, et al. Modulation of brain dead induced inflammation by vagus nerve stimulation. Am J Transplant 2010;10:477–89. 88. Smith JW, Matheson PJ, Morgan G, et al. Addition of direct peritoneal lavage to human cadaver organ donor resuscitation improves organ procurement. J Am Coll Surg 2015;220(4):539–47. 89. Cypel M, Keshavjee S. Strategies for safe donor expansion: donor management, donations after cardiac death, ex-vivo lung perfusion. Curr Opin Organ Transplant 2013;18:513–7.

7

Medical Evaluation of the Living Donor MATTHEW J. ELLIS, BRADLEY HENRY COLLINS, BRIAN EZEKIAN, and STUART J. KNECHTLE

CHAPTER OUTLINE

History of Living Donation and DonorRelated Ethics The Rationale for Living Donation Matching Donor and Recipient Global Variations in Living Donor Kidney Transplantation Organ Supply Problem Quality of the Living Donor Kidney Types of Living Donors

History of Living Donation and Donor-Related Ethics The first long-term successful organ transplant was a living donor kidney transplant between monozygotic twin brothers performed in 1954 at the Peter Bent Brigham Hospital in Boston.1 This procedure marked the first time in history that a healthy person underwent a major surgical procedure that they did not need, solely for the benefit of another person, and this reality surrounded the ethical discussion of the case. The success of the procedure from an immunologic perspective was predicated on the genetic identity of the donor and recipient, by obstetric records of the donor and recipient’s birth, and by skin grafting before the kidney transplant to confirm compatibility. Because this transplant predated the development of dialysis, it was truly a life-saving procedure, given the end-stage renal disease of the recipient. The donor lived another 56 years with a single kidney without any apparent sequelae. Additional ethical considerations and unknowns at the time were whether the twin donor would develop renal failure either because of the procedure (considered very unlikely) or because of development of the same kidney disease as his genetically identical brother (unlikely but nevertheless possible). This transplant was followed by a small but growing number of similar living donor transplants between closely related family members, even while immunosuppressive drug therapy for transplantation was in its infancy. Although living donor renal transplants initially were the only option, deceased donor renal transplantation began shortly thereafter and grew considerably with the advent of brainstem death criteria.2 The development of immunosuppressive drug therapy, consisting initially of Imuran, steroids, and antilymphocyte globulin, allowed the growth of deceased donor renal transplantation as an alternative 104

Kidney Paired Donation ABO Incompatibility Medical Evaluation Surgical Evaluation Long-Term Outcomes After Living Donation Financial Considerations Living Donor Quality Initiatives

to living donor renal transplants. The arrival of cyclosporine and muromonab-CD3 (OKT3) in the 1980s further enhanced outcomes with both deceased donor and living donor transplantation. Laparoscopic live donor nephrectomy, initially described by Ratner in 1995, reduced the pain and suffering associated with live donation and resulted in a substantial growth of living kidney donation in the US.3 Improvements in outcomes and reduction in morbidities of surgery led to a growth in living kidney donation to a maximal number in 2004 of 6647. Unfortunately, the number of living donor transplants declined to 5626 in 2015.4 Reasons for the decline in total numbers of living donor nephrectomy, despite the continual growth of the recipient waitlist, are difficult to attribute accurately, but may include increasing reliance on deceased donor kidney transplantation. Utilization of living donors varies by geographic region, race and culture, and transplant program. Additionally, the increasing body mass index (BMI) of the US population discourages the use of living donors. As living donation comes under increasing regulatory scrutiny, long-term medical follow-up has been mandated for such donors. Paired kidney donation has developed as a means of maximizing benefits and possibilities of living donation. In an attempt to increase the number of people eligible to be a living donor, donors who are older, have a higher BMI, are on one antihypertensive medication, and have other more complex medical conditions have been considered. Attitudes toward covering the medical costs of living donation vary around the world (see section on Financial Considerations). The implementation of living kidney donation reflects both medical and societal attitudes toward risk and cost sharing. However, one constant reality in the field is that the best long-term outcomes have been achieved using living donors, likely because of the superior quality of the kidneys and short preservation times that minimize graft injury associated with transplantation. 

7 • Medical Evaluation of the Living Donor

The Rationale for Living Donation Although the survival benefit of kidney transplantation is superior to any other form of renal replacement therapy, the allograft’s source confers additional benefits. For example, kidney transplantation before the initiation of dialysis, also known as preemptive transplantation, is associated with higher graft and patient survival compared with those recipients who receive their kidneys after initiating dialysis.5 This survival benefit is most pronounced in the living donor kidney population, because 31% of living donor transplants performed in the US in 2015 were preemptive, whereas only 9% of deceased donor kidney transplants were performed in patients before chronic dialysis.4 Studies have shown that renal replacement therapy by kidney transplantation is less costly than dialysis, so it is likely that the increased use of preemptive transplantation in living donation decreases the financial burden associated with renal failure.6 Recipients of living donor grafts do not wait as long for their organs as the recipients of grafts from deceased donors, who may wait for years, depending on the region in which they are listed and their level of preformed antibodies to the major histocompatibility complex. Another advantage of living donor kidney transplantation is virtual absence of delayed graft function (DGF) as a result of relatively short cold ischemia times and the lack of the physiologic perturbations associated with brain death that may lead to allograft dysfunction. The avoidance of DGF is advantageous as it has been associated with an increased incidence of acute rejection and linked to the development of chronic allograft nephropathy, which both lead to inferior graft survival.7,8 Kidneys obtained from living donors outperform those from deceased donors at all time points as evidenced, for example, by a 5-year graft survival rate of >85% for living donors versus 75% for deceased donors.5 Finally, when surgical complications, primary nonfunction, and other causes of early graft loss are excluded, the 1-year conditional half-life of living donor transplants was 15.3 years for transplants performed from 2009 to 2010, whereas the half-life of deceased donor grafts was 12.5 years during that same period.9 Living donor kidney transplantation has a number of other benefits that are harder to quantify. The procedures are scheduled electively, usually at the discretion of the donor, so they are performed during the day when the operative team is rested and all ancillary services are fully staffed. Living donation allows for the optimization of any medical comorbid conditions that might affect recipient outcome adversely. Theoretically, every living donor transplant performed leaves a deceased donor kidney for another recipient on the transplant list. However, in the US, despite the growth of the waiting list, the number of living donor kidney transplants continues to decline, and there were 1000 fewer live donors in 2016 than in 2004.10

MATCHING DONOR AND RECIPIENT Optimal human leukocyte antigen (HLA) matching of a living kidney donor with a recipient influences longterm allograft survival. A few key donor/recipient factors have emerged as predictors of long-term outcomes. Ideal HLA matching is not required for living kidney donation,

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because even a poorly matched living donor kidney may perform better than a deceased donor kidney. However, each additional HLA mismatch comes with a significant linear adverse effect on allograft survival.11 Furthermore, kidneys from deceased donors are associated with the lowest effect of HLA mismatch, kidneys from living related donors are associated with an intermediate effect from HLA mismatch, and kidneys from living unrelated donors are associated with the highest effect from HLA mismatch. ABO incompatibility (ABOi) may serve as another immunologic barrier to living donor kidney transplantation. However, 1-, 3-, and 5-year ABOi graft survival rates with peritransplant immunomodulatory therapies are now comparable to United Network for Organ Sharing data for compatible live donor kidney transplants (see section on ABO Incompatibility).12–15 Age disparity between donors and recipients also plays a role in matching. Theoretically, age matching is of considerable importance, because younger kidney transplant recipients receiving older allografts may outlive their allografts and require retransplantation, whereas older recipients may die of other causes before their allograft fails, which both lead to suboptimal organ usage. Additionally, recent data have demonstrated that increasing living donor age is associated with reduced allograft survival, particularly in longer-term follow-up.16,17 

GLOBAL VARIATIONS IN LIVING DONOR KIDNEY TRANSPLANTATION Comprehensive global assessments of living kidney donation have seldom been performed because of the varying transparency of practices between countries. Recently global trends of 69 countries with available national data have been examined.18 In 2006 about 27,000 legal living donor kidney transplants were performed worldwide, accounting for nearly 40% of all kidney transplants. In addition to legal practices, the World Health Organization estimates a significant fraction of kidney transplants worldwide involve unacceptable or illegal practices.19 In general, the number of living kidney donor transplants has grown, with 62% of countries reporting at least a 50% increase in volume from the preceding decade. The highest volume of living donor kidney transplants was performed in the US (6435), Brazil (1768), Iran (1615), Mexico (1459), and Japan (939). The current proportion of all kidney transplants from living and deceased donors shows substantial geographic variation.20 Most European countries, such as Poland, Spain, Italy, France, and Germany, derive a majority of their kidney allografts from deceased donors; thus the proportion of living donor kidney transplantation is small (50%). Notably in Japan, laws that were in place until 2010 required family consent for organ recovery despite the documented will of a donor, a practice that significantly hampered rates of deceased donation on the basis of cultural norms. Moreover, Iran is the only country in the world with a paid living

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Kidney Transplantation: Principles and Practice

unrelated kidney donation program, which accounts for about 75% of all its kidney transplants.21 Finally, in countries such as Egypt, Jordan, Pakistan, Oman, and Iceland, all kidney transplants are from living donors, because there is no deceased donor program in place. 

ORGAN SUPPLY PROBLEM The need for kidney transplants continues to far exceed the demand, although the absolute number of registrants on the list has plateaued over the past few years to just under 100,000 in the US.10 This observation has been attributed to a combination of factors, including implementation of the kidney allocation system (KAS).4 Now that waiting time is calculated from the date that dialysis was initiated, there is no benefit to maintaining a patient with end-stage renal disease (ESRD) on the waitlist in an inactive status while outstanding medical, financial, or psychosocial issues are addressed. Over the past decade, the number of kidney transplants performed each year has generally increased; however, gains in the number of kidneys recovered from deceased donors have been offset by a decline in number of living donors. For example, in 2004, 16,007 patients underwent kidney transplantation (9359 from deceased donors and 6648 from living donors).10 The number of allografts increased to 19,060 in 2016. However, that growth was driven entirely by an increase in the number of kidneys recovered from deceased donors (13,431) as the number of living donor grafts declined to 5629.10 Community outreach education initiatives, and programs through state divisions of motor vehicles where millions of drivers have provided first-person donor consent, have likely led to an increase in deceased donors, but a corresponding increase in living donors has yet to be realized.22 The current opioid epidemic in the US has also yielded an increase in deceased organ donors despite fears of disease transmission blunting the potential. In this era of sophisticated disease detection methodologies (e.g., nucleic acid testing), the risk of dying without being transplanted is higher than the risk of unintentional disease transmission.23 Another sequela of the organ donor shortage is patient mortality while on the waiting list. Of the approximately 99,000 patients waiting for kidney transplantation in 2015, almost 5000 died.4 The role for living donor kidney transplantation to improve waitlist mortality may be limited given the decreasing number of individuals willing to donate and the large percentage of living donor kidneys that are transplanted preemptively. Of the 31,672 patients removed from the kidney transplant waitlist in 2015 (because of transplantation, medical deterioration, psychosocial reasons, or death), 18% received kidneys from living donors whereas 39% underwent transplantation from deceased donors.4,10 

QUALITY OF THE LIVING DONOR KIDNEY The need for risk stratification of deceased donor organs has long been recognized. Accordingly, an evolution has occurred from the simplistic expanded criteria donor (ECD) classification to the more sophisticated Kidney Donor Risk Index (KDRI) and related Kidney Donor Profile Index (KDPI).24–26 In aggregate, these tools have helped shape

deceased donor organ allocation and provide the best available basis for patient and provider decisions regarding accepting or declining a given kidney offer. Recently the first Living Kidney Donor Profile Index (LKDPI) was developed.27 The national data used in developing the LKDPI demonstrated that donor age >50 years, African American race, ABO incompatibility, and HLA-B and HLA-DR mismatches were associated with worse graft survival, whereas higher donor estimated glomerular filtration rate (eGFR), donors unrelated to the recipient, and male-to-male donation were associated with better graft survival. This system allows direct comparison between two living donor kidneys, or comparison between a living donor kidney and one from a deceased donor. The LKDPI is particularly useful in decision making for recipients fortunate enough to have multiple potential living donors, or those who receive deceased donor kidney offers while potential living donors are under evaluation. Additionally, this index is useful in kidney paired donation (KPD). Incompatible pairs entering a KPD system can use this index to decide which alternative living donors are acceptable, and, in the case of paired donation, to evaluate the possibility of receiving a deceased donor kidney in exchange for their living donor donating to another person on the waiting list.28 

TYPES OF LIVING DONORS When educating patients and their families about kidney transplantation, it is imperative that the advantages of the living donor are emphasized: shorter waiting time, better quality kidney/function, and longer allograft survival. Many patients are still under the impression that living donors must be blood relatives; however, transplant professionals should encourage recipients to expand their searches. In this era of social media, a wider net can be cast, although the ethical considerations are still under debate.29 Patients should also be taught that any interested, reasonable donor should present for screening, because blood type matching is not always necessary given desensitization protocols and the expanding role of paired donation. Once judged with skepticism, altruistic donors are now coveted because the paired donation experience has demonstrated their importance in initiating transplant chains.30 Some centers take the patient out of the role of soliciting for a kidney and transfer that responsibility to an advocate or “champion.”31 The effect that these efforts will have on the living kidney donor pool is not known at this time. 

KIDNEY PAIRED DONATION KPD is now an option for recipients with willing and medically fit donors who are deemed poorly compatible on the basis of immunologic (e.g., ABO or HLA incompatibility) or other factors (e.g., age, gender differences, BMI mismatch), which affects up to 30% of cases.32 In these circumstances, incompatible donor/recipient pairs can be entered into a pool of one or more additional incompatible pairs who are in a similar situation. Subsequently, by exchanging donors, all recipients have the potential to receive a compatible organ match. Early paradigms consisted solely of same-day, twoway swaps performed at the same location. However, the demonstrated safety of shipping living donor kidneys from

7 • Medical Evaluation of the Living Donor

one center to another33 and the addition of nondirected donors to the donor pool has allowed feasibility of KPD across much larger geographic areas.34 The US is unique in that single-center, multicenter, and national programs that operate independently of one another coexist.35 Programs have uniformly reported at least equivalent graft survival rates compared with traditional non-KPD living donor transplants.36–38 A single, national KPD system that includes the need for uniform tissue-typing platforms, computerized matching algorithms, and a standardized organ acquisition charge has been proposed,39 but faces several logistical challenges that have impeded implementation. Such a system exists in other geographic areas, including the United Kingdom, where a national sharing scheme has been established for living donor kidneys. Matching runs are undertaken every 3 months and, from January 2018, all nondirected altruistic donors in the UK are entered into the scheme unless the donor takes exception to this. This has led to a steady increase in the number of kidneys transplanted through the scheme, with results that are comparable to related living donor transplantation40 (see Chapter 23 for more details). 

ABO INCOMPATIBILITY ABOi transplants had long been considered a contraindication to kidney transplantation with Hume et al. in the 1950s remarking, “[W]e do not feel that renal transplantation in the presence of blood incompatibility is wise.”41 However, the increasing organ shortage has stimulated the development of strategies to allow transplantation across this immunologic barrier. Current ABOi immunomodulation

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protocols variably include recipient treatment with one or more of the following: (1) plasmapheresis to remove antiA/B antibodies, (2) intravenous immunoglobulin, and (3) B cell–depleting therapies such as rituximab or splenectomy, which are combined with powerful maintenance immunosuppression posttransplantation.42 The ultimate goal of these protocols is to decrease the level of anti-A/B antibodies below a safe threshold in the immediate posttransplant period. After an approximately 2-week period of engraftment, rebound anti-A/B antibody production inevitably occurs, but this rebound does not appear to cause significant injury to the kidney allograft (a process termed accommodation).43 Increasing experience with ABOi kidney transplantation has led to outcomes that are now equivalent to ABO-compatible transplantation in both pediatric and adult patient populations.14,15 

Medical Evaluation Donors are evaluated in a multidisciplinary manner that includes an independent living donor advocate, nephrologist, surgeon, social worker, medical psychologist, and financial counselor. The medical evaluation has multiple components, some of which can start before the patient is seen at the transplant center, and culminates in the review of all data by a multidisciplinary team and a final decision regarding candidacy. These components are listed in Box 7.1, but the broad categories include: (1) a thorough medical history and physical examination including family history focused on renal disease; (2) general health laboratory

BOX 7.1  Components of the Living Donor Evaluation History and Physical Examination Interview with focus on renal disease and family history of renal disease Detailed health questionnaire Donor education and consent History and physical examinations by transplant nephrologist and surgeon Multiple complete vital signs Evaluation by mental health expert Interview with independent living donor advocate  Laboratory Testing to Evaluate Renal Function and Determine Immunologic Compatibility Blood pressure—two to three separate measurements Additional 24-hour blood pressure monitoring as indicated Urine protein assessment (via 24 h urine or spot protein to creatinine ratio) Glomerular filtration rate assessment (via 24 h creatinine clearance, iothalamate clearance, or radioisotope clearance) Oral glucose tolerance test and/or HbA1c Metabolic workup if previous history of renal stones Donor ABO typing Complete blood count with platelet count and differential Comprehensive metabolic panel to include fasting serum glucose and measurement of transaminases Fasting lipid profile Coagulation studies to include the prothrombin time, international normalized ratio, and partial thromboplastin time

Urinalysis and culture Electrocardiograph Chest x-ray Crossmatch with recipient Human leukocyte antigen (HLA) typing of the donor  Identify Transmissible Infectious Disease Human immunodeficiency virus, hepatitis B and C Rapid plasma reagin (syphilis screen) Testing for tuberculosis (TB)—TB skin testing or QuantiFERON-TB Gold Testing for Strongyloides, Trypanosoma cruzi, and West Nile virus for donors from endemic areas  Evaluation of Renal Anatomy With Cross-Sectional Imaging Abdominal imaging using computed tomography angiography or magnetic resonance angiography  Age-Appropriate Health Screening, Including Cancer Screening Prostate-specific antigen (recommendations based on donor age and family history) Gynecologic examination with Papanicolaou smear Colonoscopy Mammogram Pregnancy test if indicated Echocardiography and cardiac stress testing as indicated Pulmonary function studies and computed tomography scanning of the chest as indicated

Modified from kidney transplantation, 7th ed., Chapter 7, MacConmara and Newell.

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Kidney Transplantation: Principles and Practice

evaluation with focus on renal function, HLA typing, HLA antibody screening, ABO typing, and screening for transmissible infection; (3) age-appropriate health and cancer screening; and (4) cross-sectional imaging of kidney anatomy. The medical history focuses on possible comorbidities such as hypertension, diabetes, cardiovascular or cerebrovascular disease that must be quantified. Multiple blood pressure readings are obtained to provide a reliable baseline. Laboratory profile includes the tests shown in Box 7.1 and specifically includes urine studies to estimate renal function and to evaluate for proteinuria. In the US, measuring renal function is a requirement and can be completed by collecting 24-hour urine samples to calculate the 24-hour creatinine clearance, or glomerular filtration rate (GFR) can be measured by nuclear imaging studies. Immunologic testing includes ABO and HLA typing of the donor to allow interpretation of compatibility with the recipient, choosing between donors, if there are more than one, or pairing the donor with the most appropriate recipient in the case of paired exchange. Measurement of possible communicable infectious diseases such as hepatitis B and C and HIV is necessary. Screening for tuberculosis (TB) is highly recommended using TB skin testing or QuantiFERON-TB Gold. Donors who test positive should be treated for 6 to 9 months before proceeding with donation. Screening for syphilis is also highly recommended, and, if there is history of travel to Central or South America, Chagas’ disease as well. West Nile virus screening is also advised. Abdominal imaging is usually delayed until donors pass the medical and laboratory screening stages to avoid unnecessary risk and cost. Depending on local expertise, either computed tomography (CT) angiography or magnetic resonance angiography is performed to identify vascular anatomy, size of kidneys, and the anatomy of the urinary collecting system. All donors older than 50 and those older than 40 with cardiovascular risk factors should undergo appropriate cardiovascular diagnostic studies and imaging, such as stress testing. All donors are screened with chest x-ray, and those with a history of smoking, lung disease, or abnormal chest x-ray are screened with chest CT scan as well. Guidelines for cancer screening are published by the American Cancer Society and others according to age and gender, and guide the performance of these screening tests for donors.44 

Surgical Evaluation The surgeon’s unique role is to assess the operative risk of the donor. Factors that can contribute to increased morbidity include prior abdominal operations and elevated BMI. Transplant centers have various thresholds for maximum BMI in donors, with some extending their upper limit to 35 kg/m2.45 In this population, consideration should be given to the increased risk of hypertension, diabetes, heart disease, and renal disease before acceptance as a donor. The Scientific Registry of Transplant Recipients (SRTR) obesity rate for living donors in 2015 was 20% with a BMI range of 30 to 35 kg/m2 and 3% over 35 kg/m2.4 Elevated BMI is also a risk factor for prolonged surgical time and wound complications.

The primary surgical approach to living kidney donation is laparoscopic, and 97% of living donor kidneys in 2015 were retrieved by this method.4 Many surgeons prefer the hand-assisted technique. However, almost 40% of cases are performed completely laparoscopically. The kidney is extracted from the abdomen via either a periumbilical or Pfannenstiel incision. The choice of the kidney is usually driven by anatomic considerations, with preference for the left because of the longer, more substantial renal vein (for more details on donor nephrectomy see Chapter 8). The presence of multiple renal arteries may present challenges at implantation, so both the recovering and implanting surgeons should review preoperative imaging. Small upper pole arteries can be ligated should they pose undue risk during implantation (prolonged warm ischemia); however, every effort should be made to preserve lower pole arteries, because they usually provide blood supply to the ureter. Techniques include anastomosis to the main renal artery on the back table or separate arterial anastomoses in the recipient. To minimize warm ischemia time, some surgeons reperfuse the kidney once the main arterial anastomosis has been completed, then perform the second anastomosis at a more distal site on the native iliac artery. Immediate complications of living kidney donation that may require reoperation include injury to intraabdominal viscera, bleeding, and wound dehiscence (Table 7.1).46 Potential donors should also be made aware of other complications including lymphatic leak (chylous ascites), wound infection, hernia, and deep venous thrombosis. Death resulting from donor nephrectomy is rare; however, donors should be counseled that it is possible. Between 2011 and 2015 in the US, 7 out of 28,291 living kidney donors died (approximate incidence of 1 in 4000) because of what was termed “donation-related” causes.4 Most living donors are discharged within 2 days of surgery. In an attempt to decrease hospital stay prolonged by TABLE 7.1  Donor Complication Risks Risk (Percentage of Donations Unless Stated) Mortality MAJOR COMPLICATION Bleeding Bowel obstruction Vascular injury Open conversion Reoperation Blood transfusion Wound infection Urinary tract infection Readmission (including nausea, vomiting, gastroenteritis, abdominal pain, ileus, bowel obstruction) Hernia repair End-stage renal failure Hypertension

0.02–0.03 2.2 1.0 0.27 0.7–1.1 0.52 0.4 2.1 4.5 2–5 0.8 Hazard ratio 11.38 Additional risk in obese, elderly, and African American donors 15–25

Data from OPTN/SRTR 2015 Annual Data Report. In: Scientific registry of transplant recipients 2017; Mjøen G, Hallan S, Hartmann A, et al. Long-term risks for kidney donors. Kidney Int 2014;86:162–7; Lam NN, Lentine KL, Levey AS, et al. Long-term medical risks to the living kidney donor. Nat Rev Nephrol 2015;11:411–9.

7 • Medical Evaluation of the Living Donor

gastrointestinal complications (constipation, etc.), some centers have applied an enhanced recovery after surgery (ERAS) protocol to living donors. This includes preoperative bowel preparation, measured use of crystalloids in the operating room, and narcotic-free pain control. Convalescence for donors follows that of most major abdominal operations and includes avoiding driving and weight-lifting restrictions. However, walking is encouraged. Return to work depends on clinical assessment of recovery and the type of employment (desk job vs. construction). The rehospitalization rate for living donors is 5% at 1 year.4 Given the thorough medical evaluations that living donors are subjected to, the incidence of renal failure is low. However, as living donor criteria are extended, the incidence may increase. There are calculators that clinicians should employ to determine each candidate’s lifetime risk for renal failure.47 

Long-Term Outcomes After Living Donation Follow-up after living donation and characterization of the long-term outcomes have historically been limited by the short duration of follow-up, the high number of donors lost to follow-up, and the small number of minority donors; these limitations interfere with living donor programs accurately describing the inherent risks of kidney donation.48 One of the most worrisome outcomes after living donation is the development of ESRD. Current estimates in the US and Norway document a 7- to 11-fold increase in risk of ESRD after donation.49,50 White donors have up to a 6.1% increased risk for proteinuria development (a known risk factor for chronic kidney disease), whereas as many as 30% of donors will develop GFRs less than 60 mL/min/1.73 m2.51 The risks for proteinuria and “low” GFR are augmented by elevated systolic and/or diastolic predonation blood pressure, increased age, decreased predonation kidney function, and higher BMI (for each unit increase in BMI over 30, there is a 3% to 10% increase rate of new proteinuria and decreased GFR, respectively).51 In addition to renal-specific outcomes, donors may experience a number of other long-term risks. Matas and colleagues recently summarized what is known about postdonation, non-ESRD risks.52 Although many of these outcomes are known to be only associations, several risks have concrete, causal connections.    Cardiovascular risk: In the first few years after donation, a donor’s GFR most often increases, which is independently associated with increases in left ventricular mass, decreased aortic distensibility, and increased troponin measurements. These changes are all associated with increased rates of future cardiovascular events, including cardiac ischemia and heart failure. □  Pregnancy: Postdonation pregnancy does not carry an increased risk of maternal or fetal complications. However, donors tend to experience higher than expected rates of gestational hypertension and preeclampsia, similar to what is expected in women with prepregnancy hypertension, diabetes, and higher BMI. □ 

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Rehospitalizations: Patients who donate a kidney are at increased risk of subsequent hospitalizations in the 3 years after donation; some of these are related to donation, whereas other admissions are not. □  Mortality: Fortunately, there have been no clear signals for changes in mortality compared with the general population, with the caveat that most studies’ duration is not long enough to credibly state that there is no change. □ 

  

In 2013 the United Network of Organ Sharing (UNOS) mandated that centers report on patients’ laboratory and clinical outcomes and follow-up at 6, 12, and 24 months postdonation. Before the 2013 UNOS mandate, fewer than 50% of patients had clinical data reported, which has more recently improved to approximately 65%; similarly, less than 40% of patients had laboratory data reported, which has also improved to 56%.53,54 Patient factors associated with higher rates of follow-up include female gender, younger age, college or higher education level, and residence in the same state as the performing transplant center. Center characteristics associated with limited follow-up include lack of reimbursement and a lack of transplant center resources to accomplish follow-up.54 Donor surveys suggest that followup would be better if postdonation communication was more regular, predonation education about the need and effect of follow-up was improved, and more resources were available to assist in covering donation-related followup expenses.55 Although follow-up is commonly lacking, increased follow-up success can be achieved. Single-center reports describe living donor program improvement projects that resulted in dramatic (14-fold) increases in completed 2-year follow-up and reporting,56 with modest financial impact to the center (less than $200 per patient), despite increased services offered to the patient. An important consideration related to postdonation medical complications includes the timing of these events. Whereas 2-year follow-up is required after donation in the US, very few of the important complications, namely increased blood pressure, increased urinary protein excretion, or a fall in GFR, occur during that time. Furthermore, long-term follow-up is challenging, even in countries with universal, single-payer health insurance.57 Importantly, follow-up care is even more important in the current donation climate, in which transplant centers seek more living donors and allow more comorbid condition(s), as attention is paid to narrowing the gap between the increasing number of waitlisted patients and the relatively flat number of transplants performed each year. Currently, donors more often tend to be unrelated to the recipient, older, insured, employed, college educated, have a history of smoking and/ or hypertension, lower GFR pretransplant, and living outside of the US. An important component to medical and/or psychological follow-up is having reliable access to the healthcare system, principally a primary care provider (PCP). However, close to 25% of patients who donate have either never had a PCP or visit with a PCP irregularly before donation.58 The rate of follow-up after donation continues to be low, with only about 20% of donors seeking regular care with a PCP; this is particularly true among men who have completed less than a college education and who did not have a regular PCP before donation.58 The importance of having a PCP is highlighted

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by the fact that a donor is 14 times more likely to not have any follow-up in the first year after transplant if they had no regular PCP before transplant.53 Finally, the demographic risk factors for not having a PCP mirror those risk factors for not completing required follow-up and for increased risk of lower GFR, higher blood pressure and proteinuria, and other deleterious outcomes after donation.53,58 This suggests that screening for these factors may be as important as other, more traditional laboratory, physical examination, or medical history elements of a donor’s workup. Because the donor-derived benefits of living donation are psychological and not medical, specific attention to psychological outcomes is important. Additionally, donors are required to undergo extensive pretransplant psychological screening to understand their motivations for donation, to rule out any type of coercion, and to assure that each patient is free from any significant mental health issues that might influence the donation decision or complicate postdonation recovery. In general, there is a low rate of mental health issues among donors compared with the general population. However, the risk for postdonation depression and anxiety is real, along with its potential to negatively affect a donor’s quality of life. Up to 20% of donors report decreased postdonation quality of life; this is particularly true for nonrelated, nonspouse donors who experience a medical complication or who witness their graft fail in the recipient.52,59 Furthermore, if the donor is ambivalent before transplant or has a longer recovery (related to or independent of complications), they have a higher risk of postdonation psychological complications, specifically anxiety.59 

Financial Considerations Long-term donor outcomes can also be measured financially, from a number of different perspectives, related to both direct and indirect costs. Understanding the financial impact of donation is critical from both patient and societal

perspectives. Most would argue that a donor who has altruistically undergone nephrectomy for no direct medical benefit should incur as few negative consequences (including financial) as possible. Furthermore, when patients undergo financial hardship, including time away from activities of daily living and/or work, there is a significant societal strain. Finally, financial constraints and concerns may contribute to limiting enthusiasm for donation, a concept cited frequently for the recent stagnation in living donor rates. Pretransplant, more than 9 of 10 donors state that they incurred a cost related to their donation workup. These costs include travel, lodging, or other health-related costs.60 Whereas the demographic characteristics of donors vary across the country, data suggest that a high percentage of donors (85%) work outside of the home, with approximately 30% of these donors in professional lines of work. After donation, about 75% of donors indicate that they were out of work for 4 weeks, with approximately 20% stating that they were unable to perform their activities of daily living for this same time period.61 Impaired function translates into costs not commonly considered: 30% of donors stated that they spent money on child care or help covering required house maintenance, and so on.60 Attempts to place a financial value on direct and indirect costs is challenging and convoluted. However, after taking a number of factors into consideration, just less than 40% of donors will spend up to $500 related to their donation in the 12 months after the event, with 20% spending more than $5000 during that same time period.60 A similar effect is noted in other countries around the world, including Canada.62 Another consideration for donors pretransplant is the effect of donation on the attainment of postdonation insurance (health, life, or other). As many as 57% of transplant centers indicate that a lack of predonation insurance is an absolute (15%) or relative (42%) contraindication to donation (Table 7.2; Figs. 7.1 to 7.4).60 Although the rate of insurance among donors in the US is proportional to the rate of uninsured people in the general population,

TABLE 7.2  Absolute and Relative Contraindications to Living Kidney Donation Age Informed consent Substance abuse Hypertension

Diabetes Obesity Renal disease Renal stones Inherited renal disease Infection Cancer Cardiovascular disease Renal anatomic abnormalities

Absolute

Relative

Less than 18 years Impaired ability to make an autonomous decision because of mental or psychiatric condition Active substance abuse Multiple agents or high doses of single agents for control Evidence of end-organ damage End-organ injury Additional strong risk factors for cardiovascular disease Diabetes mellitus Morbid obesity (BMI >35) with comorbid conditions Evidence of renal disease with reduced creatinine clearance (GFR 250 mg), or hematuria Multiple or recurrent renal calculi of a metabolic condition that predisposes to the recurrence of renal calculi ADPKD, SLE, Alport’s syndrome, IgA nephropathy HIV, hepatitis B, hepatitis C, West Nile virus, Chagas’ disease Cancer current or treated but at significant risk for recurrence Coronary or peripheral vascular disease, or heart valve disease Significant discrepancy in the kidney sizes

Over 65 excluded from many programs

Borderline or control with single agents

Impaired glucose tolerance Obesity (BMI >30) with comorbid conditions Borderline creatinine clearance, microscopic hematuria low levels of proteinuria (50 Black race Diabetes Hypertension Weight >80 kg Terminal SCr >1.5 mg/dL DCD CVA death

30 20 10 0 2004

2008

2012

2016

Year Fig. 8.2  Components of the Kidney Donor Risk Index 2004 to 2015.  Significant increases in the percent of DCD donors has been observed over the past decade. These components have resulted in no net changes in overall KDRI since 2004. (OPTN/SRTR 2015 Annual Data Report. HHS/HRSA.)

mesenteric vein or portal vein can also be achieved. The aorta is cannulated after administering heparin, and in appropriate cases venous cannulation is performed. In coordination with thoracic recovery, perfusion is initiated, the aorta is clamped in a supraceliac location, and either the inferior vena cava or the right atrium are transected and suction or drainage devices are placed to facilitate perfusion. The abdominal organs are packed with ice for cooling while flushing and recovery of other organs are performed. Mobilization of the ascending and descending colon can be performed to allow for more direct exposure of the kidneys to ice. Recovery of thoracic organs, liver, and pancreas generally precedes recovery of the kidneys (Fig. 8.3). Recovery of the kidneys can be performed either individually or en bloc. Individual recovery of the kidneys is performed by transecting the left renal vein at the vena cava. The aorta and vena cava can both be transected superior to the level of cannulation (usually just superior to bifurcation) and at the origin of the superior mesenteric artery (SMA) and superior to the right renal vein. Division of the aorta should be performed by incising the base of the SMA and, with an oblique angle, entering the aorta superiorly to identify renal arteries because they often enter at this level or higher. Superior transaction of the aorta should be performed ideally to preserve a Carrel patch on both the right and left renal arteries. The right renal vein should be identified before transaction of the vena cava to preserve a

superior cuff that can be used to construct a venous extension when necessary. Individual recovery starts with either side by isolating the ureter and gonadal vein and transecting distally. Care should be taken to leave tissue around the ureter with sharp dissection to minimize the risk of devascularizing the ureter by stripping it of adjacent tissues. The anterior wall of the aorta can be longitudinally sharply transected, followed by division of the posterior wall, with care taken to identify single or multiple renal arteries and leave sufficient tissue for Carrel patches around each vessel. From an inferior approach, working from the midline and posterior to the aorta, all tissues can be sharply divided with attention to the location of the ureter to avoid inadvertent injury. Working both superiorly and laterally, the vasculature and kidneys can be separated from the lateral abdominal and retroperitoneal attachments. Posterior dissection proceeding directly against the psoas muscle will minimize the risk of injuring renal arteries. Regardless of extent, Gerota’s fascia should be removed with the kidneys to be separated at later time. The right kidney should be removed with all remaining vena cava to preserve the conduit for venous extension grafts when necessary. En bloc recovery of the kidneys is performed without longitudinal transection of the aorta or division of the renal vein. Inferior to superior dissection is performed posterior to the aorta and vena cava, and with initial isolation of the ureters to avoid injury. Separation of the kidneys is then

A

Portal vein Aorta Left gastric artery Celiac axis Splenic artery Hepatic artery Catheter in splenic vein

Incised gallbladder Transected common bile duct Right gastric artery Inferior vena cava Gastroduodenal artery

Superior mesenteric artery and vein

B R. gastric artery

Bowel, duodenum, and pancreas retracted

Hepatic artery Splenic artery and vein

Short gastric arteries L. gastric artery Portal vein Aorta

Loose ligament around retracted superior mesenteric artery

Superior mesenteric artery and vein

C

D

Celiac artery Superior mesenteric artery L. kidney

R. kidney Perfusion catheters

Kidney perfusion

Aorta Vena cava

Ureter Inferior mesenteric artery Aorta IVC

Lumbar vessels

Ureter

E

F

Fig. 8.3  Deceased donor organ retrieval.  (A) The chest and abdomen are opened through a midline incision. The abdominal cavity is inspected for any evidence of disease or injury. Initial control of the distal aorta is obtained in the case that urgent flushing becomes necessary. (B) The splenic vein is catheterized through the inferior mesenteric vein for portal perfusion. Limited portal dissection should include distal ligation of the common bile duct and incision and flushing of the gallbladder. (C) Pancreas dissection can be performed by division of the short gastric vessels and medial visceral rotation of the spleen and pancreas in a plane posterior to the splenic vein and artery. (D) The duodenum should be widely mobilized allowing for access to the superior mesenteric artery and infrahepatic vena cava. (E) The distal aorta is cannulated with a perfusion catheter after heparinization, and drainage devices may be placed in the distal vena cava. (F) Aortic cross-clamp is performed in the supraceliac location, and perfusion and cooling with ice is performed. After removal of thoracic organs, liver, and pancreas, kidney dissection is commenced. Additional attention should be directed to preserving ureteral length and aortic cuff around the origin of single or multiple renal arteries. Kidneys can be recovered individually or en bloc.

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performed after removal with the similar goals of leaving an aortic cuff for all renal arteries and the vena cava with the right kidney. Local procurement centers have preferences for marking the ureters with ligature or other labeling to identify right versus left kidneys. If concerns exist for the quality of perfusion based on the appearance of the kidneys, direct cannulation and perfusion of the right and left renal arteries can be performed on the back table. Although this step is not usually necessary, concern regarding poor perfusion or the mottled appearance of the kidneys should direct additional flushing. 

Donation After Circulatory Death Whereas in total numbers DBD donors account for the vast majority of recovered and transplanted kidneys, DCD has become an increasingly common source of deceased donor kidneys in recent years. In the US in 2015, DCD donors provided more than 2000 donor kidneys (nearly 20% of the total deceased donation). DCD donors yielded more kidneys per donor (1.56) than brain dead donors (1.44).1 Recovery of kidneys from DCD donors is performed in a similar manner to brain dead donors with a few modifications. Individual hospitals and organ procurement organizations (OPOs) set specific guidelines for time limits for recovery to be performed after withdrawal of life support that vary between 60 and 120 minutes. These waiting periods occur either in a perioperative setting or in the operating room; outside the US, this time may extend to 180 to 240 minutes. According to local practice, patients are declared deceased after cessation of pulse, cardiac rhythm, or electrical activity. The cessation of all pulseless electrical activity (PEA) has not been deemed necessary as a criterion for declaration in the absence of pulse pressure.5 An additional waiting period between 2 and 5 minutes occurs before initiation of organ recovery. The period of warm ischemic time between withdrawal of life support and the initiation of cooling and perfusion with organ preservation solutions contributes to the increased rates of delayed graft function and organ dysfunction seen with DCD organs. Thus the surgical procedure needs to be performed in an expedited fashion to cool and perfuse organs as soon as possible. A midline incision from sternal notch to pubis is rapidly performed and, using combinations of sharp and blunt dissection, the abdominal cavity is entered and the distal aorta is cannulated with a perfusion catheter with or without isolated control. Immediate perfusion should commence at this point. Transection of the distal inferior vena cava and placement of drainage device or suction catheter can be performed to facilitate perfusion. Depending on recovery of the liver or thoracic organs, the aorta can be clamped at the level of the descending thoracic aorta after opening the chest. DCD recoveries for kidneys alone can avoid opening the chest, and clamping of the aorta should occur at the supraceliac level. The abdominal cavity should then be packed with ice during perfusion. A rapid surgical technique designed to minimize the time taken to achieve cross-clamp and

explant of the organs from the abdominal cavity, and facilitate organ cooling may improve renal outcomes as has been reported with other organs.6 While infusion of the preservation solution is underway, surgical recovery of the kidneys can be performed with a similar technique to recovery in DBD donors. Whereas an expedient technique is important, precision remains paramount in these circumstances to prevent the higher rates of surgical damage and organ discard that have been reported.7 After removal of the kidneys from the abdominal cavity, additional perfusion can be performed once the kidneys are in cold solution depending on either preference or concerns regarding the quality of intraabdominal perfusion. Modified technical approaches including balloon catheter placement for in situ preservation or use of extracorporeal support after death have not achieved substantial effect in improving results.5,6 Although supportive data exist regarding the ability of hypothermic pulsatile perfusion to improve outcomes for DCD kidneys, conflicting data still exist and thus this conclusion is not uniform.8,9 Additional interest in normothermic perfusion devices has been generated in recent years. Although no definitive conclusions can be reached, potential for improved function and decreased rates of DGF are under investigation.10 Although a variety of strategies have been proposed, including initiating normothermic perfusion in situ, ex vivo at the donor hospital, or on return to the recipient center, a single system that has reliably improved outcomes has yet to be reported. 

Living Donor Nephrectomy Living renal donation provides an invaluable resource in regard to both organ quantity and quality. There are 5600 living kidney donations annually in the US, which accounts for approximately 30% of annual US renal transplant volume. The absolute number of living donors nearly equals the number of deceased donors and thus remains critical as a source of transplantable organs. Living donor kidneys are of superior quality in every objective measurement including immediate graft function rates, graft half-life, and life years gained for recipients. The available pool of donors has remained relatively stable over the recent decade, although demographics have demonstrated increases in donors over 50 years old (29.5%) and women (63.5%; Fig. 8.4). The primary responsibility of the donor surgeon is patient safety, and this overarching concern must guide every pre-, intra-, and postoperative decision. The reliably safe outcomes with donor nephrectomy and good long-term renal function of donors are paramount to preserve the justification for removing a kidney from a healthy donor. As the transplant community has continued to gain experience caring for living donors, conditions that had previously served as absolute or relative contraindications to living donation are being reconsidered. Select centers now accept donors with prior surgical histories that affect the technical complexity of the operation. These include prior histories of bariatric procedures, gynecologic operations, hernia repair, appendectomy, and cholecystectomy. Although not contraindications for surgery, these procedures may predict a more complicated technical operation.

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119

65

Percentage

60 55 Male Female

50 45 40 35 2004

2006

2008

2010 Year

2012

2014

2016

Fig. 8.4  Living kidney donors by sex.  Increasing rates of female donors has resulted in approximately 2:1 ratio of female:male donors. (OPTN/SRTR 2015 Annual Data Report. HHS/HRSA.)

Anatomic variants that once precluded donation, such as multiple renal arteries and circum- or retroaortic renal veins, no longer eliminate potential donors at many centers. These more complicated patients may be eligible for renal donation, and consideration should be given for referral to centers with experience in these conditions. 

Anesthetic Management Communication with anesthesia personnel is important to ensure that good urine output is achieved throughout the case. Pneumoperitoneum has been demonstrated to impair venous return influencing renal perfusion, and volume expansion has been demonstrated as the primary intervention to counteract this effect.11 Patients often require greater than 5 L of crystalloid to achieve a robust urine output. Mannitol can be administered in divided doses of 12.5 g to augment urine output. Urine output should be monitored and low output addressed aggressively by administering additional intravenous fluids and decreasing or eliminating pneumoperitoneum until adequate urine output is achieved. Whereas inadequate volume resuscitation is the most likely factor, identifying other confounding factors for low urine output, including relative hypotension, inability to tolerate pneumoperitoneum, or other physiologic events are important to determine whether the case should proceed. Although extremely unusual, our practice is not to proceed with donation if adequate urine output cannot be achieved. Adequate relaxation is necessary to achieve sufficient pneumoperitoneum to provide abdominal domain to perform surgery. Diminishing abdominal domain will result from patients that are inadequately paralyzed and will result in difficulty making surgical progress. This may be realized at midpoints of the case as initial paralytic agents may require redosing. Participation by experienced anesthesiologists is important throughout the procedure, but especially immediately before division of vascular structures. We do not routinely administer heparin before division of the renal vessels and have not observed complications from this practice. Some surgeons administer low-dose intravenous heparin (3000 units) before vascular division with reversal by administering protamine after removal of the kidney.

Regardless of the technical approach, control of postoperative pain should be initiated during the operative case. Intraoperative administration of narcotics provides transient pain control. The use of local anesthetics and systemic nonsteroidal agents can minimize postoperative pain and narcotic requirements. We routinely inject 0.5% liposomal bupivacaine into port and extraction sites and consider the use of intravenous ketorolac for most patients. The use of liposomal bupivacaine preparations has added to the duration of local anesthesia for up to 72 hours and we have found this useful to facilitate early postoperative pain control and discharge. Additionally, initiating regularly scheduled oral narcotics soon after surgery can prevent intense pain spikes as local agents diminish. 

Open Donor Nephrectomy Open donor nephrectomy has been nearly completely replaced by minimally invasive surgical techniques. In fact, surgeons trained in recent eras may have little or no experience with standard open or miniopen techniques. Nonetheless, these techniques may be employed by select centers and/or surgeons based on indication or preference. Relative indications may include the presence of complicated vascular anatomy, prior operations that complicate laparoscopic approaches, or right nephrectomy. Whereas these techniques deserve an appropriate place in the arsenal of living donor nephrectomy, laparoscopic techniques can be successfully used in almost all cases. Despite reduced invasiveness of miniopen incisions, laparoscopic techniques still result in comparatively decreased pain, faster return to work, and higher patient satisfaction.12,13 Standard open techniques depend on the division of muscle and possible rib resection compared with miniopen approaches that are muscle-sparing and avoid rib resection. The miniopen techniques have been reported to improve donor outcomes compared with standard open techniques.14 After the induction of general anesthesia, patients are positioned in a flexed lateral decubitus orientation on the operative table. The patient is prepped and draped from the inferior rib margin to the superior iliac crest. A lateral oblique incision is performed inferior to the 12th rib with division or separation of the oblique and transverse musculature. Segmental resection of the inferior rib may be necessary to improve exposure of the upper

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pole of the kidney. Combinations of manual and electrocautery dissection are performed around Gerota’s fascia to permit retractor placement. The peritoneal cavity is swept anteromedially as planes are created to the level of the renal vein and artery. Retractors can be placed either on fixated platforms or by handheld techniques. Retroperitoneal dissection continues around the kidney and inferiorly to identify and isolate the ureter and gonadal vessels. The ureter should be dissected close to the level of the iliac vessels to ensure adequate length. Complete mobilization of the kidney is performed, and the artery and vein are isolated at their origin and insertion in the aorta and vena cava, respectively. The adrenal gland can be separated from the parenchyma of the kidney lateral to medial. The adrenal vein on the left side may be divided between ligatures or clips to maximize renal vein length. Lumbar veins posterior to the renal vein should be divided to also maximize renal vein length. This can be performed between vascular clamps, surgical clips, or stapling devices. After complete isolation of the vascular pedicle, division of the ureter and renal vessels proceeds. The ureter and gonadal vein are divided distally with ligatures, clips, or stapling devices. The renal artery or arteries are then divided. This can be performed by ligation with or without suture or stapling device. Finally, the renal vein can be divided with a similar technique. Vascular clamps can be used to maximize vessel length with subsequent ligation and suturing of vessels after removal of the kidney. The presence of multiple vessels requires planning for the order of division. Placement of multiple vascular clamps may prove difficult with limited space, thus stapling devices may be preferred. Transfixing techniques with either sutures or staples should be used for the renal artery and vein stumps to minimize bleeding risk. Inspection for good hemostasis with or without placement of hemostatic adjuncts is then performed. Abdominal wall closure is performed in multiple layers and with preference for absorbable suture. Local anesthetic can be injected to provide local pain control and minimize systemic requirements. Similarly, intravenous nonsteroidal antiinflammatory drugs may be used to provide pain relief and minimize narcotic requirements. These should be discontinued within 48 hours. Postoperatively, patients can receive intravenous and oral narcotics and can return to normal diet and activity. 

Laparoscopic Donor Nephrectomy Initial reports were made of a laparoscopic approach to nephrectomy for tumor with morcellation and extraction in 1991.15 In 1995 this approach had been successfully applied to living donor nephrectomy as Ratner made the first report of laparoscopic nephrectomy for transplantation with immediate graft function.16 Initial comparisons of open and laparoscopic approaches reported substantial improvements in donor recovery.17 These donor benefits were confirmed in subsequent studies.18,19 A recent randomized controlled trial demonstrated improved donor satisfaction, less morbidity, and equivalent graft outcomes.20 Early large series reported concerns regarding complications, especially with regard to the ureter, associated with the laparoscopic technique. These decreased as progressive technical experience was achieved.21 The improved patient recovery and minimally invasive approach has permitted discharge for select patients on the first postoperative day.22 Additionally, the advent of laparoscopic donor nephrectomy was associated with increased living donation rates and overall volumes, providing important recipient benefits.23 In the US in 2015, 97% of living donor nephrectomies were performed by a laparoscopic approach, with a majority performed with a hand-assisted approach (Fig. 8.5). The number of cases performed via an open approach has continued to decrease over the past 5 years with 3% of donor nephrectomies performed via an open retroperitoneal or transabdominal approach.1

HAND-ASSISTED TECHNIQUE Hand-assisted techniques are the preferred approach for many groups and allow for combinations of manual dissection and retraction with laparoscopic visualization and energy devices. Most series report improved speed with hand-assisted techniques compared with other laparoscopic approaches.24 The intraabdominal presence of a hand may also be perceived as an improved safety benefit for manual control of bleeding or other injury that may occur. Whereas large series do not specifically support these concepts, most surgeons are comfortable with open techniques providing direct manual control. The hand port site is also generally used as the extraction site and does not add morbidity, although its location is generally in an upper midline

80

Percentage

60 Transabdominal Flank (retroperitoneal) Laparoscopic not assisted Laparoscopic hand assisted Unknown

40 20 0 2004

2008

2012

2016

Year Fig. 8.5  Living kidney donation by procedure type.  Laparoscopic approaches dominate technical procedure type with the majority performed hand assisted. (OPTN/SRTR 2015 Annual Data Report. HHS/HRSA.)

8 • Donor Nephrectomy

location and is thus more visible than alternate extraction sites. The technical steps for recovery are similar to the total laparoscopic approach (discussed next) with the obvious addition of a hand to assist. 

TOTAL LAPAROSCOPIC APPROACH Total laparoscopic approach for donor nephrectomy is performed with the donor in either a total or modified lateral position with flexion of the operative table to open the space between the iliac crest and the ribs (Fig. 8.6). After sterile preparation and draping of the abdomen, a Veress needle can be placed in the left lower quadrant and used to insufflate the abdomen to 15 mmHg pressure. Our preference is to use camera visualization through the first port that is placed with subsequent direct visualization of each additional port. A combination of 5-mm and 12-mm ports are placed in periumbilical, superior and inferior midabdominal, and lateral locations. Placement of a 12-mm port in the periumbilical location allows for interchange of dissecting and stapling devices. The left colon is mobilized along the line of Toldt by dividing this line with the harmonic scalpel or other energy device (Fig. 8.7). The colon and mesentery should be swept medially with care not to cause a mesenteric defect or injure mesenteric vessels. If a mesenteric defect is identified this should be repaired with suture or clips to avoid potential for internal hernia formation. After the mesentery has been swept medially off the psoas and kidney, the ureter and gonadal vein are identified. The ureter can be identified just superior to the iliac vessels or near the inferior pole of the kidney. Care should be taken not to directly grasp the ureter or use energy devices in direct proximity given the potential for unrecognized injury. A plane should be created under the ureter and gonadal vein that can then be elevated while remaining tissues are dissected (Fig. 8.8). The ureter and gonadal vein are elevated as a bundle, and a lateral window is created with an energy device. Our preference is to use an energy device because small vessels can be present in some of these tissue planes. Dissection should be carried distally

Fig. 8.6  Positioning and incision placement for laparoscopic left donor nephrectomy.  The donor is positioned in a right lateral decubitus position with flexion opening the space between costal margin and iliac crest. A 12-mm port is placed periumbilically and options for 5- to 12-mm ports in superior and inferior midclavicular and lateral midaxillary positions. Extraction can be performed through a transverse Pfannenstiel incision.

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to a level immediately superior to the iliac vessels to provide adequate recipient length. Proximal to the kidney, elevation of the ureter and gonadal vein is performed as lymphatics and vessels are identified and divided. We generally do not divide the gonadal vein; however, in certain cases this may provide additional exposure to the renal artery and vein. Almost all donors have lumbar veins that can vary from small and singular to multiple and large. Preoperative imaging will identify larger lumbar vessels but may be less effective in identifying multiple branches. Additionally, aberrant venous anatomy including multiple renal

Fig. 8.7  Mobilization of colon.  The line of Toldt and splenocolic ligament are divided with an energy device (i.e., harmonic scalpel) and the colon and mesentery are swept medially. Care must be taken to avoid or identify a mesenteric defect during medial mobilization of the colon and mesentery.

Fig. 8.8  Elevation and dissection of the ureter and gonadal vein. A plane is created under the ureter and gonadal vein. Anterior elevation of these structures allows for dissection from a distal level near the iliac vessels to a proximal location of the renal hilum. Attention to the presence of additional renal arteries and lumbar vessels is necessary as dissection proceeds superior to the hilum.

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Kidney Transplantation: Principles and Practice

Fig. 8.9  Division of the adrenal and lumbar veins.  As the kidney is elevated with instruments dissection of the lumbar vein from surrounding lymphatics can be performed. Smaller adrenal and lumbar veins can be divided with energy devices; larger vessels should either be clipped and divided or divided with a stapling device. Consideration of likely division sites of the renal artery and vein should be performed to avoid interference of clips with stapling devices.

veins, circumaortic, and or retroaortic renal veins may also be associated with variants in lumbar venous anatomy. Smaller lumbar veins can be divided with energy devices. Larger lumbar vessels (>6 mm) should be divided with either clip appliers or stapling devices (Fig. 8.9). Judgment as to the possible interference of metallic clips with subsequent stapling devices needed to divide renal artery and vein is important, because clips can interfere with proper closing and stapling. Vascular staples, in contrast, do not generally interfere with the ability to place stapling devices over or in close proximity. Elevation of the kidney from the lower pole can then reveal the renal artery and vein. Lymphatics are present in varying amounts and density around the vessels, and require dissection, isolation, and division. Division of the periaortic lymphatics demands precision with energy devices because the risk of injury and bleeding exists if these devices come into contact with blood vessels. The artery should be completely isolated from the renal vein by careful dissection and should be exposed as proximal to the aorta as is safely possible. This is of increased importance in early branching arteries that may require more extensive dissection down to the level of the aorta. Multiple arteries are present in approximately one-quarter of donors. Preoperative knowledge of the location of each additional vessel is important to anticipate as dissection is performed. Arteries that originate significantly inferior to the main renal artery require additional care in elevation of the ureter, gonadal vein, and kidney, because traction injuries become increasingly possible. Likewise, avoiding overdissection of smaller, more inferior arteries can prevent inadvertent injury. The upper pole of the kidney is separated from the renocolic and splenorenal ligaments using a combination of blunt dissection and energy devices. The spleen can be retracted medially in combination with lateral retraction of the kidney to open this space. Retraction of the spleen and surrounding tissues can also be a potentially hazardous maneuver and should be done with blunt instruments or graspers to avoid injury to the spleen. As this space is

developed, the adrenal gland requires separation from the upper pole of the kidney. The adrenal gland is often identifiable and can be gently positioned with a grasper as dissection is performed immediately lateral to the gland. In obese donors, it may be difficult to identify the adrenal gland, and dissection along separate tissue planes that belong either medially with the adrenal gland or laterally with Gerota’s fascia is performed in potentially ambiguous territory. Upper pole vessels often occupy the space between the adrenal gland and kidney; therefore closer proximity to the adrenal gland and away from the renal hilum is preferred. Dissection of the upper pole of the kidney should be carried posteriorly to the level of the psoas muscle and superiorly to the diaphragm. We perform separation of Gerota’s fascia from the diaphragm and psoas with energy devices to minimize even small amounts of venous bleeding. Care needs to be taken with dissection around the diaphragm to not inadvertently injure or perforate it with resultant pneumothorax. Unrecognized injuries manifest as progressive billowing of the diaphragm into the operative field. These injuries can be repaired laparoscopically by suturing the identified defect with reduced pneumoperitoneum and Valsalva maneuvers. The renal and adrenal veins are apparent at various stages during the procedure. The adrenal vein is usually divided from the renal vein to provide additional venous length on the left kidney. The adrenal vein should be completely isolated from the renal vein and with clear posterior planes as the renal artery and aorta are in immediate proximity. The adrenal vein can be divided with either energy devices or clip appliers. Care with clip placement is important to not interfere with stapling devices necessary for division of the renal vein. After division of the adrenal vein, the renal artery is easier to identify and can be dissected from the periaortic lymphatics. Tissues can be swept medially off the anterior surface of the renal vein to provide maximal length. Elevation of the renal vein with a blunt instrument and clearance of a posterior plane can also be completed. We perform separation of the kidney from its posterior retroperitoneal attachments at varying times during individual cases, depending on our ability to visualize key structures. As a general rule, if the kidney is mobilized too early in the case, the kidney can inadvertently rotate medially and complicate vascular dissection. We typically leave Gerota’s fascia intact with the kidney as we perform this retroperitoneal dissection. Separation of the kidney from the Gerota’s fascia, even when extensive, can be difficult with densely adherent fat that may risk capsular injury to the kidney. As the kidney is completely mobilized medially, the psoas muscle and origin of the renal artery become apparent. Dissection of the posterior and superior aspects of the renal artery can sometimes be facilitated with the kidney in a medial location. Likewise, lumbar vessels may sometimes be easier to identify and or divide with the kidney medially rotated. Extraction can be performed via either a Pfannenstiel or lower midline incision. Through either approach, the rectus is exposed and a 15-mm port is inserted to accommodate a large endocatch bag for retrieval. Alternatively, the endocatch bag can be directly placed through a small defect in the peritoneum. Care needs to be taken not to have an

8 • Donor Nephrectomy

Fig. 8.10  Division of the renal artery.  The kidney can be retracted laterally and anteriorly with instruments as a vascular stapling device is placed just beyond the origin of the renal artery. Cutting or noncutting staplers can be used, but attention to the distal location of the stapler is important to avoid clips or other improper positioning.

uncontrolled violation of the peritoneal cavity, otherwise pneumoperitoneum will not be maintained during vascular stapling. Division of the ureter and gonadal vein is performed first with a vascular staple load. This is performed distally with direct observation of the distal stapler to confirm that the iliac vessels are not in proximity. The renal artery is then divided with the kidney elevated to maximal height. If multiple arteries exist and are separated by more than 5 to 10 mm, we divide the inferior vessel first followed by new staple loads for superior arteries. If arteries are in close proximity they can be taken with a single staple load. After arteries are divided, the kidney is retracted to a maximally lateral extent and a stapler is placed on the renal vein as close to the vena cava as is safely possible. Stapling requires care and attention to the stapling device and staple loads. An experienced scrub nurse or technician should be familiar with expedient reloading of the stapler. Any concern regarding the function or proper reloading of the device justifies replacement with a new stapling device that should be immediately available in the operating room. Before firing the stapling device, direct visualization of proper alignment of the stapler, including the distal extent of the device and proper position of the staple cartridge, should be confirmed by the surgical team (Fig. 8.10). This includes care not to close the stapler across metal clips, which can cause misfire. There have been limited reports of stapler misfires; however, they can be catastrophic and require expedient management.25 The most significant danger is for improper stapling before division of the vessel with a cutting device. A transected bleeding artery or vein should be controlled directly with a laparoscopic instrument or hand if possible. If the vessel can be controlled, determination can be made whether the vessel can be restapled, clipped, or oversewn with laparoscopic techniques. If this is not possible, direct pressure should be attempted while a midline laparotomy incision is made for direct exposure and repair. Noncutting stapling devices

123

Fig. 8.11  Placement of the kidney into endocatch bag.  After division of the ureter and vascular structures, the kidney and entire ureter should be placed into an endocatch bag under direct visualization. Once all structures are inside the bag, it can be closed and extracted through the selected incision site.

may offer advantages when preserving early bifurcations because of a decreased width of the device. Additional, noncutting devices allow for confirmation of the correct placement of staples before subsequently dividing the vessel with endoscopic scissors. Plastic or metallic clips should not be used to ligate main renal vessels and the US Food and Drug Administration (FDA) issued a specific alert in 2011 that updated 2006 warnings regarding the use of Weck Hemo-Lok Ligating Clip for renal artery ligation in living kidney donors secondary to risk of postoperative dislodgement and hemorrhage.26 Furthermore, it should be noted that transfixion of tissue is the only acceptable method for renal artery division in living donor nephrectomy. After all vessels have been transected, the kidney should be confirmed to be free of all retroperitoneal attachments. Residual attachments can be divided with energy devices or additional staple loads if necessary. The endocatch bag is directly deployed under the kidney and the kidney and ureter are placed completely in the bag under direct visualization (Fig. 8.11). The bag should also be closed under direct visualization because injury to the kidney or ureter can occur if they are not contained within the bag. Rarely, a kidney may be unable to be placed in the bag because of size or other technical issues. Manual retrieval should then be performed quickly and if possible while retaining pneumoperitoneum to aid in identification and control of the kidneys. The rectus can be opened in either a vertical or transverse direction as the kidney is retrieved from the abdominal cavity. The kidney is immediately placed on ice and brought to the back table for preparation. Staple lines should be transected and direct cannulation and flushing of all renal arteries is performed until clear effluent is achieved. The extraction site can be closed with either running or interrupted absorbable (PDS or Maxon) #1 sutures. After closure of the extraction incision, pneumoperitoneum is

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Kidney Transplantation: Principles and Practice

reestablished and confirmation of good hemostasis at all dissection and vascular division sites is performed. Occasionally, gonadal vessels will require additional clip placement at the level of the ureteral division. The renal artery and vein should be directly observed. Blood is aspirated from the retroperitoneal space and near the spleen to confirm no unidentified bleeding. Hemostatic agents are not generally required, but can be placed as an adjunct to hemostatic maneuvers when necessary. Mesenteric defects can be repaired at this point if identified (as discussed earlier). Rarely, challenging bleeding can occur from adrenal, splenic, and lumbar venous sources. If adrenal or splenic bleeding cannot be confirmed to be controlled, consideration for removal should be given. Lumbar venous bleeding can be difficult to manage, and if direct control and sealing with energy device or clip placement cannot be achieved, an attempt to directly oversew the vessel should be made. The procedure should never be concluded in the absence of perfect hemostasis, and drains are almost never indicated. Ports can be removed under direct visualization. Larger port (12- and 15-mm) sites can be closed as practiced per routine of the surgical team. The extraction and port sites are anesthetized with injectable agents (lidocaine or marcaine) and closed with absorbable subcuticular sutures. Ketorolac can be used per physician discretion to minimize postoperative discomfort and narcotic use. 

Right Donor Nephrectomy Laparoscopic right donor nephrectomy is rarely performed, with rates between 1% to 4% at large US centers. Initial technical challenges with laparoscopic right nephrectomy resulted in increased vascular complications compared with left kidneys. Modifications in donor techniques to preserve donor vein length, and in the recipient to mobilize the iliac venous system, can improve these outcomes.27 Nonetheless, multiple renal arteries and anomalous renal venous anatomy are not contraindications for left donor nephrectomy. The presence of stones, cysts, or lesions within the right kidney are strong indications for right, rather than left, nephrectomy. The operative approach is modified by the requirement of liver retraction. This is achieved through limited right lobe mobilization with placement of a liver retractor to elevate the liver over the superior pole of the right kidney. The operation is further modified by the requirement for division of the right gonadal vein that inserts directly into the vena cava. The right adrenal vein generally does not need to be divided because it is separate from the right renal vein. The shorter right renal vein also requires extra attention to stapling with either cutting or noncutting vascular stapling devices. Maximum retraction of the kidney and exposure of the vena cava are performed to allow placement of the stapling device for maximum vein length. 

Single-Port Donor Nephrectomy Although multiport laparoscopic and hand-assisted donor nephrectomy techniques have supplanted the open donor nephrectomy and are clearly the most widely offered

Fig. 8.12  Cosmetic result of single-port donor nephrectomy 2 years postdonation. Single-port donor nephrectomy performed through the umbilicus with transumbilical extraction allows for minimization of the apparent incision length with minimal residual scar. (Ann Surg. 2013;257:527–33.)

donor procedure in the world, select centers perform laparoscopic donor nephrectomy through a single small incision. The technique was first described in 2008 as a feasible approach with good outcomes.28 Some supportive evidence exists that this approach offers improved recovery in comparison to standard laparoscopic techniques.29 Our center transitioned to a single-port laparoendoscopic (LESS) technique in 2009. This is now our standard approach in all cases. The rationale for this transition lay in the ability to perform the entire dissection and extraction through a small incision concealed within the umbilicus of the donor. This has led to a very small residual scar once healed (Fig. 8.12), and we have shown equivalent safety with improved patient satisfaction compared with multiport laparoscopy.30 The single-port devices that are commercially available typically allow for entry of 3 to 4 instruments (Fig. 8.13). Although the technical steps in LESS donor nephrectomy are not significantly different from those in standard multiport approaches, the surgeon’s hands are often closely opposed to each other, and instruments must frequently cross within the confines of the abdominal cavity. Although these conditions are anathema to the basic tenets of laparoscopy as taught to earlier generations, basic maneuvers can lessen their effect. The procedure can be performed with standard laparoscopic instrumentation and camera. The substitution of the single-port device for the multiple ports required in either hand-assisted or total laparoscopic approaches does not demonstrate substantial cost differences. It is difficult to describe the technique and instrumentation with absolutism, and optimum exposure and safety is typically achieved after a brief period of trial and error using alternative bed positioning (both Trendelenburg/reverse

8 • Donor Nephrectomy

125

Fig. 8.13  Single port donor nephrectomy.  Patient position and operating room setup are similar to standard laparoscopic nephrectomy. Surgeon and assistant are in close proximity as multiple instruments and camera are inserted through the umbilical port. The assistant operating the camera and/ or additional instrument must pay attention toward avoiding interference with the primary surgeon’s instruments.

Trendelenburg and leftward/rightward tilting), operating instruments of differential length (bariatric length in one hand, standard length in the other), and alternative port positioning within the single-port device. We have found that the deflectable tip 5-mm camera provides ideal visualization without undue steric hindrance to the operating surgeon. In cases of right donor nephrectomy, we use a single-port device that can accommodate a fourth port for the liver retractor. We found four techniques that were important to mastery of the single-port approach and normalization of operative times compared with total laparoscopic approaches. First, ventilation of smoke and vapor through the single-port device is critical, and recent generations of port devices have incorporated this into their design. Second, elevation of the lower pole of the kidney anteriorly and medially allows for opening of the space between the renal artery and vein for dissection. Third, retraction of the upper pole inferiorly and laterally provides separation of the kidney from splenic and adrenal attachments, and facilitates dissection of the renal artery from a superior/cephalad approach. Finally, a plan

should be determined for extraction of the kidney after division of the vasculature. Depending on the device used, the skin and fascial incisions require extension to safely deliver the kidney without significant trauma. Removal through too small a fascial or skin incision can injure the kidney and should not be aggressively attempted. Ultimately, additional port placement may be required. Once substantial experience has been gained with the technique, this tends to be required in less than 10% of cases. Commitment to early placement of additional ports in challenging cases has allowed for equivalent safety in our experience. The most critical maneuvers in any laparoscopic donor nephrectomy are the vascular dissection around the vein and artery, and subsequent stapling. These maneuvers involve fine movements that we have found not to be hindered by a single-port approach. We have reported on the normalization of our operative times and the ability to perform right and left nephrectomies with single or multiple arteries and veins.30 Although complication rates are similar to other techniques, concern for umbilical hernia necessitates careful attention to the

Kidney Transplantation: Principles and Practice

proper technique for closure of the fascia. The umbilical hernia rate is approximately 3% at our center, and the surgical technical complication rate is comparable to the rates seen in total laparoscopic and hand-assisted approaches at other centers.31 This technique continues to be our preferred approach for all living kidney donors and fits into an algorithm of preferred approaches consisting of (in order) single-port laparoscopy, multiport laparoscopy, handassisted laparoscopy, and open techniques. The improved cosmesis and potential other benefits of this technique may also translate to increased interest in living kidney donation with a further slight reduction in the invasiveness of the surgery. 

Robotic Donor Nephrectomy

100 6 weeks 6 months 12 months

80 Percentage

126

60 40 20 0 No

Yes Response

Unknown

Fig. 8.14  Complications of living kidney donation from 2010 to 2014. Overall complication rate of 8.8% observed at 12 months after kidney donation. (OPTN/SRTR 2015 Annual Data Report. HHS/HRSA.)

Robotic technology has been incorporated into laparoscopic donor nephrectomy. Thus far, reports have been limited to single-center studies, and the techniques have not become widely used by the community as a whole.32–34 Although the purported advantages of robotic technology include (1) improved visualization with three-dimensional (3D) camera systems, (2) articulating laparoscopic instrumentation allowing meticulous dissection of complicated vascular anatomy, and (3) ease of intracorporal suturing, their applicability to donor nephrectomy has yet to be broadly accepted or defined. Present robotic approaches are performed with multiple laparoscopic ports and require bedside manual assistant ports for the use of energy devices, staplers, and for renal extraction. Whereas the feasibility of robotic-assisted laparoscopic nephrectomies have been clearly demonstrated, early reports have not demonstrated significant advantages over total laparoscopic and handassisted techniques, while demonstrating increased cost.35 Single-port platforms have recently been introduced, and these platforms have thus far been used predominantly for LESS cholecystectomy.36 Following studies demonstrating the use of the single-port platform in renal surgery,37,38 our group embarked on a brief clinical trial evaluating the robotic single-port platform in donor nephrectomy.39 Although robotic technology (which offers an improved 3D field of view and articulating instrumentation) has the potential to compensate for the visual and technical limitations associated with LESS nephrectomy, current instrumentation for the single-port platform does not allow for adequate instrument articulation or the use of energy devices. Continued technologic advancement may improve the ability of robotic approaches to add significant advantages to donor surgery. 

hernia formation, and bowel obstruction (Fig. 8.14).1 In the 5-year period between 2010 and 2015, a total of 17 deaths occurred in prior living renal donors within 1 year of donation. Seven of these deaths were medically related and five were the result of accident or homicide. Prior analysis of more than 80,000 renal donors in the US who donated between 1994 and 2009 revealed a surgical mortality rate of 0.03%.40 Single center reports from large centers tend to provide more granular information regarding the types and frequencies of complications after donation. An early single-center study reporting 1200 laparoscopic renal donors demonstrated an intraoperative complication rate of 1.6% with a conversion rate of 0.92% (most commonly as a result of renovascular injury). An additional 4.0% of patients presented with a postoperative complication with only three patients requiring surgery for internal hernia or ileus.41 Our center had previously reported our experience with more than 700 donors, where we demonstrated an open conversion rate of 1.6% (again most commonly as a result of vascular injury); 1.2% of patients required blood transfusion.42 Five patients also had a bowel obstruction requiring subsequent exploration and one patient required splenic laceration repair. In another report of 1000 hand-assisted donor nephrectomies, a hernia rate of 4% was noted, with 0.3% of patients requiring transfusion and 1.5% requiring reoperation.43 We have recently reported our results with nearly 400 consecutive singleport donor nephrectomies.31 We noted an umbilical hernia rate of 3%. Although only one patient required conversion to an open procedure, an additional seven required a return to the operating room for internal hernia (2), evisceration (1), bleeding (1), enterotomy (1), and wound infection (2). 

Complications

Summary

The 2015 report from the Organ Procurement and Transplantation Network (OPTN) and Scientific Registry of Transplant Recipients (SRTR) provides the most recent compilation of donor complications rates in the US. Complications occurred in 5.3% of donors within 6 weeks of donation. Overall 8.8% of donors reported a complication potentially related to the organ donation within the first year of donation. Reported complications included bleeding,

Living donor nephrectomy can be successfully performed through a variety of techniques, both open and laparoscopic. Minimally invasive techniques have been associated with decreased morbidity and improved recovery and should be viewed as the preferred approach for the majority of patients. Nonetheless, the key principle of donor safety should be used to make final decisions regarding donation techniques. Different centers and surgeons may have a

8 • Donor Nephrectomy

variety of approaches that result in good and safe outcomes. Thus surgeon experience becomes an important consideration in determining the specific approach that is best for each patient. Acknowledgement is made to Phil Brazio, MD, for illustrating the technique of laparoscopic donor nephrectomy accompanying this chapter.

References 1. OPTN/SRTR 2015 Annual Data Report. Department of Health and Human Services, Health Resources and Services Administration; 2016. Available online at: http://srtr.transplant.hrsa.gov/annual_ reports/Default.aspx. (accessed 28.02.19). 2. Goldberg DS, Blumberg E, McCauley M, Abt P, Levine M. Improving organ utilization to help overcome the tragedies of the opioid epidemic. Am J Transplant 2016;16(10):2836–41. 3. Rao PS, Schaubel DE, Guidinger MK, et  al. A comprehensive risk quantification score for deceased donor kidneys: the kidney donor risk index. Transplantation 2009;88(2):231–6. 4. Israni AK, Salkowski N, Gustafson S, et  al. New national allocation policy for deceased donor kidneys in the United States and possible effect on patient outcomes. J Am Soc Nephrol 2014;25(8):1842–8. 5. Wind J, Snoeijs MG, van der Vliet JA, et al. Preservation of kidneys from controlled donors after cardiac death. Br J Surg 2011;98(9):1260–6. 6. Magliocca JF, Magee JC, Rowe SA, et  al. Extracorporeal support for organ donation after cardiac death effectively expands the donor pool. J Trauma 2005;58(6):1095–101; discussion 1092–101. 7. Ausania F, White SA, Pocock P, Manas DM. Kidney damage during organ recovery in donation after circulatory death donors: data from UK National Transplant Database. Am J Transplant 2012;12(4):932–6. 8. Jochmans I, Moers C, Smits JM, et  al. Machine perfusion versus cold storage for the preservation of kidneys donated after cardiac death: a multicenter, randomized, controlled trial. Ann Surg 2010;252(5):756–64. 9. Watson CJ, Wells AC, Roberts RJ, et  al. Cold machine perfusion versus static cold storage of kidneys donated after cardiac death: a UK multicenter randomized controlled trial. Am J Transplant 2010;10(9):1991–9. 10. Minambres E, Suberviola B, Dominguez-Gil B, et  al. Improving the outcomes of organs obtained from controlled donation after circulatory death donors using abdominal normothermic regional perfusion. Am J Transplant 2017;17(8):2165–72. 11. London ET, Ho HS, Neuhaus AM, Wolfe BM, Rudich SM, Perez RV. Effect of intravascular volume expansion on renal function during prolonged CO2 pneumoperitoneum. Ann Surg 2000;231(2):195–201. 12. Kok NF, Lind MY, Hansson BM, et al. Comparison of laparoscopic and mini incision open donor nephrectomy: single blind, randomised controlled clinical trial. BMJ 2006;333(7561):221. 13. Perry KT, Freedland SJ, Hu JC, et al. Quality of life, pain and return to normal activities following laparoscopic donor nephrectomy versus open mini-incision donor nephrectomy. J Urol 2003;169(6):2018–21. 14. Yang SL, Harkaway R, Badosa F, Ginsberg P, Greenstein MA. Minimal incision living donor nephrectomy: improvement in patient outcome. Urology 2002;59(5):673–7. 15. Clayman RV, Kavoussi LR, Soper NJ, et al. Laparoscopic nephrectomy: initial case report. J Urol 1991;146(2):278–82. 16. Ratner LE, Ciseck LJ, Moore RG, Cigarroa FG, Kaufman HS, Kavoussi LR. Laparoscopic live donor nephrectomy. Transplantation 1995;60(9): 1047–9. 17. Flowers JL, Jacobs S, Cho E, et al. Comparison of open and laparoscopic live donor nephrectomy. Ann Surg 1997;226(4):483–9; discussion 489–90. 18. Wolf Jr JS, Merion RM, Leichtman AB, et al. Randomized controlled trial of hand-assisted laparoscopic versus open surgical live donor nephrectomy. Transplantation 2001;72(2):284–90. 19. Nogueira JM, Cangro CB, Fink JC, et  al. A comparison of recipient renal outcomes with laparoscopic versus open live donor nephrectomy. Transplantation 1999;67(5):722–8. 20. Simforoosh N, Basiri A, Tabibi A, Shakhssalim N, Hosseini Moghaddam SM. Comparison of laparoscopic and open donor nephrectomy: a randomized controlled trial. BJU Int 2005;95(6):851–5.

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21. Jacobs SC, Cho E, Dunkin BJ, et al. Laparoscopic live donor nephrectomy: the University of Maryland 3-year experience. J Urol 2000;164(5):1494–9. 22. Kuo PC, Johnson LB, Sitzmann JV. Laparoscopic donor nephrectomy with a 23-hour stay: a new standard for transplantation surgery. Ann Surg 2000;231(5):772–9. 23. Schweitzer EJ, Wilson J, Jacobs S, et  al. Increased rates of donation with laparoscopic donor nephrectomy. Ann Surg 2000;232(3):392– 400. 24. Slakey DP, Wood JC, Hender D, Thomas R, Cheng S. Laparoscopic living donor nephrectomy: advantages of the hand-assisted method. Transplantation 1999;68(4):581–3. 25. Hsi RS, Ojogho ON, Baldwin DD. Analysis of techniques to secure the renal hilum during laparoscopic donor nephrectomy: review of the FDA database. Urology 2009;74(1):142–7. 26. Friedman AL, Peters TG, Ratner LE. Regulatory failure contributing to deaths of live kidney donors. Am J Transplant 2012;12(4):829–34. 27. Mandal AK, Cohen C, Montgomery RA, Kavoussi LR, Ratner LE. Should the indications for laparascopic live donor nephrectomy of the right kidney be the same as for the open procedure? Anomalous left renal vasculature is not a contraindiction to laparoscopic left donor nephrectomy. Transplantation 2001;71(5):660–4. 28. Gill IS, Canes D, Aron M, et al. Single port transumbilical (E-NOTES) donor nephrectomy. J Urol 2008;180(2):637–41; discussion 641. 29. Canes D, Berger A, Aron M, et al. Laparo-endoscopic single site (LESS) versus standard laparoscopic left donor nephrectomy: matched-pair comparison. Eur Urol 2010;57(1):95–101. 30. Barth RN, Phelan MW, Goldschen L, et al. Single-port donor nephrectomy provides improved patient satisfaction and equivalent outcomes. Ann Surg 2013;257(3):527–33. 31. LaMattina JC, Powell JM, Costa NA, et  al. Surgical complications of laparoendoscopic single-site donor nephrectomy: a retrospective study. Transpl Int 2017;30(11):1132–9. 32. Hubert J, Renoult E, Mourey E, Frimat L, Cormier L, Kessler M. Complete robotic-assistance during laparoscopic living donor nephrectomies: an evaluation of 38 procedures at a single site. Int J Urol 2007;14(11):986–9. 33. Gorodner V, Horgan S, Galvani C, et al. Routine left robotic-assisted laparoscopic donor nephrectomy is safe and effective regardless of the presence of vascular anomalies. Transpl Int 2006;19(8):636–40. 34. Horgan S, Vanuno D, Sileri P, Cicalese L, Benedetti E. Robotic-assisted laparoscopic donor nephrectomy for kidney transplantation. Transplantation 2002;73(9):1474–9. 35. Boger M, Lucas SM, Popp SC, Gardner TA, Sundaram CP. Comparison of robot-assisted nephrectomy with laparoscopic and hand-assisted laparoscopic nephrectomy. JSLS 2010;14(3):374–80. 36. Konstantinidis KM, Hirides P, Hirides S, Chrysocheris P, Georgiou M. Cholecystectomy using a novel Single-Site® robotic platform: early experience from 45 consecutive cases. Surg Endosc 2012;26(9):2687–94. 37. Khanna R, Stein RJ, White MA, et al. Single institution experience with robot-assisted laparoendoscopic single-site renal procedures. J Endourol 2012;26(3):230–4. 38. Kaouk JH, Autorino R, Laydner H, et  al. Robotic single-site kidney surgery: evaluation of second-generation instruments in a cadaver model. Urology 2012;79(5):975–9. 39. LaMattina JC, Alvarez-Casas J, Lu I, et al. Robotic-assisted single-port donor nephrectomy using the da Vinci single-site platform. J Surg Res 2018;222:34–8.. 40. Segev DL, Muzaale AD, Caffo BS, et  al. Perioperative mortality and long-term survival following live kidney donation. JAMA 2010;303(10):959–66. 41. Leventhal JR, Paunescu S, Baker TB, et  al. A decade of minimally invasive donation: experience with more than 1200 laparoscopic donor nephrectomies at a single institution. Clin Transplant 2010;24(2):169–74. 42. Jacobs SC, Cho E, Foster C, Liao P, Bartlett ST. Laparoscopic donor nephrectomy: the University of Maryland 6-year experience. J Urol 2004;171(1):47–51. 43. Serrano OK, Kirchner V, Bangdiwala A, et al. Evolution of living donor nephrectomy at a single center: long-term outcomes with 4 different techniques in greater than 4000 donors over 50 years. Transplantation 2016;100(6):1299–305.

9

Kidney Preservation JOHN O’CALLAGHAN, GABRIEL ONISCU, HENRI LEUVENINK, PETER J. FRIEND and RUTGER J. PLOEG

CHAPTER OUTLINE

Introduction Organ Damage After Death Cold Storage Cell Swelling Energy and Acidosis Calcium Intracellular Enzymes and Organelles Reactive Oxygen Species Clinical Use of Preservation Solutions Pharmacologic Additives Hypothermic Machine Perfusion

Introduction At the start of the first transplant programs, the donor and recipient would be operated in the same surgical center. The only preservation method therefore undertaken would be to flush out the kidney with either blood or Ringer’s lactate and to use surface cooling with ice water, because hypothermia was supposed to be protective by reducing metabolism. Very early transplant work in twins and animal studies suggested that an ischemic time of less than 1 hour should be aimed for, with irreversible damage suspected beyond 3 hours.1 This target would later be extended to 12 hours with improved flushing and cooling.1 The necessity of transporting kidneys to compatible recipients in other local centers meant adequate preservation for longer periods was needed. The first method of addressing this was the machine preservation system developed by Belzer (Fig. 9.1). It was not until the late 1960s that preservation fluids were developed that allowed static cold storage without continuous perfusion.2 Modern transplant programs often involve the sharing of organs over much larger geographic distances. The ­sharing of kidneys in this way permits better matching between donor and recipient, but may have the additional effect of longer cold ischemic times, which can affect graft survival.3 The first transplant programs used either live donors or donation after circulatory death (DCD) when the opportunity to quickly perform organ retrieval was available. In 1968 a committee at Harvard Medical School met to examine and redefine the definition of brain death.4 This was followed by an expansion in the use of organs from donation after brain death (DBD). These were typically younger people with irreversible brain damage during motor vehicle accidents, referred to as standard criteria donors (SCD). There is a declining number of this donor type, and 128

Normothermic Regional Perfusion Technical Variations Clinical Outcomes Normothermic Machine Perfusion Experimental Evidence Clinical Evidence Future Directions Tailoring Preservation Strategies

transplant programs are therefore turning to older and higher risk donors, previously defined as expanded criteria donation (ECD) and DCD. The change in the risk profile for kidneys we now use to meet the demand for organs means that it is now necessary to revisit our methods of preservation. The UK Kidney Donor Risk Index (UKKDRI)5 uses donor factors shown in Table 9.1 to predict overall transplant survival. The proportion of DBD kidneys transplanted in the UK from highrisk donors (HR ≥1.35) using this index has increased from 29% to 39% in the past 10 years.6 The Kidney Donor Profile Index (KDPI) is used to predict the risk of failure for a kidney transplant in the US; the current proportion of deceased donor kidneys with the worst KDPI (86%–100%) is 18%, having risen from 14% in 2012.7 The increasing use of DCD kidneys has also prompted a renewed interest in preservation methods; despite the adequate long-term function of kidneys from DCD, they still have a higher risk of delayed graft function (DGF) compared with kidneys from DBD. In the UK the use of DCD kidneys has risen dramatically, from 3% of deceased donor transplants in 2000 to 42% in 2017.6 In the Eurotransplant region the use of DCD kidneys has permitted a large increase in available kidneys for transplantation.8 The use of DCD in the US has increased, although not at such a rapid rate; DCD accounted for approximately 17% of deceased donor kidney transplants in the US in 2016, having increased from 10% in 2007.7 

Organ Damage After Death Organ damage around the time of death can be divided into five broad phases that have different implications for the transplant and may potentially be addressed by targeting preservation techniques at each phase (Fig. 9.2).

9 • Kidney Preservation

Cerebral injury and brain death are associated with the release of cytokines and the initiation of inflammatory processes that can directly injure organs and lead to further immune damage at reperfusion in the recipient.9–12 These changes in immunogenicity are characterized by increased expression of damage-associated molecular patterns (DAMPs) that may include cytokines, adhesion molecules, and major histocompatibility complex class II antigens in the retrieved organ.11,12 Hormonal changes after brain death include reduced levels of antidiuretic hormone and thyroid hormones.13 Brain death also causes myocardial suppression and decreased vascular tone, which results in hypotension and inadequate perfusion of organs.14 Kidneys in this environment are exposed to perfusion dynamics and inflammatory cytokines that can lead to necrosis of renal tubules and fibrous proliferation of the arterial intima.15 Organs from DCD are exposed to inflammatory cytokines, but in a less profound way to DBD. Organs from

129

DCD, however, undergo a period of warm ischemia before retrieval. The extent of this damage is related to the situation of the donor, and this may be categorized using the Maastricht system, which is shown in a modified form in Table 9.2.16,17 It should be noted that not all of these categories are acceptable in some countries. In the case of Maastricht category III donors, the warm ischemic period follows the withdrawal of supportive treatment once a retrieval team is ready, intending to minimize warm ischemic time. In some cases the withdrawal of support may be prolonged, and a systolic blood pressure of less than 50 mm Hg results in functional warm ischemia and may affect the transplant outcome. In the case of the so-called “uncontrolled” donors of Maastricht categories I and II, there may be a prolonged warm ischemic period after circulatory arrest and before cold perfusion of the organs can be achieved.16 The period between the initial flush of cold preservation fluid through the organ’s arteries in the donor and the reperfusion of an organ with blood in the recipient is the cold ischemic time (CIT). The length of this potentially modifiable period is an important factor in determining the outcome of solid-organ transplantation. Analysis of the Collaborative Transplant Study (CTS), a voluntary, multinational database of transplant outcomes, found that kidneys preserved for longer than 19 hours had worse graft survival.18 A longer CIT is also associated with an increasing risk of DGF of kidneys.19,20 The simplest method of dealing with the harmful cellular processes after donor death has been to cool the kidneys. This slows down the metabolism but does not completely stop it, leading to ongoing damage in cold-preserved organs, and hence the critical importance of limiting cold ischemic times. 

Cold Storage Fig. 9.1 The first Belzer machine perfusion unit and its transport ­system.

TABLE 9.1  Comparing the UK Kidney Donor Risk Index (UKKDRI) with the US Kidney Donor Risk Index (KDRI) and the Kidney Donor Prediction Index (KDPI) Factors Used to Calculate the UKKDRI, Watson et al.5

Factors Used to Calculate the KDRI and KDPI, OPTN7

Donor age History of hypertension Donor weight Use of adrenaline Days in hospital

Donor age History of hypertension Donor weight Donor height Ethnicity/race History of diabetes Cause of death Serum creatinine Hepatitis C virus status DCD/DBD

DBD, donation after brain death; DCD, donation after circulatory death.

Patient

Donor management

When a kidney is removed from the donor’s body, perfusion completely ceases, leading to an absence of oxygen and nutrient delivery to the renal cells, which will rapidly lead to serious metabolic problems. Suppression of metabolism is therefore essential to maintain organ viability during the preservation period. Reduction of the core temperature of the kidney below 4°C will result in a reduction of metabolism to 5% to 8% and will diminish enzyme activity.21 The concept of simple cooling with ice proved to be successful; however, it was unfit for longer preservation periods.1 The concept of simple cold static storage was investigated by several groups, resulting in new solutions and providing an insight into the side effects of ischemia in the preserved organ.2,22,23 Transplant pioneers started perfusion of kidneys with cryopreserved plasma-based solutions, leading to improved preservation, although accompanied by logistical problems.24 In current clinical practice several preservation fluids are used. Both in situ in the deceased donor, and on the theater workbench, kidneys are flushed through the renal artery with a preservation fluid until donor blood is completely cleared. Organ retrieval process

Preservation awaiting transplant

Reperfusion in the recipient

Fig. 9.2  Potential stages of the retrieval process during which kidney allografts may accrue damage that affects the future transplant function. The mechanisms of damage during each stage differ.

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Kidney Transplantation: Principles and Practice

The kidney is then packaged in a sterile bag of this fluid and kept on ice in a cool box. It is important that handling of the kidney and workbench preparation are undertaken with the organ submerged in preservation fluid. The fluid should also be kept on ice until required, to prevent warming to ambient temperature. This method is relatively cheap, easily transportable, and does not require input from the retrieval or implant team during the preservation period. The classic unwanted side effects of hypothermia are swelling, acidosis, altered enzyme activity, and production of radical oxygen species upon reperfusion. Effective preservation solutions are therefore composed to counteract these processes using different types of buffers, electrolyte compositions, and additives. These processes are summarized in Fig. 9.3.

creates a hyperosmolar intracellular environment and subsequently an influx of water.25 To reestablish the disturbed Donnan equilibrium and to prevent cell swelling, impermeants such as colloids (hydroxyethyl starch in the University of Wisconsin (UW) solution or polyethylene glycol in IGL-1) are added to preservation solutions.26,27 It was thought that intracellular composition was required to diminish the exchange of electrolytes. The high potassium, however, also leads to initial vasoconstriction, hampering flush-out in the donor.28 The extracellular-type solutions are as effective as the intracellular solutions indicating that creating an osmotic pressure is more important than the composition.29 

CELL SWELLING

TABLE 9.2  Paris Modified Maastricht Classification for Donation After Circulatory Death (DCD)

The absence of oxygen during storage results in a rapid fall in intracellular ATP levels.30 Even at 0°C to 4°C cellular ATP content is rapidly depleted, and cells will switch to anaerobic metabolism of glucose.31 This will lead not only to a much less efficient production of ATP but also to production of lactic acid. Severe acidosis activates phospholipases and proteases causing lysosomal damage and eventually cell death.32 Adequate control of pH by a buffering agent is therefore an important function of preservation solutions. 

UNCONTROLLED DCD I. Found dead

CALCIUM

The main cause of cell swelling is the impaired activity of Na+/K+ ATPase.23 As a result, sodium passively enters cells, attracted by the negative charge of cytoplasmic proteins. This

II. Witnessed cardiac arrest

Sudden unexpected cardiac arrest without any resuscitation by a medical team; may be in hospital or out of hospital Sudden unexpected irreversible cardiac arrest with unsuccessful resuscitation by a medical team; may be in or out of hospital

CONTROLLED DCD III. Withdrawal of lifePlanned withdrawal of life-sustaining sustaining treatment therapy, expected cardiac arrest IV. Cardiac arrest while brain Sudden cardiac arrest after brain death dead diagnosis during donor lifemanagement but before organ recovery Adapted from Thuong M, Ruiz A, Evrard P, et al. New classification of donation after circulatory death donors definitions and terminology. Transpl Int 2016;29(7):749–59.

ENERGY AND ACIDOSIS

Under normal physiologic conditions the free calcium concentration difference between the intracellular and extracellular fluid is maintained by ATP-dependent transporters.33 During cold preservation, cellular ATP concentrations are low, leading to increased intracellular calcium. Preservation solutions therefore contain a low concentration of calcium. Experimentally calcium blockers in preservation solutions are shown to be effective in preventing activation of calciumdependent processes such as calpain activation, an enzyme involved in the breakdown of the cytoskeleton.34,35 

INTRACELLULAR ENZYMES AND ORGANELLES Intracellular proteases are involved in the breakdown of proteins during preservation, most likely due to the absence

Na+ – – Ca2+

K+

Protein–

ROS

Na+

H2O

Cell Swelling

Continued, slow metabolism

Organelle and membrane damage

Hypoxia

Lysosome rupture

Ca2+

Lactic acidosis Acidosis

Fig. 9.3  Negative effects of cold ischemia on cells and organelles. Continued but slowed metabolism results in hypoxia, acidosis, reduced ATP synthesis, and activity of sodium and calcium pumps. Resultant sodium influx with water leads to cell swelling. Reactive oxygen species (ROS), along with acidosis and lysosomal enzymes, damage cellular organelles and membranes.

9 • Kidney Preservation

of oxygen. Also, matrix metalloproteinases (MMPs) may be activated during cold preservation leading to detachment of endothelial cells from the underlying matrix.36 Hydroxyethyl starch present in UW solution may reduce this detrimental effect.37 Another relevant family of enzymes activated during cold preservation are apoptosis-related caspases.38 The release of mitochondrial proteins leads to endoplasmic reticulum stress and dysfunctional autophagy fluxes.39,40 

REACTIVE OXYGEN SPECIES Reactive oxygen species (ROS) are generated by several processes in ischemic and postischemic reperfused organs.41 A well-studied generator of ROS is xanthine oxidase, which simultaneously produces hydrogen peroxide (H2O2) and the superoxide anion (O2−).42 The subsequent reduction of H2O2, catalyzed by iron, leads to hydroxyl radical formation.43 The infiltration of leukocytes in the graft after reperfusion also results in the production of superoxides (the respiratory burst). Lastly, mitochondrial dysfunction resulting from partial reduction of the respiratory chain is an important contributor to ROS formation after reperfusion.43 These ROS react rapidly with other intracellular molecules, causing severe damage to lipids, nucleic acids, and proteins during reperfusion. Some reports suggest that oxygen radicals are formed during reperfusion and during cold preservation.44 Modern preservation solutions contain scavengers or precursors for ATP production, which are shown to be effective in experimental research but less evident in clinical trials.45 

CLINICAL USE OF PRESERVATION SOLUTIONS Worldwide, the UW solution and histidine-tryptophanketoglutarate (HTK) solution have been most commonly used since the early 1990s when two randomized controlled trials (RCTs) showed lower DGF rates compared with Euro-Collins’ solution.46,47 Registry data from the CTS suggests that at very long preservation times (beyond 24 hours) UW-stored kidneys have a reduced risk of graft loss compared with other preservation fluids.18 Registry data from the United Network for Organ Sharing (UNOS) show that kidney preservation in UW has improved graft survival independent of preservation time.48 The lack of adequately powered studies comparing Institut Georges Lopez-1 (IGL-1) solution, Celsior, or hyperosmolar citrate (HOC) against HTK or UW so far prevents definite conclusions regarding the superiority of any newer preservation fluids. From small published studies one could conclude that results are similar to UW or HTK.49 Most studies were conducted with relatively good quality donor kidneys. Globally UW and HTK are most predominant, with some countries using other preservation fluids that were developed locally being popular alternatives, see Tables 9.3 and 9.4. There is retrospective evidence from the UK, where HOC is still used for the preservation of large numbers of kidneys, that HOC is an acceptable alternative to UW with a mean CIT of 17 hours.50 

PHARMACOLOGIC ADDITIVES A better understanding of the pathophysiology and role of ischemia reperfusion injury in organ transplantation has given us the opportunity to target certain negative aspects

131

TABLE 9.3  Key Preservation Fluids (Generic Names), Common Acronyms/Abbreviations, and When Each Was Developed Euro-Collins’ Solution (developed from Collins’ Solution) Hyper-Osmolar Citrate (Marshall’s Solution) Histidine-Tryptophan-Ketoglutarate University of Wisconsin Solution Belzer Machine Perfusion Solution Celsior Solution Institut Georges Lopez-1 Solution

EC

1960s–1970s

HOC HTK UW MPS Celsior IGL-1

1970s 1970s 1980s 1980s 1990s 1990s

of preservation.51 Several pharmacologic additives have been investigated in preclinical models. The most promising additives are trimetazidine (an antiischemic agent),52,53 innate immunity inhibitors such as complement inhibitors,54,55 and regulators of endothelial function.56,57 

Hypothermic Machine Perfusion The decreasing number of high-quality SCD kidneys triggered the reintroduction of hypothermic machine perfusion (HMP). The retrieved kidney is placed within a chamber filled with chilled preservation solution surrounded by an ice box. The renal artery is cannulated by one end of a system of tubing, and a pump is used to generate a pulsatile or continuous flow of preservation solution through the renal vessels. The fluid pours from the renal vein into the reservoir where the pump collects it again to recirculate it. The concept of machine perfusion was first described by Charles Lindberg in 1935 in a fully mechanical device able to maintain an oxygenated pulsatile perfusion.58 In the context of organ transplantation, Professor Belzer experimented in the 1960s using techniques adapted from cardiac bypass machines. Through a series of preclinical experiments using canine kidneys, he was able perform the first successful human HMP kidney transplant in 1968.59 The introduction of cold storage solutions overcoming the problems with logistics and high costs meant that machine perfusion was almost abandoned from clinical practice, although in some centers, mainly in the US, it never totally disappeared. Over more recent years the development of more transportable stand-alone machines resolved many logistic hurdles. Commercially available machines for HMP of kidneys include the RM3 and Waves (IGL Group), the Lifeport (Organ Recovery Systems), the Kidney Assist (Organ Assist), and the Airdrive (Portable Organ Perfusion) (Figs. 9.4–9.6). Several retrospective and small prospective studies indicated superior preservation compared with static cold storage, but high-quality studies have only been undertaken in more recent years. In 2009 the machine perfusion (MP) trial consortium reported that continuous HMP results in lower DGF rates for SCD, ECD, and DCD kidneys and improved graft survival for SCD and ECD kidneys.60 Overall, a reduction in DGF was observed with HMP compared with cold storage (20.8% vs. 26.5%) with no significant effect on primary nonfunction (PNF) (2.1% vs. 4.8%). Graft survival in the first year was also improved by HMP (94% vs. 90%), and in later reports the 3-year graft survival was also better (91% vs.

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Kidney Transplantation: Principles and Practice

TABLE 9.4  Composition of Preservation Solutions for Static Cold Storage and Machine Perfusion Component Type

Component

Celsior

EC

HOC

HTK

IGL-1

UW

MPS

Colloids (mM)

HES PEG Citrate Gluconate Glucose Histidine Lactobionate Mannitol Raffinose Ribose HEPES K2HPO4 KH2PO4 NaHCO3 Calcium Chloride Magnesium Potassium Sodium Allopurinol Glutathione Tryptophan Adenine Adenosine Glutamate Ketoglutarate —

— — — — — 30 80 60 — — — — — — 0.25 42 13 15 100 — 3 — — — 20 — 255

— — — — 195 — — — — — — 15 43 10 — 15 — 115 10 — — — — — — — 406

— — 80 — — — — 185 — — — — — 10 — — 40 84 84 — — — — — — — 400

— — — — — 198 — 38 — — — — — — 0.0015 32 4 9 15 — — 2 — — — 1 310

— 0.03 — — — — 100 — 30 — — — 25 — — 20 5 25 120 1 3 — — 5 — — 320

0.25 — — — — — 100 — 30 — — — 25 — — 20 5 120 30 1 3 — — 5 — — 320

0.25 — — 85 10 — — 30 — 5 10 — 25 — 0.5 1 5 25 100 — — — 5 — — — 300

Impermeants (mM)

Buffers (mM)

Electrolytes (mM)

ROS scavengers (mM) Substrates (mM)

Osmolality (mOsm)

Citrate, histidine, and lactobionate also act as buffers. Histidine, lactobionate, and mannitol also act as free radical scavengers. EC, Euro-Collins’; HEPES, 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid; HES, hydroxyethylene starch; HOC, hyperosmolar citrate; HTK, histidine-tryptophanketoglutarate; IGL-1, Institut Georges Lopez-1; MPS, machine perfusion solution; PEG, polyethylene glycol; UW, University of Wisconsin solution.

Fig. 9.5  Lifeport hypothermic machine perfusion pump from Organ Recovery Systems.

Fig. 9.4  RM3 hypothermic machine perfusion pump from IGL Group.

87%).61 Maybe even more interesting was that the severity of DGF was less in HMP-preserved kidneys, illustrated by 3 days shorter DGF on average (10 days vs. 13 days).60 The beneficial effect of HMP seems to be more pronounced in ECD kidneys as shown in the extension trial of the same MP consortium.62 The rate of PNF was also lower for ECD kidneys preserved with MP compared with cold storage (3% vs. 12%). Both 1-year and 3-year graft survival was higher after HMP (92.3% vs. 80.2%, and 86% vs. 76%). In this study, DGF significantly affected 1-year graft survival of cold stored kidneys (41% vs. 97%) but not as much if the kidney had been stored by HMP (41% vs. 97%).

The use of HMP in SCD and ECD (both DBD donor types) seems beneficial in terms of reduced DGF and graft survival. Although initially used for DCD donors, the effect of HMP on long-term survival of DCD kidneys is less evident. One of only two adequately powered RCTs in DCD kidneys showed that continuous HMP resulted in lower risk of DGF (54% vs. 70%) but no improvement in 1-year or 3-year graft survival.63 The other RCT was not able to show a difference in DGF between HMP (58%) and cold storage (56%).64 The main difference between the two studies is that in the UK study kidneys were first subjected to cold storage before connection to the machine, whereas in the Eurotransplant study kidneys were continually pumped. Meta-analyses comparing HMP with cold storage have established a reduction in DGF with HMP,65 but improvement in graft survival has largely been among ECD only.66

9 • Kidney Preservation

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Reservoir with cold UW solution

Fig. 9.6 Kidney Assist hypothermic machine perfusion pump from Organ Assist. Leukocyte depletion filter

One could speculate that the effect of MP on DCD kidneys is different from the effect on DBD kidneys because DCD kidneys experience substantial ischemic injury due to the donation procedure. The addition of oxygen during preservation is therefore an interesting approach and in preclinical models shows potential, but clinical proof is not yet available.67 The Consortium for Organ Preservation in Europe (COPE) is trying to confirm whether the addition of oxygen during HMP is helpful or not and whether end-HMP is beneficial, which may significantly simplify logistics.68 

P1

Reservoir with prime Solution

O

in

Centrifugal pump

P2

Oxygenator Heat exchanger

Markers show the sites of descending Aorta and supra-hepatic IVC clamps Pressure Transducers P1: Premembrane P2: Postmembrane

Hb, HCT, SvO , venous temperature sensor

Fig. 9.7  Illustration of a normothermic regional perfusion circuit currently used in the UK.

After pioneering work in Maastricht category II donors in Spain, abdominal normothermic regional perfusion has emerged as potentially beneficial strategy among alternative preservation techniques, with improved organ recovery rates and better outcomes in Maastricht category I and II donors. Conceptually, normothermic regional perfusion (NRP) establishes an extracorporeal circuit via arterial and venous femoral or distal aortic and vena cava cannulation to recirculate the donor blood and isolates the abdominal compartment by occluding the descending aorta. The extracorporeal circuit includes an oxygenator, a heat exchanger, a centrifugal pump, and an open circuit with a reservoir (Fig. 9.7).69–72

cannulation is undertaken via the femoral vessels using a percutaneous or a cut-down technique. A similar approach has been adopted for controlled DCD in France, Spain, and Italy. In contrast, in the UK, where premortem administration of heparin is not allowed, cannulation is undertaken via a rapid laparotomy with distal aortic and vena cava cannulation, similar to the ultrarapid recovery technique. The optimal duration of NRP is yet to be determined but around 120 minutes appears to be sufficient to restore the cellular ATP72 and increase the levels of endogenous antioxidants.73 A prolonged NRP time of 4 hours has been maintained in the setting of Maastricht category II donors with no evidence of additional benefit. One of the key benefits of NRP is the real-time, in situ, dynamic assessment of organ function, which is composite measurement of blood gases and biochemistry every 30 minutes while on the pump.70 

TECHNICAL VARIATIONS

CLINICAL OUTCOMES

After the mandatory “no-touch” period, NRP is started with a flow of 2 to 3 L/min and oxygen or air/oxygen mix is administered to maintain a PaO2 more than 12 kPa. Bicarbonate is added to maintain a pH of 7.35 to 7.45, while 2 to 4 units of red cells may be required to maintain the hematocrit at more than 20%.69–72 There are several key differences between NRP in controlled and uncontrolled DCD donors, related to administration of heparin timing and site of vascular cannulation. In the uncontrolled DCD setting, vascular cannulation and heparinization occur during a period of mechanical cardiac compression and ventilation to preserve organ perfusion post mortem. Vascular

The use of NRP has been associated with an increased organ recovery rate compared with standard DCD retrieval in controlled donation. In the UK, this was particularly noticeable for livers, where utilization increased from 27% to over 50% with a significant reduction in the ischemic biliary complications and reduced incidence of early allograft dysfunction.70 The effect of NRP on the outcomes of kidney transplantation from DCD donors is summarized in Table 9.5. Despite a high incidence of DGF in category II DCD donors Valero et al. reported an excellent 1-year survival of 87.5%.74 The authors also noted that NRP reduced the

Normothermic Regional Perfusion

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Kidney Transplantation: Principles and Practice

TABLE 9.5  Clinical Outcomes for Kidney Transplantation Using Normothermic Regional Perfusion for Donation After Circulatory Death Organs Study et al.74

Valero Demiselle et al.75 Reznik et al.76 Magliocca et al.77 Oniscu et al.70 Rojas-Pena et al.78 Minambres et al.71

Number of Patients Maastricht Category

1-Year Graft Survival (%)

1-Year Patient Survival (%)

DGF (%)

PNF (%)

16 19 44 24 32 48 37

87.5 NR 95.5 NR 87.5 NR 91.8

90 NR 100 NR 96.8 NR NR

61 53 52 8.3 40 31 27

4.4 5 0 0 6 3 5

II II II III III III III

DGF, delayed graft function; NR, not reported; PNF, primary nonfunction.

incidence of DGF compared with hypothermic regional perfusion. In France, Demiselle et  al. reported similar findings. The use of NRP led to a 27% reduction in the incidence of DGF compared with in situ cold perfusion.75 Furthermore, in multivariate analysis, the use of NRP was associated with a significantly lower risk of DGF (odds ratio [OR] = 0.17, 95% confidence interval [CIF], 0.03–0.87). At 12 months posttransplant, in an analysis adjusted for donor serum creatinine and age as well as recipient age and the incidence of posttransplant acute rejection, the use of NRP was the only predictive factor of a better renal function (eGFR > 40 mL/min/173 m2). This study also suggested that the use of NRP can improve graft function in uncontrolled DCD transplantation, given that these patients achieved comparable DGF and early graft function compared with recipients of kidneys from brain-dead donors.75 The use of NRP may also allow an extension of current acceptance criteria in uncontrolled DCD as suggested by Reznik et al.76 Four patients were transplanted with kidneys from uncontrolled DCD with 60 minutes of asystole and a 95% 1-year graft survival and renal function comparable with standard DBD at 3 and 12 months posttransplant. The expansion of NRP in controlled donation has been driven primarily by the improvement in liver transplant outcomes. However, a potential beneficial effect was also noted in the outcomes of kidney transplantation. In the initial report from the UK, although 40% of patients developed DGF, the 3- and 12-month function was comparable with that seen in a contemporaneous cohort of DBD recipients.70 At the same time, it has previously been shown by several groups, that outcomes of DCD are very good at 1 year. Lower DGF rates were also noted in reports from two US pilot studies.77,78 In a more recent study by Minambres et  al., 37 patients received a NRP-controlled DCD kidney with a 27% DGF rate and 90.9% 1-year survival.71 Antoine et al. compared the outcomes of 92 NRPcontrolled DCD renal transplants in France with 846 matched DBD controls and noted a significantly lower DGF (9% vs. 18%) and a comparable renal function at the time of discharge.79 These reports suggest a beneficial effect of NRP in terms of recovery rates, but more significantly in terms of renal function, with a reconditioning effect that requires further confirmatory studies and mechanistic evaluation. It has been advocated that NRP should become a standard method for organ recovery from DCD in the future. 

Normothermic Machine Perfusion Normothermic machine perfusion (NMP) is based on the assumption that the most effective means of preserving an organ is to replicate its physiologic milieu. The potential of maintaining tissue viability by isolated perfusion was recognized as long ago as 1812 by the physiologist Le Gallois, and its experimental feasibility was first demonstrated in much cited experiments by Carrel and Lindbergh in the 1930s.80,81 The postulated benefits of normothermic perfusion as a means of preservation are: (1) restoration of cellular energy, repair of donation/retrieval injury, minimization of ischemia-reperfusion; (2) measurement of viability; (3) delivery of organ-specific therapies; and (4) prolonged storage. All four are relevant to the most pressing current clinical challenge in kidney transplantation—the need to use suboptimal (marginal) donor organs. The wide variation in the acceptance rates of ECD organs (e.g., ranging from 29% to 62%) within the UK illustrates the need for a better way to preserve and assess donor organs.6 Current methods for assessing the transplantability of a marginal donor organ, based on donor factors and embedded in donor risk algorithms, do not provide sufficient information to determine whether to discard an individual organ.5

EXPERIMENTAL EVIDENCE In an early proof-of-concept study, the Kootstra group tested 3 hours of warm (32°C) perfusion of canine kidneys following 30 minutes hypoxia, using a complex cell-free perfusate (Exsanguineous metabolic support [EMS], Breonics Inc., US).82 Posttransplant renal function was improved, as was graft survival.82 Recovery from hypoxic injury was demonstrated by successful transplantation after 120 minutes of warm ischemia and 18 hours of perfusion.83 The same group later demonstrated the potential for delivery of gene therapy to a perfused kidney and induction of the protective protein, hemoxygenase-1.83,84 The Leicester group of Nicholson demonstrated that normothermic perfusion with oxygenated blood was able to restore depleted ATP levels and improve renal function in a porcine reperfusion model.85 This group demonstrated the feasibility of normothermic perfusion after hypothermic preservation in a porcine renal autotransplant model86 and the benefit of leukocyte-depleted blood.87

9 • Kidney Preservation

The Toronto group has studied longer periods of NMP. In a porcine DCD (30 minutes warm ischemia) autotransplant model, perfusion for 8 hours immediately after retrieval resulted in improved early renal function.88 The issue of whether to perfuse immediately from the time of retrieval or after a period of static cold storage has important logistic implications, not only for the retrieval teams, but also for the specification of the perfusion device. Using the same porcine DCD autotransplant model, evidence showed that early creatinine clearance (day 3) was significantly superior in organs perfused immediately; this also correlated with histologic and biomarker (neutrophil gelatinaseassociated lipocalin) data.89 The use of perfusion metrics to predict transplant outcome has been reported in the same model: acid–base and flow dynamics differed significantly according to the degree of ischemic injury and correlated with posttransplant renal function.90 

CLINICAL EVIDENCE There is limited clinical experience of NMP in kidney transplantation to date. The first report of a clinical implementation described 35 minutes of NMP after 11 hours cold storage of a kidney that functioned immediately.91 A subsequent paper reported 18 extended criteria kidneys, perfused for a mean of 63 minutes after static cold storage and compared with a nonrandomized control group of 47 static cold-stored extended criteria kidneys.92 Of the NMP-treated kidneys 5.6% developed DGF, compared with 36.2% of controls (p = 0.014). There was no graft survival difference. NMP criteria are now being tested clinically as a method for viability assessment. After an initial exploratory phase to establish grading criteria based on macroscopic appearance, urine output, and vascular flow, five organs were transplanted on the basis of NMP criteria out of eight DCD kidneys that had been declined because of poor in situ flushing; four kidneys had immediate function.93 

Future Directions Increasing evidence is pointing to the benefit of NMP in the assessment, preservation, and reconditioning of high-risk donor kidneys. Once the technical and logistic challenges have been resolved, such as the necessary duration to provide maximal benefit, data from rigorous controlled clinical trials will be essential to establish the role of this new technology in clinical practice. One such trial is currently underway in the UK,94 and it is likely that other studies will drive this developing field.

TAILORING PRESERVATION STRATEGIES During active preservation it is possible to deliver to the organ drugs, cells, or genes, which may recondition or repair damaged organs. One option may be to deliver compounds that localize to endothelial cell membranes, thereby

135

targeting the therapy where it is needed. One such compound is mirococept, which is an inhibitor of complementmediated damage. Mirococept is currently under clinical trial using HMP (ISRCTN49958194).95 Another class of compound that can be targeted to endothelial cell membranes is anticoagulant molecules; HMP has been used in experimental studies to deliver anticoagulant molecules, reducing vascular resistance on reperfusion.96,97 Experimental studies have also investigated propofol as an additive during machine perfusion, with some promising early results.98 The delivery of mesenchymal stem cells (MSCs) during perfusion is another potential avenue to explore. It has been shown that the administration of MSCs in  vivo enhances recovery from ischemia–reperfusion-induced acute renal failure in rats.99 The mechanism is not yet fully understood but seems to include antiinflammatory properties and enhanced tissue repair. The use of autologous MSCs as an induction therapy has been studied in an RCT of livingrelated kidney transplantation.100 This study demonstrated a lower incidence of acute rejection, opportunistic infection, and a better renal function at 1 year compared with the IL-2 receptor antibody treatment.100 Experimental and animal studies in transplantation have shown that MSCs delivered during perfusion might reduce ischemic damage in retrieved kidneys.101 MePEP (Mesenchymal stem cells in normothermic Ex-vivo PErfusion in Pigs) is an international consortium that is investigating porcine MSC therapy. For this study, MSCs are delivered to injured kidneys during NMP to determine whether MSCs have the potential reduce injury and/or trigger regeneration.102 The delivery of genes to improve organ quality during extracorporeal machine perfusion could possibly reduce the recipient’s exposure to the necessary viral vectors and target the treatment to the donor organ.103 This method of delivering a gene and targeting the renal vascular endothelium has been tested, as has the delivery of small interfering RNA (SiRNA) to block gene expression and reduce IRI.104,105 The effect of mild hypothermia in the deceased donor (34°C–35°C) was starkly shown in a recent clinical trial that was discontinued early because of overwhelming efficacy.106 Active or passive cooling of the donor reduced DGF rates from 39% to 28%.106 The Consortium for Organ Preservation in Europe (COPE) is conducting three clinical trials alongside translational studies to advance and develop organ preservation technologies (Table 9.6). These clinical trials accompany experimental models investigating a number of novel scientific approaches to organ repair and regeneration and the development of new objective methods to measure and predict the viability and outcome of donated organs. It may be the case that tailored preservation techniques require a bespoke combination of mechanisms for each stage of the organ retrieval, storage, and implantation process, dependent on the characteristics of each donor, organ, and recipient.

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TABLE 9.6  Consortium for Organ Preservation in Europe (COPE) Clinical Trials Study

Primary Outcome

A multicenter randomized controlled trial to compare the Peak AST in 7 days after liver transplant efficacy of normothermic machine perfusion with static cold storage in human liver transplantation  Cold Oxygenated Machine Preservation of Aged Renal DCD Creatinine clearance at 1 year after kidney transplant Transplants (COMPARDT)107 “In house” preimplantation hypothermic machine perfusion 1-year graft survival after kidney transplant reconditioning after cold storage versus cold storage alone in ECD kidneys from brain-dead donors (POMP)

Status and Registration Completed, published ISRCTN39731134 Completed ISRCTN32967929 Completed ISRCTN63852508

AST, aspartate transaminase; DCD, donation after circulatory death; ECD, expanded criteria donation.

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9 • Kidney Preservation 38. Oberbauer R, Rohrmoser M, Regele H, Muhlbacher F, Mayer G. Apoptosis of tubular epithelial cells in donor kidney biopsies predicts early renal allograft function. J Am Soc Nephrol 1999;10(9): 2006–13. 39. Gotoh K, Lu Z, Morita M, et al. Participation of autophagy in the initiation of graft dysfunction after rat liver transplantation. Autophagy 2009;5(3):351–60. 40. Turkmen K, Martin J, Akcay A, et  al. Apoptosis and autophagy in cold preservation ischemia. Transplantation 2011;91(11):1192–7. https://doi.org/10.097/TP.0b013e31821ab9c8. 41. McCord JM. Oxygen-derived free radicals in postischemic tissue injury. N Engl J Med 1985;312(3):159–63. 42. Schachter M, Foulds S. Free radicals and the xanthine oxidase pathway. In: Grace P, Mathie R, editors. Ischaemi-reperfusion injury. Hoboken, NJ: Blackwell Science; 1999. p. 137–56. 43. Kosieradzki M, Kuczynska J, Piwowarska J, et al. Prognostic significance of free radicals: mediated injury occuring in the kidney donor. Transplantation 2003;75:1221–7. 44. Salahudeen AK. Cold ischemic injury of transplanted kidneys: new insights from experimental studies. Am J Physiol 2004;287:F181–7. 45. Vreugdenhil PK, Belzer FO, Southard JH. Effect of cold storage on tissue and cellular glutathione. Cryobiology 1991;28(2):143–9. 46. Ploeg RJ, van Bockel JH, Langendijk PT, et al. Effect of preservation solution on results of cadaveric kidney transplantation. The European Multicentre Study Group. Lancet 1992;340(8812):129–37. 47. De Boer J, De Meester J, Smits JMA, et al. Eurotransplant randomized multicenter kidney graft preservation study comparing HTK with UW and Euro-Collins. Transplant Int 1999;12(6):447–53. 48. Stewart ZA, Lonze BE, Warren DS, et al. Histidine-tryptophan-ketoglutarate (HTK) is associated with reduced graft survival of deceased donor kidney transplants. Am J Transplant 2009;9(5):1048–54. 49. O’Callaghan JM, Knight SR, Morgan RD, Morris PJ. Preservation solutions for static cold storage of kidney allografts: a systematic review and meta-analysis. Am J Transplant 2012;12(4):896–906. 50. O’Callaghan JM, Knight SR, Morgan RD, Morris PJ. A national registry analysis of kidney allografts preserved with Marshall’s solution in the United Kingdom. Transplantation 2016;100(11):2447–52. 51. Zaouali MA, Ben Abdennebi H, Padrissa-Altes S, Mahfoudh-Boussaid A, Rosello-Catafau J. Pharmacological strategies against cold ischemia reperfusion injury. Expert Opin Pharmacother 2010;11(4):537–55. 52. Baumert H, Faure JP, Zhang K, et al. Evidence for a mitochondrial impact of trimetazidine during cold ischemia and reperfusion. Pharmacology 2004;71(1):25–37. 53. Faure JP, Petit I, Zhang K, et al. Protective roles of polyethylene glycol and trimetazidine against cold ischemia and reperfusion injuries of pig kidney graft. Am J Transplant 2004;4(4):495–504. 54. Durigutto P, Sblattero D, Biffi S, et al. Targeted delivery of neutralizing Anti-C5 antibody to renal endothelium prevents complementdependent tissue damage. Front Immunol 2017;8:1093. 55. De Vries B, Matthijsen RA, Wolfs TG, Van Bijnen AA, Heeringa P, Buurman WA. Inhibition of complement factor C5 protects against renal ischemia-reperfusion injury: inhibition of late apoptosis and inflammation. Transplantation 2003;75(3):375–82. 56. Uhlmann D, Gaebel G, Armann B, et al. Attenuation of proinflammatory gene expression and microcirculatory disturbances by endothelin A receptor blockade after orthotopic liver transplantation in pigs. Surgery 2006;139(1):61–72. 57. Gu M, Takada Y, Fukunaga K, et  al. Pharmacologic graft protection without donor pretreatment in liver transplantation from nonheart-beating donors. Transplantation 2000;70(7):1021–5. 58. Lindbergh CA. An apparatus for the culture of whole organs. J Exp Med 1935;62(3):409–31. 59. Belzer FO, Ashby BS, Gulyassy PF, Powell M. Successful seventeenhour preservation and transplantation of human-cadaver kidney. N Engl J Med 1968;278(11):608–10. 60. Moers C, Smits JM, Maathuis MHJ, et al. Machine perfusion or cold storage in deceased-donor kidney transplantation. N Engl J Med 2009;360(1):7–19. 61. Moers C, Jochmans I, Treckmann J, et al. Better graft survival with machine perfusion than cold storage after three years: follow-up analysis of the European multicentre RCT in deceased-donor kidney transplantation. Transplant Int 2011;24(S2):93. 62. Treckmann J, Moers C, Smits J, et al. Machine perfusion versus cold storage for preservation of kidneys from expanded criteria donors after brain death. Transplant Int 2011;24(6):548–54.

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63. Treckmann J, Minor T, Gallinat A, et al. Lipid peroxidation products and alpha glutathione-S-transferase in machine perfusate of older donor kidneys are associated with post-transplant outcome. Am J Transplant 2012;12:424. 64. Watson CJE, Wells AC, Roberts RJ, et  al. Cold machine perfusion versus static cold storage of kidneys donated after cardiac death: a UK multicenter randomized controlled trial. Am J Transplant 2010;10(9):1991–9. 65. O’Callaghan JM, Morgan RD, Knight SR, Morris PJ. Systematic review and meta-analysis of hypothermic machine perfusion versus static cold storage of kidney allografts on transplant outcomes. Br J Surg 2013;100(8):991–1001. 66. Jiao B, Liu S, Liu H, Cheng D, Cheng Y, Liu Y. Hypothermic machine perfusion reduces delayed graft function and improves one-year graft survival of kidneys from expanded criteria donors: a meta-analysis. PLoS ONE 2013;8(12):e81826. 67. O’Callaghan JM, Pall KT, Pengel LHM. Supplemental oxygen during hypothermic kidney preservation: a systematic review. Transplant Rev (Orlando, FL) 2017;31(3):172–9. 68. Jochmans I, Akhtar MZ, Nasralla D, et al. Past, present, and future of dynamic kidney and liver preservation and resuscitation. Am J Transplant 2016;16(9):2545–55. 69. Fondevila C, Hessheimer AJ, Ruiz A, et  al. Liver transplant using donors after unexpected cardiac death: novel preservation protocol and acceptance criteria. Am J Transplant 2007;7(7):1849–55. 70. Oniscu GC, Randle LV, Muiesan P, et al. In situ normothermic regional perfusion for controlled donation after circulatory death—the United Kingdom experience. Am J Transplant 2014;14(12):2846–54. 71. Minambres E, Suberviola B, Dominguez-Gil B, et al. Improving the outcomes of organs obtained from controlled donation after circulatory death donors using abdominal normothermic regional perfusion. Am J Transplant 2017;17(8):2165–72. 72. Gonzalez FX, Garcia-Valdecasas JC, Lopez-Boado MA, et al. Adenine nucleotide liver tissue concentrations from non-heart-beating donor pigs and organ viability after liver transplantation. Transplant Proc 1997;29(8):3480–1. 73. Aguilar A, Alvarez-Vijande R, Capdevila S, Alcoberro J, Alcaraz A. Antioxidant patterns (superoxide dismutase, glutathione reductase, and glutathione peroxidase) in kidneys from non-heart-beatingdonors: experimental study. Transplant Proc 2007;39(1):249–52. 74. Valero R, Cabrer C, Oppenheimer F, et  al. Normothermic recirculation reduces primary graft dysfunction of kidneys obtained from non-heart-beating donors. Transplant Int 2000;13(4):303–10. 75. Demiselle J, Augusto JF, Videcoq M, et al. Transplantation of kidneys from uncontrolled donation after circulatory determination of death: comparison with brain death donors with or without extended criteria and impact of normothermic regional perfusion. Transplant Int 2016;29(4):432–42. 76. Reznik ON, Skvortsov AE, Reznik AO, et al. Uncontrolled donors with controlled reperfusion after sixty minutes of asystole: a novel reliable resource for kidney transplantation. PLoS ONE 2013;8(5):e64209. 77. Magliocca JF, Magee JC, Rowe SA, et al. Extracorporeal support for organ donation after cardiac death effectively expands the donor pool. J Trauma 2005;58(6):1095–101; discussion 101-2. 78. Rojas-Pena A, Sall LE, Gravel MT, et al. Donation after circulatory determination of death: the University of Michigan experience with extracorporeal support. Transplantation 2014;98(3):328–34. 79. Antoine C, Videcoq M, Riou B, et al. Controlled donation after circulatory death (cDCD) donors may become similar to brain death donors (DBD). [abstract]. Am J Transplant 2017;17(Suppl. 3). Available online at: https://atcmeetingabstracts.com/abstract/controlleddonation-after-circulatory-death-cdcd-donors-may-becomesimilar-to-brain-death-donors-dbd/. 80. Le Gallois CJJ. Expériences sur le Principe de la Vie: Notamment sur Celui des Mouvements du Coeur, et sur le Siége de ce Principe. Paris: D’Hautel; 1812. 81. Carrel A, Lindbergh CA. The culture of whole organs. Science 1935;81(2112):621–3. 82. Stubenitsky BM, Booster MH, Brasile L, Araneda D, Haisch CE, Kootstra G. Exsanguinous metabolic support perfusion—a new strategy to improve graft function after kidney transplantation. Transplantation 2000;70(8):1254–8. 83. Brasile L, Stubenitsky BM, Booster MH, et  al. Overcoming severe renal ischemia: the role of ex vivo warm perfusion. Transplantation 2002;73(6):897–901.

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84. Brasile L, Buelow R, Stubenitsky BM, Kootstra G. Induction of heme oxygenase-1 in kidneys during ex vivo warm perfusion. Transplantation 2003;76(8):1145–9. 85. Bagul A, Hosgood SA, Kaushik M, Kay MD, Waller HL, Nicholson ML. Experimental renal preservation by normothermic resuscitation perfusion with autologous blood. Br J Surg 2008;95(1):111–8. 86. Hosgood SA, Barlow AD, Yates PJ, Snoeijs MGJ, van Heurn ELW, Nicholson ML. A pilot study assessing the feasibility of a short period of normothermic preservation in an experimental model of non heart beating donor kidneys. J Surg Res 2011;171(1):283–90. 87. Harper S, Hosgood S, Kay M, Nicholson M. Leucocyte depletion improves renal function during reperfusion using an experimental isolated haemoperfused organ preservation system. Br J Surg 2006;93(5):623–9. 88. Kaths JM, Echeverri J, Goldaracena N, et  al. Eight-hour continuous normothermic ex  vivo kidney perfusion is a safe preservation technique for kidney transplantation: a new opportunity for the storage, assessment, and repair of kidney grafts. Transplantation 2016;100(9):1862–70. 89. Kaths JM, Echeverri J, Chun YM, et  al. Continuous normothermic ex  vivo kidney perfusion improves graft function in donation after circulatory death pig kidney transplantation. Transplantation 2017;101(4):754–63. 90. Kaths JM, Hamar M, Echeverri J, et al. Normothermic ex vivo kidney perfusion for graft quality assessment prior to transplantation. Am J Transplant 2018;18(3):580–9. 91. Hosgood SA, Nicholson ML. First in man renal transplantation after ex vivo normothermic perfusion. Transplantation 2011;92(7):735–8. 92. Nicholson ML, Hosgood SA. Renal transplantation after ex  vivo normothermic perfusion: the first clinical study. Am J Transplant 2013;13(5):1246–52. 93. Hosgood SA, Thompson E, Moore T, Wilson CH, Nicholson ML. Normothermic machine perfusion for the assessment and transplantation of declined human kidneys from donation after circulatory death donors. Br J Surg 2018;105(4):388–94. https://doi. org/10.1002/bjs.10733. 94. Hosgood SA, Saeb-Parsy K, Wilson C, Callaghan C, Collett D, Nicholson ML. Protocol of a randomised controlled, open-label trial of ex  vivo normothermic perfusion versus static cold storage in donation after circulatory death renal transplantation. BMJ Open 2017;7(1):e012237. 95. Kassimatis T, Qasem A, Douiri A, et al. A double-blind randomised controlled investigation into the efficacy of Mirococept (APT070) for preventing ischaemia reperfusion injury in the kidney allograft (EMPIRIKAL): study protocol for a randomised controlled trial. Trials 2017;18(1):255.

96. Sedigh A, Larsson R, Brannstrom J, et  al. Modifying the vessel walls in porcine kidneys during machine perfusion. J Surg Res 2014;191(2):455–62. https://doi.org/10.1016/j.jss.2014.04.006. 97. Hamaoui K, Gowers S, Boutelle M, et  al. Organ pretreatment with cytotopic endothelial localising peptides to ameliorate microvascular thrombosis and perfusion deficits in ex-vivo renal haemoreperfusion models. Transplantation 2016;100(12):e128–39. 98. Snoeijs MG, Vaahtera L, de Vries EE, et al. Addition of a water-soluble propofol formulation to preservation solution in experimental kidney transplantation. Transplantation 2011;92(3):296–302. 99. Lange C, Togel F, Ittrich H, et al. Administered mesenchymal stem cells enhance recovery from ischemia/reperfusion-induced acute renal failure in rats. Kidney Int 2005;68(4):1613–7. 100. Tan J, Wu W, Xu X, et al. Induction therapy with autologous mesenchymal stem cells in living-related kidney transplants: a randomized controlled trial. JAMA 2012;307(11):1169–77. 101. Gregorini M, Corradetti V, Pattonieri EF, et al. Perfusion of isolated rat kidney with mesenchymal stromal cells/extracellular vesicles prevents ischaemic injury. J Cell Mol Med 2017;21(12):3381–93. https://doi.org/10.1111/jcmm.13249. 102. Sierra-Parraga JM, Eijken M, Hunter J, et al. Mesenchymal stromal cells as anti-inflammatory and regenerative mediators for donor kidneys during normothermic machine perfusion. Stem Cells Dev 2017;26(16):1162–70. 103. Sandovici M, Deelman LE, de Zeeuw D, van Goor H, Henning RH. Immune modulation and graft protection by gene therapy in kidney transplantation. Eur J Pharmacol 2008;585(2-3):261–9. 104. Brasile L, Stubenitsky B, Booster M, Green E, Haisch C, Kootstra G. Application of exsanguineous metabolic support to human kidneys. Transplant Proc 2001;33(1–2):964–5. 105. Zheng X, Zhang X, Feng B, et al. Gene silencing of complement C5a receptor using siRNA for preventing ischemia/reperfusion injury. Am J Pathol 2008;173(4):973–80. 106. Niemann CU, Feiner J, Swain S, et  al. Therapeutic hypothermia in deceased organ donors and kidney-graft function. N Engl J Med 2015;373(5):405–14. 107. Nasralla D, Coussios CC, Mergental H, et  al. A randomized trial of normothermic preservation in liver transplantation. Nature 2018;557(7703):50–6. https://doi.org/10.1038/s41586-018-0047-9.

10

Histocompatibility in Renal Transplantation SUSAN V. FUGGLE and CRAIG J. TAYLOR

CHAPTER OUTLINE

Historical Background The HLA System HLA Genes and Their Products HLA Class I HLA Class II HLA on the Web HLA Matching HLA-Specific Allosensitization HLA-Specific Antibody Detection and Characterization Complement-Dependent Lymphocytotoxicity Solid-Phase Binding Assays for HLA-Specific Antibody Detection and Specification Antibody Screening Strategies Patient Sensitization Profile and Definition of Unacceptable Specificities Donor Crossmatch Donor Crossmatch Techniques and Their Clinical Relevance

Historical Background The study of histocompatibility accelerated during the 1960s when the pioneers of clinical kidney transplantation recognized that graft destruction was mediated through immunologic mechanisms. In 1961 the introduction of chemical immunosuppression, first 6-mercaptopurine followed soon after by azathioprine and steroids, enabled short and medium-term success. However, 40% to 50% of deceased donor transplants were lost because of immediate or early graft failure due to irreversible rejection in the first year and thereafter there was an insidious decline in graft function. These early experiences severely limited the success of human allotransplantation and led to the study of compatibility of transplanted tissue, which, over the next 40 years gave rise to the specialty of “histocompatibility and immunogenetics” (H&I). The first human leukocyte antigens (HLA) were discovered in 1958 and subsequent years by Jean Dausset, Rose Payne, and Jon van Rood.1 Later, many more HLA antigens were characterized using antibodies in sera obtained from multiparous women and from patients after multiple blood transfusions. Such antibodies were also demonstrated in recipient sera after transplant rejection,2 and antibodies reactive with donor lymphocytes present before renal transplantation, either detected by leukoagglutination or

Complement-Dependent Lymphocytotoxic Crossmatch B Cell Crossmatch Crossmatch Serum Sample Selection (Timing) Immunoglobulin Class and Specificity Flow Cytometric Crossmatch Test Organ Allocation and Pretransplant Donor Crossmatch Testing The Virtual Crossmatch Immunologic Risk Stratification Strategies for Transplanting Sensitized and Highly Sensitized Patients Antibody Removal Paired Exchange Posttransplant Monitoring Future Directions Concluding Remarks

by cytotoxicity, were found to be associated with hyperacute rejection (HAR).3,4 HLA was quickly recognized as the human equivalent of the major histocompatibility complex (MHC), previously identified in inbred rodents, the products of which control the recognition of self and foreign antigens.5 

The HLA System The HLA system encoded on the short arm of chromosome 6 is the most intensively studied region of the human genome. The region spans over four megabases and contains in excess of 250 expressed genes, making it the most gene-dense region characterized to date.6 Approximately 28% of these genes encode proteins with immune-related functions, making the region of particular relevance to transplant clinicians and immunologists. HLA has a central role in immune recognition for defense against foreign pathogens and neoplasia, mediating T cell signaling through the presentation of self and foreign antigens in the form of short protein fragments (peptides) recognized by self-HLA restricted T lymphocytes (see Chapter 2). Recognition of nonself peptides in the context of self-HLA (i.e., altered self) is the function of the T cell antigen receptor and elicits a powerful immune response. The extensive 139

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polymorphism of HLA has evolved to enable efficient binding of peptides from the vast array of potentially pathogenic organisms that invade and colonize our bodies. Therefore the evolutionary pressures to develop and maintain diversity vary with time and geographic area. As a consequence, HLA has adapted differently according to geographic region and ethnic group, and HLA phenotypes differ across populations throughout the world.

HLA GENES AND THEIR PRODUCTS The HLA system is a complex multigene family consisting of more than 10 loci. HLA types are codominantly inherited on a maternal and paternal haplotype and transmitted as a single Mendelian trait (Fig. 10.1), and therefore an individual can express two alleles at each locus. The genes encoding HLA and their corresponding glycoprotein products are divided into two classes according to their biochemical and functional properties: HLA class I and HLA class II.

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HLA Class I HLA class I genes span two megabases at the telomeric end of the 6p21.3 region of chromosome 6. This region encodes the classical “transplantation antigens” (HLA-A, -B, and -C) that are expressed on virtually all nucleated cells.7 Genes of the HLA class I loci encode the 44 kD heavy chains which associate with intracellular peptides present within the cytoplasm. The tertiary structure is stabilized on the cell surface by noncovalent association with β2-microglobulin, a nonpolymorphic 12 kD protein encoded on chromosome 15. The heavy chain consists of three extracellular immunoglobulin-like domains (α1, α2, α3), a hydrophobic transmembrane region, and a cytoplasmic tail. The two extracellular domains distal to the cell membrane (α1 and α2) are highly polymorphic and fold to form a peptide-binding cleft consisting of eight strands forming an antiparallel beta pleated sheet, overlaid by two alpha helices. The cleft accommodates peptides of 8 to 10 amino acids in length, mostly derived from “endogenous” proteins present within

C L A S S II

-LTA -TNF -LTB -Hsp70 -C2 -Bf -C4A -C4B -CYP21B

-DRA -DRB4 -DRB5 -DRB3 -DRB1 -DQA1 -DQB1 -DQB3 -DQA2 -DQB2 -DOB -DMB -DMA -DOA -DPA1 -DPB1 -DPA2 -DPB2

27

Fig. 10.1  Genomic organization of the HLA region on chromosome 6. HLA antigens are codominantly inherited en bloc as a haplotype from maternal and paternal chromosomes. Red: pseudogenes. Green: “nonclassical” HLA genes with no known role in clinical solid-organ transplantation. Blue: genes encoding HLA products with clinical relevance to solid-organ transplantation.

10 • Histocompatibility in Renal Transplantation

the cell cytoplasm. The major areas of amino acid polymorphism line the sides and base of the cleft and thereby govern the peptide-binding repertoire of the HLA molecule. In contrast, the α3 domain (proximal to the cell membrane) is highly conserved and acts as a ligand for CD8 expressed on T lymphocytes. This interaction confers HLA class I restriction on CD8 positive T lymphocytes, which have a predominantly cytotoxic function and form the basis for cellular immunity to intracellular pathogens such as viruses. There are other class I loci and knowledge about their expression and function has emerged (Table 10.1). HLAH, -J, -K, and -L are pseudogenes and HLA-N, -P, -S, -T, -U, -V, -W, -X, -Y, and -Z are gene fragments that are not transcribed or translated. HLA-G is expressed on placental trophoblast cells, implicating a possible involvement in fetal–maternal development. HLA-E, -F, and -G have limited polymorphism and are known to act as ligands for natural killer (NK) cell inhibitory receptors (e.g., CD94). These loci may prove to be important in certain experimental xenograft models and in bone marrow transplantation (where NK cells are involved in the rejection process), but their clinical relevance in solid-organ transplantation has not been firmly established. There is, however, an emerging role for these molecules in innate immunity to persistent viruses such as cytomegalovirus (CMV) and they may prove to have an important role in post transplant viral defense. 

HLA Class II The HLA class II region consists of three main loci: HLADR, -DQ, and -DP. The glycoprotein products are heterodimers with noncovalently associated alpha and beta chains of molecular weight approximately 33 and 28 kD, respectively. Both chains consist of two extracellular immunoglobulin-like domains, a transmembrane region and a cytoplasmic tail. The membrane distal domains α1 and β1 form a peptide-binding cleft similar to, but less rigid than that of HLA class I, accommodating peptides of 10 to 20 amino acids derived predominantly from ingested (endocytosed or phagocytosed) extracellular (exogenous) proteins. The β1 domains of HLA-DR, -DQ, and -DP are highly polymorphic and govern the peptide-binding repertoire. They are constitutively expressed on cells with immune function such as B lymphocytes, activated T lymphocytes and antigen-presenting cells (monocytes, macrophages, and cells of dendritic lineage). HLA class II expression can be induced on most cell types during inflammatory responses (including allograft rejection) by cytokines such as gamma-interferon and tumor necrosis factor alpha.8–10 The conserved membrane proximal domain associates with CD4 on T lymphocytes with predominately helper/inducer function and thereby confers HLA class II restriction and forms the basis of cellular and humoral immunity to circulating pathogens such as bacteria. HLA Polymorphism and Nomenclature. Early investigations into HLA polymorphism used relatively crude alloantisera able to distinguish only a limited number of antigens. Nearly half a century later, these simple techniques have been superseded by molecular methods capable of resolving HLA variants at the DNA sequence level and identifying single amino acid polymorphisms that are indistinguishable by serology. For example, there are currently

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TABLE 10.1  HLA Genes and Their Products Name

Molecular Characteristics

HLA-A HLA-B HLA-C HLA-E HLA-F HLA-G HLA-H HLA-J HLA-K HLA-L HLA-N HLA-P HLA-S HLA-T HLA-U HLA-V HLA-W HLA-X HLA-Y HLA-Z

Class I α-chain Class I α-chain Class I α-chain Associated with Class I 6.2kB Hind III fragment Associated with Class I 5.4kB Hind III fragment Associated with Class I 6.0kB Hind III fragment Class I pseudogene Class I pseudogene Class I pseudogene Class I pseudogene Class I gene fragment Class I gene fragment Class I gene fragment Class I gene fragment Class I gene fragment Class I gene fragment Class I gene fragment Class I gene fragment Class I gene fragment Class I gene fragment (located in the HLA class II region) DR α-chain DR β1-chain determining specificities DR1 to DR18 Pseudogene with DR β-like sequences DR β3-chain determining DR52 found on DR17, DR18, DR11, DR12, DR13, and DR14 haplotypes DR β4-chain determining DR53 found on DR4, DR7, DR9 haplotypes DR β5-chain determining DR51 found on DR15 and DR16 haplotypes DRB pseudogene found on DR1, DR2, and DR10 haplotypes DRB pseudogene found on DR4, DR7, and DR9 haplotypes DRB pseudogene found on DR4, DR7, and DR9 haplotypes DRB pseudogene, probably found on all haplotypes DQ α-chain DQ β-chain determining specificities DQ1 to DQ9 DQ α-chain-related sequence, not known to be expressed DQ β-chain-related sequence, not known to be expressed DQ β-chain-related sequence, not known to be expressed DO α-chain DO β-chain DM α-chain DM β-chain DP α-chain DP β-chain DP α-chain-related pseudogene DP β-chain-related pseudogene DP α-chain-related pseudogene

HLA-DRA HLA-DRB1 HLA-DRB2 HLA-DRB3 HLA-DRB4 HLA-DRB5 HLA-DRB6 HLA-DRB7 HLA-DRB8 HLA-DRB9 HLA-DQA1 HLA-DQB1 HLA-DQA2 HLA-DQB2 HLA-DQB3 HLA-DOA HLA-DOB HLA-DMA HLA-DMB HLA-DPA1 HLA-DPB1 HLA-DPA2 HLA-DPB2 HLA-DPA3

19 HLA-DR specificities defined by serologic methods, compared with more than 2000 HLA-DRB sequence variants (alleles) detected using DNA-based typing methods. The number of newly defined alleles identified is still increasing and has now surpassed even the highest expectations of the early pioneers. Concomitant with the ever-increasing complexity of the HLA region, a nomenclature system has been developed to accurately assign HLA loci and their alleles.11 This

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nomenclature system encompasses the methodology (serology, biochemistry, and DNA sequencing) and level to which the HLA genes and their products have been resolved. The nomenclature is complex and, to those outside the field, can appear confusing.  Resolution of HLA Typing Methods. Serologically based HLA typing uses alloantisera and monoclonal antibodies that bind to tertiary epitopes of the cell surface HLA glycoproteins. There is a high degree of sequence homology between HLA specificities and identical amino acid sequence motifs (epitopes) are often shared between groups of antigens.12–14 The degree of HLA compatibility between transplant donors and recipients can be considered at many different levels of resolution, depending on the HLA typing methodology (Table 10.2). This can range from matching for serologically defined epitopes to matching for single amino acid differences detected through high-resolution DNA sequence-based methods (allele matching).  World Health Organization (WHO) Nomenclature for HLA. HLA genes and their polymorphic products have now been characterized and cloned and have been given official designations using the following principles. The genes are prefixed by the letters HLA followed by the loci or region, for example, HLA-A, HLA-B, or HLA-D. The HLA-D region has several subregions denoted HLA-DR, -DQ, -DP, -DO, and -DM (see Fig. 10.1). These are followed by the letters A or B to define the gene encoding the alpha and beta chain gene product of that subregion, respectively (e.g., HLA-DRB genes code for the DRβchain protein product). Where there is more than one A or B gene within a subregion, a corresponding number is given (e.g., HLA-DRB1; see Fig. 10.1 and Table 10.1). A new nomenclature system was launched by the WHO in 2010 to accommodate the growing number of HLA alleles being discovered.11 In this system each allele is uniquely identified by up to four sets of digits separated by colons (termed fields), prefixed by an asterisk (*). The digits in the first field usually correlate with the serologic specificity, for instance HLA-B*27 correlates with the serologic specificity HLA-B27. However, for most serologically defined antigens there is further polymorphism detectable at the DNA and amino acid sequence level. The second field denotes the subtype, listed in the order the alleles were discovered. Alleles with different numbers at this level have nucleotide substitutions that alter the amino acid sequence (e.g., HLA-B*27:01, HLA-B*27:02) and so forth. The third field indicates synonymous substitutions within the coding region (i.e., there is no change the amino acid sequence of the expressed protein) and the fourth field indicates polymorphism in noncoding regions. Some alleles or genes contain sequence defects preventing normal antigen expression at the cell surface. Nonexpressed alleles (null alleles) are indicated using the suffix “N” (e.g., HLA-DRB4*01:03:01N) whereas alleles with low expression or soluble (secreted) alleles carry the suffix “L” or “S,” respectively. The suffix “C” indicates a protein detected within the cytoplasm and not on the cell surface; “A” aberrant expression, where there is doubt whether the protein is expressed; and “Q,” questionable expression, where a given mutation has been previously shown to affect expression,

TABLE 10.2  Resolution of HLA Typing Methods and Their Application to Renal Transplantation HLA Typing Resolution

Method

HLA allele matching

High-resolution (2-field) DNA sequence-based typinga Serology and low resolution (generic) DNA typingb Serology and low resolution (generic) DNA typing Serology and low resolution (generic) DNA typing Serologically defined cross-reactive groups Serologically defined motifs/ determinants Single amino acid residues Linear peptides and conformational epitopes Supertypic antigen matching Triplet/Eplet amino acid mismatches (HLAMatchmaker)

Split HLA specificity matching Broad HLA specificity matching HLA-B, -DR matching Epitope matching

aHigh-resolution

DNA typing can be translated into low-resolution serologic equivalents (allele families). resolution HLA typing by PCR utilizes DNA primers designed to identify polymorphisms at a level comparable to serology. Adapted from Taylor CJ, Dyer PA. Maximizing the benefits of HLA matching for renal transplantation: alleles, specificities, CREGs, epitopes or residues? Transplantation 1999;68:1093–4. bLow

but the level of expression has not been confirmed for the particular allele. The HLA-DR and HLA-DP alpha chains have only limited polymorphism and therefore the HLA-DRB1 or -DPB1 allele (which code for the main polymorphic amino acid determinants present on the beta chain) is usually annotated alone. In contrast both the HLA-DQ alpha and beta chains are polymorphic. To describe one of these alleles precisely, definition of both the A and B alleles may be required (e.g., HLA-DQA1*01:01 and DQB1*05:01). Although the alpha and beta chain protein products of the A and B gene pairs associate preferentially, there is also the possibility of the formation of novel hybrid molecules. A complete list of recognized HLA genes and their expressed products can be found at www.bmdw.org (Bone Marrow Donors Worldwide; HLA information).  Extended HLA Haplotypes. The HLA region displays strong linkage disequilibrium whereby certain HLA alleles are inherited together as a conserved HLA haplotype. Therefore extended HLA haplotypes involving HLA-A, -B, -C, -DR, and -DQ commonly exist within and between ethnic groups. This greatly improves the probability of finding an HLA-matched unrelated donor as common HLA haplotypes are frequently found within a population (e.g., HLA-A*01:01, -B*08:01, -C*07:01, -DRB1*03:01, -DRB3*01:01, -DQA1*05:01, -DQB1*02:01).15 There is only relatively weak linkage centromeric to HLA-DQ because of a recombination “hot-spot” between HLA-DQ and -DP. 

HLA on the Web Information concerning the HLA system is rapidly expanding and articles such as this are always out of date by the time they go to print. However, there are a number of Internet

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websites with useful links that are regularly updated. These provide contemporary articles and information concerning HLA genes, nomenclature, polymorphism, DNA and amino acid sequences for both lay and professional readers:      

www.bmdw.org www.ashi-hla.org/index.htm www.bshi.org.uk www.efiweb.org www.anthonynolan.org.uk www.sanger.ac.uk www.epregistry.com.br   

 HLA Matching It was more than 40 years ago that HLA matching between donor and recipient was found to be associated with better transplant and patient survival.2,16–19 Matching for the class I HLA-A and -B antigens influenced survival, but matching for the class II HLA-DR antigens was shown to have the most powerful effect.19,20 A beneficial effect of HLA matching on graft survival was demonstrated in analyses of large data sets and national and international databases.21 Over the years there has been an overall improvement in transplant survival and a decrease in the survival advantage conferred by HLA matching.16,21 The improvement can be attributed to a number of factors, but one of the most powerful is advancements in the effectiveness of immunosuppression. This was clearly demonstrated in a local comparison of transplant survival in patients receiving azathioprine and prednisolone, cyclosporine and prednisolone, and triple therapy (cyclosporine, azathioprine, prednisolone) where 1-year transplant survival rates were 65%, 69%, and 81%, respectively.22 In this analysis HLA-DR compatibility still had a marked effect on the posttransplant clinical course, with an increased incidence of rejection in HLA-DR mismatched grafts, the socioeconomic effects of which were increased use of immunosuppressive drugs, longer hospital stays, and higher 3-month creatinine levels.23 Despite further improvements in immunosuppression and patient management, a beneficial effect of HLA matching is still apparent in data from recent transplants published from the Collaborative Transplant Study24 (Fig. 10.2) and from the United Network of Organ Sharing (UNOS). The UNOS data revealed a linear relationship between mismatches at HLA-A, -B, -DR, and allograft survival, independent of HLA locus, in 189,141 transplants performed between 1987 and 2013. Although the transplants analyzed were performed over a long time period, the HLA effect was present in the transplants performed in recent periods.25 In analyzing the effect of HLA on transplant outcome, it is important that other factors known to have a strong influence on outcome are taken in account. In a rigorous multivariate analysis of factors influencing the outcome of primary deceased donor transplants in a cohort of transplants performed in the UK between 1986 and 1993, the year of transplant, donor and recipient age, waiting time to transplant, diabetes in the recipient, donor cause of death, exchange of kidneys, cold ischemia time, and HLA mismatching were found to influence transplant survival

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(death with function treated as failure). The best transplant survival was achieved in transplants with no mismatches at HLA-A, -B, and -DR (“000” HLA-A, -B, -DR mismatch grade). Other well-matched transplants, termed “favorably matched transplants,” with a maximum of one HLA-A and one HLA-B antigen mismatched in the absence of mismatches at HLA-DR (110, 100, 010 mismatch grades) had a significantly improved survival over transplants of all other match grades.26,27 An analysis of factors influencing the long-term outcome of these transplants revealed that for patients with transplants functioning after 6 years, only older donor age and diabetes had a significant detrimental influence on survival. The influence of HLA mismatch on outcome of first deceased donor transplant was investigated in a cohort of patients, transplanted in the UK between 1995 and 2001. As a result of the allocation policy the recent transplants were significantly better matched than the previously analyzed cohort (1986–1993), where 46% transplants were 0-DR mismatched and 10% had 2-DR mismatches, compared with 60% 0-DR mismatched and only 3% 2-DR mismatches in the 1995 to 2001 cohort. In a multivariate analysis there was no effect of HLA-A mismatching, but a significant effect of two mismatches at HLA-B and an incremental effect of mismatching at HLA-DR.28 In recent multivariate analyses of the outcome of 7837 adult patients transplanted in the UK between 2009 to 2014, there is still a significant beneficial effect of HLA matching on graft outcome at 1 and 5 years posttransplant. There have been several publications from the Collaborative Transplant Study revealing associations between HLA mismatching and clinical events posttransplant. Increasing numbers of HLA mismatches were shown to be significantly associated with an increased requirement for antirejection treatment29 and with the cumulative incidence of death with a functioning graft resulting from cardiovascular disease or infection, but not from malignant neoplasm.30 The number of HLA-DR mismatches was shown to be associated with increased incidence of nonHodgkin’s lymphoma31,32 and hip fractures.33 It is possible that these associations result from the higher levels of immunosuppression used in the management of poorly HLA-matched transplants. In solid-organ transplantation the effects of HLA matching reported are generally based on matching at the HLA-A, -B, and -DR loci. The effect of matching other HLA loci has been analyzed, but demonstrating an independent effect is difficult because of linkage disequilibrium. Matching for HLA-DQ has been variously reported as having either a beneficial effect34 or no effect on transplant outcome35,36 However, in a recent analysis of data from the Australia and New Zealand Dialysis and Transplant Registry, HLA-DQ mismatches were found to be associated with an increased incidence of acute rejection, independent of HLA-A, -B, -DR mismatches. This effect was further increased when donors and recipients were mismatched for HLA-DR.37 Registry analysis has shown that HLA-DPB matching has an effect on the transplant survival of regrafts, but not of first transplants.38 It is possible that this effect results from matching for certain immunogenic HLA-DPB epitopes39 and undetected immunologic priming against donor-DP mismatches of the failed graft.

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Kidney Transplantation: Principles and Practice HLA-A+B+DR Mismatches Deceased Donor, First Kidney Transplants 2008–2016 100

Graft survival (%)

95 0 MM 1 MM 2 MM 3 MM 4 MM 5 MM 6 MM

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Fig. 10.2  The influence of human leukocyte antigen (HLA)-A, -B, -DR mismatch on 3-year graft survival. (A) HLA-A+B+DR mismatches, deceased donor, first kidney transplants, 2008 to 2016. (B) HLA-DR deceased donor, first kidney transplants, 2008 to 2016. (Reproduced from the Collaborative Transplant Study.)

The definition of an HLA match between donors and recipients can be considered at different levels depending on the resolution of the HLA type and consideration of areas of similarity and differences in the HLA molecules. The influence of compatibility for the broad serologic specificities, serologic split specificities, epitopes common within serologic cross reactive groups (CREGs), single amino acid differences, or epitopes has been considered in deceased donor renal transplantation,40 and matching at these various levels has been reported to be associated with improved outcomes.41–44 There is now considerable interest in epitopes on the HLA molecules and the opportunity to reduce the immunogenicity of the transplant by matching donor and recipient for immunodominant epitopes, with the aim of reducing the potential for the immune response and the development of donor-specific HLA antibodies after transplantation.45,46 This topic will be covered in a later section. 

HLA-Specific Allosensitization The single most important function of an H&I laboratory is to detect recipient immunologic priming against foreign HLA (allosensitization) and to avoid transplantation of recipients with preexisting donor HLA-specific antibodies (DSA). After an encounter with HLA alloantigens, naïve T and B lymphocytes elicit immune effector functions to isolate and destroy allogeneic tissue. In the context of transplantation, however, calcineurin-based immunosuppressive regimes are effective in blocking naïve T and B cell activation and, in the modern era, early allograft loss in nonsensitized recipients due to irreversible allograft rejection is uncommon. In contrast, memory T and B cells that have been primed by previous exposure to foreign HLA are often resistant to conventional immunosuppressive therapy and are likely to cause irreversible cellular and/or humoral allograft rejection. Although HLA matching is effective in

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avoiding transplantation between “incompatible” allosensitized donor–recipient pairs, because of the high level of heterogeneity between HLA types within and between populations, most organ transplants between genetically unrelated individuals are mismatched at one or more HLA loci. HLA-specific allosensitization can occur at both the T cell (cellular) and B cell (humoral) level but current technology to detect alloreactive memory T and B cells is limited to translational research in specialist laboratories.47,48 In the absence of large scale routinely applicable assays to detect cellular sensitization, allosensitization is determined indirectly by the presence of circulating IgG HLA-specific antibodies in recipient serum.49 HLA-specific IgG is secreted by long-lived bone marrow resident plasma cells that are formed after B cell/alloantigen engagement and cognate interaction with CD4 (helper) T cells. This results in B cell maturation, clonal expansion, immunoglobulin class switch (from IgM to IgG), and the formation of antigen-specific memory T and B cells. On repeat exposure to the same antigen, memory T and B cells elicit a rapid and aggressive immune response with potential to cause irrevocable graft damage. Therefore circulating IgG HLA-specific antibodies are an effective but incomplete surrogate for detecting alloreactive T and/or B cell memory. The most common route of patient allosensitization is by exposure to foreign (nonself) HLA after blood transfusion, pregnancy, and/or a previous allograft. Approximately 20% of pregnant women produce HLA-specific antibodies to paternally inherited fetal HLA antigens and pregnancy followed by blood transfusion is a potent stimulus for the formation of high-level and broadly reactive IgG HLA-specific antibodies. Similarly, HLA-specific antibody formation is common after a failed allograft, and many such patients become “highly sensitized” with antibodies that react to HLA alloantigens present in the majority of the potential donor population. The extent of sensitization in patients awaiting a second or subsequent transplant is related to the number of donor-recipient HLA mismatches and continuation or withdrawal of maintenance immunosuppression after graft failure and return to the transplant waiting list.50,51 Therefore, to avoid the development of high levels of sensitization, clinical management of patients with a failing graft should include consideration of the risks associated with maintaining immunosuppression together with future options and a timescale for repeat transplantation.52 In addition to these classical routes of allosensitization there is increasing awareness of naturally occurring HLA-specific antibodies that may result from cross-reactivity with infectious agents or autologous tissue damage. Such “idiopathic” antibodies are reactive with specific epitopes expressed on denatured HLA proteins (considered clinically benign) or native (conformationally folded) HLA proteins that have potential to cause graft rejection.53

HLA-SPECIFIC ANTIBODY DETECTION AND CHARACTERIZATION Over the past 15 years new technologies for the detection and characterization of HLA-specific antibodies have been developed enabling a more accurate assessment of complex antibody populations present in patient serum and comprehensive elucidation of a patient’s sensitization profile. The available technologies are outlined next. 

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COMPLEMENT-DEPENDENT LYMPHOCYTOTOXICITY The complement-dependent lymphocytotoxicity (CDC) test was the first technique applied routinely for HLA-specific antibody screening; it is also used for the donor lymphocyte crossmatch test. In this assay, lymphocyte target cells are used to detect complement-fixing IgM and IgG antibodies present in patient’s serum, as indicated by cell lysis after the addition of rabbit complement (Fig. 10.3). IgM antibodies can be differentiated from IgG antibodies by pretreatment of patient serum with dithiothreitol (DTT) that reduces the disulfide bonds in the IgM pentamer, but leaves IgG relatively intact. Patient serum is tested against lymphocyte panels obtained from volunteer blood donors that can either be “random” or alternatively “selected” to represent the HLA types in the potential organ donor population (termed panel reactive antibodies; PRA). The CDC assay is used to indicate the presence (and provide limited specificity analysis) of recipient lymphocytotoxic antibodies with potential to cause a positive donor lymphocyte crossmatch. There are a number of limitations of the CDC technique. Only complement-fixing antibodies are detected, viable donor lymphocytes are required, and the assay sensitivity is dependent on the particular batch of rabbit complement used. Characterization of complex antibody profiles in patient serum is limited, and both HLA and non-HLA lymphocytotoxic antibodies are detected. Although the use of DTT can differentiate IgM from IgG antibodies, this does not indicate the specificity of the antibody and potentially clinically relevant weak IgG HLA-specific antibodies may also be rendered negative after the addition of DTT to patient serum. Reactivity resulting from an IgM HLA-specific antibody is indistinguishable from reactivity of an IgM non-HLA-specific (often auto-reactive) antibody. However, such antibodies are frequently weak or nonreactive with lymphocytes from patients with B cell chronic lymphatic leukemia (CLL), and therefore including these cells in the screening panel can be useful in elucidating a patient’s antibody profile.54 There have been a number of approaches used to increase the sensitivity and specificity of the CDC test to detect lowlevel antibodies that are potentially harmful. These include increasing the incubation times, the wash (Amos) technique and augmentation with antihuman globulin (AHG). In the Amos technique, unbound antibody is washed from the cell suspension before the addition of rabbit complement, thus removing the anticomplementary factors and low-affinity IgM antibodies in the serum to preferentially detect clinically relevant IgG antibodies. In the AHG augmentation CDC test, antikappa light chain is added to the washed cells before the addition of complement, thus increasing assay sensitivity. 

SOLID-PHASE BINDING ASSAYS FOR HLASPECIFIC ANTIBODY DETECTION AND SPECIFICATION It is now recognized that humoral rejection caused by HLA class I- and/or class II-specific antibodies present at levels below the detection threshold of the CDC assay is a major cause of allograft rejection and year-on-year graft attrition.

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Kidney Transplantation: Principles and Practice Panel/donor lymphocytes

Recipient 1 serum

Viable cells (negative crossmatch)

Complement

Recipient 2 serum

Cell lysis (positive crossmatch)

Complement

A

B Fig. 10.3  (A) Lymphocytotoxic crossmatch test: Panel or donor lymphocytes are incubated with recipient serum in the wells of a microtiter (Terasaki) tray, followed by the addition of rabbit complement. After a second incubation period vital stains (e.g., acridine orange and ethidium bromide) are added and the wells are viewed using fluorescent (ultraviolet) microscopy to determine cell viability. (B) Lymphocytotoxic (CDC) crossmatch results. Panel A: viable lymphocytes take up acridine orange and appear a yellow-orange color (negative crossmatch). Panel B: lysed cells (have pores in the lymphocyte cell membrane caused by antibody binding and complement activation) take up ethidium bromide and appear a brown color (positive crossmatch).

This stimulated the development of new technology (solidphase binding assays; SPA) that provide increased test sensitivity (to detect low-level antibodies) and specificity (to identify antibodies likely to damage a transplanted organ).55 Various commercially available SPA kits are all based on the common principle—incubation of patient serum with purified HLA protein bound to a polystyrene surface and detection of HLA-specific antibody binding using a fluorochrome- or enzyme-labeled antihuman IgG conjugate. The first SPA techniques used for HLA-specific antibody detection and specification were enzyme-linked immunosorbent assay (ELISA) and flow cytometry, but more recently these have been largely superseded by “Luminex” technology that uses purified HLA proteins bound to polystyrene microbeads (Fig. 10.4). The microbeads are impregnated with two fluorescent dyes in different ratios to enable differentiation of up to 100 different bead populations using a dedicated dual-laser flow cytometer (Luminex platform). Each bead population is coated with purified HLA proteins of multiple or single HLA class I or HLA class II alleles which allow comprehensive detection and specification of HLA-A, -B, -C, and -DR, -DQ, and -DP specific antibodies, respectively. The antigen-coated beads are incubated with patient serum and HLA-specific

antibody binding is detected using a fluorescent-labeled antihuman-globulin antibody. Luminex single-antigen beads (SAB) enable rapid and simultaneous elucidation of multiple antibody populations in a patient’s serum and, for the first time, facilitates accurate specification of complex antibody profiles in highly sensitized patients.56,57 Although commercially available Luminex-based HLAspecific antibody detection and specification kits are currently licensed for qualitative use only, the semiquantitative readout (Median Fluorescence Intensity; MFI) has been used to indicate antibody levels that form an important function in informing a pretransplant immunologic risk assessment. However, the Luminex assay is subject to a number of in  vitro artifacts, and interpretation of MFI values requires caution and expert knowledge. SAB express variable levels of denatured HLA to which antibody binding is common, giving rise to a false-positive DSA. In addition, inhibitory factors in patient sera may block HLA-specific antibody detection and give rise to a misleadingly low assessment of DSA. Such inhibition, however, is easily overcome by serum dilution, heat inactivation, or the addition of EDTA.58,59 Furthermore, Luminex SAB screening enables real-time posttransplant antibody monitoring of DSA to support the diagnosis and response to treatment for antibody-mediated

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147

Flow cytometry/Luminex

1. Antigen-coated microparticle or plastic surface

3. Labeled secondary antibody (e.g., 2. Patient serum containing antigen- FITC conjugated anti-human IgG) to specific alloantibody detect alloantibody binding

ELISA

A

B Fig. 10.4  (A) Schematic representation of antibody screening using Luminex solid-phase binding assay: (1) Purified HLA proteins (either pooled HLA specificities or single-antigen specificities) coated onto a solid phase (e.g., microparticles [Flow cytometry/Luminex]) are incubated with patient serum; (2) HLA-specific antibodies bind to the antigen coated beads and nonspecific antibodies are washed off; (3) IgG HLA-specific antibodies bound to the antigen coated beads are detected using a conjugated (e.g., FITC antihuman IgG) secondary antibody and fluorescent signal under excitation by a laser. (B) An example of HLA-specific antibody specification using Luminex Single Antigen beads, illustrating binding to a common HLA epitope (HLA-Bw4) present on certain HLA-B antigens and Bw4-expressing HLA-A antigens (HLA-A23, A24, A25, A32).

rejection.55 These assays are more sensitive than CDC, and they primarily detect IgG, but can also be modified to detect IgM60 and complement fixing (C1q/C4a/C3d) antibodies.61–63 

ANTIBODY SCREENING STRATEGIES The aim of an antibody screening strategy is to determine whether the patient has developed HLA-specific antibodies and if so, the antibody level, immunoglobulin class, and specificity. The results facilitate the generation of a list of “acceptable” (antibody negative or antibody levels below a predefined threshold) and “unacceptable” (antibody positive) donor HLA mismatches for each patient to guide organ allocation and the selection of suitable antibodycompatible donor–recipient pairs. All laboratories supporting renal transplantation have an antibody screening

strategy but may use different approaches and technologies. One common strategy is to perform an initial screen to detect the presence of HLA class I and class II antibodies (e.g., Luminex “mixed beads”) and then to perform antibody specificity analysis using single-antigen HLA-antibody detection beads (SAB). To perform effective antibody screening, patient serum samples should be obtained at regular intervals while on the transplant waiting list to provide a historical and contemporary assessment of antibody levels and specificity. 

PATIENT SENSITIZATION PROFILE AND DEFINITION OF UNACCEPTABLE SPECIFICITIES Comprehensive knowledge of a patient’s allosensitization events, the HLA antibody specificities, levels, immunoglobulin class (IgM/IgG), and timing of appearance/

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disappearance of HLA antibodies enables the definition of “unacceptable HLA mismatches” where DSA levels above a given threshold are likely to cause uncontrolled antibody-mediated rejection and constitute a veto to transplantation. The antibody level considered as unacceptable for a given donor HLA mismatch varies between patients and centers, and is dependent on the clinically acceptable level of immunologic risk, patient clinical status, donor type (i.e., living donor, donor after circulatory death, or donor after brain death), the likelihood of alternative (lower risk) options, and the local clinical management policy for undertaking HLA-specific antibody incompatible (HLAi) kidney transplantation. HLA mismatches from a previous transplant and mismatched paternal specificities after pregnancy may also be considered unacceptable. In countries or regions where there is exchange of kidneys, these unacceptable HLA specificities are registered with the organ exchange organization to prevent unnecessary shipping of organs to HLA antibody incompatible patients with a predicted positive donor lymphocyte crossmatch (termed a “virtual crossmatch”). The list of unacceptable HLA specificities to which a patient is sensitized can be compared with the HLA types of the organ donor population to determine the proportion of donors that would be antibody incompatible with each patient on the transplant waiting list. The terms “calculated HLA antibody reaction frequency” (cRF) and “calculated panel reactive antibodies” (cPRA) are used synonymously to describe the level of allosensitization, where 0% cRF is nonsensitized, 50% cRF is antibody incompatible with half of a random donor pool, and 90% cRF would be antibody incompatible with 9 out of 10 random donors. 

Donor Crossmatch High levels of donor-specific HLA antibodies detected in the pretransplant DTT-modified CDC donor lymphocytotoxic crossmatch have a detrimental effect upon graft outcome, with the majority of transplants succumbing to hyperacute or acute humoral rejection. In the absence of preemptive antibody removal strategies such antibodies constitute a veto to transplantation. Recipient antibodies against the mismatched donor HLA bind to the vascular endothelium of the transplanted organ, disrupt the intercellular junctions, and cause release of cell surface heparin sulfate and loss of the antithrombotic state, thereby leading to rapid, uncontrollable activation of the thrombotic and complement cascades. The resultant intravascular coagulation and interstitial hemorrhage can lead to graft destruction within minutes or hours after revascularization of the organ. More recently, the clinical importance of low-level donor HLA-specific antibodies, only detectable using more sensitive Luminex-SPA and/or flow cytometric crossmatch assay (but CDC negative), have also become apparent as a cause of antibody-mediated rejection. Unlike a positive IgG-CDC donor crossmatch, weak donor HLA-specific sensitization does not necessarily constitute a veto to transplantation but instead informs an individualized immunologic risk stratification. It is therefore necessary to consider the choice of crossmatch technique(s) used in conjunction with the antibody screening strategy and the patient’s sensitization status.64

DONOR CROSSMATCH TECHNIQUES AND THEIR CLINICAL RELEVANCE The purpose of a pretransplant donor crossmatch is to detect donor-specific sensitization predictive of hyperacute, acute, and chronic rejection (cellular and humoral) and to ensure appropriate therapeutic strategies are in place that are effective at controlling the ensuing rejection response. Therefore the crossmatch strategy must define the immunologic risk by distinguishing antibodies that are likely to be harmful, the type of rejection response that is likely to occur, and therapeutic strategies to treat and control the rejection response. Because of the intricate relationship between this and the clinical program, crossmatch strategies vary between centers, dependent on laboratory and clinical facilities and expertise. 

COMPLEMENT-DEPENDENT LYMPHOCYTOTOXIC CROSSMATCH The donor lymphocytotoxic crossmatch test was established in the 1960s and has remained a cornerstone for determining donor and recipient compatibility. Recipient cytotoxic antibodies (predominantly IgM, IgG3, and IgG1) that bind donor cells cause activation of the classical complement pathway and a high percentage of cell death above background levels is interpreted as a “positive crossmatch” with the potential to damage a transplanted kidney. Ensuring a negative pretransplant donor T cell lymphocytotoxic crossmatch (detecting HLA class I donor-specific antibodies) has virtually eliminated the occurrence of hyperacute rejection, but in its simplest form, the CDC crossmatch has several major drawbacks and has therefore been subject to many modifications (see previous discussion). 

B CELL CROSSMATCH Early studies of the clinical relevance of a positive pretransplant donor B-cell crossmatch were hampered by the inability to distinguish potentially damaging HLA class I and class II specific antibodies from nonharmful “non-HLA” antibodies. Contradictory findings ranged between no effect, an enhanced graft survival and poor graft survival. These findings can now be explained by the heterogeneous antibodies that can cause a positive B cell crossmatch. In studies where antibody specificity was defined, it was clear that the majority of CDC-positive B cell lymphocytotoxic crossmatches are caused by non-HLA specific, usually B cell autoreactive, antibodies that are not harmful to a transplant. A minority of positive B cell crossmatches are caused by IgG HLA class II specific antibodies that can be deleterious to transplant outcome, but are unlikely to cause HAR. The presence of unusually high-titer HLA-DR specific antibodies can, however, cause HAR and such antibodies are more common in patients with previous graft rejection.65–68 The introduction of Luminex-based antibody screening has now enabled precise specification of donor HLA class-II specific antibodies which, when applied together with the pretransplant donor B-cell crossmatch has confirmed the importance of HLA-DR, -DQ, and -DP antibodies in kidney allograft outcome.69–73 

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149

FITC (3) vs. CD3-PE

FS (1) vs. SS (2)

50

104

1023 0

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103 102 101 0

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100

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101

102

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101

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103

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Events

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C

RPE (CD3 vs. FITC)

55

0 100

103

0 100

D

101

102 FITC Fluorescence intensity

103

Fig. 10.5  Flow cytometric crossmatch test. (A) Cells pass through a laser beam and “forward and side light scatter” is detected by photomultiplier tubes. An “electronic gate” is used to select cells of morphologic interest (in this case lymphocytes). (B) T lymphocytes are identified using a recombinant phycoerythrin (RPE)-labeled CD3-specific antibody and HLA-specific IgG bound to cells is identified with FITC labeled antihuman IgG. (C) Light emission is detected and displayed as a “fluorescence histogram.” (D) Increased FITC fluorescence (a shift to the right on the fluorescence histogram) is a measure of HLA-specific IgG bound to T lymphocytes above that of the negative control indicating a positive crossmatch.

CROSSMATCH SERUM SAMPLE SELECTION (TIMING) An essential feature of the immune system is immunologic memory and its ability to produce a rapid and vigorous secondary response on reexposure to antigens to which an individual is already primed. To avert the risk of rejection caused by an anamnestic memory response, crossmatch regimens take account of the patient’s current antibody status and historic serum samples obtained throughout a recipient’s time on the transplant waiting list, which are selected to represent peak periods of sensitization. 

IMMUNOGLOBULIN CLASS AND SPECIFICITY The findings of acceptable primary graft survival but poor regraft survival associated with a historic positive (but current negative) crossmatch prompted further modification of the CDC crossmatch assay to identify the immunoglobulin class and specificity of antibodies causing a positive crossmatch. Taylor and colleagues74 reported acceptable primary and regraft survival associated with historic IgM HLA-­ specific sensitization but poor graft survival with historic IgG HLA specific antibodies. These results indicated that past allo-sensitization events that only resulted in a transient primary response and IgM allo-antibody production could be readily controlled by conventional

cyclosporine-based immunosuppression, whereas secondary responses (denoted as IgG positive) that commonly occur after pregnancy and previous transplant rejection are indicative of immunologic priming accompanied by T and B cell memory that is poorly controlled by immunosuppression. 

FLOW CYTOMETRIC CROSSMATCH TEST Although the CDC crossmatch was effective at averting HAR, it was apparent that a number of transplants still suffered primary nonfunction or delayed graft function, and this was particularly prevalent in sensitized patients and regrafts. This indicated that early graft dysfunction in sensitized recipients may be caused by low levels of antibody, below the sensitivity threshold of the conventional CDC crossmatch. Garovoy and colleagues75 addressed this question using a flow cytometric crossmatch (FC-XM) test (Fig. 10.5) capable of detecting low-level IgG HLA specific antibodies that were undetectable by CDC. In this retrospective study there was a higher incidence of delayed graft function and graft failure in the presence of a pretransplant flow cytometric positive (but CDC negative) donor crossmatch, indicating a pathogenic role for weak, sublytic HLA-specific antibodies. Others quickly corroborated this finding, but a significant proportion of patients had an uneventful clinical course, despite a positive FC-XM. These data demonstrated

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Kidney Transplantation: Principles and Practice

a high sensitivity but lower specificity of a positive FC-XM in predicting early graft dysfunction caused by antibodymediated rejection. Many centers were concerned that “false-positive” crossmatches would unnecessarily deny patients the opportunity of a transplant and were deterred from adopting the technique in routine clinical practice.76 Nevertheless, the predictive value of a positive result was higher in sensitized patients and regrafts that carry an increased immunologic risk of rejection and the increased assay sensitivity is widely used in such scenarios.77,78 The specificity of antibodies causing a positive donor T and/or B cell flow cytometric crossmatch test for predicting graft outcome has been further enhanced by the application of Luminex-based antibody screening. It is now widely accepted that a positive donor FC-XM in patients with proven DSA, determined using single-antigen HLA-specific antibody detection beads (Luminex-SAB), is associated with increased graft loss compared with a negative FC-XM or a positive FC-XM in the absence of DSA.79 The realization of the important role of DSA in chronic allograft loss is implicated by the deposition of complement activation products on peritubular capillaries together with circulating IgG DSA (detected by Luminex SAB) as a diagnostic marker for AMR. Loupy et  al. showed that DSA detected using the C1q modified Luminex SAB assay is associated with allograft rejection, suggesting that complement-fixing IgG isotypes (IgG1 and IgG3) confer high immunologic risk.80 It is not clear, however, if the additional information obtained using the Luminex C1q-SAB assay is independent of antibody strength as the Luminex C1q-SAB and IgG-SAB MFI values are highly correlated (see reviews81,82). 

ORGAN ALLOCATION AND PRETRANSPLANT DONOR CROSSMATCH TESTING Prolonged cold ischemia time (CIT) is a significant and controllable factor that has an adverse effect on deceased donor kidney transplant outcome. There is a progressive detrimental effect of CIT on transplant outcome with 90% survival at 1 year for organs transplanted within 20 hours compared with 83% for organs transplanted at >30 hours (relative risk 1.9).83 It is therefore essential that deceased donor organ allocation and crossmatch policies are designed to ensure a safe decision-making process and minimize delays in transplantation associated with the allocation process. The technical advances afforded by molecular (PCR-based) methods and Luminex-SAB antibody screening have facilitated HLA typing, organ allocation, and donor crossmatch strategies capable of identifying suitable recipients before completion of the organ retrieval operation and thus removing delays caused by histocompatibility testing. Many histocompatibility laboratories receive donor peripheral blood obtained early in the donation process, before commencing the retrieval operation. This enables prospective donor HLA typing and completion of local and national allocation algorithms to identify potential recipients before organ donation. In addition, modern cell separation techniques using immunomagnetic particles enable the recipient crossmatch to be performed using donor peripheral blood. In selected cases (e.g., nonsensitized patients with low immunologic risk) archived sera collected within the last 3 months are used in the crossmatch test, which

can be completed before patient admission. In cases, however, where there have been recent allosensitization events, particularly in patients undergoing repeat transplantation (e.g., changes in immunosuppression), it is necessary to undertake a prospective pretransplant donor lymphocyte crossmatch using patient serum obtained within 24 hours before the operation. 

THE VIRTUAL CROSSMATCH In selected cases where a patient’s antibody profile has been completely characterized and comprehensive data concerning allosensitization events is known, deceased donor organ allocation can be undertaken based on knowledge of the donor HLA type and a negative “virtual crossmatch.” A negative virtual crossmatch is ascertained by comparing the HLA mismatches of a donor with the patient’s recent and historic antibody-defined unacceptable mismatches, and when no donor HLA-specific antibodies are present, organs can be allocated to prospective recipients that have a high probability of a negative donor lymphocyte crossmatch. Such practice has been commonplace in the UK and Eurotransplant for many years and is effective at reducing the incidence of shipping deceased donor kidneys to patients that are subsequently found to have a positive crossmatch. The efficacy of this approach is, however, critically dependent on comprehensive donor HLA typing that includes a minimum resolution to define all clinically relevant HLA specificities to which a patient may develop antibodies. Donor HLA typing for the HLA-C, -DQ, and -DP loci is not routine in all countries or centers and under such circumstances a virtual crossmatch cannot be reliably performed.84 In carefully selected donor–recipient combinations where recipient sensitization is either absent or clearly defined low-level nondonor HLA-specific antibodies are present, a negative virtual crossmatch can be predicted with sufficient confidence to omit the prospective pretransplant donor lymphocyte crossmatch and proceed directly to transplantation.85 The adoption and stringent adherence to these and similar crossmatch policies removes delays to the transplant operation associated with donor–recipient histocompatibility testing resulting in lower cold ischemia time and reduced incidence of delayed graft function.64,86 

Immunologic Risk Stratification The role of histocompatibility laboratories has progressed from providing a simple binary decision to permit or veto transplantation, to the development of immunologic risk stratification policies that inform the clinical decision whether to proceed or not to transplantation and to selection of appropriate therapeutic options. The antibody screening and donor crossmatch techniques described earlier (CDC, FC-XM, and Luminex-SAB) provide different levels of sensitivity and specificity. This information, used together, can inform an individualized pretransplant immunologic risk assessment.71 This ranges from high immunologic risk of HAR in the presence of current high-level IgG donor HLA-specific antibodies that constitute a veto to transplantation in the absence of effective antibody reduction therapy; to intermediate immunologic risk, in which HAR is unlikely, but an increased incidence

10 • Histocompatibility in Renal Transplantation

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Fig. 10.6  Pretransplant immunologic risk assessment.  Relationship between pretransplant donor crossmatch (determined using CDC and Flow Cytometry), DSA levels (determined using Luminex single-antigen beads), the immunologic risk and decision to transplant.

of humoral rejection necessitates proactive application of effective treatment strategies; to low immunologic risk caused by low-level DSA associated with an increased incidence of rejection but little evidence of overall poor graft outcome. Such generalized risk stratification is not absolute because of additional factors such as immunologic memory, peak antibody level, antibody priming source, and timing. As a guide Fig. 10.6 and Table 10.3 illustrate the level of immunologic risk based on differences in sensitivity and specificity of the antibody screening and crossmatch techniques. CDC-XM detects only high levels of complement fixing antibodies, FC-XM provides more sensitive assessment for detection of lower level antibodies (below the threshold detectable by CDC), and Luminex-SAB provides the highest level of sensitivity for antibody detection but when applied alone, provides the lowest level of specificity to predict graft rejection. 

Strategies for Transplanting Sensitized and Highly Sensitized Patients One of the benefits of defining a patient’s HLA antibody profile is that it is possible to determine the frequency of the unacceptable HLA specificities in a donor pool and thus estimate the chance of receiving crossmatch-negative transplant. In the UK a calculated HLA antibody reaction frequency or “%cRF” can be determined for patients on the transplant waiting list by using a tool that compares a patient’s unacceptable HLA specificities and blood group against a file of 10,000 UK donors. Similar tools are available within Eurotransplant and in other organizations. Patients with a high %cRF are likely to be difficult to

TABLE 10.3  Generic Risk Assessment for AntibodyMediated Rejection Immunologic Risk

CDC-XM (IgG) FC-XM

Luminex-SAB DSA

High Intermediate Lowa Standarda

Positive Negative Negative Negative

Positive (MFI >5000) Positive (MFI >2000) Positive (MFI 500–2000) Negative (MFI 7 years), and most of these patients are HSP. In the absence of a clinically urgent pediatric patient, long waiting patients have absolute priority when a suitable antibody-compatible kidney becomes available. This policy has enabled transplantation of many of these long waiting, HSPs. In future the aim is to identify patients with a very high %cRF at the time of listing and ensure that suitable kidneys are allocated to them, regardless of waiting time. Eurotransplant adopted a different approach and introduced the Acceptable Mismatch Program for HSPs. In this program extensive antibody screening was performed to identify “windows” in the patient’s immune repertoire. The HLA specificities of cells unreactive with the patient’s serum were identified as “acceptable mismatches.” The Acceptable Mismatch Program includes minimal mismatching criteria of full HLA-DR compatibility or matching for one HLA-B and one HLA-DR specificity. This has been a highly successful program, and 43% of patients entered into the program are transplanted within 6 months and 58% within 21 months.91 When this system was first introduced the antibody screening was performed on carefully selected cells with only one mismatched antigen with the HSP. This approach was extremely labor intensive and would only be possible in a laboratory with access to very large panels of HLA-typed cells. The advent of solid-phase assays with single-antigen preparations, and alternatively, cell lines expressing single HLA antigens,92 greatly expedites this type of approach. A computer algorithm “HLA Matchmaker” developed by Duquesnoy may assist in defining acceptable mismatches.14,93 In the algorithm each HLA specificity is represented as a string of amino acid triplets and it is possible to compare HLA specificities and thereby identify mismatched triplets. The theory is that if there are no triplets mismatched, then the specificity will not be recognized, and an immune response will not be generated. Clearly HLA antigens are not linear sequences, nor are amino acids in a protein “triplets”; nevertheless, the algorithm has been shown to assist in the process of specifying a patient’s sensitization profile.94–96 A recent analysis of the 10-year outcome of transplants performed in highly sensitized patients within Eurotransplant showed that patients who were transplanted through the Acceptable Mismatch Program on the basis of proven acceptable mismatches had superior graft survival to patients transplanted on the basis of unacceptable mismatches.97 This demonstrates the importance of careful HLA antibody specification on transplant outcome. 

Antibody Removal One of the options for transplanting sensitized patients is to use antibody removal techniques to reduce donor-specific HLA antibody before an HLA incompatible transplant (see Chapter 22). This is usually considered in the context

of living donation and the outcome of such transplants is an important consideration. A recent analysis of the UK National Registry for Antibody Incompatible Transplants showed that the 5-year transplant survival of HLA-incompatible transplants was 71% (95% confidence interval [CI] 66%–75%) compared with 78% (95% CI, 77%–79%) for standard living donor transplants and 88% (95% CI, 87%– 89%) for standard deceased donor transplants. This shows that the outcomes are acceptable when faced with a choice between waiting for an antibody-compatible deceased donor transplant and living donor antibody-incompatible transplantation.98 In considering patients for antibody removal, it is important that the HLA antibody specificities and DSA titers are determined before the commencement of antibody removal. This will help inform whether this approach is appropriate for a particular patient. Furthermore, during antibody removal it is important to monitor antibody levels to determine the effectiveness of the treatment regimen. Most centers use Luminex single-antigen beads for antibody monitoring and advocate that a final crossmatch against the potential donor is performed. After transplantation, antibody rebound usually occurs and monitoring antibody levels provides valuable information to indicate whether additional antibody removal is required. Experience in performing transplants after desensitization is mounting but because of the complexity in the management before and after transplantation, it may be that in the longer term, patients for transplantation after antibody removal are referred to specialist centers. 

Paired Exchange Paired exchange, or living donor exchange, is another option for patients who have a potential living donor, but for reasons of HLA or ABO antibody incompatibility the transplant cannot proceed. In such schemes reciprocally compatible donors and recipients are paired through an allocation algorithm and exchange transplants are undertaken. Simple systems pair two recipients and their respective donors and the transplants occur simultaneously, but it is possible that multiple exchanges can be undertaken when exchanges are undertaken simultaneously, although logistically complex, the process maximizes the chances that all transplants will proceed. There are other modifications of the process that facilitate chains of transplants. The first is “domino-paired donation” (DPD) whereby a chain of simultaneous living donor transplants is initiated by a kidney from a nondirected altruistic donor and ends with transplantation of the last donor kidney into a recipient registered for a deceased donor transplant.99 The second type of chain is termed nonsimultaneous extended altruistic donor (NEAD) chains. In the NEAD chains the transplants are not performed simultaneously and “bridge donors” are created, whose incompatible recipient is already transplanted and the donor waits to donate to another recipient. This process removes the requirement for complex logistics, but adds in a risk that the “bridge donor” may renege.100 There are well-established kidney exchange programs in the US and in Europe101–103 (see Chapter 23).

10 • Histocompatibility in Renal Transplantation

Of relevance to histocompatibility, to achieve efficient exchange it is crucial that the patients’ HLA antibody profiles are accurately defined to avoid positive crossmatches and disruption of planned exchanges. Most of the transplants performed by this route are antibody compatible, but in patients who are highly sensitized and thus difficult to transplant with a compatible donor from a relatively small donor pool, antibody incompatible transplantation can also be facilitated. By review the patient’s HLA antibody profile and unacceptable HLA specificities, it is possible to “delist” unacceptable specificities and achieve more favorable antibody incompatible transplants than would have been achieved with direct donation. 

Posttransplant Monitoring There is extensive literature on the development of donor HLA-specific antibodies after renal transplantation.104–106 DSA together with histologic and immunohistological (C4d staining) are features in the Banff scheme for the diagnosis of antibody-mediated rejection ABMR.107 These factors are known to have an important role in transplant failure.108–111 The proportion of recipients developing antibodies posttransplantation has been reported to range between 12% and 60%.112 This figure is not only influenced by the sensitivity of the assay system used to detect DSA, but also by clinical factors such as the nature and degree of HLA mismatching between the donor and recipient, immunosuppressive regimens and compliance with immunosuppression. The appearance of donor HLA-specific antibodies has been shown to be associated with a poorer outcome and with the occurrence of acute and chronic rejection, and is now recognized as the leading pathology of graft attrition and a major cause of graft loss.113,114 Analysis of serial posttransplant serum samples showed that donor-specific HLA antibodies are strongly predictive of allograft failure being detected before chronic rejection or transplant failure.115,116 The results of a large international prospective trial that included more than 4500 patients from 36 units also concluded that HLA antibody production precedes transplant failure.117 The temporal relationship between the appearance of DSA and onset of graft dysfunction can, however, range from months to many years and it is not yet clear that clinical intervention is effective to attenuate the clinical outcome which is dependent on antibody level and specificity.118,119 Mismatched HLA antigens are important stimuli for an alloimmune response, but antibodies to nonclassical polymorphic MHC antigens may also contribute. The MHC-related chain A and B antigens (MICA and MICB) are expressed on epithelia in response to cellular stress and on endothelium in  vitro. In the kidney MICA and MICB expression has been reported on tubular epithelia.120,121 Antibodies to MICA were reported in the sera of transplant recipients,122,123 but as the antigens are not expressed on lymphocytes124,125 MICA and MICB antibodies are not detected in standard crossmatch tests. Furthermore, donors and recipients are not routinely typed genotyped for MICA and therefore donor specificity of the MICA antibodies cannot be determined. Studies have demonstrated the presence

153

of MICA antibodies in transplanted patients and a higher incidence of antibodies in patients whose transplants failed.126,127 However, data from a large multicenter study showed that the presence of MICA posttransplant was not an independent risk factor for graft loss.128 

Future Directions The traditional approach to assessing HLA compatibility is to count the number of mismatched donor HLA specificities either for all loci together (i.e., 0–6 mismatches for HLA-A, -B, -DR) or at individual loci (i.e., 1.1.0., see previous). Since its inception, however, it has been recognized that HLA polymorphism has evolved from common ancestral genes undergoing equal and unequal recombination, gene duplication, DNA insertion, and point mutation. As a result many HLA specificities share common amino acid sequence motifs (epitopes) that give rise to extensive serologic cross-reactivity.129 Some “families” of HLA molecules are very similar, whereas others are highly divergent130 and are therefore likely to differ in their ability to evoke allograft rejection, depending on the amino acid sequence of mismatched donor HLA alleles in relation to the recipient HLA type. Historical attempts to identify “immunodominant” mismatches (e.g., taboo mismatches) that are more likely to be the target of a host rejection response have not withstood the test of time. However, modern DNA sequence-based technology now facilitates HLA typing at allele (2-field) level, which together with knowledge of tertiary protein structure enables a new approach to assess mismatched alloantigen immunogenicity. The amino acid sequence of donor HLA alleles are compared with the recipient HLA type and assessed using computer algorithms that are effective to predict alloantigen posttransplant alloantibody formation and graft outcome.131–133 Furthermore, atomic resolution homology modeling of HLA protein tertiary structure obtained by x-ray crystallography has been applied to compare surface physicochemical properties (electrostatic charge and hydrophobicity) that govern protein–protein (i.e., antibody–antigen) interaction, to provide a more precise assessment of donor alloantigen immunogenicity.130 It is now clear that assessing donor and recipient HLA mismatches at the amino acid sequence level, together with patient compliance and/or clinical reduction/withdrawal of immunosuppression are strong independent predictors of alloantibody formation and graft rejection.134,135 Such algorithms are widely accepted to provide superior assessment of donor–recipient HLA compatibility and can be used to assist pretransplant organ allocation and posttransplant immunologic risk assessment, to identify patients at increased risk of humoral rejection. In the future such algorithms will be a helpful guide for donor selection, and the choice and level of maintenance immunosuppression, with the aim of improving long-term allograft survival. 

Concluding Remarks HLA matching, definition of allosensitization, donor crossmatching, and posttransplant antibody monitoring all make important contributions to successful renal

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transplant programs. Growing knowledge of immunologic risk stratification together with accurate information about the availability and likelihood of alternative (lower risk) donor options can guide the clinical decision to proceed or not to transplantation and initiate preemptive therapy to optimize posttransplant clinical course and long-term graft outcome. Rigid adherence to unacceptable HLA mismatches defined by Luminex SAB alone may be unhelpful, but when applied together with CDC-XM and/or FC-XM, the information provides improved sensitivity and specificity to prospectively identify donor-recipient pairs with low, intermediate, and high risk of humoral rejection. High immunologic risk usually constitutes a veto to transplantation, low and intermediate risk HLAi transplantation should be avoided if alternative options are likely, and should only be undertaken with appropriate clinical caution. The immunologic risk of proceeding to transplantation should be assessed together with the clinical risk of not proceeding and the patient remaining on dialysis. The recent realization that donor HLA-specific alloantibodies are the leading cause of graft attrition has led to a reexamination of pre- and posttransplant allosensitization and the role of HLA matching. It is an exciting time as many of the traditional boundaries are being challenged to enable transplantation of patients who previously would have been unlikely to be transplanted.

References













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editors. Clinical Transplants 1998. Los Angeles, CA: UCLA Tissue Typing Laboratory; 1999. p. 107–13. 88. Fuggle SV, Martin S. Towards performing transplantation in highly sensitized patients. Transplantation 2004;78:186. 89. Fuggle SV, Johnson RJ, Bradley JA, et  al. Impact of the 1998 UK national allocation scheme for deceased heartbeating donor kidneys. Transplantation 2010;89:372. 90. Johnson RJ, Fuggle SV, Mumford L, et al. A new UK (2006) national kidney allocation scheme (2006 NKAS) for deceased heartbeating donor kidneys. Transplantation 2010;89:387. 91. Claas F, Witvliet MD, Duquesnoy RJ, et al. The acceptable mismatch program as a fast tool to transplant highly sensitized patients awaiting a post-mortal kidney: short waiting time and excellent graft outcome. Transplantation 2004;78:190. 92. Zoet YM, Eijsink C, Kardol MJ, et al. The single antigen expressing lines (SALs) concept: an excellent tool for the screening for HLA specific antibodies. Hum Immunol 2005;66:519. 93. Duquesnoy RJ, Witvliet M, Doxiadus II , et  al. HLA-matchmaker based strategy to identify acceptable HLA class I mismatches for highly sensitized kidney transplant candidates. Transplant Int 2004;17:22. 94. Duquesnoy RJ, Takemoto S, de Lange P, et al. HLA-matchmaker: a molecularly based algorithm for histocompatibility determination. III. Effect of matching at the HLA-A,B amino acid triplet level on kidney transplant survival. Transplantation 2003;75:884. 95. Goodman RS, Taylor CJ, O’Rourke CM, et al. Utility of HLAMatchmaker and single-antigen HLA-antibody detection beads for identification of acceptable mismatches in highly sensitized patients awaiting kidney transplantation. Transplantation 2006;81:1331. 96. Kosmoliaptsis V, Bradley JA, Sharples LD, et  al. Predicting the immunogenicity of HLA class I alloantigens using structural epitope analysis determined by HLAMatchmaker. Transplantation 2008;85:1817. 97. Heidt S, Haasnoot GW, van Rood JJ, et al. Kidney allocation based on proven acceptable antigens results in superior graft survival in highly sensitized patients. Kidney Int 2017;93:491. 98. Pankhurst L, Hudson A, Mumford L, et al. The UK National Registry of ABO and HLA antibody incompatible renal transplantation: pretransplant factors associated with outcome in 879 transplants. Transplant Direct 2017;3:181. 99. Montgomery RA, Zachery AA, Ratner LE, et al. Domino aired kidney donation: a strategy to make best use of live nondirected donation. Lancet 2006;368:419. 100. Aslagi I, Gichrist DS, Roth AE, et al. Non simultaneous chains and dominos in kidney paired donation-revisited. Am J Transplant 2011;11:984. 101. Segev DL, Genrty SE, Warren DS, et al. Kidney paired donation and optimizing the use of live donor organs. JAMA 2005;293:1883. 102. Johnson RJ, Allen JE, Fuggle SV, et  al. Early experience of paired donation in the United Kingdom. Transplantation 2008;86:1672. 103. De Klerk M, Kal-van Gestel JA, Haase-Kromwijk BD, et al. Eight years of the Dutch living donor kidney exchange program. Clin Transpl 2011;287. 104. Wiebe C, Gibson IW, Blydt-Hansen TD, et al. Evolution and clinical pathologic correlations of de novo donor-specific HLA antibody post kidney transplant. Am J Transplant 2012;12:1157. 105. Wiebe C, Gibson IW, Blydt-Hansen TD, et al. Rates and determinants of progression to graft failure in kidney allograft recipients with de novo donor-specific antibody. Am J Transplant 2015;15:2921. 106. Tambur AR, Wiebe C. HLA diagnostics: evaluating DSA strength by titration. Transplantation 2018;102:S23. 107. Haas M. An updated Banff Schema for diagnosis of antibody mediated rejection in renal allografts. Curr Opin Organ Transplant 2014;19:315. 108. Feucht HE, Schneeberger H, Hillebrand G, et al. Capillary deposition of C4d complement fragment and early renal graft loss. Kidney Int 1993;43:1333. 109. Terasaki PI. Humoral theory of transplantation. Am J Transplant 2003;3:665. 110. Koo DDH, Roberts ISD, Quiroga I, et al. C4d deposition in early renal allograft protocol biopsies. Transplantation 2004;78:398. 111. Cai J, Terasaki PI. Humoral theory of transplantation-mechanism, prevention, and treatment. Hum Immunol 2005;66:334.

112. McKenna RM, Takemoto S, Terasaki PI. Anti-HLA antibodies after solid organ transplantation. Transplantation 2000;69:319. 113. Loupy A, Hill GS, SuberBielle C, et  al. Significance of C4d Banff scores in early protocol biopsies of kidney transplant recipients with pre-formed donor-specific antibodies (DSA). Am J Transplant 2011;11:56. 114. Wiebe C, Nickerson P. Posttransplant monitoring of de novo human leukocyte antigen donor-specific antibodies in kidney transplantation. Curr Opin Organ Transplant 2013;18:470. 115. Lee PC, Terasaki PI, Takemoto SK, et al. All chronic failures of kidney transplants were preceded by the development of HLA antibodies. Transplantation 2002;74:1192. 116. Worthington JE, Martin S, Al-Husseini DM, et  al. Post-transplantation production of donor HLA-specific antibodies is a predictor of renal transplant outcome. Transplantation 2003;75:1034. 117. Terasaki PI, Ozawa M. Predicting kidney graft failure by HLA antibodies: a prospective trial. Am J Transplant 2004;4:438. 118. Terasaki PI, Cai J. Human leukocyte antigen antibodies and chronic rejection: from association to causation. Transplantation 2008;86:377. 119. Everly MJ, Everly JJ, Arend LJ, et al. Reducing de novo donor-specific antibody levels during acute rejection diminishes renal allograft loss. Am J Transplant 2009;9:1063. 120. Hankey KG, Deachenberg CB, Papadimitriou JC, et al. MIC expression in renal and pancreatic allografts. Transplantation 2002;73:304. 121. Quiroga I, Salio M, Koo DDH, et al. Expression of MHC class I-related chain B (MICB) molecules on renal transplant biopsies. Transplantation 2005;81:1196. 122. Zwirner NW, Marcos CY, Mirbaha F, et al. Identification of MICA as a new polymorphic alloantigen recognized by antibodies in sera of organ transplant recipients. Hum Immunol 2000;61:917. 123. Sumitran-Holgersson SS, Wilczek HE, HolgerssonJ, et al. Identification of the nonclassical HLA molecules, MICA, as targets for humoral immunity associated with irreversible rejection of kidney allografts. Transplantation 2002;74:269. 124. Zwirner NW, Fernandez-Vina MA, Stastny P. MICA, a new polymorphic HLA-related antigen, is expressed mainly by keratinocytes, endothelial cells, and monocytes. Immunogenetics 1998;47:139. 125. Zwirner NW, Dole K, Stastny P. Differential surface expression of MICA by endothelial cells, fibroblasts, keratinocytes and monocytes. Hum Immunol 1999;60:323. 126. Mizutani K, Teraski PI, Rosen A, et al. Serial ten year follow-up of HLA and MICA antibody production prior to graft failure. Am J Transplant 2005;5:2265. 127. Mizutani K, Terasaki P, Bignon JD, et  al. Association of kidney transplant failure and antibodies against MICA. Hum Immunol 2006;67:683. 128. Lemy A, Andrien M, Lionet A. Posttransplant major histocompatibility complex class i chain-related gene a antibodies and long-term graft outcomes in a multicenter cohort of 779 kidney transplant recipients. Transplantation 2012;93:1258. 129. Tambur AR, Claas FH. HLA epitopes as viewed by antibodies: what is it all about? Am J Transplant 2015;15:1148. 130. Mallon DH, Bradley JA, Taylor CJ, et al. Structural and electrostatic analysis of HLA B-cell epitopes: inference on immunogenicity and prediction of humoral alloresponses. Curr Opin Organ Transplant 2014;19:420. 131. Dankers MK, Witvliet MD, Roelen DL, et  al. The number of amino acid triplet differences between patient and donor is predictive for the antibody reactivity against mismatched human leukocyte antigens. Transplantation 2004;77:1236. 132. Kosmoliaptsis V, Sharples LD, Chaudhry AN, et al. Predicting HLA class II alloantigen immunogenicity from the number and physiochemical properties of amino acid polymorphisms. Transplantation 2011;91:183. 133. Duquesnoy RJ. HLA epitope based matching for transplantation. Transplant Immunol 2014;31:1. 134. Wiebe C, Nickerson P. Strategic use of epitope matching to improve outcomes. Transplantation 2016;100:2048. 135. Kosmoliaptsis V, Mallon DH, Chen Y, et al. Alloantibody responses after renal transplant failure can be better predicted by donor-recipient HLA amino acid sequence and physicochemical disparities than conventional HLA matching. Am J Transplant 2016;16:2139.

11

Surgical Techniques of Kidney Transplantation CHRISTOPHER J.E. WATSON, PETER J. FRIEND and LORNA P. MARSON

CHAPTER OUTLINE

Preparation of Recipient Preparation of Kidney Site Incision Preparation of Operative Bed Revascularization Arterial Anastomosis External Iliac Artery Internal Iliac Artery Venous Anastomosis Reperfusion of the Kidney Reconstruction of the Urinary Tract Ureteroneocystostomy (Anastomosis of the Transplant Ureter Directly to the Bladder) Transvesical Ureteroneocystostomy Extravesical Ureteroneocystostomy Parallel Incision Ureteroneocystostomy

Kidney transplantation is a major surgical procedure that involves both vascular and ureteric anastomoses, and it is usually performed by a dedicated transplant surgeon, although in the past it was performed predominantly by urologists or vascular surgeons. Most recipients are already established on dialysis, although some may avoid dialysis by having the transplant preemptively, and many consider this the gold standard treatment. Preemptive transplantation confers a modest benefit over transplantation after the start of dialysis, but not if the duration of dialysis is less than a year. There are concerns about equity of access to preemptive transplants, as it tends to disadvantage individuals who are less educated and from lower socioeconomic groups. In addition there is a suggestion that patients transplanted preemptively may have lower adherence to immunosuppression.1–3 Preemptive transplantation is particularly advantageous in children.4,5 Renal transplant recipients are frequently elderly, with other comorbidity (e.g., diabetes, cardiovascular disease, obesity), which increases the surgical and anesthetic challenges. In addition most have impaired platelet function through a combination of uremia and antiplatelet therapy (aspirin or clopidogrel), and some will be on warfarin for previous thromboembolic disease or prosthetic heart valves. Thus this group of patients carries a relatively high operative risk.

Double Ureters Augmented Bladder Pyelopyelostomy Pyeloureterostomy and Ureteroureterostomy Pyelovesicostomy Ureteroenterostomy Ureteric Stents Management of Catheter and Stent Closure Pediatric Recipient Pediatric Donor Double Kidney Transplant Transplant Nephrectomy

Preparation of Recipient The general preparation and selection of recipients for transplantation is discussed in Chapter 4. Potential kidney transplant recipients are carefully assessed before being placed on the waiting list. Medical and surgical risk factors will have been identified and evaluated, and periodically reassessed while waiting. On admission for transplantation, a further careful history and physical examination are required to ensure that there is no immediate contraindication to major surgery. For example, have there been changes since the patient was last assessed? Particular attention should be paid to the patient’s fluid and electrolyte status. In addition a history of recent sensitizing events should be elicited (blood transfusions, immunosuppression withdrawal in someone awaiting a retransplant). These should be brought to the attention of the histocompatibility laboratory. The patient may require dialysis before going to surgery because of fluid overload or a high serum potassium concentration; this will depend on the nature of dialysis and when this was last carried out. Potassium often rises as a consequence of anesthesia, blood transfusion, and reperfusion of the kidney; it is essential to ensure that the patient has a normal serum potassium pretransplant. It is much easier and safer to dialyze a patient before transplant than immediately posttransplant. 157

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The potential risks of a renal transplantation should be discussed with patients at the time of listing and must include general risks of surgery and specific risks of the procedure. These risks include technical complications such as arterial or venous thrombosis, bleeding or urinary complications, risk of delayed graft function (which can occur in up to 50% deceased donor kidney transplants), and of acute rejection. Careful explanation of the possible requirement for biopsy should be given. The need for immunosuppression, with its attendant drug-specific and immunosuppression-associated side effects, should also be discussed at the time of listing. Any recipient choices as to the nature of donors considered acceptable or not acceptable should be recorded (e.g., donors with a history of cancer or high risk behavior for hepatitis or HIV). At the time of admission for transplant, specific risks pertaining to the donor should be discussed with the patient where appropriate. Informed consent to proceed can then be obtained. Immunosuppression may be commenced before the patient goes to surgery. Although there is no hard evidence that preoperative immunosuppression is necessary, many centers prefer a loading dose of a calcineurin inhibitor or antimetabolite to ensure a better blood level in the first hours posttransplant. Induction agents (most typically basiliximab) are also started preoperatively. Where the recipient is receiving an antibody-incompatible graft (typically from a living donor), he or she will usually have received several days of preoperative immunosuppression in addition to undergoing antibody removal. Prophylaxis against deep vein thrombosis and pulmonary embolus should be undertaken with low dose molecular weight heparin according to hospital protocol, thromboembolic deterrent (TED) stockings, and perioperative intermittent calf compression. Although the transplant operation is a clean one, the patient will be immunosuppressed and is at high risk for wound infection. In addition it is possible for the deceased donor kidney to be contaminated during retrieval or for there to be a urinary tract infection as a consequence of the donor having a urethral catheter while on the intensive care unit before death. Infection in the vicinity of the vascular anastomosis may result in secondary hemorrhage, which is an uncommon but catastrophic complication, resulting in loss of the kidney, compromise of distal circulation, and significant mortality. Prophylactic antimicrobial therapy, with a spectrum to cover common skin organisms as well as possible urinary tract contaminants, has been shown to reduce the risk of developing sepsis with bacteremia and for developing bactiuria6; a single dose may be sufficient.7 Antimicrobial cover may also be required if the donor was known to be infected, such as donors dying from meningococcal meningitis; the advice of a specialist in microbiology is valuable in these situations. Consideration must be given at this stage to the cold ischemia time, which should be minimized. Prolonged cold ischemia is associated with increased rates of delayed graft function and worse long-term outcomes, particularly in transplants from donors after circulatory death.8 Logistical factors such as preoperative dialysis and the need for a prospective crossmatch, contribute significantly to cold ischemic times.9

After induction of anesthesia, a central venous catheter (CVC) may be inserted into the internal jugular vein (preferably under ultrasound guidance) to allow central venous pressure monitoring to ensure optimal fluid replacement and postoperative dialysis, although in some centers, the use of CVC may be reserved for those patients who will receive antithymocyte globulin (ATG) induction. In patients without hemodialysis access the selected catheter should enable postoperative hemodialysis if required. Subclavian vein cannulation should be avoided if possible because of the risk of causing subclavian venous stenosis, which would prejudice future upper-limb vascular access when the kidney has failed. Other aspects of the induction of anesthesia and monitoring during the operative procedure are discussed in Chapter 13. Once the patient is anesthetized, a urinary balloon catheter is inserted aseptically into the recipient’s bladder (see later). The skin should be prepared carefully in the operating room; body hair is removed and the skin of the abdominal wall prepared with an antimicrobial agent, typically chlorhexidine gluconate in alcohol.10 It is wise to prepare the entire abdomen from nipples to midthighs, especially in a recipient with vascular disease, because occasionally the original incision may need to be extended or abandoned and the opposite iliac fossa opened, or saphenous vein harvested to manage a vascular problem. Immediately before surgery, the World Health Organization (WHO) surgical safety check should be undertaken, giving additional consideration to checking blood group compatibility of donor and recipient and confirming the HLA crossmatch status. It is also important to ensure that the correct donor kidney is in the operating room. 

Preparation of Kidney The preparation of the deceased donor kidney should be done in advance of the transplant procedure in case some anomaly (for example, a previously unrecognized tumor) is present that would preclude transplantation, or damage is found that requires repair. Good preparation will ensure an adequate length of vessels with good hemostasis at the time of reperfusion, both in living and deceased donor kidneys. A varying degree of dissection of the kidney is required when the kidney is removed from cold storage. In the case of a deceased donor kidney removed as part of an en bloc procedure, considerable dissection needs to be performed, and this should be done carefully and with a good light on a back table with the kidney in a bowl of ice slush. The kidney should be oriented as it is in the body. The renal vein should be picked up and dissected toward the kidney, dividing small tributaries, and ligating and dividing the gonadal and adrenal veins. Dissection should not continue close to the renal pelvis. If there is more than one renal vein, smaller veins can be ligated, assuming that there is one large renal vein. If two renal veins are of equal size and are not arising from a single caval patch, there is a risk of subsequent venous infarction if one vein is ligated; it is preferable to implant both veins separately or to join the veins to form a common trunk for a single anastomosis. A short right renal vein can be extended with donor inferior vena cava or external iliac vein.

11 • Surgical Techniques of Kidney Transplantation

Once the venous preparation is complete, the renal vein may then be folded over the kidney and the artery dissected out from adherent fat. Care must be taken to define the arterial anatomy, ensuring that no polar arteries are damaged in the process. In particular, the right renal artery typically gives a branch to the adrenal which may occasionally pass on to supply the upper pole of the kidney. The ureter can now be dissected free, with care not to divide the tissue between the ureter and lower pole of kidney (the so-called golden triangle, see Chapter 29) and to retain a small amount of tissue around the ureter to preserve its blood supply. Once the kidney has been prepared, the perinephric fat can be removed. The kidney may then be flushed with 100 to 200 ml of kidney perfusion fluid, as this may remove products of metabolism and allows detection of defects in the artery or vein, which should be repaired at this stage. 

Site Although traditionally the right iliac fossa was used for implantation of the kidney,11–15 in reality there is little to choose between sides. It has been suggested that the left kidney is best placed in the right iliac fossa and the right kidney in the left iliac fossa, an approach that places the pelvis and ureter medially to facilitate future ureteric reconstruction, should it be required. In contrast, placing the deceased donor kidney on the ipsilateral side with anastomoses to the external iliac vessels avoids crossing the renal artery and vein, and may be facilitated by the use of a subrectus pouch (see later); similarly, live donor kidneys implanted using the internal iliac artery may be placed contralaterally to avoid vessels crossing. In general, however, it is reasonable to use either iliac fossa for placement of the kidney. Other factors which may dictate the optimal site of placement include the existence of previous abdominal incisions, particularly if placement of a transplant incision would result in devitalizing an area of abdominal wall. Previous venous thrombosis in one leg is an indication to use the opposite side lest the thrombus has obliterated the ipsilateral iliac veins. A history of femoral vein cannulation is also a relative contraindication to use that side for fear of iliac venous thrombosis or partial thrombosis. If a colostomy or ileostomy were emerging from one side of the abdomen, the contralateral side would usually be chosen, although it would be preferable to use the same side as an ileal conduit (urostomy) to facilitate ureteric implantation. The presence of large polycystic kidneys may dictate which side is chosen, as there may only be room to implant a kidney on one side. Occasionally the polycystic kidneys are too large to permit placement of a transplant. Such a situation should be picked up as part of the assessment process and one or both polycystic kidneys should be removed before the patient is activated on the transplant list. Polycystic nephrectomy is best done either laparoscopically or through a midline incision; a transverse incision is contraindicated to avoid later concerns regarding skin viability when performing the transplant incision. In children, in whom the vascular anastomoses of the renal vessels may be to the aorta and vena cava because of the size of the kidney, the right side is preferred because the kidney is placed behind the cecum and ascending colon.

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Where combined pancreas and kidney transplantation is performed via a vertical midline transperitoneal approach, the pancreas is usually placed in the right iliac fossa and the kidney in the left iliac fossa. To prevent torsion of the renal pedicle, the kidney is best placed in the retroperitoneal space, which is accessed by inserting an index finger into the prevesical space just lateral to the midline and developing the plane laterally.16 

Incision There are two common incisions used to expose the external iliac vessels and bladder. The oblique Rutherford Morison or curvilinear incision is made in the right or left lower quadrant of the abdomen beginning almost in the midline 2 cm above the pubic tubercle and curving upward and 2 cm parallel to the inguinal ligament and ending just above the anterior superior iliac spine of the iliac crest. Caution is taken to avoid the lateral cutaneous nerve of the thigh, which emerges through external oblique 1 cm medial to the anterior superior iliac spine. In a child or small adult, this incision can be carried up to the costal margin to increase exposure.17 The external oblique muscle and fascia are divided in the line of the incision and split to the lateral extent of the wound. This incision is carried medially on to the rectus sheath to permit retraction or division of part of the rectus muscle for later exposure of the bladder. To expose the peritoneum, the internal oblique and transverse muscles are divided with cautery in the line of the incision. The Alexandre or pararectal incision is slightly more vertical than that of Rutherford Morison. It starts 2 cm above the pubic symphysis and passes laterally and cranially along the edge of the rectus sheath, two finger breadths medial to the anterior superior iliac spine. The confluence of the oblique abdominal muscles just lateral to the rectus sheath (the Spigelian fascia) is divided to expose peritoneum beneath. Once the peritoneum is exposed, the inferior epigastric vessels may be ligated and divided to improve access, but if there are multiple renal arteries, the inferior epigastric vessels should be preserved in the first instance in case the inferior epigastric artery is required for anastomosis to a lower polar renal artery. It may also be wise to preserve the vascular supply to the rectus muscle if the muscle has been divided in previous surgery, for example, during a subcostal incision to remove an ipsilateral kidney, gallbladder, or spleen. Although division of the spermatic cord was advocated in early descriptions of the procedure and was common practice for many years, it should not be done and is rarely required for adequate exposure. The spermatic cord may be freed laterally, which allows it to be retracted medially. In females the round ligament can be divided between ligatures. 

Preparation of Operative Bed After exposure of the transversalis fascia and peritoneum, the transversalis fascia is divided, and the peritoneum is reflected upward and medially to expose the psoas muscle

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and the iliac vessels. This is best done in a caudal to cranial direction. At this stage, a self-retaining retractor is inserted to provide good exposure while allowing the assistant to have both hands free to assist with the anastomosis. Dissection proceeds in the first instance to expose the external, common, and/or internal iliac arteries, depending on circumstance: the external iliac artery is the site of first preference if there is a healthy Carrel patch on the donor renal artery; the internal iliac artery may be considered if not, and the common iliac artery if it is a second transplant or if there is significant arterial disease affecting the external iliac vessels. Considerations in children are discussed later. The lymphatics that course along the vessels are preserved where possible and separated from the artery without division. It has been suggested that lymphatics should be ligated and not cauterized when being divided, because this is said to prevent the later occurrence of a lymphocele, although what evidence there is does not support that suggestion (see Chapter 28).18 The surgeon must be careful not to mistake the genitofemoral nerve for a lymph vessel. It lies on the medial edge of the psoas muscle, and a branch may cross the distal external iliac artery. If the internal iliac artery is to be used, it is important to mobilize a length of the common and external iliac arteries so that the internal iliac artery can be rotated laterally without kinking at its origin and so that the vascular clamps can be applied to the common and external iliac arteries when the internal iliac artery is short. Care is taken to inspect the origin of the internal iliac artery, if this is to be used, for any evidence of atheroma and, similarly, any atheromatous disease in the common or external iliac artery should be noted. If there are two or more renal arteries not on a Carrel patch of aorta, the dissection of the internal iliac artery is extended distally to expose the initial branches of the internal iliac artery, which may be suitable for anastomosis to individual renal arteries. This can be done either in situ, or the bifurcation of the internal iliac removed and a back table anastomosis of the two renal arteries onto the divisions of the internal iliac artery performed, before the kidney is implanted using the resected portion of recipient internal iliac as an interposition graft.19 Having completed the exposure of the appropriate iliac arteries, dissection of the external iliac vein is performed (Fig. 11.1). If a left kidney with a long renal vein is available, dissection of the external iliac vein alone generally allows a satisfactory anastomosis without tension. Uncommonly, if the kidney has a very short renal vein, such as with a right kidney or occasionally a left kidney whose vein has been shortened, or if the recipient is obese, the internal iliac vein and usually one or two gluteal veins can be ligated and divided. This technique allows the common and external iliac veins to be brought well up into the wound, particularly if the internal iliac artery is divided, and this facilitates the performance of a tension-free anastomosis. However, division of the internal iliac and gluteal veins is not without risk, because slippage of the ligature may result in hemorrhage that is difficult to control. Alternative means of managing short renal veins are preferred, including use of the parachute technique for venous anastomosis, a more distal placement on the external iliac vein, or use of a segment of donor inferior vena cava to lengthen the renal vein. Temporary placement of the cold kidney graft into the wound assists in the selection of the sites for anastomosis on the recipient artery and vein. 

Fig. 11.1  Iliac vessels dissected free.

Revascularization Anomalies of the renal artery or vein are common, amounting to 30% deceased donor kidneys retrieved.20 In living donation, whereas kidneys are selected preferentially to have a single artery, multiple arteries are common. Because the renal arterial inflow comprises end arteries with no intrarenal communication, all arteries need to be perfused, but particularly the lower-pole artery, because it is likely to give rise to the ureteric blood supply. If multiple arteries are present and separate (i.e., not on a common Carrel patch), there are several surgical techniques that can be used: The vessels can be spatulated together to form a common trunk (Fig. 11.2),17 the internal iliac artery can be removed from the recipient and its branches used to anastomose to the renal arteries on the back table,19 a smaller artery may be anastomosed end-to-side to the larger main renal artery, a small accessory artery can be anastomosed to the inferior epigastric artery, or the renal arteries can be implanted separately into the external iliac artery. A small upper polar artery, if thought to be too small to anastomose safely to the major renal artery, may be ligated, provided that it supplies less than one-eighth of the kidney (this should be evident on perfusion of the kidney after removal). A deceased donor kidney usually has a renal artery or arteries arising from a single aortic patch, and this patch should be trimmed to an appropriate size and used for anastomosis to the external iliac artery. If two renal arteries are widely separated on the aortic patch, the patch may be divided to allow separate implantation into the external iliac artery, or the two separate patches joined together to form a shorter patch, or one may be implanted end-to-side to the external iliac artery and the other to the internal iliac artery, or both may be implanted to separate branches of the internal iliac artery.

11 • Surgical Techniques of Kidney Transplantation

End-to-end

161

End-to-side

Internal Iliac Artery

Two renal arteries on a patch

Two renal arteries separate anastomoses Ligated trunks of artery CIA

Fig. 11.3  Anastomosis of two renal arteries to the external iliac artery. (From Lee HM. Surgical techniques of renal transplantation. In: Morris PJ, editor. Kidney transplantation. London: Academic Press/Grune & Stratton; 1979. p.149.)

EA

A

the side of the glove.22 This technique not only keeps the kidney cool during the anastomosis, but also facilitates handling of the kidney.

B

Two arteries joined as a pantaloon

Interposition y-graft of native internal iliac artery

Fig. 11.2  Variations of renal artery anastomoses. (From Lee HM. Surgical techniques in renal transplantation. In: Morris PJ, ed. Kidney Transplantation. London: Academic Press/Grune & Stratton; 1979. p.150.)

Before making the arteriotomy or venotomy, the surgeon should mentally visualize the kidney in situ in its final resting place, as well as picturing the course that the renal artery and vein would take to ensure the optimal site for the anastomosis. Where the renal artery is much longer than the vein, it may either be electively anastomosed on the internal iliac artery or, more simply, the artery can be anastomosed to the external iliac artery but the kidney placed in a subrectus pouch fashioned by dissecting the peritoneum from the underside of the rectus muscle.21 In such a position, the longer artery tends to run a smooth course. When the kidney has been prepared and is ready for implantation, the vessels are now ready for clamping. Heparin may be administered in a modest dose (e.g., 30–60 IU/kg), although many surgeons simply cross-clamp the recipient vessels without heparinization in patients already on dialysis. The kidney should be kept cold during the implantation phase. This may be achieved in a number of ways, such as wrapping in a surgical gauze swab filled with crushed frozen saline. Another technique uses a surgical glove to contain the kidney together with crushed ice, the vessels being brought out through a small cut in

ARTERIAL ANASTOMOSIS External Iliac Artery An end-to-side anastomosis of the renal artery to the external iliac artery (or common iliac artery) usually is performed using an appropriately trimmed cuff of aorta attached to the renal artery (the Carrel patch) (Fig. 11.3). Vascular clamps are applied to the external iliac artery proximally and distally if an end-to-side anastomosis is to be performed, with care taken to avoid clamping diseased segments of artery wherever possible. An arteriotomy appropriately placed is performed in the external iliac artery, and the lumen is flushed out again with heparinized saline; where the donor artery has no Carrel aortic patch, a hole punch is used to create a suitably sized hole for anastomosis. The anastomosis is done with a continuous 5-0 or 6-0 monofilament vascular suture (see Fig. 11.2),17 although an interrupted technique may be necessary where no Carrel patch exists. In older patients and those who have been on dialysis some time, the intima may be calcified and may be easily displaced from the wall of the artery. Particular care should be taken to ensure that all the intima on the recipient artery is secured back in position during the anastomosis to prevent a dissection propagating along the distal artery on reperfusion. In very severe cases of calcification of the recipient artery, it may be necessary to carry out a formal endarterectomy of the iliac artery, with the distal intima stitched in place to prevent formation of a flap and subsequent dissection. 

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Internal Iliac Artery The internal iliac artery should not be used for anastomosis if the contralateral internal iliac artery has already been used for a previous transplant or if the contralateral limb relies on collaterals from the ipsilateral internal iliac for its perfusion (for example, where the contralateral common iliac artery is occluded). If the internal iliac artery is to be used, its distal branches are ligated. A vascular clamp is applied to the internal iliac artery close to its origin (to reduce the chances of clot forming in the occluded stump) or to both the common and external iliac arteries. The internal iliac artery is then divided close to or at the bifurcation maximizing its length, and the lumen is flushed out with heparinized saline. The internal iliac artery is anastomosed end-to-end to the renal artery with 5-0 or 6-0 monofilament vascular suture using a three-point anastomosis technique, as described by Carrel in 1902,23 or a two-point anastomosis (Fig. 11.4)17; alternatively, the parachute technique may be used, only tying the sutures after first placing all the sutures individually. If there is a disparity between the renal artery and the internal iliac artery, the renal artery being considerably smaller in diameter, the renal artery may be spatulated along one side to broaden the anastomosis. If one side of the renal artery is spatulated, care should be taken to place the spatulation of the renal artery appropriately, taking into consideration the final curve of the internal iliac artery and the renal artery to avoid kinking when the kidney is placed in its final position.17 If both arteries are small, the anastomosis should be performed with interrupted sutures to allow for expansion. In a child or a small adult with small arteries, the whole anastomosis should be performed with interrupted sutures. 

VENOUS ANASTOMOSIS The renal vein is anastomosed end-to-side, usually to the external iliac vein. The external iliac vein is clamped

proximally and distally with vascular clamps or a Satinsky side clamp is used. The venotomy is flushed out with heparinized saline. Where possible the site of venotomy should be proximal or distal to a valve, and if a valve is present at the site of the venotomy, it should be removed carefully. The anastomosis is fashioned using a continuous 5-0 monofilament vascular suture, with the initial sutures placed at either end of the venotomy (Fig. 11.5).17 A useful aid when doing the venous anastomosis is to place an anchor suture at the midpoint of the lateral wall, which allows the external iliac vein and the renal vein on the lateral side of the anastomosis to be drawn clear of the medial wall of the anastomosis (Fig. 11.6). This technique reduces the risk of the back wall being caught up in the suture while the medial wall is being sutured. An alternative, and one suited to larger patients, is to use the parachute technique, placing several sutures at the cranial aspect of the medial suture line before parachuting the anastomosis down. This has the benefit of distributing the tension over a wider area of vein, so there is less likelihood of the suture pulling out. The renal vein is usually anastomosed to the external iliac vein medial to the external iliac artery, although on occasion it may be lateral to the artery. Wherever the anastomosis is positioned, it is important to ensure that the renal vein is under no tension, and care should be taken that the vein is not twisted before starting the anastomosis. When a small child receives an adult kidney, it is sometimes necessary to shorten the renal vein to prevent kinking, especially when the vein is anastomosed to the inferior vena cava. If the venous anastomosis is fashioned before the arterial anastomosis (such as when the external iliac artery is to be used), it may be desirable to remove the venous clamps to permit return of blood from the leg, so shortening the duration of venous stasis. This is best achieved by placing a separate fine bulldog clamp close to the anastomosis on the renal vein before removing the iliac vein clamps, so preventing reflux of

Fig. 11.4  Internal iliac (hypogastric) artery ligated and divided, the lumen flushed with heparinized saline. (From Lee HM. Surgical techniques of renal transplantation. In: Morris PJ, editor. Kidney transplantation. London: Academic Press/Grune & Stratton; 1979. p.148.)

11 • Surgical Techniques of Kidney Transplantation

blood into the kidney. It is important that the bulldog clamp is not traumatic to the vein, and does not slip off the vein— two clamps are often better than one to ensure the latter. This maneuver also allows any bleeding from the venous anastomosis to be managed before the kidney is revascularized. The question of whether the arterial anastomosis or the venous anastomosis should be done first depends on the final position of the kidney and the ease with which the second anastomosis may or may not be done. If the renal artery is to be anastomosed end-to-side to the external iliac artery (usually with a Carrel patch of aorta), it is preferable to do the venous anastomosis first, then the end-to-side arterial anastomosis can be positioned correctly. If the renal artery is to be anastomosed to the internal iliac artery, the arterial anastomosis may be done first because this enables the renal vein to be positioned appropriately. 

REPERFUSION OF THE KIDNEY Vascular clamps are removed sequentially, starting either with the venous clamps (proximal first then distal), or the arterial clamps (distal first then proximal), depending on surgeon preference. Once the kidney is reperfused, attention should be paid to controlling significant bleeding points on the anastomoses and ligating any tributaries that were missed during the back table preparation. The quality of reperfusion is variable. Live donor kidneys and kidneys that have been subject to machine preservation reperfuse evenly and become pink very quickly. Deceased donor kidneys, particularly those with prolonged cold ischemia or those donated after circulatory death, tend to be patchy for some time. Although this usually resolves over time, it is important to ensure the following:    All the clamps have been removed. The artery is not twisted. □  The recipient has a good blood pressure. □  □ 

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There is no intimal dissection of the proximal recipient artery or the donor renal artery, the latter being a consequence of traction in the donor or extreme donor hypertension during coning.

□ 

  

Finally, if concern still exists, the Hume test can be reassuring. When the renal vein is occluded between finger and thumb, the kidney should swell and throb. When the vein is released the kidney palpably softens as the turgor goes. 

Reconstruction of the Urinary Tract Once the kidney is perfused with recipient blood and hemostasis has been secured, reconstruction of the urinary tract is carried out. Transplantation of the left kidney into the right iliac fossa and the right kidney into the left iliac fossa reverses the normal anterior-to-posterior relationship of the vein, artery, and collecting system and positions the renal pelvis and ureter of the kidney transplant so that they are the most medial and superficial of the hilar structures.13 This positioning simplifies primary (and secondary) urinary tract reconstruction if pyeloureterostomy, ureteroureterostomy, or pyelovesicostomy need to be done. The factors that determine the type of urinary tract reconstruction are the length and condition of the donor ureter, the condition of the recipient’s bladder or bladder substitute, the condition of the recipient’s ureter, and the familiarity of the surgeon with the technique. Suture material is an individual choice. Although urinary tract reconstruction with nonabsorbable sutures has been described,24,25 it leaves the recipient with the risk of stone formation. Modern synthetic absorbable monofilament sutures (e.g., polyglyconate and polydioxanone) have characteristics suitable for the immunocompromised kidney transplant recipient in whom delayed wound healing is possible.

URETERONEOCYSTOSTOMY (ANASTOMOSIS OF THE TRANSPLANT URETER DIRECTLY TO THE BLADDER) This is the usual form of urinary tract reconstruction. Its advantages are as follows:    It can be performed regardless of the quality or presence of the recipient ureter. □  It is several centimeters away from the vascular anastomoses. □  The native ureter remains untouched and therefore available for the future management of ureteric complications. □  Native nephrectomy is unnecessary. □ 

  

Fig. 11.5  Vein anastomosis with triangular stay sutures in place. (From Lee HM. Surgical techniques of renal transplantation. In: Morris PJ, editor. Kidney transplantation. London: Academic Press/Grune & Stratton; 1979. p.151.)

The goal is to anastomose the ureter to the mucosa of the bladder, with the distal ureter surrounded in a 2- to 3-cm tunnel so that, when the bladder contracts, there is a valve mechanism to prevent reflux of urine up the ureter.26–28 The efficiency of this antireflux mechanism is variable. The urinary catheter is connected to a Y connector with a bag filled with saline and an antibiotic and/or methylene blue dye on one line and a urinary collection bag on

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A

B Fig. 11.6  Color photo of (A) preparation of external iliac vein and (B) venous anastomosis.

Fig. 11.7  Y-tube system for rinsing, filling, and draining bladder or bladder substitute. (From Kostra JW. Kidney transplantation. In: Kremer B, Broelsch CE, Henne-Bruns D, editors. Atlas of liver, pancreas, and kidney transplantation. Stuttgart: Georg Thieme Verlag; 1994. p.128.)

the other (Fig. 11.7).29 The use of an antibiotic in the solution reduces the risk of postoperative urinary infection,30,31 whereas the dye reassures the surgeon it is the bladder that has been opened and not another viscus. With this system, the bladder can be filled, drained, and, if necessary, refilled during the procedure. It is especially helpful when the bladder is difficult to identify because of pelvic scar tissue, recipient obesity, or reduced capacity. After initially accommodating a small volume, the defunctioned bladder often accepts more fluid 1 or 2 hours into the transplantation procedure.32 

Transvesical Ureteroneocystostomy The traditional technique for transvesical ureteroneocystostomy is similar to that described by Merrill and colleagues13 in the first successful kidney transplant from a twin (Fig. 11.8). The dome of the bladder is identified, and stay sutures or Babcock clamps are placed on either side

of a proposed vertical midline incision. The urinary bladder is drained, and an incision is made through all layers of the anterior bladder wall. A retractor is placed into the dome of the bladder to expose the trigone. A point clear of the native ureter is selected, and a transverse incision is made in the mucosa. A submucosal tunnel is created with a right-angle clamp or small scissors for about 2 cm. The clamp or scissors is pushed through the bladder from inside to outside, and the muscular opening is enlarged to accept the kidney transplant ureter. The ureter is drawn into the bladder, where it is transected at a length that prevents tension or redundancy. The cut end of the ureter is incised for 3 to 5 mm and approximated to the bladder mucosa with fine absorbable sutures. The inferior suture includes the bladder muscle to fix the ureter distally and to prevent its movement in the submucosal tunnel. The retractor is removed, and the cystotomy is closed with a single or double layer of 3-0 absorbable suture. The bladder can be refilled to check for leakage, and points of leakage can be repaired with interrupted sutures. Some surgeons use two bladder mucosal incisions about 2 cm apart33; when this technique is used, the proximal bladder mucosal incision is closed with a fine absorbable suture. 

Extravesical Ureteroneocystostomy This is the most common technique used. Although not producing such a “physiologic” antireflux mechanism as the transvesical method, extravesical techniques are faster, do not require a separate cystotomy, and require less ureteric length, are associated with fewer urinary tract infections, leaks, and less hematuria than intravesical techniques (Fig. 11.9).34,35 Extravesical techniques are based on the procedure described by Lich and colleagues.26 Extravesical ureteroneocystostomy was adapted for renal transplantation by Woodruff in 1962,36 and it is well illustrated by Konnak and colleagues (see Fig. 11.9).37 A subsequent modification was the addition of a stitch to anchor the toe of the spatulated ureter to the bladder to prevent proximal slippage of the ureter in the submucosal tunnel with loss of the antireflux valve and disruption of the ureteric anastomosis.38,39 A double-pigtail (double-J) ureteric stent reduces the incidence of leak and stenosis40–42 and is widely used. This is passed retrograde up the donor ureter, after first cutting the ureter to a suitable length and spatulating its

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Fig. 11.8  (A–D) Transvesical ureteroneocystostomy. (From Lee DM. Surgical techniques of renal transplantation. In: Morris PJ, editor. Kidney transplantation. London: Academic Press/Grune & Stratton; 1979. p.153.)

end. The bladder is distended with an antibiotic/dye solution through the urethral catheter. The lateral surface of the bladder is cleared of fat and the peritoneal reflection, a retractor is placed medially, another is placed inferolaterally, and a third retractor is placed cephalomedially to hold the peritoneum and its contents out of the way. Some authors recommend placing the ureter under the spermatic cord or round ligament, believing that this prevents posttransplant ureteric obstruction. A longitudinal oblique incision is made for approximately 2 cm until the bladder mucosa bulges into the incision. The bladder is partially drained via the urethral catheter, and the mucosa is dissected away from the muscularis on both sides to facilitate later creation of a submucosal tunnel for the ureter. The bladder mucosa is incised and 5-0 monofilament absorbable sutures (e.g., polydioxanone) placed through both ends of the incision. The ureter is brought up to the

wound, and the mucosal sutures passed through the toe and heel of the spatulated end, and the ureter parachuted on to the bladder. The ureter is then anastomosed to the bladder mucosa with running sutures between the ureter and the mucosa of the bladder; some surgeons take a small amount of bladder muscle in the suture, whereas others suture to mucosa alone. Some authors recommend specifically anchoring the toe of the ureter with a horizontal or vertical mattress suture placed in the toe of the ureter and passed submucosally through the seromuscular layer of the bladder and tied about 5 mm distal to the cystotomy (Fig. 11.10). When handling the ureter and bladder, care should be taken to avoid crushing the delicate mucosa with forceps. Once the ureteric anastomosis is complete, the seromuscular layer is closed over the ureter with interrupted absorbable sutures, care being taken to avoid narrowing the ureter in the process. 

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Parallel Incision Ureteroneocystostomy A variant of the extravesical ureteroneocystostomy is the parallel incision ureteroneocystostomy.43 It involves two parallel vertical incisions in the bladder muscle some 2 cm apart. The ureter is tunneled submucosally through the lateral incision and out of the medial one. The ureter is then cut, spatulated, the bladder mucosa opened at the site of the medial incision, and the heel of the ureter sutured to the mucosa while the toe is sutured to both mucosa and muscle wall (Fig. 11.11). The muscle is then closed over the both incisions with an absorbable suture.44 

DOUBLE URETERS

Fig. 11.9  (A–C) Extravesical ureteroneocystostomy. (From Konnak JW, Herwig KR, Turcotte JG. External ureteroneocystostomy in renal transplantation. J Urol 1972;108:380.)

Double ureters can be managed simply by trimming them to appropriate length, spatulating them, and either anastomosing the medial edges together with a continuous or interrupted fine absorbable suture (Fig. 11.12)45,46 or joining them, one on top of the other, with a single stitch from the toe of the upper one to the heel of the lower one.47 The conjoined ureters can be treated as a single ureter by any of the previously described ureteroneocystostomy techniques. The submucosal tunnel needs to be made a bit wider. The alternative approach is to use a separate ureteroneocystostomy for each of the ureters.48 These same techniques can be used for the en bloc transplantation of pediatric kidneys or the transplantation of two adult kidneys, stacked one on top of the other,49 into one recipient. Fjeldborg and Kim50 described a pyeloureteric anastomosis for a kidney with double ureters in which both renal pelves are joined after dividing the ureters at their ureteropelvic junctions and suturing the posterior walls together, leaving the anterior halves for anastomosis with the recipient ureter (Fig. 11.13).50 If both ureters have been stented it is important to ensure that both stents are subsequently removed. 

AUGMENTED BLADDER In patients with congenital bladder abnormalities, the bladder may have been augmented as part of previous treatment or in preparation for transplantation. It is important to know the anatomy and blood supply of an augmentation patch so as not to interfere with it during the kidney transplant procedure. Ideally the ureter should be anastomosed to the bladder itself, with a submucosal tunnel for ureteroneocystostomy. Where ileum or cecum has been used, and is the most readily accessible component of the reconstructed bladder, the donor ureter may be anastomosed without a tunnel, and the anastomosis managed in a similar fashion used for an ileal conduit. Ureteric stents are usually used. 

PYELOPYELOSTOMY Fig. 11.10  One or two mattress sutures to anchor toe of transplant ureter to full-thickness bladder. This prevents ureteric slippage in the submucosal tunnel. (From Hinman Jr F. Ureteral reconstruction and excision. In: Hinman Jr F, editor. Atlas of urologic surgery. 2nd ed. Philadelphia: WB Saunders; 1998. p.799.)

Pyelopyelostomy has been used for orthotopic kidney transplantation, usually in the left flank.51 The native kidney is removed, and the kidney transplant is revascularized with the native renal artery or the splenic artery and the native renal vein. The proximal ureter and renal

11 • Surgical Techniques of Kidney Transplantation

A

B

C

D

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Fig. 11.11  (A–D) Parallel incision ureteroneocystostomy. (From Knechtle S. Ureteroneocystostomy for renal transplantation. J Am Coll Surg 1999;188(6):707–9.)

pelvis of the kidney transplant are opened medially, and the native renal pelvis is anastomosed to the kidney transplant renal pelvis with a running fine absorbable suture. After completion of one wall, a double-pigtail ureteric stent is passed with or over a guidewire through the native ureter into the bladder, and the wire is withdrawn to allow the distal end to curl within the bladder. Its position in the bladder is confirmed by reflux of bladder irrigant up the stent. The proximal coil is placed in the renal pelvis of the kidney transplant, and the remaining half of the suture line is completed. Compared with ureteroneocystostomy, an advantage of urinary tract reconstruction with the native renal pelvis or ureter is the ease with which subsequent retrograde pyelography, stent placement, or ureteroscopy can be accomplished through the normally positioned ureteric orifice. 

Fig. 11.12  Management of double ureters to make them into a single ureteric orifice.

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Kidney Transplantation: Principles and Practice

Fig. 11.13  Management of double ureters by pyelopyelostomy followed by conjoined pyeloureterostomy. (From Fjeldborg O, Kim CH. Double ureters in renal transplantation. J Urol 1972;108:377.)

PYELOURETEROSTOMY AND URETEROURETEROSTOMY Pyeloureterostomy and ureteroureterostomy usually are done: (1) when the transplant ureter’s blood supply seems to be compromised, (2) when the urinary bladder is difficult to identify because of pelvic scar, (3) when the bladder does not distend enough for a ureteroneocystostomy, or (4) as a result of surgeon preference.52–54 The techniques for ureteropyelostomy and ureteroureterostomy are similar (Fig. 11.14). The posterior, or back wall, anastomosis is completed between the kidney transplant pelvis or ureter and the side or to the spatulated end of the native ureter; a double-pigtail ureteric stent is placed, and the anterior suture line is completed. The proximal native ureter is managed by the following:    Leaving the native kidney in situ and using the side of the native ureter for the anastomosis □  Ipsilateral nephrectomy and proximal ureterectomy □  Ligation of the proximal ureter with the obstructed native kidney left in situ55,56 □ 

  

The native ureter should not be ligated in the presence of urinary tract sepsis (when a pyonephrosis of the native kidney may ensue) or where the recipient has previously undergone ureteric reimplantation to treat reflux disease (in which case the blood supply to the ureter may be severely compromised). By leaving the native ureter in continuity with its kidney, and anastomosing the pelvis or ureter of the renal transplant to the side of the native ureter, a good blood supply to the native ureter is guaranteed without the risk of an obstructed, hydronephrotic native

Fig. 11.14 Ureteropyelostomy and ureteroureterostomy. A doublepigtail stent is placed after the back wall suture line has been completed.

kidney. However, with the two caveats mentioned, ligation of the native ureter for ureteroureterostomy is normally uneventful. 

PYELOVESICOSTOMY Pyelovesicostomy has been described for urinary tract reconstruction when the native ureter and the renal transplant ureter are unsuitable or become so (Fig. 11.15).57–59 The bladder must reach the renal pelvis without tension. To achieve this the bladder may be mobilized and hitched to the psoas muscle or a bladder extension with a Boari flap may be needed.60 This technique may also be useful as a management of posttransplant ureteric stenosis. 

URETEROENTEROSTOMY Ureteroenterostomy into an intestinal conduit or an intestinal pouch is indicated where the bladder has been removed or is unusable.61,62 It is preferable to create the conduit before the transplant, at the time of listing if it has not been created previously. The conduit or pouch is washed with antiseptic before surgery commences. The ureteric

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MANAGEMENT OF CATHETER AND STENT The urinary bladder or reservoir catheter usually is removed on postoperative day 5. Some units test the urine at the bedside for nitrites and send for bacterial culture. If the urine is shown to be infected, an antibiotic is chosen based on sensitivity results and is prescribed for 10 to 14 days. Where the stent has been fixed to the urinary catheter it will come out as the catheter is withdrawn,64 otherwise the stent is removed at 6 weeks using flexible cystoscopy. Early stent removal has the advantage of reducing urinary tract infections while still reducing other complications.64,65 If a ureteric stent is in situ it should be removed if infection is present. Care should be taken to identify all patients with stents in situ lest one be forgotten. 

Closure

Fig. 11.15  Pyelovesicostomy. (From Firlit CF. Unique urinary diversions in transplantation. J Urol 1977;118:1043.)

anastomosis is done with the spatulated end of the ureter being anastomosed to the full thickness of the bowel wall. If it is difficult to identify the intestinal conduit or pouch because of surrounding intestines, the addition of methylene blue dye to the irrigant stains the conduit or pouch and may make it easier to find,63 or placing a finger in the lumen may help. This topic is discussed more completely in Chapter 12. 

Many units obtain a biopsy specimen of the kidney routinely before closure of the wound (a “time zero biopsy”). This biopsy can be used to provide baseline histology to identify chronic changes and any unknown renal disease; it may also show evidence of ischemia/reperfusion injury or early antibody-mediated damage, but the time taken for these to manifest histologically is generally longer than the average transplant operation (see Chapter 26). Methods of closing the wound vary, but closure of all musculofascial layers with a nonabsorbable material such as nylon is preferred to avoid herniation. Skin closure with a subcuticular absorbable suture gives the best cosmetic result. Some surgeons prefer to drain the surgical bed to give early warning of bleeding or urinary leak, whereas others argue that the drain is a portal for entry of microorganisms. If drainage is performed it should be a closed system and drains should be removed at the earliest opportunity. The exit site of the drain should be cleaned and dressed daily until the drain is removed. The historical practice of capsulotomy of the transplanted kidney, where the renal capsule is carefully split along its convex border from pole to pole to minimize damage to the kidney as the parenchyma swelled in response to reperfusion injury is no longer performed.66,67 

URETERIC STENTS

Pediatric Recipient

Stents have been shown to reduce many of the urologic complications of ureteric anastomoses but are associated with an increased incidence of urinary tract infections.40–42 Indications for their selective use, where stenting is not routine practice, include edema; a thickened bladder; and when a pyelopyelostomy, pyeloureterostomy, or ureteroureterostomy have been performed; or when the ureter has been anastomosed to an intestinal conduit or pouch. The ideal length of the stent is determined by the estimated distance between the renal pelvis of the kidney graft and the bladder (or its substitute). A double-pigtail 5 French stent of 12 cm in length is generally suitable for an adult transplant kidney located in the iliac fossa and anastomosed to the native bladder. 

For older children, the transplant procedure is the same as for adults if their weight is more than 20 kg.5,68,69 The renal vessels are anastomosed end-to-side to the iliac vessels or to the aorta and vena cava.70 In smaller children (weight 70% stenosis on angiography. DSE showed improved accuracy over MPS for detecting CAD (P = 0.02) when all 22 studies were included in the analysis; however, this difference became insignificant when the authors excluded studies that did not use a reference threshold of ≥70% stenosis on coronary angiography. Although noninvasive testing for CAD in ESRD is certainly imperfect, abnormal MPS and DSE test results have been associated with prognostic value for major adverse cardiac events (MACE) in this patient population. In a study of 126 patients with ESRD who underwent technetium99m MPS as part of their pretransplantation assessment, a reversible defect was associated with three times the risk of posttransplantation cardiac events and nearly twice the risk of death compared with normal test results.42 A metaanalysis of 12 studies involving either thallium-201 scintigraphy or DSE demonstrated that ESRD patients with inducible ischemia had six times the risk of MI and four times the risk of cardiac death as patients without inducible defects, whereas patients with fixed defects had nearly five times the risk of cardiac death.43

13 • Perioperative Care of Patients Undergoing Kidney Transplantation

Other studies suggest that cardiac risk assessment should begin with the analysis of easily obtainable clinical variables rather than with the wide pursuit of expensive tests with limited sensitivity and specificity.44 For example, a history of chest pain is a helpful starting point in detecting CAD in these patients because it has a sensitivity and specificity of 65% for CAD.45 A more comprehensive system, the revised cardiac risk index (RCRI), was originally derived from retrospective data and shown in a prospective population to predict cardiac risk for nonrenal failure patients undergoing noncardiac surgery.46 It focuses on the presence or absence of six variables: (1) high-risk surgical procedure; (2) history of ischemic heart disease (excluding previous coronary revascularization); (3) history of heart failure; (4) history of stroke or transient ischemic attacks; (5) preoperative insulin therapy; and (6) preoperative creatinine levels higher than 2 mg/dL (152.5 μmol/L). With zero or one risk factor, the rate of a major perioperative cardiac event is quite low; however, the rates rise rapidly to 6.6% and 11.0% when two or at least three of these risk factors are present. Although the RCRI was not designed specifically for patients with ESRD, a study by Hoftman et al. found this risk index to be an effective tool for predicting perioperative cardiovascular complications in patients undergoing KTx. Of the 325 patients included in the study, 7.1% suffered cardiac complications. An increasing number of RCRI risk factors was significantly associated with a higher rate of perioperative cardiac morbidity (receiver operating characteristic area, 0.77; P < 0.0001).47 The guidelines for perioperative cardiovascular evaluation and management for noncardiac surgery published by the American College of Cardiology (ACC) and the American Heart Association (AHA) do not take into consideration the unique clinical characteristics of patients with ESRD. Additionally, cardiovascular screening and treatment practices vary widely across transplant programs and are often inconsistent with published guidelines. In response, the ACC and AHA worked with the American Society of Transplant Surgeons, the American Society of Transplantation, and the National Kidney Foundation to develop the expert consensus document entitled “Cardiac Disease Evaluation and Management Among Kidney and Liver Transplantation Candidates.”48 This document provides recommendations for appropriate cardiovascular screening and management of kidney transplantation candidates, as well as ongoing surveillance. A summary of these recommendations can be found in Table 13.1. Overall, these guidelines have a lower threshold for formal cardiac testing. For example, the guidelines recommend that providers consider noninvasive stress testing in kidney transplantation candidates with no active cardiac conditions based on the presence of multiple CAD risk factors regardless of functional status. Relevant risk factors in this population include DM, prior cardiovascular disease, more than 1 year on dialysis, LV hypertrophy, age greater than 60 years, smoking, hypertension, and dyslipidemia. Depending on risk factors and the results of screening tests, patients may require medical management or a revascularization procedure. The benefit of revascularization is controversial. Data from the CARP trial, where revascularization was performed before vascular surgery, showed no benefit of revascularization compared with medical

187

management. In the COURAGE trial, an examination of the subgroup of patients with chronic kidney disease found no benefit of percutaneous coronary intervention versus medical management.49–51 Medical management for these patients at high perioperative cardiac risk often includes beta-blockade. Several studies throughout the late 1990s established that perioperative beta-blockade provides significant protection from major cardiac events in high-risk, nontransplant patients, although the efficacy of perioperative beta-blockade in patients undergoing noncardiac surgery remains controversial. In 2009 the DECREASE-IV trial demonstrated a safe and effective way to provide perioperative beta-blockade to patients with an estimated risk of MI or cardiovascular death greater than 1%.52 However, no prospective randomized trials have been conducted with perioperative beta-blockade in the ESRD or kidney transplant population. Currently it is unknown whether such treatment can be applied safely to these patients, especially those with DM. No existing guidelines specifically address the evaluation and management of pulmonary function in KTx candidates. However, a thorough pulmonary history and physical examination should be performed before transplantation, with additional studies pursued when deemed appropriate. Patients with severe pulmonary limitations, such as a baseline oxygen requirement, uncontrolled asthma, cor pulmonale, or severe obstructive or restrictive disease may be too high risk to undergo KTx surgery. Active smokers should be encouraged to quit preoperatively.53 Coagulation status, as reflected by the prothrombin time, international normalized ratio, partial thromboplastin time, fibrinogen, and platelet count, is routinely assessed before surgery. The bleeding time is not a useful screening test to predict intraoperative bleeding.54 Patients who are on anticoagulants or antiplatelet agents as maintenance medications to prevent thrombosis of their dialysis access or because of cardiovascular pathology should discontinue these medications and potentially receive a reversal agent as soon as they are notified of a transplant. However, because deceased organ transplants are scheduled for surgery urgently with minimal advanced notice, anticoagulation and antiplatelet therapy often cannot be discontinued sufficiently early. One center’s review of 105 patients on a variety of anticoagulants and antiplatelet medications before KTx found no difference in reoperation rates and transfusion utilization compared with a control group of transplant patients not on these medications.55 Despite these potential coagulation problems, blood loss during renal transplantation is normally less than 250 mL in experienced centers. Patients should be typed and crossed for blood. It is usually appropriate to have at least two units of packed red blood cells available given the risk of major vascular bleeding. More blood products may be ordered in anemic patients and those taking antiplatelet and anticoagulant agents. Another preoperative consideration is pregnancy testing in female patients. The American Society of Anesthesiologists recommends offering pregnancy testing with informed consent to female patients of childbearing age for whom the result would alter management. In some institutions, preoperative pregnancy testing is performed routinely. Although fertility is decreased in patients with ESRD, irregular menses

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TABLE 13.1  ACA/AHA Recommendation for Perioperative Cardiac Evaluation of Kidney Transplant Recipients Evaluation and Management Categories

ACA/AHA Recommendations

Determining active cardiac conditions

Perform a thorough history and physical examination to identify active cardiac conditions before solid-organ transplantation. Consider noninvasive stress testing in KTx candidates with no active cardiac conditions based on the presence of multiple CAD risk factors regardless of functional status. Relevant risk factors among transplantation candidates include DM, prior cardiovascular disease, more than 1 year on dialysis, left ventricular hypertrophy, age greater than 60 years, smoking, hypertension, and dyslipidemia. The usefulness of periodically screening asymptomatic KTx candidates for myocardial ischemia while on the transplant waiting list to reduce the risk of MACE is uncertain. It is reasonable to perform preoperative assessment of left ventricular function by echocardiography in potential KTx candidates. There is no evidence for or against surveillance by repeated left ventricular function tests after listing for kidney transplantation. It may be reasonable to consider ESRD patients with moderate AS to be equivalent to “rapid progressors” who warrant a yearly echocardiogram. It is reasonable to evaluate KTx candidates with echocardiographic evidence of significant pHTN. It may be reasonable to confirm echocardiographic evidence of elevated pulmonary arterial pressures in KTx candidates by right heart catheterization. If right heart catheterization confirms the presence of significant pulmonary arterial hypertension, referral to an expert consultant and advanced vasodilator therapies is reasonable. A preoperative resting 12-lead ECG is recommended for potential KTx candidates with CAD, peripheral arterial disease, or any cardiovascular symptoms. A preoperative resting 12-lead ECG is reasonable in potential KTx candidates without known cardiovascular disease. Annual 12-lead ECG after listing for KTx may be reasonable. Cardiac troponin level at the time of evaluation for KTx may be considered as an additional prognostic marker. The usefulness of noncontrast CT calcium scoring and cardiac CT angiography is uncertain for the assessment of pretransplantation cardiovascular risk. KTx candidates who have an LVEF 50%) left main stenosis or significant (>70%) stenoses in three major vessels or in the proximal LAD artery plus one other major vessel, regardless of left ventricular systolic function. It is not recommended that routine prophylactic coronary revascularization be performed in patients with stable CAD, absent symptomatic or survival indications, before transplantation surgery. Among patients already taking beta-blockers before KTx, continuing the medication perioperatively and postoperatively is recommended to prevent rebound hypertension and tachycardia. Among potential KTx candidates with clinical markers of cardiac risk (DM, prior known CAD, prior heart failure, extracardiac atherosclerosis) and those with unequivocal myocardial ischemia on preoperative stress testing, it is reasonable to initiate beta blockers preoperatively and to continue them postoperatively provided that dose titration is done carefully to avoid bradycardia and hypotension. Perioperative initiation of beta blockers in beta blocker–naïve patients may be considered in KTx candidates with established CAD or two or more cardiovascular risk markers to protect against perioperative cardiovascular events if dosing is titrated and monitored. Initiating beta blocker therapy in beta blocker–naïve patients the night before and/ or the morning of noncardiac surgery is not recommended.

Noninvasive stress testing in KTx candidates without active cardiac conditions

Cardiac surveillance after listing for transplantation Resting echocardiography in KTx candidates

Echocardiographic surveillance for ESRD patients with moderate aortic stenosis (AS) Evaluation and management of KTx candidates with echocardiographic evidence of significant pulmonary hypertension (pHTN)

Preoperative 12-lead ECG in KTx candidates

Biomarkers for cardiac evaluation in KTx candidates Cardiac computed tomography (CT) in KTx candidates Referral to a cardiologist

Coronary revascularization and related care before KTx

Perioperative medical management of cardiovascular risk before KTx

Modified based on JACC 2012;60(5):152–67.

13 • Perioperative Care of Patients Undergoing Kidney Transplantation

can make pregnancy testing especially important. Serum beta-HCG can be falsely elevated due to ESRD. Urine HCG is the recommended confirmatory test in such cases, but it is often not possible to obtain due to anuria. For patients on the transplant list, serial serum beta-HCG testing can be helpful to establish an elevated baseline value that can be distinguished from the rapid rise in HCG characteristic of pregnancy.56,57 Patients with DM presenting for KTx can be considered to have full stomachs despite preoperative fasting. Gastric volumes greater than 0.4 mL/kg were seen in 50% of diabetic uremic patients but in only 17% of nondiabetic uremics.58 The routine prophylactic administration of antacids may be advocated for patients with symptoms of esophageal reflux; a single dose of sodium citrate (30 mL) immediately before surgery is appropriate. Histamine H2-receptor antagonists can be given to reduce gastric hyper-acidity (e.g., ranitidine 150 mg orally 2 hours before the procedure or ranitidine 50 mg IV 30 minutes before surgery). Phenothiazine antiemetics and metoclopramide should be administered with care because they may cause prolonged sedation and extrapyramidal side effects in patients with renal failure. 

Intraoperative Considerations Spinal anesthesia was used in the first reports of anesthesia for KTx performed in Boston.1 Today, the vast majority of transplant centers use general endotracheal anesthesia; however, neuraxial anesthesia can provide adequate surgical conditions and excellent postoperative analgesia. Intraoperative management should focus on tailoring the anesthetic to the patient’s medical status rather than on the type of anesthesia used. Patients presenting for kidney transplant range from the young and otherwise healthy with IgA nephropathy to the elderly with severe hypertension, DM, and CAD. Anesthetic depth and pharmacologic interventions need to be tailored to two different biological systems—the transplant recipient and the allograft—with sometimes conflicting management needs. For example, maintenance of adequate anesthetic depth to avoid intraoperative awareness may also reduce blood pressure and perfusion pressure to the newly reperfused graft. Aggressive fluid loading to optimize graft perfusion may be dangerous in patients with a low ejection fraction and a history of congestive heart failure. Intraoperative monitoring includes standard monitors as recommended by the American Society of Anesthesiologists for all patients. Patients with advanced cardiac disease, such as CAD or heart failure, may require additional invasive monitoring, such as continuous arterial pressure or central venous pressure (CVP) monitoring, or both. Pulmonary artery catheters and transesophageal echocardiography are rarely indicated. Nevertheless, there is no consensus on appropriate intraoperative monitoring, and most protocols are based on institutional preference and experience. Care must be taken when positioning these patients, with special attention to arteriovenous grafts or fistulae. Grafts and fistulae must be properly padded, and anesthesiologists should confirm appropriate thrill intermittently throughout the procedure. Venous and arterial lines and noninvasive blood pressure (NIBP) cuffs should not be placed on a

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limb with an AV graft or fistula. Occasionally, anesthesiologists will elect to place the NIBP cuff on a lower extremity to avoid interference with the flow of an intravenous line. Before placing a lower extremity NIBP cuff, the anesthesiologist must confirm with the surgeon that the kidney graft will not be transplanted on the same side as the NIBP cuff, as this could compromise blood flow to the new graft. Significant acute changes in blood pressure may occur throughout the surgical procedure, with hypotension (50%) being more likely than hypertension (27%) in one series.59 Patients on multiple antihypertensive medications can have severe hypotension when volatile and intravenous anesthetic agents are administered, especially during induction of general anesthesia.60,14 Hypotension during KTx has been associated with delayed graft function, which, in turn, is associated with short- and long-term complications.61 Hypertension is commonly seen just before induction of anesthesia and during endotracheal intubation, during emergence from anesthesia, and in the postanesthesia care unit. Several methods have been used to achieve adequate heart rate and blood pressure control during the critical periods of induction and endotracheal intubation, including high potency opioids, beta blockers, and intravenous lidocaine. Fentanyl, with a time to peak effect of 3.6 minutes, can blunt the sympathetic response to laryngoscopy and tracheal intubation at doses of 2 to 6 mcg/kg.62 However, patients frequently experience hypotension immediately and well after induction with these moderate to large doses of fentanyl. Subsequently, they will often require vasoconstrictors to maintain adequate blood pressure, especially because there is little surgical stimulation once the fascia is dissected. The short-acting, potent opioid remifentanil, which is rapidly metabolized in the plasma, is an effective drug for heart rate control both during induction and maintenance of anesthesia. Remifentanil dosing can be titrated to rapidly adjust anesthetic depth. The short-acting β-adrenergic blocker, esmolol, is an excellent choice for blunting the hemodynamic response to endotracheal intubation and is well suited for kidney transplant patients with preserved ventricular function. Patients with long-standing severe hypertension often require high doses of esmolol, best given in increments. In a comparison study of hemodynamics with fentanyl, lidocaine and esmolol for intubation, esmolol at 2 mg/kg prevented tachycardia and hypertension with intubation, fentanyl (3 mcg/kg) blocked hypertension but not tachycardia, and lidocaine (2 mg/kg) was ineffective.63 The single most common agent used for the induction of general anesthesia during KTx is propofol. Other hypnotics such as thiopental and etomidate have also been used successfully. Several studies have demonstrated that the induction dose of propofol needed to achieve clinical hypnosis and appropriate reduction of the bispectral index (a quantitative indicator of depth of anesthesia) was 40% to 60% higher in patients with ESKD compared with normal patients.64,65 In the study by Goyal and colleagues, 0.2 mg/kg of propofol was titrated every 15 seconds to predefined end points. The authors found a negative correlation between required propofol dose and preoperative hemoglobin level.64 However, caution is advised when considering these studies. Propofol is a vasodilator and larger induction doses can cause significant hypotension particularly in volume-depleted patients dialyzed immediately before surgery.

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Neuromuscular blockade is useful for both endotracheal intubation and surgical muscle relaxation. The most common nondepolarizing neuromuscular blocking agents used today are rocuronium, vecuronium, atracurium, and cisatracurium. Vecuronium is primarily metabolized and eliminated by the liver, with up to 25% renally excreted. The principal metabolite is also a potent neuromuscular blocker and can cause prolonged effect in patients with renal failure. Rocuronium is also primarily eliminated in the liver, with 10% to 25% renal excretion, but with no active metabolites. Rocuronium at a bolus dose of 0.6 mg/kg also has a prolonged duration of action in patients with renal failure.66 Although many anesthesiologists will avoid these drugs in patients with ESRD, rocuronium and vecuronium can be safely used with appropriate clinical monitoring and understanding of their prolonged duration. Atracurium and cisatracurium are metabolized primarily by spontaneous Hofmann degradation, an organ-independent metabolism. The parent agent, atracurium, is associated with histamine release, but cisatracurium is not.62 Succinylcholine is a very short acting depolarizing neuromuscular blocker and is the drug of choice in rapid sequence intubations. Succinylcholine is known to cause an increase in extracellular potassium. The increase in serum potassium after an intubating dose of succinylcholine was found to be the same, approximately 0.6 mEq/L, for patients with and without ESRD.67 This increase can be tolerated without significant risk of arrhythmia even by patients with an initial serum K+ concentration greater than 5 mEq/L. The use of succinylcholine therefore is not absolutely contraindicated in patients with ESRD.68 As previously mentioned, rapid sequence intubation may be required to reduce the risk of aspiration during induction in ESRD patients with uremic or diabetic gastroparesis, or with other typical indications such as acid reflux or full stomach. If there is a contradiction to succinylcholine, high-dose rocuronium (1.2 mg/kg) can provide rapid intubating conditions. However, high-dose rocuronium in a patient with ESRD will likely have a significantly prolonged effect. Sugammadex is a reversal agent for rocuronium, acting via selective binding to rocuronium. The rocuroniumsugammadex complex is then eliminated by the kidneys. Sugammadex is an effective reversal agent in patients with ESRD, however excretion of rocuronium and sugammadex is significantly slower in patients with ESRD. This complex will remain in the plasma for a prolonged period. The effects of prolonged exposure to the rocuronium-sugammadex complex is not clear.69 Therefore neostigmine is the preferred neuromuscular blocker reversal agent for patients with ESRD. It can be used for reversal of all of the nondepolarizing neuromuscular blockers. Of note, neostigmine is also partially eliminated in the kidneys, with an elimination half-life of 3 hours versus 1.3 hours in patients with normal renal function.70 Overall, there is no evidence that the type of anesthetic used during KTx is associated with patient and graft outcomes. Most commonly, an inhaled volatile is used, either desflurane, isoflurane, or sevoflurane. All three of these volatile anesthetics have been reported to be safe during KTx. The metabolism of sevoflurane has been implicated in renal toxicity, but there are no controlled studies identifying safety

concerns or harm associated with sevoflurane administration in the setting of a newly transplanted kidney. There are two elements of potential concern with regard to sevoflurane and renal toxicity: (1) production of fluoride ion from the metabolism of sevoflurane; and (2) generation of “compound A” from the breakdown of sevoflurane by sodium or barium hydroxide lime. Sevoflurane appears to have a very good safety record; it has been administered to millions of patients worldwide without conclusive evidence of renal toxicity. Two volunteer studies have found biochemical evidence of renal injury during sevoflurane anesthesia, whereas five other volunteer studies have not.71–77 Nevertheless, KTx may represent a period of increased risk for renal injury, as defined by Artru.78 One study found that exposure to sevoflurane or isoflurane had no significant effect on renal function parameters such as serum creatinine or creatinine clearance in patients with baseline renal insufficiency (Cr >1.5 mg/dL).79–81 Additionally, a study of 200 patients who underwent KTx reported no difference in postoperative creatinine, postoperative dialysis, and the incidence of rejection between patients who received sevoflurane and those who received isoflurane during transplantation.82 Intraoperative management during KTx should primarily focus on hemodynamic stability with preservation of adequate perfusion pressure to the graft. KTx surgery often has prolonged periods of minimal stimulation. Blood loss rarely exceeds 300 mL and large fluid shifts are not common. Hypotension is frequently encountered during periods of minimal surgical stimulation and may be aggravated with unclamping of the iliac vessels and reperfusion of the graft. Individualized fluid management is the cornerstone of intraoperative hemodynamic management, whereas usage of vasoconstrictors with strong α-adrenergic effects, such as phenylephrine, is discouraged. Maintenance of intravascular fluid status can be accomplished using natural colloids (albumin), synthetic colloids (hydroxyethyl starches, dextrans, gelatins), and crystalloids (normal saline, Ringer’s lactate, plasmalyte). Given the minimal blood loss and fluid shifts during KTx, crystalloids are sufficient for volume replacement and should be the preferred choice of fluid. Data for natural and synthetic colloids in KTx are sparse. Therefore the routine use of these fluids in KTx cannot be recommended. The contents of the crystalloid solution administered during KTx should be considered. In large amounts, normal saline can cause a hyperchloremic metabolic acidosis, whereas Ringer’s lactate and plasmalyte both contain potassium, which raises concern for hyperkalemia in the patient with ESRD. A prospective, randomized, doubleblinded study compared normal saline to Ringer’s lactate for intraoperative intravenous fluid therapy during KTx. The study was terminated for safety reasons and interim analysis showed no difference in postoperative creatinine levels. However, it demonstrated higher rates of severe hyperkalemia and metabolic acidosis in the normal saline group.83 Most recently, a 2016 Cochrane Review metaanalysis investigated the effect of lower-chloride solutions versus normal saline on delayed graft function, hyperkalemia and acid–base status in kidney transplant recipients. The authors found no difference in the rates of delayed graft function or hyperkalemia, but showed that intraoperative

13 • Perioperative Care of Patients Undergoing Kidney Transplantation

balanced electrolyte solutions were associated with higher blood pH, higher serum bicarbonate and lower serum chloride.84 The debate continues over whether CVP monitoring is required to guide fluid administration during KTx. When CVP monitoring is in place, most centers recommend maintaining the CVP at 10 to 15 mm Hg. The effect of timing and duration of fluid replacement during KTx were examined in a prospective randomized trial.85 Patients were randomized to a continuous crystalloid infusion or a CVP-targeted crystalloid infusion with a low CVP target of 5 mm Hg throughout most of the case and a CVP target of 15 mm Hg at the end of renal vascular anastomoses (achieved by rapid infusion). Primary endpoints were markers of allograft function within 5 postoperative days. Although both groups received equal total volumes of crystalloid, the CVP-targeted group had better early allograft function. However, several confounding factors in the study design warrant larger studies. A small prospective study by Hadimioglu et  al. demonstrated a highly significant relationship between peripheral venous pressure (PVP) and CVP in patients undergoing kidney transplantation, suggesting that PVP may be a reasonable surrogate for CVP in patients without significant cardiac dysfunction.86 Pharmacologic blood pressure support using α-agonist vasoconstrictors is usually discouraged based on some limited experimental animal data. Taken together, studies indicate that there is a substantial attenuation of renal hemodynamic responsiveness in transplanted kidney grafts with α-agonist administration. Furthermore, the studies suggest that the transplanted, denervated kidney loses its capacity for autoregulation and that the renal response to sympathomimetics is altered with a shift toward timedependent flow reduction to the kidney. In one rat study, the response to sympathomimetics in the transplanted kidney was shifted toward renal blood flow reduction. The authors postulated enhanced vasoconstriction via stimulation of α-adrenoceptors and blunted vasodilatation via stimulation of β-adrenoceptors as a possible mechanism.87,88 However, the clinical significance of these findings in human kidney transplant recipients remains unclear. A retrospective study compared 75 renal transplant recipients who required phenylephrine intraoperatively to 75 matched controls who did not. The authors found no difference in rates of delayed graft function or in serum creatinine 30, 90, and 365 days after transplant.89 Intraoperative urine production, a surrogate for allograft function, is frequently augmented with mannitol and loop diuretics. Mannitol is freely filtered and not reabsorbed by the nephron, causing osmotic expansion of urine volume. It may also have a protective effect on the cells lining the renal tubule. It is usually administered during the warm ischemia phase; thus mannitol may protect against ischemic injury, as well as induce osmotic diuresis in the newly transplanted kidney. In most centers, relatively low doses of mannitol are administered, ranging between 0.25 and 0.5 mg/kg. Some data have shown that delayed graft function of the deceased donor renal allograft can be prevented by intraoperative administration of mannitol.90 Low-dose dopamine (2–3 μg/kg/min) is commonly used to stimulate DA1 dopaminergic receptors in the kidney vasculature and thereby induce vasodilation and increase urine

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output. Some small trials have shown improved urine output91 and creatinine clearance92 with low-dose dopamine during KTx, whereas other larger studies have shown no significant improvement in either parameter.93,94 The utility of this approach has been questioned on the basis that a newly transplanted, denervated kidney may not respond to low-dose dopamine normally. Doppler ultrasound examination of newly transplanted kidneys found no significant change in blood flow with dopamine infusion rates of 1 to 5 μg/kg/min.95 Pain associated with surgery is moderate and is typically managed in the immediate postoperative phase with intravenous opioids, often using patient-controlled analgesia. Patients are transitioned to oral opioids quickly. When continuous epidural is placed for intraoperative anesthesia, it can provide excellent postoperative analgesia as well, but it is typically not necessary. As shown in Table 13.2, the opioids morphine, meperidine, and oxycodone should be used cautiously in patients with ESRD because they (or their active metabolites) are renally excreted and thus may accumulate in such patients. This risk of opioid accumulation persists in the period after transplantation when the allograft may suffer from delayed graft function. In contrast, the opioids fentanyl, sufentanil, alfentanil, and remifentanil have been shown to be safe alternatives, with fentanyl being the most commonly used.96 Ketamine is a nonopioid analgesic with the active metabolite norketamine, which is also metabolized by the kidney and can cause prolonged effect. The large dose of steroid (usually methylprednisolone) given intraoperatively for induction of immunosuppression contributes an important analgesic effect as well. Intrathecal opioid and transversus abdominis plane (TAP) blocks have been studied in kidney transplant patients as part of enhanced recovery pathways, with improved satisfaction and decreased hospital length of stay.97 Some institutions instead utilize TAP blocks as a rescue method for patients with severe pain postoperatively.98 Intraoperative and postoperative hyperglycemia are common, especially, but not exclusively, in diabetics, due to the stress response to surgery and the large dose of corticosteroids administered. A Cochrane Review showed limited evidence that more intensive insulin therapy had any effect on graft survival, all-cause mortality and adverse effects.99 A larger Cochrane Review of more than 1400 surgical patients recommended caution with intensive perioperative glycemic control compared conventional glycemic control. Although mortality was unchanged, a post hoc analysis showed more hypoglycemic episodes in the intensive glycemic control group.100 

Postoperative Care All renal transplant patients should be considered for postoperative extubation using standard criteria. Postoperatively, most kidney transplant recipients are admitted to the postanesthesia care unit (PACU), with only a small percentage requiring admission to the intensive care unit (ICU).101 However, some centers do elect to admit all kidney transplant patients to the ICU. In the PACU, patients are managed according to institutional protocols with pain management guidelines tailored

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TABLE 13.2  Clearance of Commonly Used Opioids and Effect of Renal Failure SAFE TO USE IN PATIENTS WITH RENAL FAILURE Fentanyl Sufentanil Alfentanil Methadone Remifentanil

Metabolized by liver, no active metabolites Fentanyl congener, same as above Fentanyl congener, same as above Metabolized by liver, no active metabolites Hydrolyzed rapidly by plasma esterases, no active metabolites

CONSIDER CAUTION IN PATIENTS WITH RENAL FAILURE Oxycodone Metabolized by liver, with multiple metabolites, oxymorphone is active metabolite which can accumulate in renal failure. Large interindividual variation. About 10% excreted unchanged by kidney. Hydromorphone Metabolized in liver, hydromorphone-3-glucuronide is metabolite excreted in kidney. Hydromorphone-3-glucuronide has no analgesic effect but may have neuroexcitatory effect. AVOID IN PATIENTS WITH RENAL FAILURE Morphine Hydrocodone Codeine Meperidine

Metabolized in liver to normorphine, morphine-3-glucuronide, and morphine-6-glucuronide (10%), also 40% metabolized by kidney. Metabolites excreted by kidney. Morphine-6-glucuronide is active metabolite, potent agonist at mu-receptor, can accumulate in renal failure. Metabolized to hydromorphone and hydromorphone-3-glucuronide, both can accumulate in renal failure. Multiple active metabolites including codeine-6-glucuronide, morphine, and morphine-6-glucuronide, which can accumulate in renal failure. Primarily metabolized by liver, normeperidine is the active metabolite with a potent analgesic effect and neuroexcitation causing seizures. Normeperidine is renally excreted, accumulates in renal failure.

Modified based on Miller RD, Eriksson LI, Fleisher LA, et al. Miller’s Anesthesia. 7th ed. Philadelphia, PA: Churchill Livingstone/Elsevier; 2010:2113; Dean M. Opioids in renal failure and dialysis patients. J Pain Symptom Manage 2004;28(5):497–504.

to ESRD patients, as previously discussed. Particular attention must be paid to graft function, which is primarily evaluated by urine output over time. The majority of living donor kidney transplant recipients have immediate graft function. In a study by Yadav et al., 84% of living donor kidney transplant recipients experienced immediate graft function.102 Delayed graft function is more likely with deceased donor grafts, especially from hypertensive donors, older donors, or other extended criteria donors. Poor graft function may be attributable to the graft itself, the vessels, the ureter, or clotting of the Foley catheter, all of which should be considered in the differential diagnosis. The Foley catheter should be irrigated to ensure that clot or tissue has not affected its patency. Flow in the arterial and venous anastomoses can be examined with ultrasound. Lastly, surgical reexploration should not be delayed if kinking of the vascular attachments or obstruction of the ureter along its course or at the site of bladder reimplantation is suspected. In cases of delayed graft function, patients may require dialysis postoperatively. Patients without preexisting hemodialysis access may require urgent placement of a hemodialysis line. This includes those patients who used peritoneal dialysis preoperatively, if their peritoneal dialysis catheter has been removed during the transplant surgery. 

Anesthesia for Patients After Kidney Transplantation Patients with functioning grafts as determined by laboratory values (blood urea nitrogen, creatinine) and with sufficient urine volume should be considered to have normal renal function. The average glomerular filtration rate (GFR) 6 months after deceased renal transplantation is almost 50 mL/min.103 About 50% of patients will manifest a slow decline in GFR over the course of several years, but 30% will

have a stable GFR. In a study that followed patients 10 or more years post-KTx, GFR decline over the first 12 months after transplantation was an independent predictor of longterm allograft failure.104 Despite the significant improvement in overall mortality, post-KTx patients remain at high risk of cardiovascular disease. Cardiac disease is the primary cause of death after KTx, with cardiac death 10 times more likely than in the general population. Patients are 50 times more likely to have a fatal or nonfatal cardiovascular event annually than the general population.70 One study found considerable progression of coronary artery calcification in renal transplant patients at least 1 year after surgery.105 Nevertheless, post-KTx patients have an overall lower risk of cardiovascular morbidity compared with pretransplant ESRD patients.106 Cho and colleagues documented that some patients with low ejection fractions secondary to uremic cardiomyopathy normalized their cardiac function after successful KTx.107 Fig. 13.1 shows that patients who remain on the transplant list have a persistent 3% per year incidence of MI, whereas patients who are transplanted have an initial rise in MI rate—probably due to perioperative stress—followed by a slower increase in the rate of MI compared with patients who do not receive a transplant.108 The lower MI risk in living donor transplant recipients compared with deceased donor graft recipients is also notable. The Kidney Disease: Improving Global Outcomes (KDIGO) clinical practice guideline recommends aspirin therapy for all posttransplant patients with atherosclerosis.109 Congestive heart failure, LV hypertrophy, and ischemic heart disease remain important complications in KTx recipients. This is largely due to pretransplant risk factors that persist posttransplantation, such as hypertension, diabetes, dyslipidemia, and metabolic syndrome. In addition, graft rejection, viral infection, anemia,23,110 and immunosuppressive medications cause significant cardiovascular

13 • Perioperative Care of Patients Undergoing Kidney Transplantation

Cumulative incidence of AMI

10% 9% 8%

ist

gl

itin Wa

7% 6%

nor

do ased Dece plant trans

5% 4% 3%

donor Living nt la p trans

2% 1% 0% 0

12 24 Months post WL or TX

36

Fig. 13.1  Cumulative (Kaplan–Meier) incidence of acute myocardial infarction (AMI) on the waiting list (WL) and after kidney transplantation (TX). Most transplant recipients also spent time on the waiting list, but time was reset to “0” at transplantation. Most of the difference in AMI incidence in recipients of deceased versus living donor kidney transplants occurred very early after transplantation. Thereafter, the incidence of AMI was similar in deceased and living donor transplant recipients, with both eventually having a lower incidence than patients on the waiting list. (From Kasiske BL, Maclean JR, ­Snyder JJ. Acute myocardial infarction and kidney transplantation. J Am Soc Nephrol 2006;17:900–7.)

morbidity. Corticosteroids and calcineurin inhibitors contribute to hypertension and hyperlipidemia and can cause new-onset diabetes. Azathioprine and mycophenolate can cause anemia. 

Kidney–Pancreas Transplantation Far less common than KTx, simultaneous pancreas–kidney transplantation (SPK) is offered to patients with poorly controlled DM and diabetic nephropathy causing ESRD. Over 80% of SPK transplants are performed in type 1 diabetics. In 2015, 947 pancreas transplants were performed in the US. Approximately 80% received a SPK, and the others received either pancreas transplantation alone or pancreas transplantation after kidney transplantation. However, pancreas transplantation overall has decreased more than 30% since 2006, matching a decrease in demand and likely reflecting both an improvement in medical management of DM as well as the complications associated with transplantation.111 Interestingly, despite the decline in pancreas transplantation in the US, the number of pancreas transplants has been increasing internationally, particularly in Europe and Asia.112 Patients with ESRD superimposed on DM are subject to the same hemodynamic, volume, and electrolyte problems as those with ESRD alone. Most are maintained on some form of dialysis to manage fluid overload and accumulation of electrolytes. These patients may also have the same problems of chronic anemia and uremic coagulopathy as those with renal failure alone. In addition to the hypertension often seen in ESRD, patients with diabetes often have accelerated atherosclerosis and autonomic nervous system dysfunction. Historically, candidates for pancreas transplantation have been younger than those listed for kidney transplantation, and therefore tended to have fewer long-term

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manifestations of DM. More recently, however, increasing numbers of older diabetic patients are being considered for pancreas transplantation. In 2015, 25% of SPK candidates in the US were older than 50 years of age, up from 18% in 2004.111 These older patients with long-term DM and ESRD therefore face elevated cardiovascular risk for surgery. After successful SPK, cardiac pathology such as diastolic dysfunction and LV hypertrophy can improve or stabilize.113 It is not clear whether other manifestations of DM, such as accelerated atherosclerosis, neuropathy, or vascular insufficiency, improve or stabilize after SPK.

PREOPERATIVE CONSIDERATIONS In addition to the preoperative assessment process required for KTx alone, diabetic patients should be queried about blood glucose control and antiglycemic medications. Orally administered antiglycemic agents should not be taken on the day of surgery to avoid unrecognized hypoglycemia under anesthesia. Blood glucose level should be checked preoperatively and corrected as appropriate before surgery. Insulin-dependent patients who experience large swings in serum glucose levels are at risk for ketosis and intraoperative acidemia. Given their significant risk factors for cardiac disease, an extensive cardiac workup is indicated in diabetic ESRD patients before surgery to rule out severe CAD. Preoperative evaluation by history and physical examination, ECG, treadmill testing, echocardiography with or without dobutamine stress, radionuclide scintigraphy, and cardiac angiography represent the full spectrum of workup that may be applicable. 

INTRAOPERATIVE CONSIDERATIONS SPKs are long and surgically demanding operations involving extensive abdominal exposure. Therefore general endotracheal anesthesia with neuromuscular blockade is the best anesthetic approach for these cases. As mentioned previously, patients with DM and uremia often have gastroparesis and large residual gastric volumes. These patients may benefit from a nonparticulate antacid and a rapid sequence induction. Patients may have more significant postoperative pain given the larger incision and more extensive abdominal dissection compared with KTx alone, so placement of an epidural catheter for postoperative pain control may be warranted. However, epidural local anesthetic may cause sympathetic blockade, which in theory could compromise graft perfusion. Therefore some centers prefer to defer epidural placement. Standard monitors (five-lead ECG, NIBP measurement, pulse oximetry, end-tidal gas concentrations, and temperature) are required as with any general anesthetic. Patients require frequent intraoperative and postoperative assessment of serum glucose and electrolytes and an arterial line or central venous catheter can facilitate frequent blood draws. Select patients may warrant both an arterial line and central venous catheter depending on their underlying comorbidities. Patients with autonomic neuropathy are often considered to be at greater risk for severe cardiovascular depression during the induction of anesthesia. However, no

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studies have shown a difference in hemodynamic response to induction between diabetic patients with preexisting autonomic neuropathy and nondiabetic uremic patients undergoing transplantation. Hemodynamic stability over long periods may be best achieved using a balanced anesthetic technique that involves both inhaled and intravenous anesthetic agents as well as intravenous opioids. Blood pressure and fluid management can be challenging during SPK. As with KTx, perfusion pressure is important for a newly anastomosed pancreas. A lengthy intraabdominal procedure may necessitate significant amounts of fluid. However, patients with hypertension and diastolic dysfunction may be at risk for heart failure from volume overload. Therefore fluid administration should be guided by an assessment of volume status, as determined by heart rate, blood pressure, plethysmography variability index and pulse pressure or systolic pressure variation, for example. As opposed to in KTx alone, colloid administration is sometimes advocated in SPK instead of large volumes of crystalloid due to theoretical concern for pancreatic swelling, although no controlled studies have been conducted. Blood products should be administered per standard criteria. Abdominal muscle relaxation is essential for SPKs with their extensive intraabdominal dissection. As with KTx alone, attention to the metabolism of neuromuscular blockers is required. Cisatracurium remains a good choice as it does not rely on renal metabolism. A continuous infusion of cisatracurium can be used given the long case duration, allowing for titration of the depth of the neuromuscular block with reliable reversibility. Intermittent administration of vecuronium, if titrated by train-of-four monitoring, can also provide excellent relaxation conditions. For patients who are undergoing pancreas transplant alone or pancreas transplant after KTx and have adequate renal function, any intermediate-acting nondepolarizing muscle relaxant may be used. Intraoperative blood glucose control is important to prevent ketoacidosis in patients with unopposed counterregulatory hormone secretion and to assess the function of the transplanted pancreas. Before the pancreas is reperfused, glucose should be checked hourly and treated as appropriate. Hyperglycemia may cause depressed immune function and impaired wound healing and puts patients at risk for more severe neurologic injury should brain ischemia occur.114 After the pancreas is reperfused, glucose should be checked every 30 minutes to monitor for both hyperglycemia, which may harm pancreatic graft beta cells, and hypoglycemia. Typically, glucose concentrations decrease by approximately 50 mg/dL/h after the pancreas is unclamped.115 A randomized trial of intraoperative glucose management in insulin-dependent type 2 diabetics compared a continuous glucose-insulin infusion with intermittent intravenous insulin injections during both major and minor surgery. No difference was found in the ability to control intraoperative and postoperative glucose levels and metabolism.116 Similarly, a study of intraoperative glucose management during pancreas transplantation and SPK found no significant difference in glycemic control when comparing continuous insulin infusion with intermittent intravenous insulin boluses.117 Therefore the manner of lowering glucose does not appear to be as critical as the glucose level itself. 

POSTOPERATIVE CARE Successful pancreas transplantation usually results in rapidly declining insulin requirements. Blood glucose levels should be monitored closely in the recovery room or the ICU to avoid hypoglycemia. With SPK as with KTx alone, urine output should also be closely monitored to detect reversible kidney graft injury. Postoperative pain control can be managed with epidural or patient-controlled analgesia. Patient and graft survival in SPK have increased significantly over the past several decades.118 During the period of 2010 to 2014, SPK patients in the US had a 1-year survival of 97.4%, pancreas graft survival was 91.3% and kidney graft survival was 95.5%.112 SPK does not appear to decrease the success of the kidney graft compared with KTx alone in diabetic patients. Like patients post KTx, cardiovascular disease remains the primary cause of death post SPK.112

References

















1. Vandam LD, Harrison JH, Murray JE, et  al. Anesthetic aspects of renal homotransplantation in man. With notes on the anesthetic care of the uremic patient. Anesthesiology 1962;23:783–92. 2. Ko CW, Chang CS, Wu MJ, et  al. Gastric dysrhythmia in uremic patients on maintenance hemodialysis. Scand J Gastroenterol 1998;33(10):1047–51. 3. Global Observatory on Donation and Transplantation. http://www. transplant-observatory.org. Accessed October 1, 2017. 4. United Network of Organ Sharing, Transplant Trends. https://www. unos.org/data/transplant-trends/#transplants_by_organ_type+y ear+ 2016. Accessed October 1, 2017. 5. OPTN/SRTR 2015 Annual Data Report: Introduction. Am J Transplant 2017;17(1):11–20. 6. Liefeldt L, Budde K. Risk factors for cardiovascular disease in renal transplant recipients and strategies to minimize risk. Transplant Int 2010;23(12):1191–204. 7. Weir MR, Burgess ED, Cooper JE, et  al. Assessment and management of hypertension in transplant recipients. J Am Soc Nephrol 2015;26:1248–60. 8. Brown JJ, Dusredieck G, Fraser R, et  al. Hypertension and chronic renal failure. Br Med Bull 1971;27(2):128–35. 9. Prasad GVR, Ruzicka M, Burns KD, et  al. Hypertension in dialysis and kidney transplant patients. Can J Cardiol 2009;25(5):309–14. 10. Gavras H, Oliver JA,PJ. Cannon, Interrelations of renin, angiotensin II, and sodium in hypertension and renal failure. Annu Rev Med 1976;27:485–521. 11. Craig RG, Hunter JM. Recent developments in the perioperative management of patients with chronic kidney disease. Br J Anaesth 2008;101(3):296–310. 12. Converse Jr RL, Jacobsen RN, Toto RD, et  al. Sympathetic overactivity in patients with chronic renal failure. N Engl J Med 1992;327(27):1912–8. 13. Toto RD. Treatment of hypertension in chronic kidney disease. Semin Nephrol 2005;25(6):435–9. 14. Sear JW, Jewkes C, Tellez JC, et al. Does the choice of antihypertensive therapy influence haemodynamic responses to induction, laryngoscopy and intubation? Br J Anaesth 1994;73(3):303–8. 15. Comfere T, Sprung J, Kumar MM, et al. Angiotensin inhibitors in a general surgery population. Anesth Analg 2005;100:636–44. 16. Kheterpal S, Khodaparast O, Shanks A, et al. Chronic angiotensinconverting enzyme inhibitor or angiotensin receptor blocker therapy combined with diuretic therapy is associated with increased episodes of hypotension in noncardiac surgery. J Cardiothorac Vasc Anesth 2008;22(2):180–6. 17. Smith I, Jackson I. Beta-blockers, calcium channel blockers, angiotensin converting enzyme inhibitors and angiotensin receptor blockers: should they be stopped or not before ambulatory anaesthesia? Curr Opin Anesthesiol 2010;23:687–90.

13 • Perioperative Care of Patients Undergoing Kidney Transplantation 18. Florens N, Calzada C, Lyasko E, et  al. Modified lipids and lipoproteins in chronic kidney disease: a new class of uremic toxins. Toxins 2016;8(12):376–402. 19. Goldberg IJ. Lipoprotein metabolism in normal and uremic patients. Am J Kidney Dis 1993;21(1):87–90. 20. Wolfe RA, Ashby VB, Milford EL, et  al. Comparison of mortality in all patients on dialysis, patients on dialysis awaiting transplantation, and recipients of a first cadaveric transplant. N Engl J Med 1999;341(23):1725–30. 21. Grundy SM. Hypertriglyceridemia, insulin resistance, and the metabolic syndrome. Am J Cardiol 1999;83(9B):25F-9F. 22. Lentine KL, Hurst FP, Jindal RM, et  al. Cardiovascular risk assessment among potential kidney transplant candidates: approaches and controversies. Am J Kidney Dis 2010;55(1):152–67. 23. Rigatto C. Clinical epidemiology of cardiac disease in renal transplant recipients. Semin Dial 2003;16(2):106–10. 24. Gallon LG, Leventhal JR, Kaufman DB. Pretransplant evaluation of renal transplant candidates. Semin Nephrol 2002;22(6):515–25. 25. Humar A, Kerr SR, Ramcharan T, et al. Peri-operative cardiac morbidity in kidney transplant recipients: incidence and risk factors. Clin Transplant 2001;15(3):154–8. 26. Gill JS, Pereira BJ. Death in the first year after kidney transplantation: implications for patients on the transplant waiting list. Transplantation 2003;75(1):113–7. 27. Foley RN, Parfrey PS, Harnett JD, et  al. Clinical and echocardiographic disease in patients starting end-stage renal disease therapy. Kidney Int 1995;47(1):186–92. 28. Ansari A, Kaupke CJ, Vaziri ND, et al. Cardiac pathology in patients with end-stage renal disease maintained on hemodialysis. Int J Artif Organs 1993;16(1):31–6. 29. Burke SW, Solomon AJ. Cardiac complications of end-stage renal. Adv Ren Replace Ther 2000;7(3):210–9. 30. Eschbach JW, Kelly MR, Haley NR, et al. Treatment of the anemia of progressive renal failure with recombinant human erythropoietin. N Engl J Med 1989;321(3):158–63. 31. Marsh JT, Brown WS, Wolcott D, et al. rHuEPO treatment improves brain and cognitive function of anemic dialysis patients. Kidney Int 1991;39(1):155–63. 32. Lietz K, Lao M, et  al. The impact of pretransplant erythropoietin therapy on late outcomes of renal transplantation. Ann Transplant 2003;8(2):17–24. 33. Pivalizza EG, Abramson DC, Harvey A. Perioperative hypercoagulability in uremic patients: a viscoelastic study. J Clin Anesth 1997;9(6):442–5. 34. Ando M, Iwata A, Ozeki Y, et  al. Circulating platelet-derived microparticles with procoagulant activity may be a potential cause of thrombosis in uremic patients. Kidney Int 2002;62(5):1757–63. 35. Schoonjans R, Van B, Vandamme W, et  al. Dyspepsia and gastroparesis in chronic renal failure: the role of Helicobacter pylori. Clin Nephrol 2002;57(3):201–7. 36. Strid H, Simren M, Stotzer PO, et  al. Delay in gastric emptying in patients with chronic renal failure. Scand J Gastroenterol 2004;39(6):516–20. 37. Goldfarb-Rumyantzev A, Hurdle JF, Scandling J, et  al. Duration of end-stage renal disease and kidney transplant outcome. Nephrol Dial Transplant 2005;20(1):167–75. 38. Lentine KL, Costa SP, Weir MR, et al. Cardiac disease evaluation and management among kidney and liver transplantation candidates. JACC 2012;60(5):434–80. 39. Herzog CA, Marwick TH, Pheley AM, et al. Dobutamine stress echocardiography for the detection of significant coronary artery disease in renal transplant candidates. Am J Kidney Dis 1999;33(6):1080–90. 40. Sharma R, Pellerin D, Gaze DC, et  al. Dobutamine stress echocardiography and cardiac troponin T for the detection of significant coronary artery disease and predicting outcome in renal transplant candidates. Eur J Echocardiogr 2005;6(5):327–35. 41. Wang LW, Fahirn MA, Hayen A, et al. Cardiac testing for coronary artery disease in potential kidney transplant recipients. Cochrane Database Syst Rev 2011;12:CD008691. 42. Wong CF, Little MA, Vinjamuri S, et  al. Technetium myocardial perfusion scanning in prerenal transplant evaluation in the United Kingdom. Transplant Proc 2008;40:1324–8. 43. Rabbat CG, Treleaven DJ, Russell JD, et al. Prognostic value of myocardial perfusion studies in patients with end-stage renal disease assessed for kidney or kidney-pancreas transplantation: a metaanalysis. J Am Soc Nephrol 2003;14:431–9.

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44. Grayburn PA, Hillis LD. Cardiac events in patients undergoing noncardiac surgery: shifting the paradigm from noninvasive risk stratification to therapy. Ann Intern Med 2003;138(6):506–11. 45. Schmidt A, Stefenelli T, Schuster E, et  al. Informational contribution of noninvasive screening tests for coronary artery disease in patients on chronic renal replacement therapy. Am J Kidney Dis 2001;37(1):56–63. 46. Lee TH, Marcantonio ER, Mangione CM, et  al. Derivation and prospective validation of a simple index for prediction of cardiac risk of major noncardiac surgery. Circulation 1999;100(10): 1043–9. 47. Hoftman N, Prunean A, Dhillon A, et  al. Revised Cardiac Risk Index (RCRI) is a useful tool for evaluation of perioperative cardiac morbidity in kidney transplant recipients. Transplantation 2013;96(7):639–43. 48. Lentine KL, Costa SP, Weir MR, et al. Cardiac disease evaluation and management among kidney and liver transplantation candidates: a scientific statement from the american heart association and the american college of cardiology foundation. JACC 2012;60(5): 434–80. 49. Boden WE, O’Rourke RA, Teo KK, et  al. Optimal medical therapy with or without PCI for stable coronary disease. N Engl J Med 2007;356(15):1503–16. 50. McFalls EO, Ward HB, Moritz TE, et  al. Coronary-artery revascularization before elective major vascular surgery. N Engl J Med 2004;351(27):2795–804. 51. Sedlis SP, Jurkovitz CT, Hartigan PM, et al. Optimal medical therapy with or without percutaneous coronary intervention for patients with stable coronary artery disease and chronic kidney disease. Am J Cardiol 2009;104(12):1647–53. 52. Dunkelgrun M, Boersma E, Schouten O, et  al. Bisoprolol and fluvastatin for the reduction of perioperative cardiac mortality and myocardial infarction in intermediate-risk patients undergoing noncardiovascular surgery: a randomized controlled trial (DECREASEIV). Ann Surg 2009;249:921–6. 53. Mittel AM, Wagener G. Anesthesia for kidney and pancreas transplantation. Anesthesiol Clin 2017;35(3):439–52. 54. Peterson P, Hayes TE, Arkin CF, et  al. The preoperative bleeding time test lacks clinical benefit: College of American Pathologists’ and American Society of Clinical Pathologists’ position article. Arch Surg 1998;133(2):134–9. 55. Eng M, Brock G, Li X, et al. Perioperative anticoagulation and antiplatelet therapy in renal transplant: is there an increase in bleeding complication? Clin Transplant 2011;25(2):292–6. 56. Fahy BG, Gouzd VA, Atallah JN. Pregnancy tests with end-stage renal disease. J Clin Anesth 2008;20(8):609–13. 57. Committee on Quality Management and Departmental Administration. Pregnancy Testing Prior to Anesthesia and Surgery Committee of Origin: Quality Management and Departmental Administration. American Society of Anesthesiology; 2016. Available online at: http://www.asahq.org/quality-and-practice-management/practice-guidance- resource-documents/pregnancy-testing-prior-toanesthesia-and-surgery. 58. Reissell E, Taskinen MR, Orko R, et al. Increased volume of gastric contents in diabetic patients undergoing renal transplantation: lack of effect with cisapride. Acta Anaesthesiol Scand 1992;36(7): 736–40. 59. Orko Heino AR, Rosenberg PH. Anaesthesiological complications in renal transplantation: a retrospective study of 500 transplantations. Acta Anaesthesiol Scand 1986;30(7):574–80. 60. Sear JW. Kidney transplants: induction and analgesic agents. Int Anesthesiol Clin 1995;33(2):45–68. 61. Sandid MS, Assi MA, Hall S. Intraoperative hypotension and prolonged operative time as risk factors for slow graft function in kidney transplant recipients. Clin Transplant 2006;20:762–8. 62. Miller RD, Eriksson LI, Fleisher LA, et al. Philadelphia, PA: Churchill Livingstone/Elsevier. 7th ed. Miller’s Anesthesia, ;831. 2010. p. 2112–6. 880. 63. Feng CK, Chan KH, Liu KN, et  al. A comparison of lidocaine, fentanyl, and esmolol for attenuation of cardiovascular response to laryngoscopy and tracheal intubation. Acta Anaesthesiol Sin 1996;34(2):61–7. 64. Goyal P, Puri GD, Pandey CK, et  al. Evaluation of induction doses of propofol: comparison between end-stage renal disease and normal renal function patients. Anaesth Intensive Care 2002;30(5): 584–7.

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65. Kirvela M, Olkkola KT, Rosenberg PH, et  al. Pharmacokinetics of propofol and haemodynamic changes during induction of anaesthesia in uraemic patients. Br J Anaesth 1992;68(2):178–82. 66. Robertson EN, Driessen JJ, Booij LH. Pharmacokinetics and pharmacodynamics of rocuronium in patients with and without renal failure. Eur J Anaesthesiol 2005;22(1):4–10. 67. Powell DR, Miller R. The effect of repeated doses of succinylcholine on serum potassium in patients with renal failure. Anesth Analg 1975;54(6):746–8. 68. Thapa S, Brull SJ. Succinylcholine-induced hyperkalemia in patients with renal failure: an old question revisited. Anesth Analg 2000;91(1):237–41. 69. Staals LM, Snoeck MM, Driessen JJ, et  al. Reduced clearance of rocuronium and sugammadex in patients with severe to end-stage renal failure: a pharmacokinetic study. Br J Anaesth 2010;104(1):31–9. 70. Neale J, Smith AC. Cardiovascular risk factors following renal transplant. World J Transplant 2015;5(4):183–95. 71. Ebert TJ, Frink Jr EJ, Kharasch ED. Absence of biochemical evidence for renal and hepatic dysfunction after 8 hours of 1.25 minimum alveolar concentration sevoflurane anesthesia in volunteers. Anesthesiology 1998;88(3):601–10. 72. Ebert TJ, Messana LD, Uhrich TD, et al. Absence of renal and hepatic toxicity after four hours of 1.25 minimum alveolar anesthetic concentration sevoflurane anesthesia in volunteers. Anesth Analg 1998;86(3):662–7. 73. Eger 2nd EI, Gong D, Koblin DD, et  al. Dose-related biochemical markers of renal injury after sevoflurane versus desflurane anesthesia in volunteers. Anesth Analg 1997;85(5):1154–63. 74. Eger 2nd EI, Koblin DD, Bowland T, et  al. Nephrotoxicity of sevoflurane versus desflurane anesthesia in volunteers. Anesth Analg 1997;84(1):160–8. 75. Frink Jr EJ, Malan P, Morgan S, et al. Renal concentrating function with prolonged sevoflurane or enflurane anesthesia in volunteers. Anesthesiology 1994;80(5):1019–25. 76. Frink Jr EJ, Malan TP, Morgan SE, et  al. Sevoflurane degradation product concentrations with soda lime during prolonged anesthesia. J Clin Anesth 1994;6(3):239–42. 77. Munday IT, Stoddart PA, Jones RM, et al. Serum fluoride concentration and urine osmolality after enflurane and sevoflurane anesthesia in male volunteers. Anesth Analg 1995;81(2):353–9. 78. Artru AA. Renal effects of sevoflurane during conditions of possible increased risk. J Clin Anesth 1998;10(7):531–8. 79. Conzen PF, Kharash ED, Czerner SF, et  al. Low-flow sevoflurane compared with low-flow isoflurane anesthesia in patients with stable renal insufficiency. Anesthesiology 2002;97(3):578–84. 80. Conzen PF, Nuscheler M, Melotte A, et al. Renal function and serum fluoride concentrations in patients with stable renal insufficiency after anesthesia with sevoflurane or enflurane. Anesth Analg 1995;81(3):569–75. 81. Nishimori A, Tanaka K, Ueno K, et al. Effects of sevoflurane anaesthesia on renal function. J Int Med Res 1997;25(2):87–91. 82. Teixeira S, Costa G, Costa F J, et al. Sevoflurane versus isoflurane: does it matter in renal transplantation? Transplant Proc 2007;39:2486– 8. 83. O’Malley CM, Frumento RJ, Hardy MA, et al. A randomized, doubleblind comparison of lactated Ringer’s solution and 0.9% NaCl during renal transplantation. Anesth Analg 2005;100(5):1518–24. 84. Wan S, Roberts MA, Mount P. Normal saline versus lower-chloride solutions for kidney transplantation. Cochrane Database Syst Rev 2016;8:1–27. 85. Othman MM, Ismael AZ, Hammouda GE. The impact of timing of maximal crystalloid hydration on early graft function during kidney transplantation. Anesth Analg 2010;110(5):1440–6. 86. Hadimioglu N, Ertug Z, Yegin A, et  al. Correlation of peripheral venous pressure and central venous pressure in kidney recipients. Transplant Proc 2006;38(2):440–2. 87. Gabriels G, August C, Grisk O, et al. Impact of renal transplantation on small vessel reactivity. Transplantation 2003;75(5):689–97. 88. Morita K, Seki T, Nonomura K, et  al. Changes in renal blood flow in response to sympathomimetics in the rat transplanted and denervated kidney. Int J Urol 1999;6(1):24–32. 89. Day KM, Beckman RM, Machan JT, et al. Efficacy and safety of phenylephrine in the management of low systolic blood pressure after renal transplantation. J Am Coll Surg 2014;218(6):1207–13. 90. Koning OH, Ploeg RJ, van Bockel JH, et al. Risk factors for delayed graft function in cadaveric kidney transplantation: a prospective

study of renal function and graft survival after preservation with University of Wisconsin solution in multi-organ donors. European Multicenter Study Group. Transplantation 1997;63(11):1620–8. 91. Grundmann R, Kindler J, Meider G, et  al. Dopamine treatment of human cadaver kidney graft recipients: a prospectively randomized trial. Klin Wochenschr 1982;60(4):193–7. 92. Carmellini M, Romagnoli J, Giulianotti PC, et al. Dopamine lowers the incidence of delayed graft function in transplanted kidney patients treated with cyclosporine A. Transplant Proc 1994;26(5):2626–9. 93. Kadieva VS, Friedman L, Margolius LP, et al. The effect of dopamine on graft function in patients undergoing renal transplantation. Anesth Analg 1993;76(2):362–5. 94. Sandberg J, Tyden G, Groth CG. Low-dose dopamine infusion following cadaveric renal transplantation: no effect on the incidence of ATN. Transplant Proc 1992;24(1):357. 95. Spicer ST, Gruenewald S, O’Connell PJ, et  al. Low-dose dopamine after kidney transplantation: assessment by doppler ultrasound. Clin Transplant 1999;13(6):479–83. 96. Dean M. Opioids in renal failure and dialysis patients. J Pain Symptom Manage 2004;28(5):497–504. 97. Halawa A, Rowe S, Roberts F, et  al. A better journey for patients, a better deal for the NHS: the successful implementation of an enhanced recovery program after renal transplant surgery. Exp Clin Transplant 2018;16(2):127–32. Available online at: https://doi. org/10.6002/ect.2016.0304. 98. Forbes RC, Concepcion BP, King AB. Intraoperative management of the kidney transplant recipient. Curr Transpl Rep 2017;4:75–81. 99. Lo C, Jun M, Badve SV, et  al. Glucose-lowering agents for treating pre-existing and new-onset diabetes in kidney transplant recipients. Cochrane Database Syst Rev 2017;27(2):1–54. 100. Buchleitner AM, Martínez-Alonso M, Hernández M, et  al. Perioperative glycaemic control for diabetic patients undergoing surgery. Cochrane Database Syst Rev 2012;12(9):1–96. 101. Kogan A, Singer P, Cohen J, et al. Readmission to an intensive care unit following liver and kidney transplantation: a 50-month study. Transplant Proc 1999;31(4):1892–3. 102. Yadav B, Prasad N, Agrawal V, et  al. Urinary kidney injury molecule-1 can predict delayed graft function in living donor renal allograft recipients. Nephrology 2015;20(11):801–6. 103. Gill JS, Tonelli M, Mix CH, et  al. The change in allograft function among long-term kidney transplant recipients. J Am Soc Nephrol 2003;14(6):1636–42. 104. Park JS, Oh IH, Lee CH, et al. The rate of decline of glomerular filtration rate is a predictor of long-term graft outcome after kidney transplantation. Transplant Proc 2013;45(4):1438–41. 105. Schankel K, Robinson J, Bloom R, et  al. Determinants of coronary artery calcification progression in renal transplant recipients. Am J Transplant 2007;7(9):2158–64. 106. Bittar J, Arenas P, Chiurchiu C, et  al. Renal transplantation in high cardiovascular risk patients. Transplant Rev (Orlando) 2009;23(4):224–34. 107. Cho WH, Kim HT, Park CH, et al. Renal transplantation in advanced cardiac failure patients. Transplant Proc 1997;29(1-2):236–8. 108. Kasiske BL, Maclean JR, Snyder JJ. Acute myocardial infarction and kidney transplantation. J Am Soc Nephrol 2006;17(3):900–7. 109. Kasiske BL, Zeier MG, Craig JC, et  al. Special issue: KDIGO clinical practice guideline for the care of kidney transplant recipients. Kidney Disease: Improving Global Outcomes (KDIGO) transplant work group. Am J Transplant 2009;9(Suppl 3):1–155. 110. Ponticelli C, Villa M. Role of anaemia in cardiovascular mortality and morbidity in transplant patients. Nephrol Dial Transplant 2002;17(Suppl 1):41–6. 111. Kandaswamy R, Stock PG, Gustafson SK, et  al. OPTN/SRTR 2015 annual data report: pancreas. Am J Transplant 2017;17(Suppl 1):117–73. 112. Gruessner AC, Gruessner RW. Pancreas transplantation of US and non-US cases from 2005 to 2014 as reported to the United Network for Organ Sharing (UNOS) and the International Pancreas Transplant Registry (IPTR). Rev Diabet Stud 2016;13(1):35–58. 113. Oppert M, Schneider U, Boksch W, et  al. Improvement of left ventricular function and arterial blood pressure 1 year after simultaneous pancreas kidney transplantation. Transplant Proc 2002;34(6):2251–2. 114. Sieber FE. The neurologic implications of diabetic hyperglycemia during surgical procedures at increased risk for brain ischemia. J Clin Anesth 1997;9(4):334–40.

13 • Perioperative Care of Patients Undergoing Kidney Transplantation 115. Spiro MD, Eilers H. Intraoperative care of the transplant patient. Anesth Clin 2013;31:705–21. 116. Hemmerling TM, Schmid MC, Schmidt J, et  al. Comparison of a continuous glucose-insulin-potassium infusion versus intermittent bolus application of insulin on perioperative glucose control and hormone status in insulin-treated type 2 diabetics. J Clin Anesth 2001;13(4):293–300.

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117. Halpern H, Miyoshi E, Kataoka LM, et  al. Glycemic control during pancreas transplantation: continuous infusion versus bolus. Transplant Proc 2004;36(4):984–5. 118. Gruessner AC. 2011 update on pancreas transplantation: comprehensive trend analysis of 25,000 cases followed up over the course of twenty-four years at the International Pancreas Transplant Registry (IPTR). Rev Diabet Stud 2011;8(1):6–16.

14

Early Course of the Patient With a Kidney Transplant PAUL M. SCHRODER, LORNA P. MARSON, and STUART J. KNECHTLE

CHAPTER OUTLINE

Overview Perioperative Management Graft Dysfunction Surgical Complications Urinary Problems Urinary Obstruction Bleeding Into the Urinary System Urine Leak Vascular Problems Arterial Stenosis Arterial Thrombosis Renal Vein Thrombosis Postoperative Bleeding Graft Loss and Transplant Nephrectomy Rejection During the Early Postoperative Period

A successful long-term outcome for a new kidney transplant recipient depends on the early perioperative management and course after surgery. Important factors affecting long-term outcome include the occurrence of delayed graft function (DGF); episodes of acute rejection; early surgical complications, such as urinary obstruction, urine leak, or vascular complications; and sepsis. Toxicity from calcineurin inhibitors (CNIs) can lead to chronic transplant damage later in the posttransplantation course. Donor and recipient factors affect long-term outcome, particularly the use of high kidney donor profile index (KDPI) donors or highly sensitized recipients. The early recognition and management of risk factors in the immediate postoperative period may lessen their long-term negative effect and improve outcome.

Overview PERIOPERATIVE MANAGEMENT A patient’s journey to a successful kidney transplant begins long before the patient meets the surgical and anesthesiology teams, at the time of diagnosis of chronic kidney disease where the patient and his or her nephrologist discuss and initiate the process of waitlist candidacy. Surgical management of the kidney transplant recipient begins in the immediate preoperative period. The initial evaluation includes a careful history and physical examination to determine whether potential contraindications 198

Hyperacute Rejection Antibody-Mediated Rejection Acute Rejection Borderline Rejection Medical Complications Delayed Graft Function Nephrotoxicity From Calcineurin Inhibitors Prerenal Azotemia and Volume Depletion Other Drug Toxicity Recurrent Disease Infection Hypertension Management of Graft Dysfunction Summary

to transplantation exist. For instance, the presence of significant cardiac disease may preclude successful surgery. Characteristics such as tobacco use, diabetes, obesity, hypertension, and dyslipidemia have all been shown to be independent predictors of cardiovascular disease in kidney transplant recipients and should prompt further cardiac evaluation, particularly in the symptomatic preoperative candidate.1–3 The Revised Cardiac Risk Index has also been demonstrated to be a useful perioperative tool for evaluating adverse cardiac event risk in kidney transplant recipients, particularly for those older than age 50.4 In addition, peripheral vascular disease and vascular insufficiency are more common in end-stage renal disease (ESRD) patients and represent a barrier to successful transplantation, with a higher incidence of postoperative renal transplant artery stenosis, graft failure, and mortality. Thus a simple pulse examination before surgery with ankle brachial indices in select patients can help stratify perioperative risks of vascular morbidity in kidney transplant recipients.5 Assessment of the recipient’s pretransplant fluid status and electrolyte levels to determine the need for dialysis is also important in the perioperative period. However, routine hemodialysis immediately before transplantation is not warranted except in cases of metabolic derangements (e.g., hyperkalemia) or fluid overload because preoperative hemodialysis has been associated with an increased risk of delayed graft function.6 Knowledge of the donor status is also helpful in the early postoperative management of the transplant recipient. With an ideal deceased donor or a living related donor, the expected outcome is

14 • Early Course of the Patient With a Kidney Transplant

an immediately functioning transplant that may preclude posttransplant dialysis. Kidneys procured from high KDPI donors or donation after circulatory death (DCD) donors have a higher likelihood of DGF, which can lead to volume overload and the need for urgent dialysis.7 Technical considerations include the need for vascular reconstruction, which may prolong surgery and contribute to postoperative DGF. Recipient factors also affect the early postoperative course. Significant risk factors for early posttransplant dysfunction include pretransplant sensitization, obesity, younger or older age, and anatomic considerations that complicate the surgery. In the early perioperative period, attention to fluid and electrolyte balance is crucial. Careful monitoring of urine output is essential, and any decrease in urine flow must be evaluated. The Kidney Disease: Improving Global Outcomes (KDIGO) guidelines recommend measuring urine volume every 1 to 2 hours for at least 24 hours after transplantation and daily until graft function is stable.8 In addition, serum creatinine should be measured daily until hospital discharge, and frequently thereafter. For example, creatinine should be measured two to three times per week for a month, and a tapering frequency of measurements in ensuing weeks.8 A decrease in urine volume may be a result of acute tubular necrosis, hypovolemia, urinary leak, ureteric obstruction or, most significantly, vascular thrombosis or acute rejection. Assessment of the patient’s volume status may help eliminate hypovolemia as a cause of decreasing urine output. DGF can be ascertained further with duplex ultrasonography to assess perfusion of the graft and to exclude renal artery or vein thrombosis. Duplex ultrasonography also allows the diagnosis of a urinary complication such as obstruction or leak. Measures to decrease the likelihood of DGF often are used during the operative procedure and in the perioperative period. Maintenance of adequate blood pressure and fluid status may be accomplished with intravenous albumin or crystalloid.9 There is no evidence for the superiority of one type of fluid during kidney transplant; however, the use of normal saline is associated with a higher incidence of acidosis.10 Shorter cold ischemia or pulsatile perfusion of the donor organ also may decrease the likelihood of postoperative DGF, and there is ongoing evaluation of normothermic perfusion techniques in this context. Some centers have used intraarterial calcium channel blockers, such as verapamil, to improve renal blood flow.11 It is common practice to administer mannitol (12.5 g) about 10 minutes before the kidney is reperfused, which helps trigger an osmotic diuresis and might be protective. Loop diuretics are also commonly used at the time of renal reperfusion. Oral calcium channel blockers have been used to decrease the incidence of DGF.12 There is controversy about the early initiation of CNIs because of the potential for nephrotoxicity. Some centers delay the use of CNIs until there is established diuresis. If additional immunosuppression is desired, polyclonal or monoclonal anti–T-cell antibodies may be used as induction therapy. 

GRAFT DYSFUNCTION Early complications of renal transplantation may be mechanical/surgical or medical. Early medical problems are more common than posttransplant surgical problems

199

TABLE 14.1  Early Surgical and Medical Complications After Transplantation Surgical/Mechanical

Medical

Ureteral obstruction Hematuria Urine leak Arterial thrombosis/stenosis Renal vein thrombosis Postoperative hemorrhage Lymphocele

Acute rejection Delayed graft function Acute calcineurin inhibitor nephrotoxicity Prerenal/volume contraction Drug toxicity Infection Recurrent disease

(Table 14.1). The most common early posttransplant medical problem is DGF, which occurs in 20% of patients who received kidneys from ideal deceased donors and in nearly 40% of patients in whom the donors were older than age 55 years.13 After or concomitant with DGF, acute rejection may become a significant clinical problem. Other reasons for early medical complications include acute cyclosporine or tacrolimus nephrotoxicity, prerenal azotemia, other drug toxicity, infection, and early recurrent disease. An uncommon but serious posttransplantation medical problem is thrombotic microangiopathy (discussed later). Thrombotic microangiopathy may be induced by rejection or as a secondary consequence of cyclosporine, tacrolimus, or sirolimus therapy.14 CNI blood levels should be measured regularly during the immediate postoperative period until target levels are reached,8 as this measurement may indicate the likelihood of CNI toxicity versus rejection in the diagnosis of graft dysfunction. The level of mammalian target of rapamycin (mTOR) inhibitor should also be measured regularly if this class of drugs is used. Mechanical problems usually are the result of complications of surgery or specific donor factors, such as multiple arteries, that lead to posttransplantation dysfunction. Mechanical/surgical factors include obstruction of the transplant, hematuria, urine leak or urinoma, and vascular problems such as renal artery or vein stenosis or thrombosis. Postoperative bleeding is another potential complication that may cause compression of the transplant because the transplant usually is placed in the retroperitoneal space. Posttransplant lymphoceles are another common cause of early transplant dysfunction. Lymph drainage from transected lymphatic channels accumulates in the perivascular and periureteral space and can cause ureteral obstruction or lower-extremity swelling from iliac vein compression. 

Surgical Complications URINARY PROBLEMS Urinary Obstruction After implantation of a living donor kidney transplant, urine output begins immediately or within minutes. (See Chapter 29 for a more complete discussion of urinary problems.) The same is not generally true of deceased donor kidneys, in which urine output may not be apparent for 1 hour or more after implantation and may be sluggish or nonexistent for days if the kidney has been injured (DGF) by donor factors or preservation. If a kidney that was formerly making urine

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A

B

C

Fig. 14.1  This patient presented with an elevated creatinine level. Ultrasound showed pelvicaliceal dilation. (A) A percutaneous nephrostomy tube was placed, and the next day a nephrostogram was obtained. (B) The midureteral stenosis was crossed successfully with a guidewire, and the ureter was dilated with a balloon (the waist of the dilated balloon corresponds to the stricture). (C) Subsequently, a double-J stent was placed from the renal pelvis into the bladder across the dilated stricture.

slows down or stops and does not respond to fluid administration, urinary obstruction must be considered in the differential diagnosis. The initial evaluation is to check the patient’s vital signs and physical examination to ensure adequate hydration and to check that the Foley catheter is functioning correctly. Obstruction of the Foley catheter by blood clots easily may occur and can be cleared by gentle irrigation. If these problems are not present, renal transplant ultrasound is the fastest, most accurate, and least expensive method to assess the renal pelvis for obstruction. Pelvicaliceal and/or ureteral dilation seen by ultrasound implies distal obstruction. If the bladder is collapsed rather than full, the problem is likely to be ureteral obstruction. Treatment should be immediate decompression of the renal transplant pelvis by percutaneous insertion of a nephrostomy tube. Subsequently (usually 1 or 2 days later to allow blood and edema to clear after nephrostomy tube placement), a nephrogram can be obtained to evaluate the ureter for stenosis or obstruction. The diagnosis is confirmed by a decline in the serum creatinine level after decompression of the renal pelvis. After the Foley catheter is removed, the most common cause of urinary obstruction is not ureteral stenosis, but rather bladder dysfunction. This problem is particularly common in diabetic patients with neurogenic bladders. Initial management is replacement of the Foley catheter and a trial of an alpha-blocker, such as tamsulosin, doxazosin, or terazosin. If bladder dysfunction persists after one or two such trials, it may be necessary to start intermittent self-catheterization. In rare instances in which bladder dysmotility is severe and urinary tract infections are common, it may be preferable to drain the transplant ureter into an ileal conduit to the anterior abdominal wall. Ideally, a patient with a neurogenic bladder should have been evaluated before transplantation with urodynamic studies, and a decision should have been made about management at that time (see Chapters 4 and 12). During the first 1 or 2 weeks after transplantation, obstruction usually is caused by a technical problem related to surgery (see Chapter 29). If a ureteral stent was placed at the time of surgery, it is highly unusual to have obstruction. Indeed, the incidence of major urologic complications after kidney transplant in patients who had a prophylactic

stent placed during surgery is significantly lower compared with those who did not have a ureteral stent placed during the transplant.15 However, placement of ureteral stents during transplant carries a higher risk of infection so it is recommended that a sulfa-based antibiotic prophylaxis be administered to these patients.16 Possible explanations for obstruction are a twisted ureter or anastomotic narrowing. Generally, obstructions appear several weeks postoperatively, after the stent has been removed, and occur most frequently at the anastomosis between ureter and bladder.17 Usually, these obstructions can be crossed by a guidewire and dilated percutaneously by an interventional radiologist (Fig. 14.1). If the nephrostogram shows a long (>2 cm) stricture, especially a proximal or midureteral stricture, it is likely to be a result of ischemia and is not usually amenable to balloon dilation, necessitating surgical repair (Fig. 14.2). The operation of choice for a long stricture or one that has failed balloon dilation is ureteroureterostomy or ureteropyelostomy using the ipsilateral native ureter. The spatulated ends of the transplant and native ureters are anastomosed using running 5-0 absorbable suture. This anastomosis can be done over a 7 French double-J stent, which is left in place for 4 to 6 weeks. If no ipsilateral ureter is available, it may be necessary to use the contralateral ureter. If neither the ipsilateral ureter nor the contralateral ureter is available, alternatives include bringing the bladder closer to the kidney using a psoas hitch or fashioning a Boari flap, but these measures are seldom necessary.18 Another method is endoureterotomy; experience with this method is growing.19 Even if urinary obstruction is clinically silent (i.e., the patient is asymptomatic with a normal creatinine value), urinary obstruction manifested by dilation of the pelvis and calices on ultrasound should be treated because it ultimately leads to thinning of the renal cortex and loss of renal function. Urinary obstruction should be treated immediately to minimize damage to the transplanted kidney. 

Bleeding Into the Urinary System Gross hematuria is common immediately postoperatively because of surgical manipulation of the bladder. The Leadbetter–Politano procedure for ureteroneocystostomy is associated with more hematuria compared with the

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retroperitoneal position, a urinoma collects around the kidney and bladder and causes a bulge in the wound and pain with direct displacement of adjacent viscera, including the bladder. The diagnosis should be suspected if the serum creatinine level is increasing (or not decreasing appropriately). Adjunctive tests to help make the diagnosis of urine leak, if it is not obvious clinically, include a renal scan, which would show urine in the retroperitoneal space surrounding the bladder or around loops of bowel, or an ultrasound, which would show a fluid collection outside the bladder and when aspirated has a high creatinine level. Urine leak generally is because of a surgical problem with the ureteroneocytostomy or ischemic necrosis of the distal ureter. Other causes include postbiopsy injury and ureteral obstruction. Such a leak should be immediately repaired surgically because the risk of wound infection increases with delay in treatment. 

VASCULAR PROBLEMS

Fig. 14.2  This intraabdominal kidney transplant was found by ultrasound to be obstructed. A nephrostomy tube was placed, and a nephrostogram was obtained the next day. The kidney had rotated medially and twisted the ureter proximally. The patient was managed operatively by placing the kidney laterally in a retroperitoneal pocket and performing ureteroureterostomy using the ipsilateral native ureter.

extravesical approach typified by the Lich-Gregoir technique or the technique described by us (see Chapter 11).20 The advantage of the latter technique is that it effectively prevents reflux and can be done with excellent long-term results. Occasionally, continuous bladder irrigation is necessary if gross hematuria is associated with clots, although intermittent manual irrigation usually is adequate. Bladder outlet obstruction by a blood clot is an emergency; vigilant nursing care is required to ensure that it does not occur. It is preferable not to distend the bladder in the immediate postoperative period to avoid disrupting the bladder sutures or causing a leak, and continuous bladder irrigation and cystoscopy ideally are avoided. Minor hematuria without clots is common in the first 1 or 2 days regardless of the surgical method of ureteroneocystostomy and does not require treatment; it resolves over time without specific treatment. 

Urine Leak A leak of urine from the transplanted kidney in the early postoperative period may be clinically obvious if the patient presents with abdominal pain, an increasing creatinine level, and a decrease in urine output. Urine in the peritoneal cavity causes peritonitis and pain. More commonly, assuming that the kidney was placed in the

Arterial Stenosis Transplant renal artery stenosis is a relatively common vascular complication after kidney transplant with an incidence of 1% to 23%.21 It may manifest in the early postoperative period by: (1) fluid retention, (2) elevated creatinine levels, and (3) hypertension.22 (See Chapters 28 and 30 for a more complete discussion of vascular problems.) Commonly, the patient does not tolerate cyclosporine or tacrolimus because these drugs exacerbate the preexisting ischemia at the glomerular arteriolar level. The aforementioned triad of clinical findings need not all be present, and the diagnosis should be suspected for any one of the three clinical signs. Cytomegalovirus (CMV) infection and DGF have been described as risk factors for transplant renal artery stenosis.23 If the creatinine level is greater than 2 mg/dL, renal arteriography is best avoided because of the nephrotoxicity of the contrast dye. Magnetic resonance angiography usually can give an accurate delineation of the arterial anatomy. Ultrasound also is safe, but less discriminatory, and may be helpful if jetting of flow beyond a stricture is seen. As the population of renal transplant recipients has become older and includes more diabetic patients and patients with vascular disease, transplant renal artery pseudostenosis has become increasingly common. Pseudostenosis refers to arterial stenosis in the iliac artery proximal to the implantation of the transplant renal artery. Although the anastomosis and renal artery may be completely normal, a more proximal iliac artery stenosis can lead to hypoperfusion and resulting high renin output by the transplanted kidney. Treatment of transplant renal artery stenosis and pseudostenosis includes both percutaneous interventions and surgery. Generally, ostial stenosis, long areas of stenosis, and stenosis in tortuous arteries difficult to access radiographically are not treated as successfully with percutaneous interventions (balloon dilation or stenting) as with surgery. Stenoses within smaller branches of the renal artery may be treatable only by angioplasty. Iliac artery disease causing pseudostenosis may be treated by angioplasty, but risks embolization or dissection, leading to thrombosis or further ischemia. A recent systematic review of transplant renal

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A

B

Fig. 14.3  This patient presented with fluid retention, hypertension, and an elevated creatinine level. (A) An arteriogram showed that the artery to the lower pole arising from a common aortic patch was stenotic proximally. (B) This stenosis was successfully treated with balloon angioplasty with resolution of the patient’s symptoms.

artery stenosis treated with either percutaneous angioplasty or stenting demonstrated equivalent outcomes with success rates ranging from 65% to 94%.24 Surgical options include bypass of the stenosis using autologous saphenous vein, a prosthetic graft, or an allogeneic arterial graft procured from a deceased donor. The risk of the procedure has to be weighed against the potential benefit of improving renal transplant blood flow. In addition to the serum creatinine determination, a biopsy may be useful to assess the quality of the renal parenchyma. In advanced chronic rejection with an elevated creatinine level for more than 1 month, it may not be prudent to repair such arteries, but this problem is not generally encountered in the early posttransplant course. Fig. 14.3 shows a renal artery stenosis in the lower pole artery that was managed successfully by balloon angioplasty. 

Arterial Thrombosis Renal transplant arterial thrombosis usually occurs early (within 30 days) in the posttransplant period, but is a rare event and is generally caused by a technical error at the time of surgery.25 It usually is related to an intimal injury to the donor kidney during procurement or to anastomotic narrowing or iliac artery injury during implantation. The incidence of renal transplant arterial thrombosis is around 1% to 2%.26 Kidneys from donors younger than 5 years old have been associated with a higher risk of thrombosis.27 The kidney tolerates only 30 to 60 minutes of warm ischemia before it is irreversibly injured, making it difficult to diagnose and correct this problem before it is too late to salvage the kidney. The diagnosis should be suspected in a patient who has had a transplant hours to days before and has had good urine output but who suddenly has a decrease in urine output. A high degree of suspicion has to be present, and the patient should be returned to the operating room promptly. Although some reports of catheterbased thrombolysis for renal artery thrombosis have been described, the majority of cases require operative intervention and if unsuccessful require transplant nephrectomy.28 If the patient had urine output preoperatively from the native kidneys, the diagnosis is difficult to make in a timely manner because urine output may continue after the renal transplant has thrombosed. The advantage of diagnostic ultrasound has to be weighed against the disadvantage of delaying a return to the operating room. Almost all kidney transplants with arterial thrombosis are lost because of ischemic injury.

In cases of more than one renal transplant artery in which arterial reconstruction is performed at implantation, there may be increased risk of thrombosis of one or more arteries. This increased risk is a particular concern if there is a small accessory renal artery supplying the lower pole of the kidney and providing the ureteral blood supply. Thrombosis of a branch artery may manifest as an increase in serum creatinine levels associated with hypertension. Angiography shows partial thrombosis and loss of perfusion of a wedge-shaped section of renal parenchyma. The risk of this situation, in addition to potential long-term hypertension, is caliceal infarction and urine leak in the early postoperative period. Such kidneys, with partial infarction, generally can be salvaged. Urine leaks occurring through the outer cortex of the kidney after partial infarction may be managed by nephrostomy tube placement for urinary drainage and placement of another drain adjacent to the kidney to prevent urinoma. When the transplant ureter necroses as a result of arterial ischemia, alternative urinary drainage needs to be provided surgically; this would be managed most often by ureteropyelostomy using the ipsilateral native ureter. 

Renal Vein Thrombosis Renal vein thrombosis occurs in between 0.1% and 4.2% of recipients and is more common in deceased donor transplants.29 Thrombosis may occur as a technical complication when the donor renal vein was narrowed by repair of an injury or when the vein was twisted or compressed externally, but it may occur in the absence of a technical complication. Risk factors for renal vein thrombosis include use of the right donor kidney, prolonged ischemic time, older donors, older recipients, use of peritoneal dialysis pretransplant, hypercoagulable states in the recipient, and perioperative hypotension in the recipient.30 The diagnosis is indicated by sudden onset of gross hematuria and decrease in urine output, associated with pain and swelling over the graft. Ultrasound shows absence of flow in the renal vein, diastolic reversal of flow in the renal artery (Fig. 14.4), and an enlarged kidney, often with surrounding blood. Ultrasound can point to this diagnosis definitively. Only if it is immediately recognized and repaired can this problem be reversed. Immediate surgical repair of the vein and control of bleeding are required, and it is generally necessary to remove the kidney and revise the venous anastomosis. However, some instances of catheter-directed thrombolytic therapy or thrombectomy have been successfully reported

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long the kidney has been in place. If nephrectomy is performed within 4 weeks, there are minimal adhesions, and the vessels are exposed easily for ligation and transplant nephrectomy. At later times, it is usually easiest to reopen the transplant incision and enter the subcapsular plane around the kidney. The kidney is dissected free in the subcapsular space, and a large vascular clamp is placed across the hilum. The kidney is amputated above the clamp, and 3-0 polypropylene (Prolene) is used to oversew the hilar vessels. The ureter also is oversewn (see Chapter 11). 

Rejection During the Early Postoperative Period Fig. 14.4 Ultrasound shows absence of flow in the renal vein and reversal of diastolic flow in the renal artery. This kidney was enlarged to 14 cm in length with a surrounding fluid collection that represented blood. These ultrasound findings were pathognomonic of transplant renal vein thrombosis. The condition was treated surgically with excision of the kidney, placement of a venous extension graft using donor iliac vein obtained from a third-party donor, and reimplantation of the kidney. Three weeks later, the patient had a normally functioning kidney transplant.

in the setting of early postoperative renal vein thrombosis.31 Bleeding from the swollen and cracked kidney surface usually can be controlled with hemostatic agents. 

POSTOPERATIVE BLEEDING As with all surgery, postoperative bleeding may complicate renal transplant outcomes. Bleeding generally occurs during the first 24 to 48 hours after transplantation and is diagnosed by a decreasing hematocrit, swelling over the graft with a bulging incision, or significant blood seepage from the incision. Postoperative bleeding occurs in roughly 12% of kidney transplant recipients and is more likely to occur in those with calcified iliac vessels who receive higher doses of heparin as prophylactic anticoagulation and in patients taking anticoagulation agents for other medical problems such as coronary artery or cerebrovascular disease.32 Patients treated with clopidogrel for underlying cardiac disease are at significant risk for postoperative bleeding; this class of medications should be avoided or discontinued 1 week before renal transplantation if acceptable from a cardiac perspective.33 If the hematoma is not clinically obvious, an ultrasound or computed tomography (CT) scan can define its size and help determine whether or not surgical evacuation is appropriate. Treatment includes immediate surgery and blood transfusions as necessary. 

GRAFT LOSS AND TRANSPLANT NEPHRECTOMY During the early posttransplant period, if a renal transplant loses perfusion because of thrombosis or because of hyperacute, acute, or accelerated vascular rejection, it must be removed. Otherwise, the systemic toxicity of a necrotic kidney may cause fever, graft swelling or tenderness, and generalized malaise. Loss of perfusion can be assessed by nuclear scan or duplex ultrasound. The technically easiest way to perform a transplant nephrectomy depends on how

HYPERACUTE REJECTION Hyperacute rejection is the immediate rejection of the donor kidney upon reperfusion and is mediated by preformed antibodies against the donor. The risk of hyperacute rejection or of antibody-mediated rejection (AMR) is increased when a renal transplant is performed in the setting of ABO mismatch or a positive lymphocytotoxic crossmatch (see Chapter 22). Hyperacute rejection is now a rare event because of our understanding of transplant immunology and the implementation of more stringent immunologic testing of donors and recipients to prevent such occurrences. Current guidelines recommend molecular human leukocyte antigen (HLA) typing both the recipient and donor before kidney transplant because HLA matching for HLA-A, HLAB, and HLA-DR, with an emphasis on HLA-DR matching, has been shown to improve kidney transplant outcomes.34 For nonsensitized patients with no preformed antibodies, it is reasonable to proceed with transplantation with no prospective crossmatch and this strategy of “virtual crossmatching” has been developed to minimize cold ischemic time.35 For sensitized patients that have preformed antiHLA antibodies, the selection of donors toward whom the patient has no preformed antibodies is critical for the success of the transplant. Therefore highly sensitized patients should undergo further serologic typing of the donor and high-resolution HLA typing of both the donor and recipient.36 In addition, sensitized kidney transplant candidates should undergo a complement dependent cytotoxicity crossmatch and a flow cytometric crossmatch with the putative donor to prevent hyperacute and acute rejection.34 Although this rigorous immunologic testing of donor and recipient has drastically reduced the incidence of hyperacute rejection, there are reports of hyperacute rejection occurring even in the setting of negative crossmatch results.37 A hyperacutely rejected kidney has no perfusion on renal scan because of microvascular thrombosis and should be removed. The introduction of solid-phase assays based on the Luminex platform may help identify those with donor-specific antibody (DSA) that may cause a problem in the absence of positive crossmatch results, but these assays require more rigorous validation and standardization. The incidence of hyperacute rejection is not 100% in those with preformed antibodies, presumably because some antibodies have lower affinity, lower density, do not bind complement, or cause accommodation.38 In some cases, blood type A2 donors may be transplanted successfully to type O recipients

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because type A2 expresses less of the putative antigen, but this strategy also has increased risk of graft loss.39 Desensitization is a strategy to remove preformed antibody before transplantation to prevent hyperacute and antibody-mediated rejection. Desensitization regimens include the use of plasmapheresis combined with intravenous immunoglobulin and/or rituximab and are a growing area of research.40 If at all possible, a crossmatch-negative, ABO-compatible recipient should be identified for the transplant candidate or the kidney can be shipped to a center that has such a patient awaiting a kidney, potentially in exchange for a kidney to which the intended recipient has a negative crossmatch. A strategy such as this will maximize outcomes and utility for the kidney transplant community.

ANTIBODY-MEDIATED REJECTION Despite a negative T-cell crossmatch test preoperatively, some patients may develop an early aggressive form of rejection, termed antibody-mediated rejection (AMR).38 The incidence of AMR is greater than 20% in sensitized patients.41 The diagnosis of AMR is based on the presence of DSA in recipient serum and biopsy of the transplanted kidney demonstrating microvascular inflammation (glomerulitis or peritubular capillaritis), immune cell infiltration, and usually evidence of complement activation by C4d staining of peritubular capillaries.42 AMR is seen most often in sensitized patients with DSA of high mean channel fluorescence by flow crossmatch. Often such patients have had a previous transplant. The time course of this type of rejection is typically within days to weeks of the transplant, although it may occur at any time; it tends to be poorly responsive to steroids and occasionally resistant to all forms of antirejection therapy. Indeed, renal transplant patients who develop DSA have 60% 5-year graft survival compared with 80% graft survival in those who do not develop DSA.43 Although successful prophylaxis of rejection has been described using intravenous immunoglobulin, rituximab, plasmapheresis, or thymoglobulin in highly sensitized patients, when this form of rejection has started there is no standard treatment.44 The KDIGO guidelines recommend that such rejection be treated with one or more of the following, with or without steroids: plasmapheresis, intravenous immunoglobulin, anti-CD20 antibody, or other lymphocyte-depleting antibody.8 Other novel strategies to treat AMR include targeting complement, targeting plasma cells with proteasome inhibitors, targeting the germinal center reaction with anticytokine or cytokine receptor antibodies or costimulatory blockade (belatacept), or directly targeting antibodies by enzymatic cleavage.45 Randomized controlled trials are needed to determine which of these therapies (or combination of therapies) is most effective in treating AMR.46 

ACUTE REJECTION The most common form of immunologic rejection in the early posttransplant period is acute cellular rejection, mediated predominantly by host T lymphocytes responding to the allogeneic major histocompatibility complex (MHC) antigens on the donor kidney. Without adequate immunosuppression, acute rejection typically occurs 5 to 7 days after

transplantation, but it can occur at virtually any later time. The highest incidence of acute rejection is within the first 3 months, and overall rates of rejection vary from 5% to 25% within the first 6 months, depending on HLA matching and the immunosuppressive protocol. The clinical harbingers of acute rejection include an increasing creatinine level, weight gain, and graft tenderness. Often, there are no physical signs or symptoms, making the diagnosis largely dependent on laboratory assessment of renal function. Better diagnostics based on urine or blood molecular analysis have been developed but are at early stages of clinical application.47–49 The current diagnosis of acute rejection is based on kidney transplant biopsy and histopathologic changes, including tubulitis (invasion of tubules by lymphocytes), glomerulitis, and arteritis, which are classified according to the Banff Classification System.50 The importance of biopsy confirmation of rejection relates to the risk of increasing immunosuppression in patients whose graft dysfunction is not caused by rejection but perhaps infection or other causes that might be exacerbated by increased immunosuppression. First-line treatment of acute cellular rejection is bolus steroid therapy with methylprednisolone sodium succinate (Solu-Medrol). Many regimens are used successfully, but typical dose and duration are 10 mg/kg intravenously daily for 3 days (up to a maximum single dose of 500 mg/ day). About 85% to 90% of acute cellular rejection episodes are steroid-responsive. If the patient’s serum creatinine level has not begun to decrease by day 4 of therapy, alternative treatment must be considered, such as antilymphocytic globulin, alemtuzumab (Campath-1H), or rituximab (anti-CD20) as lymphocytotoxic therapy. Many centers use antibody-depleting therapy first line for all severe vascular rejections (Banff 2A and 3), particularly if anti-IL-2 induction was used. However, antibody-depleting therapies may be associated with an increase in infectious complications when used to treat rejection compared with when used for induction.51 A recent systematic review of randomized trials in treating acute rejection demonstrated that antilymphocyte antibody therapies are likely superior to steroids in the initial treatment of acute cellular rejection in terms of reversing rejection and preventing graft loss, but there was no difference in subsequent rejection episodes or patient survival, and the antibody therapies carry a higher rate of adverse events compared with steroid treatment.52 Rejection that does not respond to treatment with steroids or antibody therapy occurs in less than 5% of patients, although more frequently in sensitized patients or repeat transplants with significant DSA present. The effect of acute cellular rejection on graft survival depends on the response to treatment, with minimal effect if treatment results in return to baseline function but negative effect with incomplete response or repeated rejection episodes.53 Whether or not an early rejection episode predisposes the kidney to chronic rejection is controversial but likely depends on the complete resolution of the rejection and associated DSA. 

BORDERLINE REJECTION The entity of borderline rejection on kidney transplant biopsy is of uncertain significance. Whereas some studies demonstrate that treatment of borderline rejection with an

14 • Early Course of the Patient With a Kidney Transplant

increase in the patient’s immunosuppression can improve graft function, others have found little benefit in treating those with borderline rejection on biopsy results.54 Therefore if a kidney biopsy is interpreted as “borderline” by Banff criteria, we suggest the decision to treat be made on an individual basis according to the clinical picture of the recipient. 

Medical Complications DELAYED GRAFT FUNCTION DGF is the most common early complication after kidney transplantation. The definition of DGF has been the subject of much debate but has been traditionally defined as the need for dialysis during the first week after transplantation. A more recent and objective definition of DGF termed functional DGF is defined as the failure of serum creatinine to drop by 10% on three consecutive days in the first posttransplant week.55 The most recent data from the Organ Procurement and Transplantation Network (OPTN) and Scientific Registry of Transplant Recipients (SRTR) Annual Data Report 2012 reports rates of DGF in the United States at 15% to 20%. This rate is higher for deceased donors at around 20% to 25%, with recipients of DCD kidney transplants carrying the highest rates of DGF at about 40%. The long-term clinical consequences of DGF are significant. Recent reports have demonstrated that DGF is associated with a 38% increase in acute rejection and a 53% increased risk of mortality in recipients of deceased donor kidneys.56 Both donor and recipient factors contribute to the risk for DGF. The most notable risk factors associated with DGF are cold ischemic time, receipt of a DCD kidney, donor age, body mass index (BMI), and terminal creatinine level. Other donor factors associated with increased risk for DGF include anoxic or cerebrovascular cause of death, a history of hypertension, increased warm ischemia time, and greater HLA mismatch. Recipient characteristics associated with increased risk of DGF include male sex, black race, history of diabetes, longer time on dialysis, increased BMI, frailty, elevated Panel Reactive Antibody (PRA), prior transplant, previous blood transfusions, elevated pretransplant phosphate levels, and a mismatch in body size between the donor and the recipient.57 Despite this knowledge, a reliable method for predicting DGF in kidney transplant recipients remains elusive. Several methods are available to help reduce the risk for DGF. For instance, it appears that the incidence of DGF may be reduced by the use of pulsatile perfusion of the procured renal allograft; however, the effect of this technology on long-term graft outcomes is unclear.58 The pathophysiology of DGF is not completely understood. It is thought to be a multifactorial process attributed to multiple donor and recipient factors that together mediate an ischemia-reperfusion injury that ultimately results in oxidative stress and an inflammatory cascade resulting in cell injury and death within the graft.57 The diagnosis of DGF is usually apparent during the first 24 hours after transplantation; the most common clinical scenario is a decline in urine output unresponsive to a fluid challenge. The differential diagnosis of DGF includes the same prerenal, renal, and postrenal causes of acute kidney injury as for native kidneys with additional emphasis on potential technical

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problems with the vascular or ureteral anastomoses. The major differential diagnostic considerations in a recipient with decreasing or absent urine output are volume depletion or an acute vascular or urologic complication. Other conditions that can mimic DGF are rejection and recurrent focal segmental glomerulosclerosis (FSGS). This differential diagnosis can be evaluated with urgent ultrasound or radionuclide renal scanning. Typically, a transplant with DGF shows good renal perfusion and good parenchymal uptake of orthoiodohippurate (123I-OIH) or mercaptoacetyltriglycine (99mTc-MAG3) with poor or no renal excretion. A biopsy of the kidney transplant should be performed to assess for rejection and acute tubular necrosis and is the gold standard for diagnosis. Hemodialysis should be used when clinically indicated in the posttransplant period in recipients with DGF; however, careful attention to fluid status is paramount to decrease the frequency and necessity for dialysis. The usual time course of DGF is 10 to 14 days. A major concern for transplant recipients with DGF is the potential for early acute rejection. DGF may lead to activation of the immune system with release of cytokines and adhesion molecules (see Chapter 25). This situation may result in an alloimmune response, leading to an increased frequency of acute rejection. A recent study of pooled data reported 49% of DGF patients experienced an episode of acute rejection, compared with 35% of those without DGF.59 This increase in rejection rate may contribute to the reported decrease in allograft survival in DGF patients.60 The diagnosis of rejection in patients with DGF may be hindered because the primary clinical monitoring tool is a decrease in serum creatinine levels. For this reason it is often useful to obtain periodic biopsies of the transplanted kidney in recipients with DGF to assess for rejection, and this may be performed as often as every 7 to 10 days while on dialysis for DGF.8 Although the use of antilymphocyte agents such as thymoglobulin or alemtuzumab will not necessarily treat the DGF, some centers use these agents to prevent or decrease the incidence of rejection in patients with DGF.61 Prevention of DGF and early recognition of rejection are important goals to help improve early and long-term graft survival. 

NEPHROTOXICITY FROM CALCINEURIN INHIBITORS Early institution of the CNIs cyclosporine and tacrolimus at the time of transplantation is important to prevent acute rejection episodes. Because of the potential for additive nephrotoxicity, however, some centers avoid instituting CNIs until there is adequate function of the transplanted kidney. Centers that delay the onset of CNIs usually use antibody induction therapy to lower the incidence of early acute rejection.60 Other centers, including ours, begin administering CNIs early in the posttransplant course, whether or not the allograft is functioning well or in DGF. Both of the CNIs, cyclosporine and tacrolimus, are effective in preventing acute rejection episodes, but they can lead to nephrotoxicity. Acute CNI-induced nephrotoxicity is a dose-dependent and reversible process that occurs early after the initiation of CNI therapy. This acute nephrotoxicity after initiation of CNI therapy has been reported to occur in roughly 20% of renal allograft recipients.62 Development

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of CNI nephrotoxicity may have long-term consequences for the kidney allograft because it has been associated with the later development of chronic allograft nephropathy.63 Clinical risk factors associated with the development of acute CNI nephrotoxicity include the following: systemic overexposure to cyclosporine or tacrolimus, interactions with other drugs such as mTOR inhibitors that interfere with ABCB1-mediated transport in tubular epithelial cells, interactions with drugs such as ketoconazole that alter the metabolism of CNIs by CYP3A enzymes, older kidney age, use of NSAIDs, use of diuretics, and salt depletion.64 The pathophysiology of this acute nephrotoxicity is related to vasoconstriction of the afferent arterioles, which is mediated by an increase in the production of vasoconstrictors such as endothelin and thromboxane, and activation of the renin angiotensin system by supratherapeutic levels of cyclosporine or tacrolimus. Increased free radical formation and activation of the sympathetic nervous system in native kidneys also play a part in acute CNI nephrotoxicity.64 Although there are many clinical parameters that have been advocated to differentiate CNI nephrotoxicity from rejection, most clinical parameters are of insufficient sensitivity to predict confidently the cause of the transplant dysfunction. In patients with DGF, it may be more difficult to diagnose acute rejection or CNI nephrotoxicity reliably. Suspicion of acute CNI nephrotoxicity should be raised when renal allograft function declines and there is evidence of elevated drug levels of cyclosporine or tacrolimus. The most reliable way of differentiating CNI nephrotoxicity from rejection is percutaneous renal allograft biopsy. Generally, biopsies can be performed safely soon after transplantation, using real-time ultrasound imaging and automated biopsy needle devices. Although it can be difficult to differentiate between CNI nephrotoxicity and other potential diagnoses in the renal allograft, there is a scoring system based on histologic features of CNI toxicity that can aid in the diagnosis and that correlates with future graft function.65 Most cases of acute CNI nephrotoxicity are reversible by lowering the dose of the CNI. Because of the variability of intestinal absorption in the early transplant period, underdosing and overdosing of these agents are common, which can lead to rejection episodes or CNI nephrotoxicity. Monitoring cyclosporine and tacrolimus levels is valuable in preventing significant increases in blood levels, which may lead to nephrotoxicity.8 Some centers routinely use a high-dose CNI protocol to prevent rejection and accept a certain level of nephrotoxicity as a consequence. 

PRERENAL AZOTEMIA AND VOLUME DEPLETION Prerenal azotemia from volume depletion may lead to deterioration of allograft function during the immediate postoperative period. Overuse of diuretics and uncontrolled blood glucose are two common causes of volume depletion and prerenal azotemia in the posttransplant kidney recipient. Because most patients are already receiving CNIs, which decrease renal blood flow, the concurrent insult of volume depletion may lead to elevated blood urea nitrogen and serum creatinine levels. It may be difficult to distinguish prerenal azotemia from an episode of acute rejection, but persistent elevation in serum creatinine even after appropriate volume repletion should prompt further workup with

a transplant biopsy if clinical suspicion for acute rejection is high. Antihypertensive medications should be used carefully in the posttransplant period to avoid hypotension, which may further worsen renal blood flow. Meticulous attention to daily weights, intake and output, and assessment of orthostatic blood pressure changes can diagnose volume depletion as a contributing factor to renal allograft dysfunction. Volume repletion with intravenous or oral fluids is indicated in the setting of prerenal azotemia from volume depletion in the postoperative kidney transplant recipient. 

OTHER DRUG TOXICITY Transplant patients often have complex pharmacologic regimens at the time of transplantation, which may include nephrotoxic medications or medications that may cause concomitant nephrotoxicity with CNIs. Examples of the former include nonsteroidal antiinflammatory drugs and nephrotoxic antibiotics such as amphotericin and aminoglycosides. Tacrolimus and cyclosporine are metabolized by the cytochrome P-450-3A4 system (CYA P-450-3A4), and medications that are also metabolized by CYA P-450-3A4 may increase their blood levels. Examples of drugs that may interact with the metabolism of CNIs include nondihydropyridine calcium channel blockers such as diltiazem and verapamil, erythromycin, ketoconazole, and fluconazole.64 Grapefruit juice also has been shown to increase the gastrointestinal absorption of cyclosporine (see Chapters 16 and 17). Selective serotonin reuptake inhibitor antidepressants are another class of pharmacologic agents that need to be used with care. In particular, nefazodone and fluvoxamine are metabolized by CYA P-450-3A4 and may increase CNI blood levels.66 Routine drug level monitoring is important when drugs that are metabolized by CYA P-450-3A4 are used. Adjustment of the daily dose of cyclosporine and tacrolimus to attain therapeutic blood levels helps prevent episodes of nephrotoxicity from the concomitant use of these agents. Avoidance of medications that interfere with drug metabolism is desirable. Some studies have demonstrated a personalized approach to deciding the best immunosuppressive regimens for kidney transplant recipients as associations of drug toxicities with some CYP3A genotypes or singlenucleotide polymorphisms in certain genes can influence the metabolism of these drugs and the interaction between the immunosuppressants and other drugs.62 

RECURRENT DISEASE Most causes of renal failure do not recur in the transplanted kidney; when they do, it is usually later in the posttransplant course. (See Chapters 4 and 32 for further discussion of recurrent disease.) Two diseases may occur in the immediate posttransplant period and lead to significant graft dysfunction or graft loss if not treated aggressively. FSGS is the most common glomerular disease that can recur in the immediate postoperative period.67 The overall recurrence rate is approximately 30% to 40%, with most cases recurring in the first posttransplant year.68 The pathogenesis of recurrent FSGS, like primary FSGS, remains poorly understood, but evidence points to a circulating factor or factors present in the serum as the likely culprit mediating this disease.69 Several

14 • Early Course of the Patient With a Kidney Transplant

risk factors have been associated with an increased risk of developing recurrent FSGS after kidney transplant: these include younger age at primary diagnosis, rapid progression of primary FSGS to ESRD (90 mmHg on at least two occasions) and treated aggressively to a goal blood pressure of