Hematology in Clinical Practice [5th Edition] 0071626999, 9780071626996, 9780071766531

Table of contents :
Title page......Page 4
Contents......Page 6
Preface......Page 8
Normal Erythropoiesis......Page 10
Clinical Approach to Anemia......Page 19
Marrow- Damage Anemia......Page 36
Anemias Associated with a Reduced Erythropoietin Response......Page 51
Iron-Deficiency Anemia......Page 62
Thalassemia......Page 74
Hemoglobinopathies .......Page 88
Macrocytic Anemias......Page 103
The Dysplastic and Sideroblastic Anemias......Page 118
Blood Loss Anemia......Page 133
Hemolytic Anemias......Page 145
Anemia in the Elderly......Page 164
Erythrocytosis and Polycythemia Vera......Page 172
Disorders of Porphyrin Metabolism......Page 185
Hemochromatosis......Page 191
Normal Myelopoiesis......Page 204
Quantitative and Qualitative Disorders of
Neutrophils......Page 214
The Acute Myeloid Leukemias......Page 224
Chronic Myelogenous Leukemia and the
Myeloproliferative Disorders......Page 238
Normal Lymphopoiesis and the
Lymphatic System......Page 254
Lymphopenia and Immune Deficiency......Page 267
Chronic Lymphocytic Leukemia and Other Leukemic Lymphoproliferative Diseases
......Page 277
Non-Hodgkin Lymphomas......Page 288
Hodgkin Lymphoma......Page 310
Acute Lymphocytic Leukemia......Page 320
Plasma Cell Disorders......Page 328
Monocyte-Macrophage Disorders......Page 343
Normal Hemostasis......Page 350
Clinical Approach to Bleeding Disorders......Page 356
Vascular Purpura......Page 365
Thrombocytopenia......Page 373
Platelet Dysfunction and von Willebrand Disease......Page 393
Hemophilia and Other Intrinsic
Pathway Defects......Page 407
Extrinsic and Common Pathway Coagulopathies......Page 420
Consumptive Coagulopathies......Page 429
Thrombotic Disorders......Page 437
Anticoagulation in the Management of
Thrombotic Disorders......Page 456
Blood Component
Therapy......Page 474
A
......Page 486
B
......Page 488
C
......Page 490
D
......Page 492
E
......Page 493
F
......Page 494
H
......Page 495
I
......Page 498
L
......Page 499
M
......Page 500
N
......Page 502
P
......Page 503
R
......Page 506
S
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T
......Page 509
U
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W
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Z
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Citation preview

HEMATOLOGY IN CLINICAL PRAC TICE

Notice

Medicine is an ever-changing science. As new research and clinical experience broaden our knowledge, changes in treatment and drug therapy are required. The authors and the publisher of this work have checked with sources believed to be reliable in their efforts to provide information that is complete and generally in accord with the standards accepted at the time of publication. However, in view of the possibility of human error or changes in medical sciences, neither the editors nor the publisher nor any other party who has been involved in the preparation or publication of this work warrants that the information contained herein is in every respect accurate or complete, and they disclaim all respon­ sibility for any errors or omissions or for the results obtained from use of the information contained in this work. Read­ ers are encouraged to confirm the information contained herein with other sources. For example and in particular, readers are advised to check the product information sheet included in the package of each drug they plan to adminis­ ter to be certain that the information contained in this work is accurate and that changes have not been made in the recommended dose or in the contraindications for administration. This recommendation is of particular importance in connection with new or infrequently used drugs.

A Lange Medical Book

HEMATOLOGY IN CLINICAL PRAC TICE Fifth edition ROBERT S. HILLMAN, M.D. Chairman Emeritus, Department of Medicine Maine Medical Center Portland, Maine Professor of Medicine Maine Medical Center-Tufts University School of Medicine Boston, Massachusetts

KENNETH A. AULT, M.D. Direaor Emeritus Maine Medical Center Research Institute Portland, Maine Associate Professor of Medicine University ofVermont College of Medicine Burlington, Vermont

MICHEL LEPORRIER, M.D. Professor of Hematology Head, Clinical Hematology Department

Centre Hospitalier & Universitaire Caen, France

HENRY M. RINDER, M.D. Direaor, Hematology Laboratories Yale-New Haven Hospital Professor of Laboratory Medicine and Internal Medicine ( Hematology)

Yale University School of Medicine New Haven, Connecticut

edical New York Chicago San Francisco Lisbon London Madrid Mexico City Milan New Delhi San Juan Seoul Singapore Sydney Toronto

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CO NTE NTS Preface

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SECT I O N I I

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28 Normal H emostasis . ............... ............... ............................ 341 29 Clinical Approach to Bleeding Disorders . .. . . . 347 30 Vascular Pu rpu ra .................................................................... 356 3 1 Thrombocytopenia ................................................................ 364 32 Platelet Dysfunction and von Willebrand Disease ........................................................ 3 84 33 Hemophilia and Other Intrinsic Pathway Defects ..................................................................... 3 98 34 Extrinsic and Common Pathway Coagulopathies . .. . . . . . .. . .. . .. .. ... . 411 35 Consumptive Coagu lopathies . . . .. . .. ... . . . ......... ..420 36 Thrombotic Disorders . ... .... . . . . . . . . . . .. ...... . . .. . .428 37 Anticoagulation in the Management of Thrombotic Disorders . ... . . .. ... . . . . .. . . . . . 447 .

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Normal Myelopoiesis ............................................ ... ...........195 Quantitative and Qualitative Disorders of Neutrophils .. . .. .. . . . . . . ...... . . ... . . . . .. ..... . . .. . . .205 The Acute Myeloid Leukemias ....................... . ................ .215 Chronic Myelogenous Leukemia and the Myeloprol iferative Disorders . .. . . . . .. . .... . .. .. 229 Normal Lymphopoiesis and the Lymphatic System . . . . . ..... . . . . . .. . . . .. . .. . . .. 245 Lymphopenia and Immune Deficiency ..... . .. . . . ... . . . . 258 Chronic Lymphocytic Leukemia and Other Leukemic Lymphoproliferative Diseases . . . . . 268 Non-Hodgkin Lymphomas .. . . ... . . . . . . . . 279 Hodgkin Lymphoma .............................................................. 30 I Acute Lymphocytic Leukemia . .... ........ ... .. ............. ..... .. 311 Plasma Cell Disorders .......................................................... 3 1 9 Monocyte-Macrophage Disorders ..................................... 334 .

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SECT I O N I I WHITE BLOOD C E LL DISORDERS 16

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Normal Erythropoiesis ............................................................. 1 Clinical Approach to Anemia . . .. . . . . . I0 Marrow-Damage Anemia . ...... .. .... ... ...... .. . .. ..... . . .. .. 27 Anemias Associated with a Reduced Erythropoietin Response .... .... . .. ...... ... ...... . .. ... . . ...42 I ron-Deficiency Anemia .......................................................... 53 Thalassemia ............................................................................... 65 Hemoglobinopathies . . . .. .. . . . . . .. . . 79 Macrocytic Anemias .. .. . . ... . .. ...... .. .. .. . .. . .. .. .. . . 94 The Dysplastic and Sideroblastic Anemias .. .. .. . . . . .. 1 09 Blood Loss Anemia .. ... .. ............................ ...................... .. l 24 Hemolytic Anemias ................................................................ l 36 Anemia in the Elderly............................................................ I SS Erythrocytosis and Polycythemia Vera .............................. 1 63 Disorders of Porphyrin Metabolism ..................................176 Hemochromatosis ........ ... ..... ..... ............. ........... .............182 .

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P RE FAC E Hematology in Clinical Practice , fifth edition, is written specifi­ cally for clinicians-medical students, physicians in training in­ cluding residents and fellows, primary care internists or family practitioners, and hematologists/oncologists. It is a practical guide to the diagnosis and treatment of disorders of red blood cells, white blood cells, and hemostasis. Each disease state is dis­ cussed in terms of the underlying pathophysiology, clinical fea­ tures that suggest the diagnosis, the use of state-of-the-art laboratory tests in the diagnosis and differential diagnosis of the

condition, and current management strategies. For the student or physician in training, chapter sections additionally provide a case-based discussion of the systematic approach to the workup of a patient with hematologic disease, providing a foundation for clinical training. We would like to thank Dr. Joseph P. Fanning and Dr. J ames McArthur for photographs from their personal collections, and Catherine Hartung for her artwork.

vii

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SECTION I Red Blood Cell Disorders N O RM A L E RYT H RO PO I ES I S The oxygen required by tissues for aerobic metabolism is supplied by the circulating mass of mature erythrocytes (red blood cells) . The circulating red blood cell population i s continually renewed by the erythroid precursor cells in the marrow, under the control of both humoral and cellular growth factors. This cycle of nor­ mal erythropoiesis is a carefully regulated process. Oxygen sen­ sors within the kidney detect minute changes in the amount of oxygen available to tissue and by releasing erythropoietin are able to adjust erythropoiesis to match tissue requirements. Thus, normal erythropoiesis is best described according to its major components, including red blood cell structure, function, and turnover; the capacity of the erythroid marrow to produce new red blood cells; and growth factor regulation.

S T RU C T U R E O F T H E R E D B LO O D C E L L The mature red blood cell is easily recognized because of its unique morphology ( Figure 1-1 ) . At rest, the red blood cell takes the shape of a biconcave disc with a mean diameter of 8 J..tm , a thickness of 2 J..tm , and a volume of 90 fL. It lacks a nucleus or mitochondria, and 33% of its contents is made up of a single protein, hemoglobin. Intracellular energy requirements are largely supplied by glucose metabolism, which is targeted at maintaining hemoglobin in a soluble, reduced state, providing appropriate amounts of 2,3-diphosphoglycerate ( 2 ,3 -DPG ), and generating adenosine triphosphate (ATP) to support membrane function. Without a nucleus or protein metabolic pathway, the cell has a limited lifespan of 100-120 days. However, the unique structure of the adult red blood cell is perfect for its function, providing maximum flexibility as the cell travels through the microvasculature (Figure 1-2 ) .

•

1

Membrane A. Inner and Outer Layers The shape, pliability, and resiliency of the red blood cell are largely determined by its membrane. The structure of this mem­ brane is illustrated in Figure 1-3 . It is a lipid sheath, just two mol­ ecules thick, consisting of closely packed phospholipid molecules. The various surface lipids are in constant motion, forming microdomains or "rafts," which play imporrant physiologic roles. The external surface of the membrane is rich in phosphatidyl­ choline, sphingomyelin, and glycolipid, whereas the inner layer is largely phosphatidylserine, phosphatidylethanolamine, and phos­ phatidylinositol. This asymmetry is maintained by flippase, an ATP-dependent aminophospholipid translocase that rapidly transporrs phosphatidylserine and ethanolamine from the outer to the inner membrane. A second calcium-activated transporter, scramblase, can disrupt the distribution of membrane phospho­ lipids, leading to a relocation of phosphatidylserine to the cell sur­ face with a resulting increase in the thrombogenic potential of the cell surface. More importantly, accumulation of excess phos­ phatidylserine on the red cell surface plays a role in red cell senes­ cence and macrophage destruction. Membrane phospholipids are also vulnerable to oxidation by reactive oxygen species (ROS ) resulting in an alteration of the surface organization. This is counteracted by an elaborate antioxidant system, as well as an ATP-dependent regeneration of phospholipids from plasma fatty acids. Approximately 50% of the red blood cell membrane is made up of cholesterol that is in equilibrium with the unesterified cholesterol in the plasma. Because of this, the cholesterol content of the membrane is influenced by plasma cholesterol levels, as well as by the activ­ ity of the enzyme lecithin cholesterol acyltransferase ( LCAT) and bile acids. Patients with liver disease who have impaired

2

SECTION I

R E D B LOO D C E L L D I SO R D E R S

with protein 4. 1 and complementary spectrin heterodimers to form a hexagonal lattice framework under the lipid bilayer. Defects in the vertical structure of the membrane (deficiency of spectrin, ankyrin, or band 3, or loss of lipid) result in spherocyte formation. Damage to the horizontal spectrin framework results in severe red cell fragmentation or mild elliptocytosis. The integral proteins and surface glycosphingolipids are also responsible for the cell 's antigenic structure. More than 300 red blood cell antigens have now been classified with the ABO and Rh blood group antigens being of primary importance in typing blood for transfusion (see Chapter 3 8 ) . Autoantibodies against minor blood group antigens can result in increased red blood cell destruction by the reticuloendothelial cells.

Hemoglobin FIGURE 1-1 . Red blood cell morphology. On the stained blood smear. red blood cells appear as a relatively uniform population of anucleate. biconcave cells with a diameter of approximately 8 11m and a width of 2 11m.

LCAT activity accumulate excess cholesterol on the red blood cell membrane, which results in abnormal red blood cell mor­ phology (targeting) and at times a shortened survival.

B. Reticular Protein Network The outer lipid membrane layer is affixed to a reticular protein network consisting of spectrin and actin. As shown in Figure 1-3 , the integral proteins glycophorins ( A through C ) and band 3 , which function as anion exchangers, extend vertically from the spectrin lattice framework through the lipid layer to make contact with the cell surface. Spectrin heterodimers interact horizontally

The red blood cell is, basically, a container for hemoglobin­ a 64,500 Da protein made up of 4 polypeptide chains, each con­ taining an active heme group. Each heme group is capable of binding to an oxygen molecule. The respiratory motion of hemoglobin, that is, the uptake and release of oxygen to tissues, involves a specific change in molecular structure (Figure 1-4 ) . A s hemoglobin shuttles from its deoxyhemoglobin t o its oxyhe­ moglobin form, carbon dioxide (C0 2 ) and 2,3-DPG are expelled from their position between the �-globin chains, opening the molecule to receive oxygen. Furthermore, oxygen binding by one of the heme groups increases the affinity of the other groups to oxygen loading. This interaction is responsible for the sig­ moid shape of the oxygen dissociation curve. Inherited defects in hemoglobin structure can interfere with this respiratory motion. Most defects are substitutions of a sin­ gle amino acid in either the a- or �-globin chains. Some interfere with molecular movement, restricting the molecule to either a

FIGURE 1 -2. Red blood cell shape and pliability. A: On scanning EM. the biconcave shape of the red cell at rest is readily apparent. B: The exceptional pl iability of circulating red cells is shown in this section of a small blood vessel.

N O R M A L E RY T H RO P O I E S I S

CHAPTER I

3

Glycophorin A Spectri n -Ankyrin-Band interaction

3

Chol esterol

Spectrinj dimers interaction FIGURE 1-3. Red blood cell membrane structure. The red blood cell membrane consists of a two-molecule-thick lipid sheath fixed to an intracellular protein network. The outer lipid layer is rich in phosphatidylcholine, sphingomyelin, and glycolipid; the inner layer is made u p of the phosphatides of serine, ethanolamine, and inositol. Almost half of the lipid layer is cholesterol. The mem­ brane proteins, glycophorin and band 3 , penetrate the lipid sheath and make vertical contact with the reticuloproteins; spectrin; protein 4. 1; actin; and in the case of band 3, ankyrin. Spectrin heterodimers provide a horizontal framework by bridging protei n 4. 1 t o complementary spectrin dimers.

Oxyhemogl o bi n 1 00

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50

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25

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25

50

75

Tissue P02 (mm Hg)

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FIGURE 1-4. Hemoglobin-oxygen dissociation curve. Hemoglobin is capable of a respiratory motion where oxygen loaded at the lung is u nloaded at the tis­ sue level. To accept oxygen, 2,3-DPG and carbon dioxide are expel led, salt bridges are

ruptured, and each of the 4 heme groups opens to receive a molecule of e> � '0 � f: .a

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N O R M A L E RY T H R O P O I E S I S

02

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Normal release 1 00

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Tissue P02 (mm Hg) FIGURE 1-7. pH and hemoglobin-oxygen affinity. Oxygen delivery responds to

Red blood cells play a central role in oxygen transport. At the cellular level, oxygen supply is a function of the number of red blood cells perfusing the tissue and their hemoglobin oxygen­ carrying capacity. The unique physiology of the hemoglobin­ oxygen dissociation curve allows an onsite adjustment of oxygen delivery to match tissue metabolism. At the same time, compo­ nents such as pulmonary function, cardiac output, blood volume, blood viscosity, and adjustments of regional blood flow are also important contributors to oxygen transport.

tissue metabolism and blood pH-the Bohr effect. When acid products are

H emoglobin-Oxygen Dissociation Curve

metabolizing tissues. This reciprocal interaction promotes optimal exchange of oxygen and carbon dioxide during exercise. When the amount of oxygen removed by tissues continues at a high level (widened arterial-venous difference ) , the result­ ing increase in deoxyhemoglobin in the cell stimulates an increased production of 2,3 -DPG. This situation will be true regardless of whether the cause of the hemoglobin desaturation is hypoxia, cardiac failure, or anemia. The rise in intracellular 2 ,3 -DPG sustains the shift of the dissociation curve to the right and provides significant compensation for a chronic anemia or hypoxia. 2,3-DPG metabolism also responds to systemic acidosis or alkalosis. The initial shift of the curve to the right in a patient with acidosis will be corrected over the next 1 2-36 hours by a compensatory reduction in the 2,3-DPG level. The Bohr effect is reversed by the lower 2,3-DPG and the curve shifts back to normal. Although this shift readjusts the level of oxygen deliv­ ery to match tissue requirements, it can create a problem if the acidosis is suddenly corrected. Because it takes a number of hours to replace the intracellular 2,3 -DPG, a sudden return to a nor­ mal pH will shift the oxygen dissociation curve to the left owing to the lower than normal 2,3-DPG level. Theoretically, this can be of concern in the treatment of severe diabetic ketoacidosis.

Under normal conditions, arterial blood enters tissues with an oxygen tension of 95 mm Hg and hemoglobin saturation greater than 97%. Pooled venous blood returning from tissues has an oxygen tension of 40 mm Hg and a saturation of 7 5%-80%. Thus, only the top portion of the hemoglobin-oxygen dissocia­ tion curve is used in the basal state (Figure 1-7 ) . This provides a considerable excess capacity for increased oxygen delivery to support increased oxygen requirements. The sigmoid shape of the hemoglobin-oxygen dissociation curve also helps in this regard by releasing oxygen more easily as the tissue Po 2 falls below 40 mm Hg. The affinity of hemoglobin for oxygen is also influenced by temperature, pH, C0 2 concentration, and by the level of red cell 2,3-DPG . As shown in Figure 1-6 , the position of the hemoglobin-oxygen dissociation curve is affected by the rate of tissue metabolism, C0 2 production, and blood pH ( the Bohr effect) . When a tissue generates increasing amounts of CO 2 and acid metabolites, the resulting acidosis shifts the dissociation curve to the right. This shift permits the release of more oxygen for the level of tissue Po 2 . The reverse is also true. With an increase in pH, such as with an acute respiratory alkalosis, the hemoglobin-oxygen dissociation curve shifts to the left, reducing the amount of oxygen available at any tissue Po 2 . The Bohr effect is instantaneous and can be highly localized to a specific site. For example, the blood perfusing an exercising muscle will be able to deliver 75% or more of its oxygen because of the low tissue Po 2 and the acidosis-induced Bohr effect. Oxygen unloading simultaneously lowers the C0 2 tension in the red cells (Haldane effect) , thereby facilitating its diffusion from

released at the tissue level, the hemoglobin-oxygen dissociation curve of red blood cells in the vicinity immediately responds with a shift of the curve to the right. This shift has the effect of releasing more oxygen to tissues and opening hemoglobin

to receive additional amounts of C02. Alkalosis has the opposite effect. It shifts the hemoglobin-oxygen d issociation curve to the left and effectively red uces the amount of oxygen released to tissue.

Hemodynamic Factors The self-regulating capacity of the oxygen dissociation curve takes care of most of the variation in tissue oxygen requirements in the basal state. With maximal exercise, the untrained subject will reach a limit determined not by oxygen loading but by a low maximal cardiac output resulting in poor oxygen delivery to tissues. In contrast, highly trained athletes have a greatly

6

SECTION I

R E D B LOO D C E L L D I SO R D E R S

increased cardiac output, so that pulmonary loading and peripheral transport determine their limits. The role of the red cell mass in determining exercise capacity has been demonstrated in profes­ sional sports, where erythropoietin and blood doping have been used by athletes to improve their performance.

A. Anemia The oxygen dissociation curve will also compensate for an anemia of moderate severity. However, once the hemoglobin falls below 9-1 0 g/dL, components such as changes in blood vol­ ume, cardiac output, and regional blood flow come into play. Localized vasodilation is a fundamental response to tissue hypoxia. The level of red cell deoxyhemoglobin may be directly linked to this response by acting as a nitrite reductase with the release of nitric oxide and ATP. Both the pulse rate and stroke volume also increase in patients with severe anemia and there is a redirection of blood flow to vital organs. These hemodynamic changes are often appreciated symptomatically by patients. As their anemia worsens, they are increasingly aware of the force of ventricular contraction and often complain of pounding headaches, especially with physical exertion.

B. Oxygen Supply Impairments in lung function also affect oxygen supply. Although the sigmoid shape of the hemoglobin-oxygen dissoci­ ation curve does counterbalance reductions in alveolar P02 , there is a limit to this compensation. Moreover, desaturation of hemoglobin results whenever unsaturated venous blood is shunted through areas of damaged lung tissue. The physiologic response to a decreased oxygen tension in ambient air, for example, the oxygen tension at moderately high altitudes (3,000-4,000 m), is an increase in 2,3-DPG to raise the P50 , that is, shift the oxygen dissociation curve to the right. Moderate exercise will still fur­ ther elevate the P 50 via the Bohr effect to maintain oxygen delivery to tissues. Under conditions of more marked hypoxia (altitudes >4,000 m ) , reflex hyperventilation results in reduced Pco2 and respiratory alkalosis. The latter shifts the oxygen dis­ sociation curve to the left with a reduction in oxygen delivery to tissues. Still, high hemoglobin affinity for oxygen provides a physiological advantage for acclimatization to high altitudes. Subjects born with high-affinity hemoglobin, such as hemoglo­ bin Andrew-Minneapolis ( P50 1 7 mm Hg) , demonstrate normal arterial oxygen saturations at altitudes up to 4,000 m, smaller increases in heart rate, and little or no increases in erythropoi­ etin when compared with normal individuals. Animals that nor­ mally live at high altitudes also have high-affinity hemoglobins.

C. Blood Viscosity Sustained hypoxia usually results in a compensatory rise in the red blood cell mass and hematocrit. Although this increases the oxygen-carrying capacity of blood, it also increases blood v iscosity. The interaction of the hematocrit level and blood viscosity is discussed extensively in Chapter 1 3 . Tissue oxygen delivery theoretically is maximal at a hematocrit of 33 %-36% (hemoglobin of 1 1- 1 2 g/dL) , assuming no changes in cardiac output or regional blood flow. Above this level, an increase in

viscosity will tend to slow blood flow and decrease oxygen deliv­ ery. From a physiological standpoint, this effect is relatively minor until the hematocrit exceeds 50%, at which time blood flow to key organs such as the brain can be significantly reduced. e

R E G U LAT I O N O F E RY T H RO P O I E S I S

Red Blood Cell Production The rate of new red blood cell (RBC) production varies according to the rate of red blood cell destruction and tissue oxy­ gen requirements. Changes in the oxygen delivery to tissue are sensed by peritubular interstitial, fibroblast-like cells in the kidney. A decrease in the oxygen content of hemoglobin (pul­ monary dysfunction ) , the hemoglobin level ( anemia) , or the hemoglobin affinity for oxygen (shift in the oxygen dissociation curve) will stimulate an increased production of erythropoietin by renal interstitial cells. This is accomplished by recruitment of new cells to initiate transcription of erythropoietin messenger ribonucleic acid (mRNA) by a single gene on chromosome 7. The mechanism o f regulation involves the sensing o f oxygen tension by a flavoheme protein that controls the level of hypoxia inducible factor (HIF- 1 ) . The latter interacts with response elements in nuclear DNA to activate erythropoietin gene expression. Erythropoietin then travels to the marrow, where it binds to a specific receptor (EPOR) on the surface of committed ery­ throid precursors. This receptor is a 508-amino acid glycopro­ tein coded by a gene on chromosome 19. Within hours, there is a detectable increase in deoxyribonucleic acid ( DNA) synthesis. This is followed by proliferation and maturation of committed stem cells to produce an increased number of new red blood cells. Erythroid progenitor apoptosis is also inhibited. The full marrow response takes several days. Given a sustained increase in erythropoietin stimulation, a rise in the reticulocyte index will not occur for 4-5 days and a detectable increase in hemat­ ocrit will take a week or more.

A. Measuring the Erythropoietin Response The erythropoietin response to anemia can be directly measured by assaying the serum erythropoietin level ( Figure 1-8 ) . Once the hemoglobin level falls below 12 g/dL, there is a logarithmic increase in the serum erythropoietin level. At the same time, it is important to note that with mild anemia (a hemoglobin level greater than 1 2 g/dL) , the erythropoietin level is not increased. This probably reflects the compensation of the 2,3-DPG-induced shift in the hemoglobin-oxygen dissociation curve combined with the sensitivity level of the renal sensor.

B. Other Factors Influencing Erythropoietin Level Although the erythropoietin response is primarily a function of the severity of anemia or hypoxia, other factors, such as the ery­ throid marrow mass and levels of inflammatory cytokines, will influence the serum erythropoietin level. Erythropoietin binds avidly to erythroid progenitors and is removed ftom circulation.

CHAPTER I

N O R M A L E RY T H R O P O I E S I S

7

blood cells can show increases in new red blood cell production of 2-3 times normal; that is, the release of 40-60 mL of new red blood cells per day. With a chronic hemolytic anemia, even higher production levels can be attained. Therefore, the capac­ ity of the erythroid marrow to compensate for an anemia or hypoxia is a key parr of the definition of "normal" erythropoiesis.

Measu rement

Normal

3

6

9-26

t

mU/mL

9

Hemoglobin (g/dl) FIGURE 1-8. Erythropoietin production and anemia. Once the hemoglobin level falls below 1 2 g/dL the plasma erythropoietin level increases logarithmically. Patients with renal disease or the anemia associated with chronic inflammation show a lower than predicted response for their degree of anemia

Therefore, with aplastic anemia, extremely high levels of serum erythropoietin reflect both an increased production and a decreased clearance. In contrast, with chronic hemolytic anemias, the expansion of marrow erythroid precursors results in a more rapid clearance of erythropoietin from circulation and, there­ fore, a lower serum level. Inflammatory cytokines, including interleukin- 1 , interleukin-6, tumor necrosis factor (TNF- a ), and transforming growth factor � also play a role in regulating erythropoietin production and ' erythroid progenitor proliferation. They are responsible for the lower than normal erythroid marrow response in patients with inflammatory disease states (see Chapter 4 ). Finally, direct sup­ pression of the erythroid marrow response is seen in patients receiving certain drugs (chemotherapeutic agents, cyclosporin A, and theophylline) or who are infected with human immun­ odeficiency virus (HIV ) . Two other factors, angiotensin I I and insulin-like growth factor- I (IGF- 1 ) , may also play an erythropoietin-like role in cer­ tain settings. The erythropoietin-independent growth of erythroid progenitors in polycythemia vera (see Chapter 1 3 ) may involve a hypersensitivity to IGF- 1 , whereas hypoxia has been shown to induce IGF- 1 binding protein. Evidence for a role for angiotensin II is indirect. Post-renal transplant erythrocytosis can be reversed by the administration of angiotensin-converting enzyme inhibitors, without affecting the serum erythropoietin level. e

E RYT H RO I D M A R ROW P RO D U C T I O N

Erythroid marrow production is most often defined for the basal state. When it comes to anemia diagnosis, however, it is more important to recognize the capacity to increase red blood cell production according to the severity of the anemia. Patients who experience acute blood loss or sudden hemolysis of circulating red

The level of production can be assessed from several measure­ ments of red blood cell production and destruction (Table 1-1 ) . Clinically, the marrow E/G ratio and reticulocyte index are of the greatest value. The marrow E/G ratio (the ratio of erythroid to granulocytic precursors) is determined by inspecting a stained smear of aspirated marrow particles. As long as the granulocyte production of the marrow is normal, it is possible to estimate the proliferation of erythroid precursors. In the basal state, there will be approximately 1 erythroid precursor for every 3-4 granulocytic ( myelocytic ) precursors. With anemia and high levels of erythropoietin stimulation, the number of erythroid precursors increases dramatically to give ratios of 1 : 1 or greater. The morphology of the precursors is also important. Normal pro­ liferation shows a balanced increase in erythroid precursors at all stages of maturation. If the number is skewed toward a younger population, especially a population with abnormal mor­ phology, this suggests a defect in DNA synthesis or cytoplasmic maturation. These defects can result in a failure of cells to mature and early death in the marrow, so-called ineffective ery­ thropoiesis. Effective red blood cell production is measured clinically by counting the number of reticulocytes (new red blood cells con­ taining increased amounts of RNA) entering the circulation. Although both the E/G ratio and reticulocyte count are at best semiquantitative, they do provide sufficient information for clinical diagnosis. A measurement of radioiron incorporation into red blood cells (erythron iron turnover) can provide a more accurate measurement of red blood cell production. This technique was used originally to define and classify red blood cell disorders as defects in either marrow proliferation (hypoproliferative anemias) , precursor maturation ( ineffective erythropoiesis ) , or red blood cell destruction (hemorrhagic and hemolytic anemias) .

TABLE 1 - 1

•

Measurements of red blood cell production and

destruction Production

Destruction

Marrow EJG ratio

Change in hematocrit

Reticulocyte index

Indirect bilirubin

Erythron iron turnover

Lactic dehydrogenase (LDH) 5 1 Cr-red blood cell survival CO excretion/stool urobilinogen

8

SECTION I

R E D B LOO D C E L L D I SO R D E R S

The performance of the erythroid marrow can also be extrapolated from studies of red blood cell destruction. Clinical indicators of red blood cell destruction include the serum lac­ tic dehydrogenase level, the indirect bilirubin, and observation of the rate of rise or fall of the hematocrit over time. Research measurements that are more accurate in defining levels of red blood cell destruction include carbon monoxide (CO) excre­ tion, stool urobilinogen, and a direct measurement of radio la­ 5 beled red blood cell survival ( 1 Cr red blood cell survival) . The latter has been used clinically to define both the rate and the site of destruction, whether in spleen or liver. The other meas­ urements are not as practical.

Basal and Stimulated Erythropoiesis The ability of the erythroid marrow to increase red blood cell production in response to anemia or hypoxia is a basic charac­ teristic of "normal" erythropoiesis. Therefore, when evaluating a patient with an anemia, there is a definable level of response of the marrow (E/0 ratio) and the reticulocyte index for acute and chronic anemia (Table 1-2 ) . A normal 70-kg adult has a circulating red blood cell mass of approximately 2,000 mL (300 x 109 red blood cells per kg). Since red blood cells have a lifespan of 1 00- 1 20 days, 1% of the red blood cell mass, approximately 20 mL of red blood cells, is destroyed daily and replaced by new red blood cell production. This steady state is clinically appreciated from the E/G ratio of 1 :3 and the reticulocyte index (the reticulocyte count corrected for hematocrit and reticulocyte shifr; see Chapter 2 ) . With an acute anemia secondary to hemorrhage or hemolysis, the marrow will respond with a 3-fold increase in cell production within 7-10 days. This can be detected from the increase in the E/0 ratio to 1 : 1 or higher and a rise in the reticulocyte index to 3 times normal. With a chronic hemolytic anemia , red blood cell production can increase further, reaching levels of 5-8 times normal. These patients show E/0 ratios greater than 1 : 1 and reticulocyte indices greater than 5 times normal. The highest levels of red blood cell production in patients with hemolytic anemias require an expan­ sion of the erythroid marrow mass to new areas of the marrow cavity. This process takes time and is most prominent in patients who have congenital, lifelong hemolytic anemias. Several factors play important roles in defining the marrow's response to anemia or hypoxia. Obviously, the severity of the anemia or hypoxia and the adequacy of the erythropoietin response are extremely impotrant in setting a level of"expectation." A chronic hypoproliferative anemia develops, for example,

TABLE 1 -2

•

>5

:::::Ill

e0

1

4

. Normal . Iron deficient . Hemolytic

c::

� c::

� u -5 e

Q. :::: Q) u "t) 0

I

3

2

..5!

.Q "t)

�

None

Normal response to anemia Anemia (Hb Basal (Hgb > 1 3 g/dL)

when a patient cannot produce increased amounts of erythro­ poietin because of renal damage. Other factors that determine the marrow's responsiveness include its anatomical structure, the presence of a normal pool of stem cells, and the supply of essential nutrients. The anatom­ ical structure of the marrow is organized to provide a nurturing environment for cell development. Erythroid precursor cells are maintained in a network of reticular cells and fibers in close proximity to vascular sinusoids. The marrow syncytium is designed to sustain the developing cells in a nutrient-rich envi­ ronment while they proliferate and mature. Cells lining the sinusoids have the ability to regulate the exit of cells from the marrow into circulation, allowing only those cells that have completed maturation to leave. The importance of these marrow characteristics cannot be overemphasized. An abnormality in marrow structure, as seen with radiation damage or myelofibrosis, significantly impairs new red blood cell production. Overgrowth of other cellular components, as with myeloid leukemias or infiltrating tumors or lymphomas, will decrease red blood cell production by occu­ pying the space required for red blood cell precursor growth. The supply of nutrients to the marrow is also important. The most important nutrient is the iron required for hemoglobin formation. The level of the normal marrow 's response to a hem­ orrhagic or hemolytic anemia is essentially a reflection of iron supply (Figure 1-9). In response to a hemorrhagic anemia, a normal individual with normal iron stores will be able to maintain a

Moderate

Marked

Anemia severity

1:1

Reticulocyte index

1 .0

2-3

3-8

worsening anemia, a normal individual with 500- 1 ,000 mg of reticuloendothelial iron stores can increase red blood cell production 2- to 3-fold. An individual with iron deficiency will be unable to increase production above basal levels. In con­ trast. patients with chronic hemolytic anemias show production levels in excess of

3-5 times normal, with moderate to marked anemia.

CHAPTER I

serum iron level sufficient to support a production increase of up to 3 times normal. As shown in the figure, this level of pro­ duction is attained as the hematocrit falls to levels between 20% and 30%. More severe anemia with a greater erythropoietin response does not result in a greater marrow production response. The cause of this plateau is the limitation of iron deliv­ ery from normal stores. Figure 1-9 also shows the effect of variations in iron supply. With iron deficiency, the erythroid marrow will be unable to respond despite a high level of erythropoietin stimulation. The patient with iron deficiency appears to have a hypoproliferative anemia even though the erythropoietin level is increased and the marrow morphology appears to be normal. In contrast, patients who have hemolytic anemias, in which the destruction of adult red cells provides a major source of iron for recycling to the marrow, can have marrow production that increases to lev­ els well above 3 times normal. Chronically, these patients can achieve production levels in excess of 5 times normal.

P O I N T S TO R E M E M B E R The circu lating red blood cells and the hemoglobin they carry are responsible for oxygen delivery to all organs and tissues. The mature red blood cell is highly special ized-it lacks a nucleus and is extremely pl iable to allow it to squeeze through capillaries and withstand the stress of high velocity blood flow. The red blood cell's hemoglobin can instantaneously adjust to local tissue oxygen demands by a shift in the hemoglobin-oxygen disso­ ciation cu rve.

N O R M A L E RY T H R O P O I E S I S

9

While a sustained shift in the hemoglobin-oxygen dissociation curve can compensate for a mild anemia, changes in cardiac output and regional blood flow come into play with more severe anemia. An oxygen sensor in the kidney governs the production of erythro­ poieti n, the principal regulator of new red cell p roduction­ erythropoiesis. The capacity to increase erythropoiesis in response to hypoxia or anemia depends on the level of erythropoietin released by the kid­ ney, a normal marrow structu re to su pport red cell precursor growth, and an adequate su pply of n utrients, especially the iron needed for hemoglobin synthesis. An uncompensated anemia can result, therefore, because of a loss of renal function, damage to the marrow structure, nutrient defi­ ciency, poor iron supply, or an excessive loss of circulating red cells from hemorrhage or hemolysis. Measurements of the level of marrow red cell precu rsor expansion (the E/G ratio) and new red cell production (reticulocyte index) can be used clinical ly to determ ine the adequacy of the erythro­ poietic response to anemia. As a rule, a normal individual with ade­ quate iron stores can increase red blood cell production 2- to 3-fold (marrow E/G ratio > I :2 and reticulocyte index >2) in response to a fall in the hemoglobin below 9- 1 0 g/dl. Based on these two meas­ urements and changes in mature red blood cell morphology, an ane­ mia can be classified as a hypoprol iferative anemia (defect in erythropoietin production, damage to the marrow structure, iron deficiency, or inflammation); a marrow precursor maturation disor­ der with ineffective eryth ropoiesis (vitamin deficiency states, myelodysplasia, or preleukemia); or an excessive loss of matu re red blood cells (hemorrhage or hemolysis).

B I B L I O G RA P H Y Chen JJ : Regulation of protein synthesis by the heme­ regulated elF2a. kinase: relevance to anemias. Blood 2007; 1 09: 2693 . Crawford JH et al: Hypoxia, red blood cells, and nitrite regulate NO-dependent hypoxic vasodilation. Blood 2006; 107:566. Goodnough LT, Skikne B, Brugnara C: Erythropoietin, iron, and erythropoiesis. Blood 2000;96:823 . Hillman RS, Finch CA: Red Cell Manual, 7th ed. FA Davis, 1997.

Hsia CCW: Respiratory function of hemoglobin. N Engl J Med 1 998;338:239. Lichtman MA et al: Williams Hematology, 7th ed. McGraw-Hill, 2006. Ponka P: Tissue-specific regulation of iron metabolism and heme synthesis: distinct control mechanisms in erythroid cells. Blood 1 997;89: 1 . Zwaal RFA, Schroit AJ : Pathophysiologic implications of membrane phospholipid asymmetry in blood cells. Blood 1 997;89: 1 1 2 1 .

C LI N I CA L A P P ROAC H TO A N E M IA

A

C A S E H I S T O RY

•

2

Part I

48-year-old man with poorly controlled type I d ia­ betes is referred for evaluation of a worsening anemia. He reports a long-standing history of general fatigue and poor exercise tolerance, which he feels have worsened of late. Complications of his diabetes include severe retinopa­ thy, peripheral vascular disease with one flight claudication, and worsening neuropathy. On physical examination, he appears chronically ill with a sallow complexion and pale conjunctiva. Findings include bilateral retinal hemorrhages, diminished pulses, and impaired sensation and position sense in both feet. CBC: Hematocrit/hemoglobin - 29%/9.5 g/dL (IU - 95 giL) MCV - 9 1 fL MCH - 30 pg MCHC - 33 g/d L RDW-CV - I 3.5% RDW-SD - 48 fL WBC count - 8,800/J.!L Platelet count - 1 50,000/J.LL

• SM EAR MORPHOLOGY Normocytic and normochromic with minimal anisocytosis and no polychromasia.White cell and platelet numbers and morphology appear to be within normal limits.

Reticulocyte count/index - 2.0%/ 1 .2 Sedimentation rate - 30 mm/h (Westergren)

Questions • •

•

How should this anemia be described ? What physiological factors may be playing a role? Are there other tests that can be ordered to find the cause?

CHAPTER 2

The presence and nature of an anemia may be apparent from the clinical presentation. Acute blood loss, when severe, can be expected to produce a hemorrhagic anemia; chronic blood loss will generally result in an iron deficiency anemia. More often, however, a routine measurement of the complete blood count (CBC) provides the most sensitive method for both detection and diagnosis. Thus, the clinical approach to an anemia involves both a bedside evaluation and the skilled use of the laboratory.

C L I N I C A L P R E S E N TAT I O N The signs and symptoms of an anemia are a function of its sever­ ity, its rapidity of onset, and the age of the patient. Mild anemias produce little in the way of symptoms other than a loss in stam­ ina and an increase in heart rate and dyspnea with exercise. This reflects the ability of the hemoglobin-oxygen dissociation curve to compensate for modest reductions in the hemoglobin level in the basal state. It also shows the loss of the capacity of the hemoglobin­ oxygen dissociation curve to respond to situations of increased demand once it is used to compensate for the anemia. With more pronounced anemia, the patient's exercise capac­ ity can be markedly reduced. Any exertion is accompanied by palpitations, dyspnea, a pounding headache, and rapid exhaus­ tion. In younger individuals, these symptoms and signs do not appear until the hemoglobin has fallen below 7-8 g/dL (hema­ tocrit of less than 20%-25%). However, older individuals, espe­ cially those with atherosclerotic cardiovascular disease, can become symptomatic with more modest anemia (a hemoglobin of 1 0-1 2 g/dL) . This can include worsening of ischemic mani­ festations, including angina and claudication. Moreover, ane­ mia can precipitate heart failure in the older patient with underlying heart disease. The rapidity of onset of the anemia is also important. Although the hemoglobin-oxygen dissociation curve can rap­ idly compensate for modest falls in the hemoglobin level, cardio­ vascular compensation for more severe anemia takes time. This situation is worsened if the anemia is the result of acute blood loss (a deficit in both red blood cells and plasma volume) . The reduction in total blood volume jeopardizes the cardiovascular response. Patients with acute hemorrhagic anemias are at risk for signs and symptoms of both tissue hypoxia and acute vascu­ lar collapse. In contrast, patients with long-standing anemias are able to expand their total blood volume over time and com­ pensate with an increase in cardiac stroke volume and changes in regional blood flow.

C L I N I C A L EVA L UAT I O N The cause of anemia may be suggested from the history and physical examination. Ongoing blood loss is an obvious and dra­ matic clue to the cause of the patient 's anemia. The history can be equally revealing in diagnosing other types of anemia. A doc­ umented history of anemia that reaches back to childhood is highly suggestive of a hereditary disorder, especially a congeni­ tal hemolytic anemia. The sudden onset of pancytopenia in an

C L I N I C A L A P P ROA C H TO A N E M I A

II

otherwise healthy individual may be explained from the patient's history of occupational or environmental exposure to toxic chemicals or the introduction of a new medication j ust prior to development of the cytopenia. A more gradual onset of anemia or a pancytopenia may herald myelodysplasia or other marrow disorder. Race can also be an important clue, because many of the hemoglobinopathies and enzyme deficiency states follow ethnic lines.

History The patient should be questioned extensively regarding the tim­ ing of the onset of symptoms, transfusion history, past blood count measurements, nutritional habits, alcohol intake, and any associated symptoms of acute or chronic illness such as weight loss, fever, or night sweats. A few complaints are unique to spe­ cific types of anemia. For example, the adult iron-deficient patient may report craving ice, whereas children may be observed eating dirt or clay (picophagia) . Complaints of a sore mouth and difficulty swallowing are expressed by patients with vitamin B12 and iron deficiency. The sickle cell anemia patient will have a lifelong history of episodic bone and joint pains.

Physical Examination The physical signs of an anemia depend very much on the acu­ ity of onset. The patient with acute blood loss will show signs of hypovolemia and hypoxia. A loss of more than 30% of the blood volume in less than 12 hours cannot be compensated by the nor­ mal mechanisms of venospasm and redirection of regional blood flow. Such patients will show signs of hypovolemia, including postural hypotension and tachycardia with exertion. Once the acute volume loss exceeds 40% of the total blood volume, the patient will exhibit all the symptoms and signs of hypovolemic shock, including anxiety, confusion, air hunger, diaphoresis, rest tachycardia, and hypotension even while supine. The appear­ ance of symptoms and signs of hypoxia in such patients is as much a result of inadequate perfusion of vital organs because of a decreased blood volume as a reflection of their anemia. When an anemia develops gradually so that the plasma vol­ ume has time to increase, compensation is accomplished by a combination of the shift in the hemoglobin-oxygen dissociation curve, an increase in cardiac output, and a redistribution of blood flow (Figure 2-1 ) . By physical examination, it is possible for one to detect the changes in cardiac output and blood flow. The patient demonstrates a more forceful apical impulse, a wide pulse pressure, and tachycardia with exertion. Flow murmurs secondary to increased blood turbulence are frequently heard as midsystolic or holosystolic murmurs at the apex or along the sternal border with radiation to the neck. An anemia may also be suggested from the patient 's general appearance. In fair-skinned patients, skin and mucous mem­ brane pallor are relatively good indicators of anemia. However, skin color is a less reliable measure of the hemoglobin level in heavily pigmented patients, or in those with marked vasocon­ striction or dilatation. Marked edema, as seen in patients with nephrotic syndrome or myxedema, can also interfere with

12

R E D B LOO D C E L L D I SO R D E R S

SECTION I

� ......

.!;;

.Q

..5!

�

e

1 00

TABLE 2-1 '

75

Q) .c:

50

�

25

8l

0

'

� .2

Red blood cell number--Red blood cell count, hemoglobin, hematocrit Red blood cell indices-Mean cell volume (MCV), mean cell hemoglobin (MCH), mean cell hemoglobin concentration (MCHC), red blood cell distribution width (ROW) Reticulocyte count, immature reticulocyte fraction--Reticulocyte production index White blood cell count-White blood cell differential Platelet count Blood film morphology-Cell size, hemoglobinization, anisocytosis, poikilocytosis, polychromasia

curve shi ft '

'

25

0

t

50

t

Routine laboratory tests in anemia diagnosis

Complete blood count

Hgb - 02

....

0 t:

•

.

75

Cardiac output redistribution

1 00

l=l �

Marrow examination

Marrow aspirate-E!G ratio, cell morphology, iron stain Marrow biopsy-Cellularity, morphology I ron studies

Iron transport-Serum iron, total iron-binding capacity Iron stores-Serum ferritin, marrow iron stain

FIGURE 2- 1 . Tissue oxygen supply. Delivery of oxygen to tissues is a function of the hemoglobin level, the hemoglobin-oxygen dissociation curve, and the char­ acteristics of tissue blood fiow. With anemia, the hemoglobin-oxygen dissociation

curve shifts to the right so as to del iver additional oxygen for a level of tissue Po2• As the anemia worsens, cardiac output increases and there is a redistribution of blood fiow to critical organs.

anemia detection. To avoid these confounding variables, it is best for one to look at the conjunctiva, mucous membranes, nail beds, and palmar creases of the hand when assessing the hemo­ globin level.

Laboratory Eval uation Although the history and physical examination may point the way to the presence of anemia and suggest its cause, a thorough laboratory evaluation is essential to the definitive diagnosis and treatment of any anemia. The routine hematology laboratory offers several tests relevant to anemia diagnosis: the more rou­ tine tests such as the CBC and reticulocyte count as well as stud­ ies of iron supply that serve both as screening tests and a jumping-off point to diagnosis (Table 2-1 ) . A larger number of more specific tests come into play when one is confirming the diagnosis of specific anemic conditions.

A. Complete Blood Count The CBC includes determinations of the hemoglobin, hemat­ ocrit, red blood cell count, red blood cell volume; and hemoglo­ bin content, platelet count, and white blood cell count. These measurements are provided by any of the common automated counters, including instruments manufactured by Abbott, Bayer, Beckman-Coulter, Sysmex, and Technicon Instruments vary somewhat in their technology, with most using either a combi­ nation of a highly focused light source, an electric field, laser­ based flow cytometry, or a radiofrequency wave to discriminate

between cells. Newer instruments that incorporate technologies such as flow cytometry not only measure the white blood cell count, but also perform a 3- or 5-part automated white blood cell differential that also flags bands, immature and atypical cells, and blasts. Automated instruments are not only fast but extremely accu­ rate. The coefficient of variation ( measurement error) of an automated counter is usually less than 2%, and each of the major measurements, including the hemoglobin level, red blood cell count, and mean cell volume, can be standardized inde­ pendently with commercial red blood cell and hemoglobin stan­ dards. A printout of an automated blood count is shown in Figure 2-2. A range of normal values with 95% confidence lim­ its is provided as a part of the report.

B. Hemoglobin/Hematocrit The hematocrit and hemoglobin levels are used interchange­ ably in identifying the presence of an anemia. Many counters directly measure the hemoglobin and then calculate the hema­ tocrit from measurements of the red blood cell count and mean cell volume (MCV ) . Other counters measure the hematocrit from the red blood cell size-distribution curve. This can make the hemoglobin measurement somewhat more accurate, because artifacts introduced by cell agglutination can increase the MCV and falsely elevate the hematocrit. This is usually flagged by the automated counters because of the simultaneous marked increase in the mean corpuscular hemoglobin concentration (MCHC ) . To diagnose a n anemia, any patient value must b e compared with a "normal" reference range. Table 2-2 summarizes the mean normal values for hemoglobin and hematocrit according to age and sex. At birth, the hemoglobin averages 1 7 g/dL with a hematocrit of 5 2 % . These values then decrease during childhood only to recover during adolescence until a mean

CHAPTER 2

C L I N I C A L A P P ROA C H TO A N E M I A

13

WBC Differential

Sam p l e resu lts for a patient with a normocytic/normochro m i c anemia

IC

t

WBC count

8.8

RBC count

3. 0 9

Hemoglobin 1 Hematocrit

Mean red blood cell indices

9 .5

M 5.4 ± 0 . 7 F 4.8 ± 0.6

x1 06

HGB g/dl HCT

91

j..l3

.

13 5

ROW

ROW - SO

48

ROW

1 50 7.5

M 1 6.0 + 2 F 1 4. 0 ± 2

M 47 ± 5 F 42 ± 5

MCV 90 ± 9 (fl) MCH 32 ± 2 pg MCHC 33 ± 3 g/d l

ROW - CV

Platelet count and platelet volume

II

RBC

%

33

,c

8±3

x1 03

29

30

J1 1

WBC

PLT

x1 03

M/F

13 ± 1%

42 ± 5

fl

M/F

1 40 - 440

I 1 J

M PV M/F !l3 (fl) 8.9 ± 1 . 5

Cll

.!::! (/)

0

7

C o m plexity

X

Neutrophil Lymphocyte Monocyte Eosinophil Basophil

1 03fj..l l

3.26

4.55

.626 .358

. 005

/o

o

37 52

7

4

.05

Normal values FIGURE 2-2. CBC results. Direct measurements on an automated counter include the white blood cell count, red blood cell count, hemoglobin, MCV, platelet count, and the mean platelet volume. Calculated values include the hematocrit, MCH, MCHC, and ROW A 3- or 5-part white blood cell differential also is provided by many of the automated counters. As shown in the right­ hand data plot, white blood cells can be separated and counted based on their light scatter characteristics. Abnormal white blood cells (blasts, promyelocytes, and metamyelocytes) also can be identified and counted.

hemoglobin level of 16 g/dL (hematocrit of 47%) is reached in adult men and 14 g/dL (hematocrit of 42%) in adult women. These are mean values, however, and any normal population of men or women will vary around the mean in a Gaussian dis­ tribution (Figure 2-3 ) . Therefore, it is common practice to state 95% confidence limits (2 standard deviations [SO) ) for the mean normal value. For the purpose of clinical decision making, it is best to focus on a set of lower limit of normal values that best separates normal from anemic individuals. As shown in Table 2-2, data from Scripps-Kaiser and NHANES studies have been used to derive a set of lower limits of normal for adults liv­ ing at sea level, which should exclude all but 5% of normal indi­ viduals (95% confidence limit ) . At the same time, the lower limits of normal for apparently healthy American black men and women are approximately 1 g/dL lower ( 1 2.9 g/dL for black men and 1 1 .5 g/dL for black women) . The probability that a patient's hemoglobin i s normal will also depend on the incidence of disease in any population, as

illustrated in Figure 2-3 . When the prevalence of a hematolog­ ical abnormality is high, for example, as in the inheritance of a hemoglobinopathy, the overlap of abnormal and normal popu­ lations will increase, thereby reducing both the sensitivity and specificity of the hemoglobin and hematocrit measurements. This effect may well play a role in determining the lower limits of normal for black men and women. A higher incidence of iron deficiency and a.-thalassemia has been detected in the Scripps­ Kaiser population studies, which, at least in part, explains the difference between white and black values. Normal values for the hemoglobin and hematocrit are also influenced by several environmental and physiologic factors. Populations living at higher altitudes have predictable increases in their hemoglobin levels of approximately 1 g/dL of hemoglobin for each 3 %--4% decrease in arterial oxygen saturation. The same effect is pro­ duced by cigarette smoking because carbon monoxide decreases the hemoglobin-oxygen saturation. A patient who smokes more than one pack of cigarettes per day will show an increased

14

SECTION I

TABLE 2-2

•

R E D B LOO D C E L L D I SO R D E R S

RBC

Normal hemoglobin/hematocrit values

Age/Sex

Hgb (gldL)

Hct (%)

At birth

17

52

Childhood

12

36

Adolescence

13

40

MCV

t

Lower Limit of Normal

( Hgb)•

50

1 00

1 50

200

Adult man 60

14 (± 2)

42 (± 6)

1 2.2

Mean cell volume (fL)

curve offers a sensitive method for detecting small populations of macrocytic or microcytic red blood cells.

•Based on Scripps-Kaiser and NHANES data--Beutler E, Waalen j: Blood 2006; 1 0 7: 1 747.

hemoglobin level of between 0.5 and 1 g/dL. During normal pregnancy, there is a steady decline in the hemoglobin level to 1 1- 1 2 g/clL during the second and third trimesters. This decline is caused by an expansion of plasma volume and does not repre­ sent a true anemia. In fact, a pregnant woman's red blood cell mass is actually increased late in pregnancy.

C. Mean Cell Volume Automated counters produce a size-distribution curve for the red blood cell population (Figure 2-4 ), which is then used to calcu­ late the mean MCV. The normal MCV ± 2 SO is 90 ± 9 fL and

generally coincides with the peak of the Gaussian distribution of red blood cell size. The "normal" MCV in black populations can be 1-2 fL lower (88.5 ± 7 ) . Again, this in part represents the incidence of iron deficiency and a-thalassemia in American black populations. The MCV accurately detects any general increase (macrocytosis) or decrease (microcytosis) in red blood cell volume. It is less sensitive to the presence of small popula­ tions of microcytes or macrocytes, because they have little impact on the mean. To detect small numbers of abnormal cells, the cli­ nician should look at the calculated red cell distribution width and the shape of the size-distribution curve, or, even better, inspect the stained blood smear. Figure 2-5 shows the effect on the distribution curve of blood transfusions in a patient with thalassemia. The broad two-peak distribution curve can be

Normal popul ation

Abnormal individuals

3

5

7

9

11

13

15

17

19

Hemoglobin (g/dL) FIGURE 2-3. Distributions of normal and abnormal hemoglobin values. The

FIGURE 2-5. Mixed populations of red blood cells. As seen in this thalassemic

unshaded area shows the expected distribution for a normal population of adu lt

patient with marked microcytosis and targeting, blood transfusions will distort the

males. Patients with red blood cell disorders may or may not fall outside this nor­

MCV size-distribution curve (shown on the left as a superimposition of 2 distinct

mal distribution (shaded area).Very anemic patients will have hemoglobin values

distribution curves) and result in a greater-than-normal RDW value. Examina­

well below the normal distribution, whereas those with less severe disease may fall

tion of the smear clearly shows the differences between the two populations:

within the normal range.

microcytidhypochromidtargeted cells versus normocytic, normochromic cells.

CHAPTER 2

explained by the coexistence of a microcytic population (red curve) and a normocytic population (blue curve) . Although the MCV is both accurate and highly reproducible, errors may be inrroduced by red blood cell agglutination, distor­ tions in cell shape, the presence of very high numbers of white blood cells, and sudden osmotic swelling. The latter is seen in patients with very high blood glucose levels or, rarely, with hypernatremia, when the red blood cell sample is diluted for counting. Since the diluent is isotonic, cells containing excess glucose or sodium will act as tiny osmometers and swell.

C L I N I C A L A P P ROA C H TO A N E M I A

IS

RBC 1 00

� � 5i:;, '-

width RDW-CV .....- Histogram MCV =

tr

2!

II:

20

50

1 00

1 50

Mean cell volume (fL)

D. Mean Cell Hemoglobin The automated counter provides a calculated mean cell hemo­ globin (MCH; ie, the hemoglobin level divided by the red blood cell count) . The normal MCH is 32 ± 2 pg. This is an excellent measure of the amount of hemoglobin in each individual red blood cell. Patients with iron deficiency or thalassemia who are unable to synthesize normal amounts of hemoglobin show signif­ icant reductions in the MCH.

E. Mean Corpuscular Hemoglobin Concentration The counter also provides a calculated mean corpuscular hemo­ globin concentration (MCHC ) . The normal value of the MCHC is 33 ± 3 g/dL. This is the least revealing value provided by the counter. Although it should provide a measurement of the relative concentration of intracellular hemoglobin, it is not very sensitive to disease states where hemoglobin production is defective. This is in part due to counter error, but primarily reflects the fact that defects in hemoglobin production are accompanied by a simultaneous reduction in cell size. Thus, empty cells are also small cells. The principal value of the MCHC is to detect patients with hereditary spherocytosis who have very small, dense spherocytes in circulation. These sphe­ rocytes represent cells that have lost considerable intracellular fluid because of a membrane defect. When present in signifi­ cant numbers, they will cause the MCHC to increase to levels in excess of 36 g/dL. F.

FIGURE 2-6. Red blood cell distribution width (RDW). Automated counters provide measurements of the width of the red blood cell distnbution curve. The RDW-CV is calculated from the width of the histogram at I SD from the mean divided by the MCV The normal RDW-CV is I 3 ± I %. The RDW-SD is the arith­ metic width of the distnbution curve measured at the 20% frequency level. The normal RDW-SD is 42 ± 5 fl.

Both measurements of the ROW are essentially mathemati­ cal representations of anisocytosis ( ie, variations in red blood cell size ) . Increases in the ROW suggest the presence of a mixed population of cells. Double populations, whether microcytic cells mixed with normal cells or macrocytic cells mixed with normal cells, will widen the curve and increase the ROW. The ROW-SO is more sensitive to the appearance of minor popula­ tions of macrocytes or microcytes since it is measured lower on the red cell volume-distribution curve (Figure 2-6). At the same time, it is overly sensitive to the impact of increased numbers of reticulocytes, which, because of their larger MCV, will broaden the base of the distribution curve. The RDW-CV is less sensitive to the appearance of small populations of microcytes, true macrocytes, or reticulocytes, but better reflects the overall change in size distribution seen with well-established macro­ cytic or microcytic anemias.

G. Stained Blood Film Red Blood Cell Distribution Width

In addition to the MCV, MCH, and MCHC, automated coun­ ters provide an index of the distribution of red blood cell volumes, termed the red blood cell distribution width (ROW ) . Counters may use 2 methods t o calculate this value. The first is referred to as the RDW-CV. As shown in Figure 2-6, the RDW­ CV is the ratio of the width of the red blood cell distribution curve at 1 SO divided by the MCV (normal RDW-CV = 13 ± 1 % ) . Since i t i s a ratio, changes in either the width o f the curve o r the MCV will influence the result. Microcytosis will tend to magnify any change in the RDW-CV simply by reducing the denomina­ tor of the ratio. Conversely, macrocytosis will tend to counter­ balance the change in the width of the curve and thereby minimize the change in the RDW-CV. A second method of measuring the ROW, the ROW-SO, is independent of the MCV. The RDW-SD is a direct measurement of the red blood cell dis­ tribution width taken at the 20% frequency level ( normal ROW-SO = 42 ± 5 fl. ) .

Although automated instruments provide accurate red blood cell counts and indices and white blood cell counts and differ­ entials in both healthy and diseased individuals, red blood cell morphology can provide important additional information as to the nature of the anemia. Blood films are easily prepared by hand using glass slides ( Figure 2-7 ) or by using automated slide preparation technology coupled to the cell counter. The well-dried blood film is then stained with Wright stain to bring out cytoplasmic and nuclear detail. On inspection, red blood cells should form a single cell layer with most of the cells appearing biconcave , that is, having the distinctive doughnut shape associated with biconcavity ( Figure 2-8 ) . If the film is too thick, cells will overlay each other and appear overly dense. When the film is too thin, as, for example, at the feathered edge of a hand-prepared blood smear, cells will lose both their biconcavity and round shape. Therefore, it is extremely important that any interpretation of red blood cell morphology be based on inspection of the best area of a

16

SECTION I

FIGURE 2-7.

R E D B LOO D C E L L D I SO R D E R S

Blood film preparation. Blood films can be prepared by hand or

as part of an automated cell count. Using 2 glass slides and a small drop of antico­ agulated blood. it is easy to draw the blood along the length of the slide with a sin­ gle smooth motion. Once the film is completely dry. the slide is stained with Wright stain. The slide is first flooded with stain for 2-3 minutes and then a buffer solution is added unti l a green sheen appears on the surface. After another 3-5 minutes, the slide is rinsed with tap water and air-dried. To interpret red blood cell mor­ phology, one shou ld select an area on the film where the red blood cells show the typical biconcave, doughnut shape.

well-prepared film. This is usually close to but not at the feathered end of the film. The blood film complements the automated counter meas­ urements of MCV and MCH. Visible changes in cell diameter, shape, and hemoglobin content can be used to distinguish both microcytic and macrocytic cells from normocytic/normochromic red blood cells (Figure 2-9 ) . It should be emphasized, however, that the diagnosis of microcytosis or macrocytosis on a blood film involves extrapolation from an observed change in cell diameter to a volume estimate. This is not as sensitive or accu­ rate as the direct measurement of cell volume by an automated counter. Therefore, the counter MCV should be used as the gold standard measurement for average changes in cell volume. At the same time, the stained film provides a more sensitive way to detect small populations of microcytic or macrocytic cells that are missed in the mean cell volume measurement.

The blood film is also used to detect and describe variations in red blood cell size (anisocytosis) and shape (poikilocytosis) (Figure 2-1 0 ) . The former complements the automated counter measurement of the ROW. Film morphology provides more information than the ROW, however. It is possible to not only grade the degree of anisocytosis on a scale of 0-4+ but also com­ ment on the population mix, whether microcytic, macrocytic, or another distinctive red blood cell shape (spherocytes, sickle cells, etc). Poikilocytosis can only be appreciated from the blood film. It is an important finding, because increasing poikilocyto­ sis is associated with defects in red blood cell precursor matura­ tion and certain types of red blood cell destruction. Like anisocytosis, it is graded on a scale of 0-4+ . The presence o f polychromatic macrocytes ( polychro­ masia) -cells that are slightly larger than the normal red cell by 1-2 J..l.m (cell volume > 100 fL ) , are of bluish-grayish color, and often lack the normal biconcave shape-is an important finding ( Figure 2- 1 0 B ) . These cells represent young reticulo­ cytes ( immature marrow reticulocytes) that still contain large amounts of RNA and ribosomes. Their presence, even in small numbers, indicates a "shift" of marrow reticulocytes into circulation in response to an increased level of erythropoietin stimulation. Polychromasia can be used, therefore, to assess the adequacy of the erythropoietin response to anemia. It is also a key finding when it comes to calculating the reticulo­ cyte index. Other distinctive changes in red blood cell morphology, such as red cells that contain small inclusions (nuclear remnants, Howell-Jolly bodies, Pappenheimer bodies, siderocytes) , sickle cells, spherocytes, target cells, and elliptocytes are seen in patients with various hemoglobinopathies, marrow damage, and loss of normal splenic function. The morphologic appearance of each of these abnormalities is illustrated and discussed exten­ sively in the chapters and sections dealing with individual ane­ mic states.

B

FIGURE 2--8. Normal red cell morphology. The red blood cells on a normal blood smear (low power-A high power-B) typically are u niform i n size and shape and show a clear center area because of their biconcave shape. Their diameter (com­ pared to the single leukocyte in the center of this photograph) is roughly one-half the diameter of a leukocyte or only slightly smal ler than a mature lymphocyte.

CHAPTER 2

C L I N I C A L A P P ROA C H TO A N E M I A

17

8 FIGURE 2-9. Microcytosis versus macrocytosis. Example of a slightly microcytic (A) versus a macrocytic (B) smear. The lym­ phocyte on each smear can be used as a reference point; normocyte red cells are only slightly smaller than a mature I ymphocyte.

H. Reticulocyte Count The reticulocyte count is an essential component of the CBC and plays a prominent role in initially classifying any anemia. The reticulocyte is a young red blood cell containing resid­ ual ribosomal RNA that can be stained with a supravital dye such as acridine orange or new methylene blue. In the man­ ual method, a drop of fresh blood is incubated with a few drops of new methylene blue solution and a blood smear is then prepared. The dye precipitates and stains the RNA, marking the cell as a reticulocyte and permitting a techni­ cian to count the number of reticulocytes versus the number of adult red blood cells (Figure 2-1 1 ) . For accuracy, at least 1 ,000 red blood cells should be counted to determine the reticulocyte percentage. The relative intensity of RNA stain­ ing can also provide a clue to the presence of marrow reticu­ locytes in circulation.

A

Most automated counters now incorporate technologies that allow direct instrument measurement of the reticulocyte count. As one example, the Abbott Cell-Dyne instrument uses a pro­ prietary dye that binds to reticulocyte RNA and emits fluores­ cence that is detected using an Argon-ion laser. The presence of marrow reticulocytes can also be measured as an immature retic­ ulocyte fraction, that is, macrocytic cells containing larger amounts of RNA. The normal reticulocyte count for both the automated and new methylene blue methods is 1 % with a range of 0.6%-2.0%. Even though the standard error for the manual method is quite high because it is based on a limited count, the accuracy is gen­ erally good enough for clinical purposes. In response to anemia, the reticulocyte count will increase several-fold in patients with normal renal ( erythropoietin production) and bone marrow function. In addition, high levels of erythropoietin stimulation

8 FIGURE 2-1 0. Abnormalices of size and shape. The blood smear is also invaluable for the detection of anisocytosis (varia­ tions in cell size) and poikilocytosis (variations in cell shape) (A), and polychromasia (polychromatophilic macrocytes or shift cells) in circulation (B).

18

SECTION I

R E D B LOO D C E L L D I SO R D E R S

Normoblasts and reticul ocytes (days)

Blood reticulocytes (days)

Hematocrit (%) 45 35 25 15 FIGURE 2-1 2. Reticulocyte shift. As anemia worsens and the level of erythro­ r-----

poieti n stimulation increases. marrow reticulocytes leave the marrow at an earlier point in their maturation. This prolongs their maturation time in circu lation. Wheneas the normal neticulocyte matunes in less than a day. neticulocytes in anemic patients take from I .5-2.5 days. This must be taken into account when calculating

FIGURE 2- 1 I . Reticulocyte stain. The new methylene blue stain allows neady

the neticulocyte production index.

identification of neticulocytes-4) .

45

B . Marrow and Erythropoietin Studies The diagnosis of a hypoproliferative anemia that is clearly asso­ ciated with a known inflammatory disorder, renal disease, or an abnormality in thyroid or pituitary function usually does not require a marrow aspirate or biopsy. The combination of normo­ cytic, normochromic morphology, and a lower than predicted reticulocyte response without polychromasia is enough to con­ firm the hypoproliferative nature of the anemia. Performance of a marrow aspirate merely to assess the E/G ratio is unproduc­ tive. Moreover, as long as the patient demonstrates normal leukocyte and platelet counts, it is unlikely that a marrow biopsy specimen will identify a defect in marrow morphology or cellularity. When a serum ferritin level is unavailable or is in a range that does not support the diagnosis , a marrow aspirate stained with Prussian blue can be used to distinguish true iron deficiency from the anemia of chronic disease. Patients with absolute iron deficiency should have no visible iron stores in reticuloendothe­ lial cells once the percent saturation of transferrin is below 1 5 % . Patients with a low serum iron secondary t o inflammatory dis­ ease will have normal to increased iron stores on the Prussian blue stain. In patients with chronic inflammatory disease, iron stores often appear increased, with extra large hemosiderin gran­ ules in the marrow reticuloendothelial cells. Direct measurements of the serum erythropoietin level are not helpful in either identifying this class of anemias or in sep­ arating individual abnormalities. Although a reduced erythro­ poietin response is an inherent component of the anemia, the observed range of measured values is quite large. Patients can demonstrate erythropoietin levels that are above basal, although they fall short of the levels achieved by the normal individual responding to a blood loss anemia. This phenomenon is best illustrated by the observed pattern of serum erythropoietin meas­ urements in patients with renal disease (Figure 4-3 ) .

3

6

9

15

Hemoglobin (g/dL) FIGURE 4-3. Serum erythropoietin levels in renal disease. Serum erythropoi­ etin levels in patients with the anemia of end-stage renal disease fall well below the levels observed in normal individuals responding to a hemorrhagic event.

46

SECTION I

rl

R E D BLOOD C E L L D I S O R D E RS

C A S E H I S T O RY

'�----------------------------�

Pa rt 2

I

Based on smear morphology and the red blood cell indices (MCV, MCH, MCHC), the patient has a normocytic, nor­ mochromic anemia of mild to moderate severity. From a physiological perspective, it is a hypoproliferative anemia, that is, an anemia resulting from a failure of the marrow to respond to and compensate for the anemia. This is appar­ ent from the reticulocyte index of less than I . Furthermore, the absence of polychromas ia suggests a failure to increase erythropoietin production. Additional stud ies of immediate importance include serum iron, iron-binding capacity, serum ferritin, renal func­ tion studies (BUN and creatinine/creatinine clearance), and thyroid function studies (T4 and TSH).The following results were obtained:

Serum i ron - 30 Jlg/dl I ron-binding capacity - 230 J.tg/d l % Saturation - 1 3% Serum ferritin 1 80 J.tg/L BUN I S mg/dl Serum creatinine - 0.6 mg/dl T4 and TSH - Within normal limits

D I AG N O S I S

and assessing its severity. In this case, even a mild anemia should be evaluated with a full panel of studies-CBC, reticulocyte count, sedimentation rate/C-reactive protein, and serum iron studies, including a serum ferritin level.

The approach to diagnosis of a hypoproliferative anemia in a patient with an acute or chronic inflammatory disease, renal damage, or a hypometabolic state depends on the nature and severity of the primary illness and the severity of the anemia (Table 4-2 ) . Since mild to moderate anemia in a patient with progressive renal failure is predictable, there is less need to repeatedly assess the patient for other possible causes of anemia. For patients with acute or chronic inflammatory disease, def­ inition of the anemia can be helpful in diagnosing the disorder

TABLE 4-2 Diseases associated with reduced erythropoietin response •

I nflammatory states

Acute and chronic bacterial infections Collagen vascular disorders AIDS Malignancies Renal disease

Nephritis End-stage renal disease Hypometabolic states

Protein deprivation Endocrine disorders

Hypothyroidism Hypopituitarism Hyperparathyroidism

-

-

Questions • • •

What does this pattern of i ron studies suggest? Are there other studies that will confirm your diagnosis? What treatment is indicated?

Acute I nflammatory States

Anemia is a common component of acute inflammatory states, especially bacterial infections and collagen vascular disorders. Viral diseases are less likely to produce anemia, or if they do, the anemia is secondary to an autoimmune process or a general fail­ ure of stem cells that results in pancytopenia. Parvovirus infec­ tion in patients with congenital hemolytic anemias produces a reversible suppression of marrow erythroid precursors without affecting other cell lines ( see Chapters 3 and 1 1 ) . Anemia appears rapidly with the onset o f an acute bacte­ rial infection. It is not unusual to see the patient's hemoglo­ bin fall to levels of 1 0- 1 2 g/dL (hematocrit of 30%-3 6 % ) within 1 o r 2 days after the onset o f a bacterial infection, such as acute lobar pneumonia. This initial fall in the hemo­ globin level results from a loss of older red blood cells, which are nearing the end of their natural lifespan in circulation, demonstrating the sensitivity of older cells to changes in the external environment. The release of various cytokines, fever, and local changes in the infected tissue may all play a role in stressing the older red blood cell beyond its metabolic capacity to maintain hemoglobin solubility and cell mem­ brane continuity. Even though the first step in the evolution of an acute inflammatory anemia is a self-limited hemolytic event, the prin­ cipal defects are a failure in the erythropoietin response and a limitation in iron supply, both of which inhibit the erythroid marrow response. Therefore, the erythropoietic profile is typically hypoproliferative. Red blood cell morphology is normocytic

CHAPTER 4

A N E M I A S A S S O C I AT E D W I T H A R E D U C E D E RY T H R O P O I E T I N R E S P O N S E

and normochromic, the reticulocyte count remains low ( a reticulocyte index < 2 ) , and there is little o r no polychromasia apparent on the blood film. Iron studies confirm the nature of the anemia. Within a matter of hours of the onset of an inflam­ matory condition, serum iron and TIBC fall and the ferritin level begins to rise. Serum transferrin receptor levels remain low, resulting in a low ( z ) . A failure in a-globin chain synthesis can result in hemo­ globin H, a tetramer of �-globin chains.

Quantity of Hemoglobin and Diagnosis G lobin gene expression varies with the patient's age. Throughout fetal life, red blood cells contain only hemoglo­ bin F (Figure 6--2 ). During the first several months of life, "(-globin gene expression is gradually suppressed and both �-globin and 0-globin syntheses are activated. ln adults, red blood cells contain primarily hemoglobin A (96%-9 7 % of the cell's hemoglobin) and only small amounts of hemoglobin A 2 ( 10 g/dL) because of a more modest bleeding episode or as a result of transfusion, oral iron therapy should be modified to encourage gastrointestinal tolerance and patient compliance. Otherwise, the patient will not cooperate with the prolonged course of iron therapy, which is required for the reconstitution of iron stores.

C. Iron Dextran Therapy Patients with malabsorption or a marked intolerance to oral iron will not be amenable to oral iron therapy. Their anemia can obviously be corrected with red blood cell transfusions. They will need to receive parenteral iron, however, to correct their iron balance and rebuild stores. Iron can be given intravenously or intramuscularly as iron dextran complex . Detailed instruc­ tions for the administration of iron dextran are presented in Chapter 5 . When iron dextran is used to treat a patient who is recovering from a blood loss anemia, it is best given as a single, total dose infused intravenously. Iron dextran can also be of value in treating patients with chronic blood loss. Hereditary hemorrhagic telangiectasia is perhaps the best example of a clinical condition where a relent­ less, daily loss of blood from the gastrointestinal tract can over­ whelm the normal routes of iron supply. Reticuloendothelial stores are quickly exhausted, and even maximum iron absorp­ tion on a full oral regimen cannot match cell losses of 50 mL or more of red blood cells each day. As these patients become severely anemic, they develop a severe iron-deficiency anemia with marked microcytosis and hypochromia. They can also exhibit signs of tissue iron deficiency. Acute, severe episodes of bleeding in patients with heredi­ tary hemorrhagic telangiectasia should be treated with red blood cell transfusions, just like any acute blood loss anemia. To counteract the slower, daily loss of blood in these individuals, attempts should be made to provide maximum iron therapy (see Chapter 3 0 ) . Not only should the patients receive a constant regimen of oral iron but they should also receive periodic intra­ venous injections of iron dextran, according to the rate of blood loss. The combination of oral iron and iron dextran can be quite effective (Figure 1 0-2 ) . In severely anemic patients with hered­ itary telangiectasia, red blood cell production levels of up to 5-6 times normal may be achieved for several weeks following an intravenous inj ection of 500-1 ,000 mg of iron dextran. To maintain erythroid marrow production at its maximum level over a prolonged period, the iron dextran injections must be given every 3-4 weeks. Otherwise, the level of red blood cell production will fall gradually back to basal level as the release of iron from the iron dextran complex slows. Larger complex particles in the preparation are only slowly dissolved by the reticuloendothelial cell. In fact, the release from some particles can fall behind the rate of the patient's blood loss, so

IRON DEXTRAN INJECTIONS

500 - 1000 mg IV

0

2

3 4 Weeks

5

6+

FIGURE I 0-2. Marrow production levels following iron dextran injection. Patients with severe anemia and chronic blood loss can be treated with a combi­ nation of oral iron and intenmittent intravenous injections of iron dextran. Each bolus of intravenous iron will i ncrease red blood cell prod uction to as high as S-6 times nonmal for several weeks.

that microcytosis and hypochromia will appear despite the pres­ ence of visible iron dextran particles within marrow reticuloen­ dothelial cells. This phenomenon needs to be recognized in the laboratory evaluation of anemia in patients with hereditary hemorrhagic telangiectasia who receive long-term iron dextran therapy. They may present with characteristic findings of an iron-deficiency anemia but have easily visible or even increased iron stores of their marrows on the Prussian blue stain.

Perisurgical Blood Loss Management Elective surgery patients undergoing major noncardiac proce­ dures are candidates for autologous blood storage, perisurgical recombinant erythropoietin therapy, acute normovolemic hemodilution, and blood salvage, alone or in combination. Patients who are moderately anemic (hemoglobins between 10 and 13 g/dL) or of small body size can also benefit, even when the anticipated surgical blood loss is not above 1 ,000 mL. Together, these several techniques should make it possible to avoid, if not significantly reduce, exposure to homologous blood transfusion. Benefits are considerable. Allogeneic blood transfu­ sion is associated with a demonstrable decrease in cellular immu­ nity, and the postoperative infection rate in patients receiving transfusions has been reported to increase 7- to 1 0-fold. Further­ more, the postoperative length of stay and hospital charges can be correlated with the number of homologous units transfused, a relationship that is not seen in a comparable group of patients given autologous blood or erythropoietin.

A. Autologous Blood Storage The amount of blood that can be deposited for subsequent trans­ fusion (autologous donation) will depend on the patient's initial hematocrit and marrow production response. As long as the hemoglobin is above 13 g/dL, the average-sized patient should be able to donate 3-4 U of red cells . Smaller patients with

CHAPTER I 0

hemoglobins below 13 g/dL will require simultaneous erythro­ poietin therapy to donate more than 2 U without causing the hematocrit to fall below 33%. Autologous blood storage is notoriously expensive. When blood is stored for surgical procedures with a low risk of major hemorrhage (hysterectomy, transurethral prostatectomy, normal vaginal delivery, etc ) , up to 90% of the units collected will be discarded. Even with higher-risk procedures, 50% or more of the units will go unused. There is also the issue of postoperative anemia, which can be made worse by autologous donation. Together these drawbacks tend to discourage its use. The marrow response to erythropoietin correlates with the dose and the duration of treatment. When given in a dose of 1 00-150 IU/kg ( approximately 1 0,000 U) subcutaneously twice a week for 3 weeks, patients will produce 300-400 mL of red blood cells, the equivalent of 1 .5-2 U of red cells. This will usu­ ally guarantee storage of up to 4 autologous units. In addition, they will enter surgery with a higher than normal reticulocyte count. Much higher erythropoietin doses will result in greater production but at considerable financial cost. An adequate iron supply is very important. Patients must be maintained on oral iron, 1 tablet of Feosol 3 times per day ( 200 mg of elemental iron per day ) , or receive intravenous iron as iron dextran ( 1 ,000 mg single infusion) or iron saccharate ( 200 mg at the time of each autologous donation).

B. Perisurgical Recombinant Erythropoietin Therapy Perisurgical erythropoietin therapy without autologous donation can also help decrease homologous (allogeneic) blood exposure. Dosing studies have looked at a number of regimens, including daily 1 00-300 IU/kg inj ections for 1 0 days preoperatively to 4 days postoperatively to once or twice per week injections of 600 IU/kg subcutaneously. Aggressive iron supplementation is again key to the patient's response. This therapy will generally produce a 1-2 g/dL rise in the hemoglobin level (3 %--6% rise in hematocrit) , the equivalent of a 1-2 U red cell transfusion. When continued postoperatively, erythropoietin therapy will also accelerate the rate of recovery of the hemoglobin level.

C. Acute Normovolemic Hemodilution In selected settings, acute normovolemic hemodilution can help decrease the need for homologous blood. Normovolemic hemodilution follows the same principle as autologous blood storage. Whole blood is removed using standard blood storage bags just prior to surgery and replaced with crystalloid/colloid to maintain normovolemia. It can then be reinfused during or after the procedure to treat major blood losses. Advantages include the elimination of testing requirements, less preoperative plan­ ning, and a lower cost. Candidates for this approach include patients without symptomatic cardiovascular disease who are expected to experience a blood volume loss in excess of 20% of their blood volume. Acute normovolemic hemodilution can be combined with erythropoietin therapy, autologous blood stor­ age, and intraoperative blood salvage to further reduce the need for homologous transfusion.

B L00 D L0SS A N E M I A

1 33

D. Blood Salvage Intraoperative blood salvage provides another method for reduc­ ing exposure to homologous blood. It is most effective in ortho­ pedic and vascular surgery patients where blood can be scavenged from a relatively sterile field. Cell-washing devices can handle blood losses equivalent to 10 U/h of stored blood. This can be lifesaving in patients with massive blood losses asso­ ciated with vascular procedures. Blood can also be recovered postoperatively from surgical drains and reinfused. The blood collected is, however, partially hemolyzed and contains activated platelets as well as cytokines released from fragmented cells. Devices such as the Haemonetics Cell Saver incorporate a saline wash and centrifugation to remove white blood cells, platelets, plasma, and anticoagulants prior to reinfusion.

E. Coagulopathy Management Depending on the condition of the patient prior to surgery, every attempt should be made to promote normal hemostasis. Throm­ bocytopenic patients are at great risk for uncontrollable capillary bleeding if the platelet count at the time of operation is less than 50,000/J..LL ( see Chapter 3 1 ) . They should, therefore, be trans­ fused perioperatively to maintain the platelet count as close to 100,000/J..LL as possible. DDAVP can be used immediately before and for several days afrer an operation to improve platelet func­ tion in patients with a prolongation of the bleeding time second­ ary to von Willebrand disease, aspirin ingestion, mild hemophilia A, or uremia (see Chapter 3 1 ) . Coagulation factor replacement with purified or recombinant factor preparations is essential in patients with severe hemophilia A or B ( see Chapter 3 2 ) . Patients with consumptive coagulopathies must b e aggressively supported with platelet transfusions and factor replacement (see Chapter 3 3 ) . For certain clinical situations where activation o f the fibri­ nolytic system is an issue (cardiac, prostate, or orthopedic sur­ gery; liver transplantation; and following a subarachnoid hemorrhage) , E-aminocaproic acid ( EACA) or tranexamic acid can be used to inhibit plasminogen activation to plasmin. EACA is given as a loading dose of 1 00- 1 5 0 mg/kg intra­ venously followed by a constant infusion of 1 0- 1 5 mg/kg/h. Tranexamic acid, a more potent inhibitor, is given as a loading dose of 10 mg/kg followed by a constant infusion of 1 mg/kg/h. Recombinant factor VIla (rFVIIa) may play an important role in patients with uncontrollable diffuse hemorrhage. A num­ ber of anecdotal studies of the use of rFVIIa in perioperative and postoperative patients have reported improvement in the coag­ ulopathy and a significant decrease in subsequent transfusion requirements. Dosages have ranged from 40- 1 20 J..Lg/kg admin­ istered intravenously over 2-5 minutes, sometimes with repeated doses as needed. However, most studies report a good result afrer a single dose. F.

Controlled Hypotension

A deliberate reduction in systolic blood pressure to 80-90 mm Hg (- 30% reduction in baseline mean arterial pressure) may be used to reduce intraoperative blood loss. This can be attained with anesthetic techniques or by the administration of a vasodilator

1 34

SECT I O N I

RED BLOOD CELL D ISORD E RS

C A S E H I S T O RY

Pa rt 3

The patient's need for red blood cell replacement depends on his physiological status, the continued rate of blood loss, and the need to keep his hematocrit at a level a ppropriate for general anesthesia. His initial CBC (as wel l as repeat hematocrits during the first several hou rs) is of little value in as much as the hematocritlhemoglobin will not reflect

(eg, sodium nitroprusside, nitroglycerin, calcium channel block­ ers, prostaglandin E 1 ) . Proper patient selection and experience with this technique are essential. It has been used in elective orthopedic surgery with positive results.

Massive Blood Transfusion The experience in the acute resuscitation of the severely wounded in the Iraq and Afghanistan conflicts has emphasized the need for the immediate transfusion of fresh whole blood or its equivalent in massively bleeding patients. Uncontrolled hem­ orrhage has been the leading cause of preventable death in 7-8% of combat casualties. This has put extra emphasis on the need for robust resources and an aggressive approach to resusci­ tation. Delays in transfusion of blood products by the over­ reliance on volume expanders such as Ringer's lactate, hydroxyethyl starch, or dextran solutions run the risk of a signif­ icant increase in death rate. Their use not only runs the risk of prolonged hypoxemia, acidosis, and tissue necrosis, but also pro­ motes the early depletion of platelets and key coagulation factors needed for hemostasis. Therefore, when faced with massive blood loss, the following guidelines should apply: •

•

•

•

•

Minimize the use of crystalloid or colloid expanders and begin aggressive transfusion as early as possible of type-specific red blood cells and fresh frozen plasma in a ratio of 1 : 1 or 2 : 1 at most. For every 10 U of red cells/plasma administer a 6-pack of stored platelets or a platelet pheresis unit (the latter is pre­ ferred because of the larger number of viable platelets) . When component therapy i s unavailable, transfuse fresh whole blood ( unrefrigerated blood drawn within a few hours prior to administration from a type-specific donor) . I f bleeding i s ongoing, consider the administration o f rFVIIa before the patient becomes acidotic (pH < 7 . 1 ) . When faced with a life-threatening coagulopathy (dissemi­ nated intravascular coagulation [DIC] ) and uncontrolled bleeding, administer both additional platelets and cryopre­ cipitate (fibrinogen) .

When these guidelines were followed in combat support hos­ pitals in Iraq and Afghanistan, the survivals of patients requir­ ing massive transfusion increased to 7 5 %-80%.

the magnitude of his blood loss until the plasma volume loss has been ful ly corrected. As for his platelet count and coagulation profile, they need to be monitored closely, espe­ cially if blood loss during surgery is inordinate and the patient requires massive transfusion, at which time platelet and coagulation factor replacement are essential.

P O I N T S TO R E M E M B E R There Is a predletable physlologleal response

to

aeute blood loss

that reflects the loss of blood volume rather than the reduction in red cell mass. It is important, therefore, to estimate the volume lost from the patient's appearance and physical signs and immediately begi n volume replacement. Effective blood volume suppo rt can be attained using electrolyte solutions (Ringer's lactate and normal saline), colloid solutions (albu­ min, hydroxyethyl starch, and dextran), fresh whole blood, or red cells plus fresh frozen plasma. When resuscitating with electrolyte sol utions, a volume of 3--4 L must be infused to attain a blood volume expansion of 1 ,000 This reflects the rapid equilibration of electrolyte with the extravas­ cular space.

mL.

The need for red blood cell replacement must be determined according to the age and physiological status of the patient, the rate of blood loss, and the overall management plan, especially if the patient needs surgery with general anesthesia. Measurements of the hematocrit/hemoglobin are of limited val ue, especially in the first 24--48 hours when the plasma volume has yet to normalize. The erythroid marrow's response to an acute bleed follows a pre­ dictable course. The release into circulation of a few immature mar­ row reticulocytes (polychromasia) d riven by a rising tide of erythropoietin may be appreciated in the first 24--48 hours. A rise in the E/G ratio and the absolute number of reticulocytes (reticu­ locyte index) is seen by day 3-6 and peaks at day 7- 1 0. I ron deficiency, renal disease, marrow damage, or a concomitant inflammatory ill ness can dampen this response. While i ron defi­ ciency may not be immediately apparent, i ron stores are limited and once exhausted will suppress erythroid precursor proliferation and, over time, will result in an iron-deficiency anemia. Therefore, treat­ ment with oral or parenteral iron is required in all patients with sign ificant acute or chronic bleeding. Blood components available for transfusion include red blood cells, fresh frozen plasma, cryoprecipitate, pheresis or pooled random platelets, and, in some trauma centers, fresh whole blood.

CHAPTER I 0 Patients suffering from catastrophic blood loss and requiring mas­ sive transfusion need to be treated as soon as possible with either fresh whole blood or a balanced combi nation of red cells, fresh frozen plasma, and platelets. Large-volume electrolyte or colloid expander infusions should be avoided.

B L00 D L0SS A N E M I A

1 35

Allogeneic blood transfusion during surgery can be minimized using several techniques, including perisu rgical erythropoietin administra­ tion, autologous blood storage, blood salvage, and in selected cases, normovolemic hemodilution.

B I B L I O G RA P H Y Adamson J : Perisurgical use of epoietin alfa in orthopedic surgery patients. Semin Hematol 1 996;33 : 5 5 ( suppl 2 ) . Blumberg N : Allogeneic transfusion and infection: economic and clinical implications. Semin Hematol 1997;34:34. Cazzola M, Mercuriali F, Brugnara C: Use of recombinant erythropoietin outside the setting of uremia. Blood 1 997 ;89: 4248. Goldberg MA: Perioperative epoietin alfa increases red blood cell mass and reduces exposure to transfusions: results of ran­ domized clinical trials. Semin Hematol 1997;34:4 1 . Goodnough LT et al: Transfusion medicine: blood conserva­ tion. N Engl J Med 1 999;340:525. Hoffman MR et al: Excessive bleeding in surgery and trauma: new concepts in coagulation theory and an updated treatment paradigm. Surg Rounds (suppl) 2002; October.

Lichtman MA et al: Williams Hematology, 7th ed. McGraw­ Hill, 2006. Nessen SC et al: War Surgery in Afghanistan and Iraq: A Series of Cases, 2003-2007. Office of the Surgeon General, Department of the Army, United States of America, 2008. Thompson JF: Interoperative blood salvage. Haematol Rev 1 992;7:55. Tobias JD: Strategies for minimizing blood loss in orthopedic surgery. Semin Hematol 2004;4 1 : 145. Weiskopf RB: Mathematical analysis of isovolemic hemodi­ lution indicates that it can decrease the need for allogeneic blood transfusion. Transfusion 1 995;35:3 7 .

H E M O LYT I C A N E M I A S

A

C A S E H I S T O RY

•

11

Pa rt

54-year-old woman presents with a 2-3 month history of increasing fatigue, dyspnea on exertion, and ankle edema. She denies any recent ill ness and her review of sys­ tems is basically negative, including any prior history of ane­ mia. Examination reveals an anxious middle-aged woman with pale conjunctiva and slightly jaundiced sclera Vital signs: BP - 1 50/60 mm Hg, P - 1 1 0 bpm, R - 20 bpm T - normal. Signs of congestive heart failure include inspiratory rales heard over both lung bases, cardiomegaly, a systolic mur­ mur at the apex, and 2+ pitting edema in both ankles.There is no hepatosplenomegaly or lymphadenopathy. CBC: Hematocrit/hemoglobin - 1 8%/5 g/dL MCH - 33 g/dL MCV - I 00 fL MCHC - 36 pg RDW-CV - 1 4% RDW-SD - 53 fL Reticulocyte count/index - 22%/>3 White blood cell count - 1 1 ,000/�-tL Platelet count - 220,000/�-tL

The distinguishing feature of all hemolytic anemias is the increased rate of adult red blood cell destruction. Clinical pres­ entation will vary according to the disease process. Some hemolytic anemias present as acute, self-limited episodes of red blood cell destruction, and others as chronic, well-compensated hemolytic states. Signs and symptoms of hemolysis will also dif­ fer according to the mechanism of red blood cell destruction. Sudden intravascular hemolysis results in hemoglobinemia and hemoglobinuria, whereas destruction limited to the extravascu­ lar monocyte-macrophage system may only be apparent from a fall in hemoglobin level and a rise in the serum bilirubin and lactic dehydrogenase ( LDH) levels. Chronic, well-compensated hemolytic anemias are easily detected from the red blood cell production response ( ie, increase in the reticulocyte index) .

Questions • How should this anemia be described/classified ? • Are there additional tests that will confirm this

classification and help identify a possible etiology?

Red blood cell hemolysis can result because of environmen­ tal factors or an inherent defect in red blood cell structure or function. Even normal red blood cells can fall victim to environ­ mental challenges such as mechanical trauma, infection, or autoimmune attack. Patients who inherit defects in membrane strucrure, hemoglobin stability, or metabolic function demon­ strate both spontaneous shortening of red blood cell lifespan and a greater sensitivity to environmental factors.

N O R M A L R E D B LO O D C E L L T U R N OV E R Red blood cells are extremely pliable, resilient cells that survive for 1 00 or more days in circulation. Their capacity to survive is

CHAPTER I I

a tribute to the strength of the membrane and the metabolic pathways that supply the high-energy phosphate needed to maintain the membrane and keep hemoglobin in a soluble, reduced state (see Chapter 1 ) . As red blood cells become older, however, metabolic pathways decay, oxidized hemoglobin accu­ mulates, and oxidized phospholipids, especially phosphatidylser­ ine, appear on the surface of the cell. A concomitant loss of flexibility interferes with the cell's ability to move through the microvasculature and initiates the process of removal by the monocyte-macrophage system via the CD36 receptor.

Role of the Spleen The spleen plays a maj or role in red blood cell destruction ( Figure 1 1- 1 ) . The structure of the spleen is a testing ground of cell flexibility and viability. Blood is delivered by terminal arte­ rioles to the splenic red blood cell pulp, where the volume of plasma is reduced and the cell is subjected to a relatively hypoxic environment. This situation tests the metabolic pathways and, in older or diseased cells, results in a further loss of pliability. To escape and reenter circulation, the red blood cell must then squeeze through a 2-5 Jlm opening in the sinusoidal wall. In effect, this traps rigid cells and leads to phagocytosis and destruc­ tion by reticuloendothelial cells lining the sinusoids. The uniform quality of red blood cell morphology on the blood film is a tribute to splenic function. The trapping-filtering mechanism of the spleen efficiently removes red blood cell inclusions including residual iron granules, nuclear remnants (Howell-Jolly bodies ) , and any denatured hemoglobin (Heinz bodies) . Spleen reticuloendothelial cells also display receptors for the Fe fragment of immunoglobulin and the C3b component

H E M O LY T I C A N E M I A S

1 37

of complement. In patients with autoimmune hemolytic ane­ mias, the spleen is the principal site of red blood cell destruction.

Pathways of Red Blood Cell Destruction The pathways of red blood cell destruction effectively recover heme iron for new red blood cell production. This process is true whether the red blood cells break down in circulation (intravascular destruction) or by the normal reticuloendothe­ lial cell pathway (extravascular destruction). Destruction of senescent cells is largely limited to the extravascular pathway ( Figure 1 1-2 ) . Red blood cells are phagocytized by reticuloen­ dothelial cells, the membrane is disrupted, and hemoglobin is broken down by lysozymal enzymes. Iron recovered from heme is then stored or transported back to the marrow for new red blood cell production. Amino acids are also recovered. At the same time, the protoporphyrin ring is metabolized to the tetrapyrrol (bilirubin) with the release of carbon monoxide. Bilirubin is subsequently transported to the liver, where it is con­ j ugated and excreted into bile. Intravascular red blood cell destruction follows a different pathway. Free hemoglobin either dissociates into a-� dimers that bind to haptoglobin or is oxidized to methemoglobin that

EXTRAVASCU LAR

INTRAVASCULAR

Spl e en red blood cell pulp FIGURE 1 1 -2. Pathways of red blood cell destruction. Red blood cel l destruc­ tion can occur in the extravascu lar or intravascular space. With extravascular destruction, red blood cells are phagocytized by reticuloendothelial cells, the mem­ brane structure is broken down, and the hemoglobin is reduced to its essential components. Iron is recovered for transport by transferrin back to the erythroid

FIGURE I l - l . Splenic function. The anatomic structure o f the spleen i s ideal

marrow. The porphyrin ring is broken, and a molecule of carbon monoxide is

for testing the metabolic machinery and pliability of red blood cells. Withi n the

released.The remaining portion of the porphyrin ring is then transported as biliru­

splenic pulp, red blood cells are concentrated and their intracellular metabolic

bin to the liver for conjugation and excretion in bile. With intravascular red blood

pathways stressed. The red cells must then pass through 2-5 11m pores to enter

cell destruction, free hemoglobin binds either to haptoglobin or hemopexi n or is

the sinusoidal system. Unusually rigid cells or a cel l containing inclusion bodies will

converted to methemalbumin. These proteins are cleared by the live� where the

be unable to pass and will be destroyed by sinusoidal reticuloendothelial cells.

heme is broken down to recover iron and produce bilirubin.

I 38

RE D BL00D CE LL D I S0RD E RS

SECTI 0N I

then dissociates to release the heme group for binding with albu­ min and hemopexin. The binding step prevents immediate loss of the heme group by glomerular filtration and allows clearance by hepatocytes. The liver then breaks down the heme group to recover iron and produce bilirubin. The final common pathway for both extravascular and intravascular red blood cell destruction is the conjugation of bilirubin by the hepatocyte, its excretion in bile, and the subse­ quent conversion by gut bacteria to urobilinogen and urobilin. These end products are excreted in both stool and urine.

C l i nical Measurements of Red Blood Cell Destruction The rate of red blood cell destruction can be assessed from meas­ urements of several steps in the process. The most important clinical measurements are listed in Table 1 1-1 . The reticulo­ cyte production index provides an indirect measure of red blood cell destruction. When the reticulocyte index is greater than 3 times normal in a patient with a stable or falling hematocrit, the destruction index (the absolute number of red blood cells destroyed) can be assumed to be 3 times normal or higher. Direct measurements of red blood cell lifespan are possible using a 5 1 Cr red blood cell survival. LDH and indirect bilirubin measurements provide a qualitative measure of cell turnover. From a research standpoint, ferrokinetics, carbon monoxide excretion, and urobilinogen excretion have all been employed to quantitate red blood cell destruction.

the disease process. Even normal subjects who have had a splenectomy will demonstrate abnormal forms. An overtaxed monocyte-macrophage system will also leak free hemoglobin back into circulation, resulting in a fall in serum haptoglobin level.

Haptoglobin and Hemopexin C learance Pathways Intravascular hemolysis easily overwhelms haptoglobin and hemopexin clearance pathways. When hemoglobin binds to either haptoglobin or hemopexin, the complex is quickly cleared by the hepatocyte. The amount of hemoglobin that can be bound and removed depends on the rate of new haptoglobin and hemopexin production. Generally, intravascular lysis of more than 20--40 mL of red blood cells per day will effectively deplete both systems; haptoglobin levels will fall to undetectable levels ( Figure 1 1-3 ) . Once this occurs, free hemoglobin will be detected in both the patient's serum and urine, and methemal­ bumin levels will rise.

Recovery after an I ntravascu lar Hemolytic Event It is also important to recognize the pattern of recovery follow­ ing an intravascular hemolytic event. As shown in Figure 1 1-3 , following a self-limited intravascular hemolytic event, serum hemoglobin levels will drop rapidly as free hemoglobin is cleared

Hemolysis and Abnormal Red Blood Cells

Hemolytic event

Very high levels of hemolysis can overwhelm the extravascular and intravascular pathways for heme iron recovery. There is a limit to the capacity of the reticuloendothelial system to clear abnormal red blood cells. When this capacity is exceeded, mor­ phologically abnormal red blood cells appear in circulation. Depending on the cause of disease, these abnormal cells include microspherocytes, "bite" cells, fragmented red blood cells, and red blood cells with abnormal inclusion bodies. The presence of these cells in circulation suggests that either the capacity of the spleen is overwhelmed or splenic function is reduced as part of

TABLE I 1 - 1

•

Measurements of red blood cell destruction

�

0 I

Indirect measurements

0

4

2

I

8

I

12

Changes in hematocrit Reticulocyte production index Serum lactic dehydrogenase Serum indirect bilirubin

acute hemolytic event, measurements of plasma and urine hemoglobin, serum hap­

Direct measurements

toglobin, serum methemalbumin, and urine hemosiderin fol low a characteristic

(LDH)

51

Cr red blood cell survival Ferrokinetics CO excretion Urobilinogen excretion

Days FIGURE I 1 -3. Measurements of acute intravascular hemolysis. Following an

pattern. Hemoglobinem ia, hemoglobinuria, methemalbuminemia, and a fall in the seru m haptoglobin level are all present d uring the first 24 hours. If hemolysis does not conti nue, the patient will demonstrate a gradual return of the serum haptoglobin to normal and the appearance of hemosiderin in the urine for up to 7- 1 0 days. Methemalbumin may be detectable for more than I week

CHAPTER I I

into urine. Hemoglobinuria will also be relatively short-lived. Haptoglobin levels then rise gradually over the next 24--7 2 hours. At the same time, methemalbumin levels in plasma will stay elevated for 5-10 days and patients will continue to shed tubu­ lar cells containing hemosiderin granules into urine for 1 week or more.

C L I N I CA L F EAT U R E S Most hemolytic anemias are associated with few specific symp­ toms or signs. When anemia is severe, patients will complain of increasing fatigue or exercise intolerance and may develop con­ gestive heart failure. This is really no different from the clinical presentation seen with any severe anemia. In contrast, acute intravascular hemolysis may be associated with fever, chills, and severe lower back pain. This is most often seen in patients who receive incompatible or infected blood products. A severe intravascular hemolytic event with lysis of more than 20-40 mL of red blood cells will produce noticeable hemoglobinuria. Since many hemolytic anemias are related to another disease state, a careful history and physical examination are always nec­ essary. A search should be made for any evidence of autoimmune disease. Racial and family background are important. It is also important to try to document the chronicity of the anemia. Patients with congenital hemolytic anemias are frequently aware of other involved members in their family and may know the results of their own past blood counts.

Laboratory Studies Diagnosis of a hemolytic anemia depends heavily on the labo­ ratory. Any workup begins with several screening tests to clas­ sify the patient's disorder. This then provides a guide to the application of a larger number of specific tests of cell structure and function.

A. The Complete Blood Count A complete blood count (CBC) with inspection of the film and measurement of the reticulocyte count is extremely valuable in both detecting a hemolytic anemia and pointing the way to diagnosis. An acute hemolytic event may only be heralded by a sudden fall in the patient's hemoglobin/hematocrit. Chronic hemolytic states are more easily detected. These patients have a moderate to severe anemia, a reticulocyte production index of greater than 3 times normal, and, in most cases, some abnormal­ ity of red blood cell morphology. Most hemolytic anemias are normocytic, normochromic, although the presence of large numbers of microspherocytes on the blood film is accompanied by a rise in the mean corpuscular hemoglobin concentration (MCHC ) . Very high reticulocyte counts with marked polychromasia may be associated with a rise in the mean cell volume ( MCV) to levels between 1 00 and 1 10 fL. An MCV greater than 1 1 0 fL is seen when the uncor­ rected reticulocyte count exceeds 25%-30%. This situation simply reflects the fact that when large numbers of marrow reticulocytes

TABLE I 1 -2

•

H E M O LY T I C A N E M I A S

1 39

Chronic hemolytic anemia erythropoietic profile

Red blood cell morphology

Normocytic, normochromic­ abnormalities in red blood cell shape

Polychromasia

Present

Reticulocyte index

>3-5

Marrow EIG ratio

>1:1

Marrow morphology

Normoblastic

Serum ironfTIBC

Normal/normal

Serum bilirubin (mg!dl}

1 -3

LDH (IU/ml}

> 1 ,000

are added to the circulating normocytic red blood cell popula­ tion, the MCV will rise. It will also be reflected in an increase in the red blood cell distribution width (ROW-SO). The full erythropoietic profile of a chronic hemolytic anemia is shown in Table 1 1-2. The marrow ratio of erythroid to granu­ locytic precursors (E/G ratio) is increased; red blood cell precur­ sor morphology is usually normoblastic unless the patient becomes folic acid deficient. Iron studies demonstrate a normal serum iron and total iron-binding capacity, and a normal or slightly elevated ferritin level. Iron stores on the Prussian blue stain of the marrow are normal to somewhat increased. In patients with very high levels of red blood cell turnover, reticu­ loendothelial cells are filled with a finely granular, dustlike hemo­ siderin, which may reflect the rapid turnover of storage iron. The indirect bilirubin and serum LDH levels are the most clinically useful measures of total red blood cell destruction. With significant hemolysis, the serum LDH level will quickly rise to levels in excess of 1 ,000 IU. Levels of 5 ,000 IU/mL or higher are not unusual. The indirect bilirubin level will increase to levels of 1-3 mg/dL in patients with significant hemolysis. Chronic elevations of the indirect bilirubin are also seen in patients with inherited defects in bilirubin conjugation (Crigler­ Najjar and Gilbert disease) .

B . Detection o f Intravascular Hemolysis The laboratory profile after an acute intravascular hemolytic event will vary according to the time elapsed. Acute hemolysis is associated with hemoglobinemia, hemoglobinuria, methemal­ buminemia, and a rapid depletion of the serum haptoglobin level. Intravascular hemolysis several days prior to evaluation may only be detected by measurements of serum methemalbu­ min level and urine hemosiderin (see Figure 1 1-3 ) . I . Plasma hemoglobin level-Intravascular lysis o f even small amounts of red blood cells ( 1 0-20 mL of packed red blood cells) will impart a pink tint to plasma for a few hours; more severe hemolysis will make plasma look like rose or red wine ( Figure 1 1-4 ) . The amount of hemoglobin in plasma can be quantitated, but observation of the plasma for color changes will

1 40

SECT I O N I

RED BLOOD CELL D ISORD E RS

FIGURE I 1 -5. Urine hemosiderin. Detection of tubular cel ls containing visible iron granules on Prussian blue stain is a sensitive measure of recent i ntravascular hemolysis.

FIGURE I 1 -4. Intravascular hemolysis. Intravascular hemolysis of even a smal l amount of red blood cells will impart a pink to deep red tint to the plasma, as shown in th is spun sample of heparinized blood.

usually suffice. A venous sample should be collected carefully using heparin or ethylenediaminetetraacetic acid (EDTA) as an anticoagulant, immediately centrifuged, and the color of the plasma observed. Quantitation of the plasma hemoglobin is per­ formed using a dye such as benzidine or ortholidine, both of which turn blue in the presence of hemoglobin and hydrogen peroxide. A plasma hemoglobin level of 50 mg/dL or higher suggests intravascular hemolysis. It is at this point that the plasma first becomes pinkish. Once the level exceeds 1 50-200 mg/dL, plasma will be bright red (see Figure 1 1--4) and there will be accompanying hemoglobinuria. Plasma hemoglobin levels below 50 mg/dL cannot be accu­ rately measured and may be the result of phlebotomy-induced hemolysis. The Hemastix test used for detecting hematuria should never be used to screen for hemoglobinemia. It is much too sensitive and will invariably give a positive result, even in normal subj ects. 2. Urine

hemoglobin-Hemoglobinuria is suggested when the urine is red or brownish in color after centrifugation to remove intact red blood cells. A qualitative measurement is possible using the Hemastix but the Hemastix reaction does not distin­ guish hemoglobinuria from myoglobinuria. If the plasma hemo­ globin level is elevated, it can be assumed that the pigment in urine is hemoglobin. If this is not the case, the 2 pigments must be separated using electrophoresis or differential solubility in ammonium sulfate. 3. Urine hemosiderin-Urine hemoglobin is reabsorbed by renal tubular cells and broken down to form hemosiderin.

Following an intravascular hemolytic event, patients will shed tubular cells containing visible hemosiderin granules for several days to a week or more. This can be detected by performing a Prussian blue stain on the spun sediment of a random urine. A true positive should have distinct blue granules within intact tubular cells (Figure 1 1-5 ) . Free iron outside of cells is gener­ ally a contaminant. 4. Serum haptoglobin-Haptoglobin is an az -globulin that binds in an equal molar ratio to free hemoglobin. The complex is then cleared from circulation by the liver. Both intravascular and severe extravascular hemolysis are associated with a deple­ tion of the serum haptoglobin level. Normal serum haptoglobin is 50-200 mg/dL or higher in patients with inflammatory illness. The serum haptoglobin level is easily quantitated by standard turbidometric methods and is often provided as a routine part of a serum protein profile. The pattern of behavior of the serum haptoglobin level after a hemolytic event is illustrated in Figure 1 1-3 . It is possible to see a normal haptoglobin level immediately after the initiation of an intravascular hemolytic event, simply because the haptoglobin-hemoglobin complex has not yet been cleared from circulation. Conversely, abnormally low or absent haptoglobin levels are commonly seen in patients with liver failure or, rarely, due to genetic absence of the pro­ tein or a defect in binding sites on the molecule. 5. Methemalbumin-Following an intravascular hemolytic

event of sufficient severity to deplete serum haptoglobin, increased amounts of methemalbumin may be detectable in plasma for several days (see Figure 1 1-3 ) . Methemalbumin can be measured using a spectrophotometer from its absorption band at 625 nm. A more sensitive and quantitative measurement is possible using the Schumm test.

C. Detection of Extravascular Hemolysis Several laboratory methods are used to detect and diagnose abnor­ malities of red blood cell membrane, hemoglobin, or intracellu­ lar metabolism that lead to an increased rate of extravascular

CHAPTER

Laboratory methods in the diagnosis of extravascular hemolysis

TABLE I 1 -3

•

Tests of hemoglobin stabil ity

Hemoglobin electrophoresis Heinz body stains Isopropanol and heat denaturation tests Tests of membrane structure

Osmotic fragility Autohemolysis test Tests of metabolic machinery

Autohemolysis test G6PD screen/quantitative assay GSH assay Specific enzyme assays (eg, pyruvate kinase) Tests of immune destruction

Direct and indirect antiglobulin tests (Coombs test or DAT) Cold agglutinin titer Complement levels Donath-L.andsteiner test for PCH

hemolysis (Table 1 1-3 ). Some of these are provided as routine clinical tests, whereas others require the expertise of a special hematology laboratory. I . Tests of hemoglo b in stability-Many of the inherited hemoglobinopathies are associated with an increased rate of cell destruction. As discussed in Chapter 7, common hemoglo­ binopathies such as hemoglobin SS, CC, SC, and compound heterozygotes with thalassemia can be screened with high­ performance liquid chromatography (HPLC) and then diag­ nosed using routine hemoglobin electrophoresis. In addition, Heinz bodies ( intracellular inclusion bodies-Figure 1 1-6) may

I I

H E M O LY T I C A N E M I A S

141

be detected using phase microscopy or a dried blood smear, with or without the supravital stains, brilliant cresyl blue and crystal violet, in patients with unstable hemoglobins or thalassemia. The isopropanol and heat denaturation tests are similarly used to detect patients with unstable hemoglobins. 2. Tests of membrane structu re-The

osmotic fragility and incubated autohemolysis tests are used to confirm the presence of the membrane structural defect seen in patients with heredi­ tary spherocytosis. The osmotic fragility test involves subject­ ing the patient's red blood cells to an increasingly hypotonic environment (Figure 1 1-7 ) . Normal red blood cells are resistant to hemolysis. This situation is also relatively true for fresh cells from patients with hereditary spherocytosis. Once the cells are incubated for 24 hours, however, the fragility of spherocytic red blood cells is far greater than that observed for normal red blood cells, and they consequentially lyse at higher salt concentrations than do incubated normal cells. The autohemolysis test can help in diagnosing arypical cases of hereditary spherocytosis. This test is performed by incubat­ ing defibrinated whole blood with and without the addition of glucose for 48 hours, followed by the measurement of the plasma hemoglobin level (see Figure 1 1-7 ) . Normal red blood cells show 2% lysis without glucose and even less when glucose is added to the incubated specimen. Hereditary spherocytosis patients show marked hemolysis without glucose, which is largely corrected when glucose is added. Intracellular enzyme defects also give abnormal test results for both the osmotic fragility and autohemolysis tests, but the hemolysis is less correctable by the addition of glucose. 3. Tests of metabo l i c machinery-Although the osmotic fragility and incubated autohemolysis tests provide a screening

I NC U BAT E D OS MOT I C FRAG I L I T Y

I NC U BAT E D A UTOH E M OLYS IS 1 00

?J �

Py ruvate kinase

Normal

Hered ita ry phe rocytosis

Normal

.7

.

6

.5

.4

.3

.2

NaCL concentration (g/dl)

1 00

0

Without glucose

(%)

FIGURE 1 1 -7. Incubated osmotic fragility and autohemolysis tests. Defects in red blood cell membrane structure (eg, hered itary spherocytosis) and intracellu­ lar metabolism (eg, enzymopathies) can be detected and classified using the i ncu­ bated osmotic fragility and autohemolysis tests. Hereditary spherocytosis patients show a much greater tendency to cell lysis as the cells are suspended in solutions of decreasing salt concentration. This is enhanced by incubating the blood sample

FIGURE I 1 -6. Heinz bodies. Heinz bodies-refractile intracellular hemoglobin

for 24 hours. The incubated autohemolysis test can distinguish between heredi-

precipitates--can be detected in patients with unstable hemoglobins, thalassemias,

tary spherocytosis and pyruvate kinase deficiency based on sensitivity to lysis with

and G6PD deficiency.

and without glucose in the medium.

1 42

SECT I O N I

RED BLOOD CELL D ISORD E RS

method for detecting defects in one of the metabolic pathways, they do not identify the specific enzyme defect. To look at indi­ vidual enzymes, assays to directly measure red cell levels of glu­ cose-6-phosphate dehydrogenase (G6PD) and glutathione reductase (GSH) are the most useful, simply because of the prevalence of these gene defects, and the relative ease of testing. a. G6PD dye decolorization screening test-A simplified G6PD dye decolorization screening test can be used to detect deficient patients who are at risk of hemolysis. A small amount of patient blood is added to a solution containing G6PD, nicoti­ namide adenine dinucleotide phosphate (NADP ) , and oxidized glutathione incubated for 5-10 minutes at room temperature and then spotted on filter paper. Once dry, the spot is observed for decolorization. A false-negative test result can occur in patients with the African American (A)-variant of G6PD defi­ ciency following an acute hemolytic event. This result reflects loss of older, G6PD-deficient cells and the appearance in circu­ lation of a population of young reticulocytes with normal or even increased levels of G6PD activity. The severe deficiency seen in Mediterranean-type G6PD deficiency will always show a positive test regardless of a high level of reticulocytosis. Since G6PD deficiency is sex linked, women who are heterozygotes will have only moderately reduced levels of the enzyme. A quan­ titative G6PD assay is required to detect the enzyme deficiency in most individuals. b. Test for GSH deficiency--GSH deficiency can also result in acute, drug-induced hemolysis and rarely in a chronic hemolytic anemia. A quantitative assay of GSH is possible by measuring the rate of reduction of oxidized glutathione. Severe enzyme deficiency ( < 5 % normal activity) is associated with hemolytic events. Riboflavin is an essential cofactor in this reaction, and riboflavin deficiency should also be tested for by adding riboflavin to the reaction mixture. c. Tests for uncommon enzyme defects-Less common enzyme defects in the anaerobic pathway ( eg, glucose phosphate iso­ merase, phosphofructokinase deficiency, hexokinase deficiency, etc) present as nonspherocytic hemolytic anemias. Some may be picked up with the incubated autohemolysis screening test, but definitive diagnosis requires a direct assay of enzyme activity. 4. Tests of i m m u n e destru ctio n Diagnosis of an autoim­ mune hemolytic anemia depends on the laboratory detection of abnormal autoantibodies capable of red blood cell destruction. The direct antiglobulin test (DAT) and cold agglutinin titer test are routinely used to screen for an autoimmune hemolytic anemia. A more detailed characterization of the class of immunoglobulin involved, its specificity for red blood cell mem­ brane antigens, and the involvement of complement in the hemolytic process are also important in guiding the diagnosis and management of the individual patient. a. Polyspecific DAT-Measurement of abnormal amounts of immunoglobulin on the surface of red blood cells is possible using a polyspecific OAT (Figure 1 1-8 ) . The OAT is also referred to as the direct Coombs test and has been employed for decades in blood banks as a basic method in red blood cell cross­ matching. When applied to the diagnosis of autoimmune -

FIGURE 1 1 --8. The direct antiglobulin test (DAT or Coombs test). The DAT is performed by incubati ng the patient's red blood cells with a polyspecific or monospecific antihuman globulin antiserum.The antiglobulin i nteracts with surface lgG or C3 and promotes red blood cel l agglutination.This is routinely measured by assessing the tendency to agglutinate after gentle centrifugation. A quantitative measure of red blood cell surface antibody is possible using radiolabeled antiglob­ ulin reagents.

hemolytic anemia, the polyspecific OAT will detect significant amounts of IgG and C3 on the red blood cell membrane. It is also possible to detect whether one or both are present using monospecific anti-lgG, and anti-C3b and anti-C3d reagents. To perform a DAT, polyspecific or monospecific antiglob­ ulin serum is added to washed red blood cells. After centrifu­ gation, the specimen is examined for agglutination as cells are gently resuspended. The degree of agglutination can be graded on a scale of 0-4+. Patients can have an autoimmune hemolytic anemia with a negative OAT when the number of molecules of autoantibody on the red blood cell surface is relatively low. In such cases, more sensitive techniques may need to be employed. The OAT technique can also be used to detect free (not red cell-bound) antibody in the patient's plasma (indirect Coombs test) . This technique is performed by incubating patient plasma with washed normal (reagent) red blood cells, followed by addi­ tion of antihuman globulin. In the patient with a severe autoim­ mune hemolytic anemia (where there is excess antibody in plasma) , this test can be strongly positive. The ability to detect free antibody can also be employed to determine the specificity of the antibody to red blood cell antigens. In multiparous women and heavily transfused patients, lgG autoantibodies gen­ erally have specificity for the Rh antigens or a minor blood group antigen. In contrast, autoantibodies responsible for idio­ pathic, acquired hemolytic anemias are usually not directed against a particular blood group antigen.

CHAPTER I I

C A S E H I S T O RY

H E M O LY T I C A N E M I A S

1 43

Pa rt 2

The patient has a severe anemia associated with signs of tissue hypoxia and congestive heart failure and character­ ized by a marked reticulocytosis and the appearance of spherocytes on the blood smear. Based on the CBC find­ ings, the patient almost certainly has a major hemolytic ane­ mia; a reticulocyte response of this magnitude (index >3) is unlikely following blood loss. The presence of spherocytes suggests either a hereditary spherocytic anemia or the recent onset of an autoimmune hemolytic anemia. Meas­ urements of the indirect bilirubin and the serum LDH can be used to confirm the hemolysis. Diagnostic testing is best organized according to the sus­ pected defect, whether an abnormality in the environment,

b. Cold agglutinin titer test-Patients who appear to have an autoimmune hemolytic anemia with a positive anti-C3 and neg­ ative anti-IgG DAT should be screened for the presence of an IgM cold agglutinin. To measure the titer of the cold agglutinin, nor­ mal donor red blood cells are suspended in serially diluted patient plasma followed by incubation at 4°C for at least 1 -2 hours or, even better, overnight to encourage agglutination. Titers of 1 : 1 000 or higher are associated with hemolytic anemia. Patients with severe cold agglutinin disease can demonstrate titers in excess of 1 : 10,000. For titers less than 1 : 1 000, the thermal amplitude of the agglutinin can be measured. If there is no agglutination at 20°C, it is unlikely that the patient has severe cold agglutinin disease; by contrast, positive activity of the antibody at higher temperatures, such that agglutination is observed at 30°G-3 rC, indicates that the cold agglutinin is clinically important. Measurements of serum complement levels can also help in diagnosing a cold agglutinin hemolytic anemia. Red blood cell destruction by IgM cold agglutinins requires the binding of com­ plement to the cell membrane, thereby depleting serum com­ plement levels. An assay of serum complement levels (C3 , CHSO) can therefore provide indirect evidence of an active IgM antibody. IgM cold agglutinins in patients with infectious mononucleosis demonstrate specificity for i antigen. This situa­ tion is easily tested for by reacting the patient's serum with cord blood cells (fetal red blood cells) that express large amounts of i antigen. Cold agglutinins associated with Mycoplasma infec­ tion generally react with the I antigen. c. Donath-Landsteiner test-Paroxysmal cold hemoglobinuria (PCH) is a rare form of autoimmune hemolytic anemia that is associated with a unique autoantibody that does not react in routine antibody screening tests. The Donath-Landsteiner test for PCH involves incubating reagent red blood cells with the patient's plasma in 3 aliquots: 1 at 0°C, 1 at 3 7°C, and 1 chilled

cell mem brane, hemoglobin structure, or intracellular metabolism. From a practical sta ndpoint, tests for the pres­ ence of a warm or cold antibody should be done immedi­ ately. They are routinely provided by the blood center laboratory as a part of transfusion services and are auto­ matically performed whenever blood is ordered and there is a problem with crossmatching. In this case, the blood center laboratory reports a DAT (direct antiglobulin test) positive for anti-lgG and negative for anti-CJ.A cold agglutinin titer was < I :256.

Questions • Do the antibody tests support a specific diagnosis?

to 0°C and then warmed to 3 7°C. When the PCH antibody is present, there is visible hemolysis of the cells that are chilled and then brought back to 3 7°C, but not in the other aliquots (the PCH antibody, known as a biphasic hemolysin, can only bind in the cold and mediate hemolysis when subsequently warmed) . This antibody often demonstrates anti-P specificity.

D I AG N O S I S The approach to diagnosis of a hemolytic anemia has to match the clinical presentation. Key observations in planning the workup include whether the anemia is acute or chronic and whether the hemolysis is intravascular or extravascular in narure. Therefore, the first step in diagnosis is to try to deter­ mine from the clinical setting, the patient's medical history, and routine clinical and laboratory studies the answers to the follow­ ing questions: •

•

Is the patient experiencing an acute hemolytic episode, or is there evidence for a long-standing, compensated hemolytic anemia? If the anemia is acute, is the hemolysis occurring intravascu­ larly or extravascularly ?

Acute I ntravascular Hemolysis When there is evidence of an intravascular hemolytic event, the history and examination of the patient usually suggests the cause (Table 1 1-4 ) . For example, when a red blood cell trans­ fusion results in severe back pain, hemoglobinuria, and fever, there is a good chance the patient has received an ABO mis­ matched transfusion (usually when a unit of type A blood is given to a type 0 recipient) or bacterial infected blood. Other

1 44

SECT I O N I

TABLE I 1 -4

•

RED BLOOD CELL D ISORD E RS

Causes of intravascular hemolysis

Blood transfusion

ABO mismatched transfusion Infected blood Thermal burns Snake bites Bacterial/parasitic infections

Clostridial sepsis Malaria Babesiosis Bartonellosis

Mycoplasma pneumoniae

Mechanical heart valves Paroxysmal hemoglobinuria

PNH PCH

causes for acute intravascular hemolysis include severe thermal burns; snake bites; acute infections with Clostridium perfrin­ gens, falciparum malaria, babesiosis, or bartonellosis; and the appearance of a high-titer cold agglutinin. Low grade, chronic intravascular hemolysis is seen in patients with mechanical heart valves or paroxysmal nocturnal hemoglobinuria (PNH) . Throm­ botic complications can also occur with ongoing hemolysis; free hemoglobin in the plasma (hemoglobinemia) rapidly depletes nitric oxide (NO) and releases erythrocyte arginase, which fur­ ther inhibits NO synthesis. This has major implications regard­ ing smooth muscle function and clot formation. Speed is essential in the diagnosis and management of these patients. Both plasma and urine should be examined immedi­ ately to document the intravascular nature of the hemolysis. Any obvious cause must also be identified without delay. For example, when a patient is receiving an ABO incompatible unit of blood, the transfusion must be stopped immediately and diure­ sis with fluids and mannitol initiated without delay. Similarly, patients with clostridial or severe parasitic infections will only survive if appropriate therapy is begun without delay. When an intravascular hemolytic event is less severe, it will often escape detection for several days. In this situation, measurements of serum haptoglobin, methemalbumin, and urine hemosiderin will need to be used to confirm the intravascular nature of the hemolysis and provide information as to the rate and course of the process (see Figure 1 1-3 ) . A self-limited hemolytic episode can be retrospectively diagnosed from the pattern of recovery of the serum haptoglobin level and the urine hemosiderin. The CBC and peripheral blood film can also pro­ vide important information. For example, in patients with mechanical heart valves, widespread malignancy, or chronic dis­ seminated intravascular coagulation (DIC), the presence of frag­ mented red blood cells in circulation suggests ongoing hemolysis (Figure 1 1-9 ) . As the patient improves, these cells tend to

FIGURE I 1 -9. Red cell fragmentation. Schistocytes are commonly seen in patients with thirc-degree bums, mechanical heart valves, widespread malignancy, and DIC.

disappear. Red blood cell agglutination ( Figure 1 1- 1 0 )­ clumping of red cells in a disorganized mass-can be seen in patients with high-titer cold agglutinins, secondary to mycoplasma infection or, more rarely, an lgM paraprotein.

Acute Extravascular Hemolysis A sudden fall i n hemoglobin level without ev idence of bleeding or intravascular hemolysis ( hemoglobinemia or hemoglobinuria) suggests an acute extravascular hemolytic event. Once again, the clinical setting will provide valuable information as to the potential cause (Table 1 1-5 ) . Acute extravascular hemolysis is frequently seen in association with drug therapy in normal individuals as well as patients with enzyme deficiencies, patients with autoimmune diseases, and after certain viral and bacterial infections. Patients who have a

FIGURE I 1 - 1 0. Red cell agglutination. C l ump i ng of red blood cells in disorgan­ ized masses is typically seen with high-titer cold aggluti nins.

CHAPTER I I

TABLE I 1 -5

•

Causes of extravascular hemolysis

Bacterial and viral infections

Malaria Babesiosis

Mycoplasma pneumoniae

Infectious mononucleosis Drug-induced hemolysis

G6PD/GSH deficiency Autoimmune drug reactions Strong oxidant drugs/chemicals Autoimmune hemolysis

Warm-reacting (lgG) AIHA Cold-reacting (lgM) AI HA Hemoglobinopathies (see Chapter 7) Membrane structural defect

Hereditary spherocytosis Hereditary elliptocytosis Acanthocytosis

H E M O LY T I C A N E M I A S

1 45

More severe hemolysis is seen in patients with malaria (Figure 1 1-1 1 ) , babesiosis, bartonellosis, clostridial sepsis, and Epstein-Barr virus ( EBV ) and mycoplasma infections. The severity of the hemolysis in malaria patients depends on the organism involved. Most patients with vivax and other non­ falciparum malaria have relatively mild extravascular hemoly­ sis. However, up to 20% of patients with falciparum malaria can have severe intravascular hemolysis (black water fever) . The patient's ABO blood type is a significant factor in determining both the incidence of infection and the severity of hemolysis. Type 0 patients are relatively resistant to both infestation and marked hemolysis, while type A individuals are at great risk of overwhelming infection, severe intravascular hemolysis, and cytokine-induced marrow suppression. In babesiosis, the sever­ ity of the anemia correlates with the percentage red blood cells seen to contain the organism; levels greater than 50% are asso­ ciated with high morbidity and mortality. Clostridial sepsis can also be associated with severe, life-threatening intravascular hemolysis. A self-limited, usually mild hemolytic event is ofren seen during the convalescent phase of Mycoplasma pneumo· niae in association with the appearance of high-titer polyclonal

E nvironmental disorders

Malignancy/DIC TTP/HUS (see Chapter 3 1 ) Eclampsia or preeclampsia

chronic, well-compensated hemolytic anemia can also demon­ strate dramatic falls in their hemoglobin (hematocrit) second­ ary to an increased rate of red blood cell destruction or a sudden failure in red blood cell production (eg, parvovirus infection) . The relationship of the sudden hemolysis t o the chronic hemolytic state may not be apparent if the patient has not been previously diagnosed. To diagnose an acute, extravascular hemolytic event, cli­ nicians must have a high level of suspicion; otherwise, the event can go undetected for several days. This delay can make diagno­ sis much more difficult. It is also important to methodically con­ sider and test for more common causes of extravascular hemolysis, especially infections, drugs, and autoimmune disease. Other conditions that must be considered in the differential diagnosis are microangiopathic (fragmentation) hemolysis sec­ ondary to malignancy, hemolytic uremic syndrome, and throm­ botic thrombocytopenic purpura (see Chapters 3 1 and 3 5 ) . In pregnant women, acute hemolysis may be observed late in the third trimester in association with eclampsia, preeclampsia, or HELLP syndrome.

A

A. Bacterial and Viral Infections Extravascular hemolysis can occur with several bacterial, para­ sitic, and viral infections. Mild, self-limited destruction of older red blood cells in circulation is typical of almost all bacterial infections ( see Chapter 4 ). This is not associated with ongoing hemolysis; septic patients typically present with a hypoprolifer­ ative anemia.

8 FIGURE I 1 - 1 I . Malaria. Immature ring forms (A) and mature (B) trophozoites of Plasmodium vivax in ad ult red blood cells.

1 46

SECT I O N I

RED BLOOD CELL D ISORD E RS

cold agglutinins. Acute EBV infection (infectious mononucle­ osis) can also produce an impressive hemolytic anemia second­ ary to marked cell-mediated immune response or proliferation/ activation of the macrophage system.

B. Drug-Induced Hemolysis Drugs induce hemolysis by an immune mechanism or by chal­ lenging metabolic machinery of the red blood cell. The latter is a very common scenario in patients with G6PD or GSH deficiency. Drugs associated with acute hemolysis in G6PD­ deficient patients are listed in Table 1 1-6. They all share the characteristic of be ing oxidant compounds that overwhelm the phosphogluconate pathway, which results in denaturation of hemoglobin. Chemicals and drugs such as dapsone, phenyl­ hydrazine, aniline dyes, and potassium or sodium chlorates can produce hemolysis in normal indiv iduals by the same mechanism. I . X-Iinked A-variant G6PD deficiency-The most common form of G6PD deficiency in the United States is the X- linked A-variant. Up to 10% of African American males are at risk. Typically, A-variant G6PD-deficient patients, who have normal basal hemoglobin levels, will demonstrate a decrease in the hemoglobin to 9-1 1 g/dL in association with an acute illness, often while taking 1 or more oxidant drugs (see Table 1 1--6 ) . The mechanism involved i n G6PD deficiency i s a failure to generate sufficient NADPH to maintain GSH levels and pre­ vent hemoglobin oxidation. Intracellular aggregates of dena­ tured hemoglobin, called Heinz bodies ( see Figure 1 1-6) , form and result in red cell trapping and destruction within the spleen. Hemolysis is self-limited once the population of older cells that have low G6PD levels are lost from circulation. In the A-variant form of the disease, younger red blood cells have nor­ mal or even high G6PD levels (reticulocytes) . Therefore, as long as the patient is able to increase red blood cell production, the anemia will correct, even if the causative drug is continued. The ability of the patient to recover spontaneously must be recognized both in diagnosis and management. If there is a delay

TABLE I 1 -6

•

Drugs associated with hemolysis

Oxidant drugs-G6PD deficiency

Antibiotics (nalidixic acid, nitrofurantoin, sulfa drugs, dapsone) Antimalarials (primaquine) Pyridium Doxorubicin I mmune mediated

Drug-specific antibodies-penicillin (cephalosporins, synthetic penicillins) Antibody-haptene (drug) combination (quinidine) Autoantibody to Rh antigens (a-methyldopa) T-cell immunomodulation (fludarabine, cladribine) Antigen-antibody complex (stibophen) Complement-fixing antibody (streptomycin)

in detecting the anemia, a hematologic evaluation can show a brisk reticulocytosis and return of the hemoglobin level toward normal. In addition, it is not essential that all drugs with oxi­ dant potential be withdrawn. For example, in patients who require malarial prophylaxis, the drug(s) can be continued, rec­ ognizing that the patient will compensate with a sustained increase in red cell production. Patients (up to 5% of Ashkenazi Jews, Asians, and Mediterranean populations) with the Mediter­ ranean form of G6PD deficiency or severe GSH deficiency are at risk for more severe hemolysis. Drug therapy or fava bean ingestion can precipitate a severe, even fatal hemolytic event with both extravascular and intravascular hemolysis. In such patients, the offending agent must be stopped. 2. D rug-ind uced i m m u n e hemolytic anemia Drug­ induced immune hemolytic anemia has been observed with sev­ eral drugs (see Table 1 1-6) . At least 4 different mechanisms can be involved, including the formation of antibodies specific to the drug, the induction of antibodies to natural antigens on the red blood cell membrane, the formation of an antigen-antibody complex, and the selective binding of the antibiotic to the cell membrane with formation of a complement-fixing antibody. Penicillin is the best example of the first phenomenon, because if given in high doses, it binds to the red blood cell membrane. If the patient then forms an antibody against the penicillin, red blood cells will be removed and destroyed by the monocyte­ macrophage system. The hemolytic process is rapidly controlled by simply withdrawing the penicillin. Cephalosporins and semi­ synthetic penicillins show cross-reactivity with penicillin anti­ bodies. Moreover, second- and third-generation cephalosporins have been associated with severe autoimmune hemolytic anemia and should be automatically discontinued in any patient who presents with a positive DAT. Quinidine can cause immune hemolysis as well as immune thrombocytopenia. The quinidine acts as the haptene for an incomplete anti-red blood cell anti­ body. Therefore, withdrawal of the drug stops the hemolysis. a-Methyldopa is an example of a drug that somehow alters T-cell suppressor function to induce an autoantibody to the Rh antigens on the red blood cell membrane. Up to 40% of patients taking a-methyldopa will develop a positive DAT; however, very few patients ( < 1 %) ever develop a hemolytic anemia. Stibophen appears to act by the formation of antigen-antibody complexes that bind to red blood cells and induce hemolysis. Streptomycin binds specifically to the M or D antigens on the red blood cell membrane. If patients develop a complement-fixing antibody to streptomycin, they can demonstrate hemolysis. A common theme in all patients with drug-induced immune hemolytic ane­ mias is the presence of a positive DAT for IgG. Patients receiv­ ing streptomycin can show a positive DAT with both anti-IgG and anti-C3 sera. The use of purine nucleoside analogues ( fludarabine and cladribine) in the treatment of patients with malignant lympho­ proliferative disorders has also been associated with the appear­ ance of a warm antibody that causes some hemolysis. The mechanism behind this is unclear, though it has been proposed that a suppressed autoantibody to red cell membrane antigen(s) is released secondary to treatment-related T-cell lymphopenia. -

CHAPTER I I

It is important that therapy be immediately discontinued to avoid a fatal outcome.

TABLE 1 1 -7

•

H E M O LY T I C A N E M I A S

1 47

Antibody testing in AIHA OAT

C. Autoimmune Hemolytic Anemia Autoimmune hemolytic anemias can be anticipated in such clinical situations as viral/bacterial infections and collagen vascular diseases and in association with lymphoproliferative disorders. I . Patterns of hemolysi s- Each clinical situation tends to have a predictable pattern of hemolysis. For example, patients who are recovering from M. pneumoniae can develop a high­ titer cold agglutinin that results in an acute hemolytic episode over several days. Patients with acute infectious mononucleo­ sis can develop an IgM cold agglutinin with anti-i specificity some weeks into the illness, associated with both hemolysis and thrombocytopenia. If the clinician watches and documents the temporal nature of the hemolytic event, the diagnosis should be relatively easy. In both groups of patients, it should be possible to document a rise in the cold agglutinin titer, a negative anti-IgG DAT, and in some patients, a positive anti-C3 DAT. The demonstration of anti-i specificity in infectious mononucleosis patients is diag­ nostic. On occasion, acute EBV infection will stimulate prolif­ eration and activation of the macrophage system with striking hemophagocytosis apparent in the marrow. These patients can exhibit pancytopenia and marrow hypoplasia, together with severe liver dysfunction and coagulopathies. Acute and chronic extravascular hemolysis can accompany collagen vascular disease and lymphomas. Patients with lupus erythematosus will often present with a DAT-positive hemolytic anemia or immune thrombocytopenia or both. Autoimmune hemolytic anemia is an anticipated complication in the man­ agement of patients with chronic lymphocytic leukemia, a sit­ uation made worse by the possibility of inducing a warm antibody by treatment with fludarabine or cladribine (see sec­ tion on drug-induced hemolytic anemias) . Immune hemolysis has also been seen following stem cell and solid organ transplan­ tation. However, the most common presentation of an immune hemolytic anemia is as an autoimmune idiopathic hemolytic anemia (AIHA).

2. Auto i m m u n e idiopathic hemolytic anemia-AIHA patients usually have no clinical manifestations of other disease; their only finding is the extravascular hemolytic anemia. In most cases, the erythropoietic profile is typical of a relatively severe hemolytic anemia. The marrow E/G ratio is increased to greater than 1 : 1 and the reticulocyte index to greater than 3 times nor­ mal. Red blood cell morphology is generally normocytic, nor­ mochromic, although a varying number of cells may be spherocytic. Fragmentation is not observed and there is little evidence of poikilocytosis. Measurements of cell destruction ( ie, the serum indirect bilirubin and LDH levels) are both increased. Patients with very severe AIHA can show reticulocytopenia in the face of marrow erythroid hyperplasia. In this situation, autoantibody is responsible for the rapid removal of newly released reticulocytes.

AIHA

Anti- lgG

Anti-Cl

Cold Agglutinins

Warm-reacting antibody 70%

Positive

Negative

20%

Positive

Positive

1 0%

Negative'

Weakly positive

Cold-reacting antibody

Negative

Positive

< 1 :256

I :5 1 2- 1 : I 0,000

'The routine DAT (Coombs test) will not deteaAIHA patients with small num­ bers of lgG molecules per red blood cell. However, much more sensitive testing can be done in specialty laboratories.

AIHA is classified by laboratory testing as being secondary to either a warm-reacting ( IgG) or cold-reacting (IgM) antibody. Rare patients present with a "mixed" AIHA in which both warm- and cold-reacting antibodies are detected. Patients with a warm-reacting ( IgG) AIHA typically show IgG alone, although some express low levels of C3 (Table 1 1-7 ) . Patients with a cold-reacting (IgM) AIHA will have a negative DAT for IgG and a positive test for C3 , a surrogate marker for the presence of an lgM antibody. 3. Cold agglutinin hemolytic anemia-A small percentage of patients with lgM monoclonal proteins (see Chapter 26) will present with a high-titer cold agglutinin capable of causing extravascular red cell hemolysis and, rarely, acute episodes of intravascular hemolysis on exposure to cold. Unlike the tran­ sient anemia seen with polyclonal cold agglutinins ( M . pneumo­ niae ) , monoclonal cold agglutinins are associated with more severe, chronic AIHA that is especially resistant to therapy. The typical polyclonal cold agglutinin lgM protein has l/i antigen specificity and variable temperature specificity. As a rule, low­ titer cold agglutinins are inactive at temperatures above 20°C, while very high titer agglutinins show much wider thermal amplitudes ( ie, they will bind to red cells and activate the com­ plement cascade at temperatures even well above 25°C). There­ fore, the titer and temperature of activation generally correlate with the severity of the patient's hemolytic anemia.

C h ronic (Lifelong) Extravascular Hemolysis Patients with inherited defects in cell membrane function, hemoglobin structure, or intracellular metabolism generally present with a lifelong history of anemia. Racial background and family history provide important clues to the nature of the ane­ mia. The erythropoietic profile reflects a compensated hemolytic anemia with marked expansion of marrow erythroid progenitors ( E/G ratio > 1 : 1 ) and a reticulocyte production index that is 3 times normal or higher. Depending on the level of red cell production, the severity of the anemia can be quite variable. For

1 48

SECT I O N I

RED BLOOD CELL D ISORD E RS

example, patients with hereditary spherocytosis ( HS ) , as long as they are healthy, can maintain an increased level of red cell production sufficient to nearly normalize their hemoglobin level. The detection and diagnosis of a chronic hemolytic anemia is largely a laboratory exercise. It helps to have a well-organized approach to the workup, one that starts with simple tests avail­ able from the routine laboratory. From this viewpoint, the exam­ ination of the peripheral blood film for abnormalities of red blood cell morphology is the best starting point (Table 1 1-8 ) . Unique red blood cell shape changes such a s sickling, targeting, and spherocytosis are obvious clues to the cause of the hemolytic anemia. In fact, when taken in the context of the clinical pic­ ture, red blood cell morphology may be enough to make the diagnosis. If not, it at least guides the selection of additional con­ firmatory laboratory tests. It also helps to systematically con­ sider the most likely causes of chronic hemolysis, grouped according to the broad categories of hemoglobinopathies, defects in membrane structure, abnormalities in intracellular metabo­ lism, and disorders of the environment.

A. Hemoglobinopathies Inherited abnormalities of hemoglobin structure and stability can result in a significant shortening of red blood cell lifespan. When severe, the erythropoietic profile will fit the picture of a chronic hemolytic anemia. Homozygous sickle cell disease is an excellent example of this presentation ( see Chapter 7 ) . Patients with thalassemia major or unstable hemoglobins can also have a hemolytic component to their disease. The laboratory detec­ tion and diagnosis of these conditions are discussed more exten­ sively in Chapters 6 and 7. It involves the selective use of

Red blood cell morphology in the diagnosis of hemolytic anemias

TABLE 1 1 -8

•

Red Blood Cell

Confirmatory

Morphology

Possible Diagnoses

Tests

Sickle cells

Sickle cell anemia, SC disease, and $- �-thalassemia

Hemoglobin electrophoresis

Target cells

Hemoglobin C or SC disease, thalassemia, and severe liver disease

Hemoglobin electrophoresis

Spherocytes

Hereditary spherocytosis, autoimmune hemolytic anemia

Osmotic fragility, incubated autohemolysis, and DAT

Elliptocytes

Hereditary elliptocytosis

Stomatocytosis

Cirrhosis, malignancies, cardiovascular disease, and Rh antigen deficiency

Acanthocytosis

Cirrhosis/pancreatitis and abetalipoproteinemia

Fragmentation

Heart valves, DJC, malignancies, thermal burns, TTP, HUS

Lipoprotein assay

laboratory methods such as hemoglobin electrophoresis, bril­ liant cresyl blue and crystal violet stains for Heinz bodies, and the isopropanol and heat-stability screening tests.

B. Membrane Structural Defects Abnormalities in membrane protein composition can result in lifelong, well-compensated hemolytic anemia. Hereditary sphe­ rocytosis (HS) and hereditary elliptocytosis ( HE) are the best clinical examples of this disorder. I . Hereditary spherocytosis-HS is inherited in an autoso­ mal dominant pattern in 60%-70% of patients and tends to have a similar clinical picture from generation to generation. Sporadic mutations of the dominant type make up another 20% of cases, whereas from 10%- 1 5 % of patients are classified as recessive. In the latter case, both parents have minor signs of disease and the patient presents with a much more severe ane­ mia. HS is the most common inherited hemolytic anemia in Europe and the United States, with a frequency as high as 1 in 1 ,000-2,500 individuals. Multiple null and missense mutations and abnormalities in RNA processing result in unique muta­ tions for each kindred. The principal molecular defect in HS is a deficiency in spec­ trin or ankyrin or, less frequently, band 3 or protein 4.2, all of which are key membrane skeletal proteins. Most HS patients of northern European extraction demonstrate a silencing of the ankyrin gene, which then interferes with spectrin tethering and causes spectrin-rich vesiculation of the red cell membrane. This "vertical defect" results in a progressive loss of membrane lipid and surface area, as well as intracellular fluid leading to the formation of dense microspherocytes ( see Chapter 1 and Figure 1 1- 1 2 ) . Clinically, HS is most often first detected because of the presence of spherocytes on the peripheral blood film and/or an increase in the MCHC to greater than 3 5 % (a reflection of a disproportionate loss of membrane and intracel­ lular fluid). The incubated osmotic fragility test can be used to confirm the HS membrane defect (see Figure 1 1-4 ) . Patients with H S can b e clinically silent or have a compen­ sated hemolytic anemia that ranges from very mild to quite severe. About a third of HS patients have a very mild form of the disease, with little or no anemia and a reticulocyte produc­ tion index of 2-3 times normal but no higher. They have a fully compensated hemolytic "anemia" and may show few if any spherocytes on smear. The majority of HS patients, however, have a mild to moderately severe anemia, a reticulocyte index greater than 3, and prominent spherocytosis. They also have splenomegaly and may present with jaundice when their hemol­ ysis is further increased in association with a viral or bacterial infection. These patients also complain of easy fatigability and a loss of vitality that is disproportionate to the severity of their anemia. Fewer than 5% of patients will present as neonates with a severe, life-threatening anemia. The latter are generally cases of autosomal recessive inheritance. Regardless of the severiry of the anemia, all HS patients are at risk for episodes of hemolytic or aplastic crisis and the devel­ opment of pigment gallstones. Since the threat of gallstone cholecystitis is very high, laparoscopic cholecystectomy should

CHAPTER I I

A

B FIGURE 1 1 - 1 2. Spherocytosis. Patients with hereditary spherocytosis will exhibit varying numbers of microspherocytes in circulation, from relatively few (A) to overwhelming numbers (B) , depending on the severity of their disease.

H E M O LY T I C A N E M I A S

1 49

FIGURE I 1 - 1 3 . Parvovirus infection. Note the diagnostic finding of large nuclear inclusions in erythroid progenitors.

and is most prevalent in areas of endemic malaria. Depending on the origin of a patient's family, the frequency of HE can range from 3 in 100 to 1 in 4,000. Genetically, HE can result from a variety of mutations involving spectrin, protein 4. 1 , and the gly­ cophorin C genes. Most patients with HE are heterozygous for one or another genetic mutation. Fewer than 10% of HE patients are homozygous or compound heterozygous and demon­ strate severe hemolysis and marked anemia. The diagnosis of the most common heterozygous form of HE is usually an incidental finding on a routine CBC. Most red blood cells on the peripheral blood film (50%-100%) have a uniform elliptical (oval) shape (Figure 1 1- 1 4 ) . Occasional rodshaped cells may also be present. In contrast to other conditions where a few oval cells may be observed ( eg, megaloblastic anemias) , there is little or no poikilocytosis and the MCV is normal in HE. Rarely do patients with common HE variant develop significant hemolysis or anemia. In contrast, patients

be considered in most patients with moderately severe HS or those who develop biliary colic. An increase in hemolysis and transient worsening of the anemia (hemolytic crisis) is a recur­ rent problem with any viral or bacterial infection. Aplastic cri­ sis is associated with parvovirus B 1 9 infection. The virus attacks red cell precursors (Figure 1 1- 1 3 ) and produces a profound but transient ( 1 0- to 14-day) failure in new red cell production with marked reticulocytopenia. Once antibody formation occurs, the parvovirus infiltration is cleared and the patient is immune to recurrences. Megaloblastic anemia can result from relative folic acid deficiency, since HS patients have an increased require­ ment for folate due to their high levels of red cell production. 2. H e reditary e l l i pto c ytosis- Patients

with HE have an abnormality of the interaction of spectrin molecules, spectrin with the 4. 1 protein, or with glycophorin C in the red cell mem­ brane. This abnormality interferes with "horizontal stability" and pliability, making it difficult for the red blood cell to regain its biconcave shape after distortion in the microcirculation (see Chapter 1 ) . HE is inherited as an autosomal dominant disorder

FIGURE I 1 - 1 4. Elliptocytosis. Patients with hereditary elliptocytosis demonstrate a uniform population of oval-shaped cells that is virtually diagnostic of this condition.

I SO

SECTI 0N I

RE D BL00D CE LL D I S0RD E RS

with homozygous or compound heterozygous defects present with moderate to severe, even transfusion-dependent hemolytic anemias. Other less common forms of elliptocytosis include sphero­ cytic elliptocytosis (a phenotypic hybrid of HS and HE) ; South­ east Asian elliptocytosis (a band 3 mutation) ; and hereditary pyropoikilocytosis (HPP). Each has a somewhat different mor­ phology. This is especially true of HPP, which presents as a severe hemolytic anemia with bizarre poikilocytes, budding red cells, and red cell fragments on smear. The name of the disorder is derived from the observation that the red cells have an unusual thermal instability pattern. The underlying defect, how­ ever, as in HE, involves a spectrin mutation. Southeast Asian elliptocytosis may have a protective effect against malaria. 3. Laboratory confirm atio n of H S/ H E d i agnosis­ Characteristic morphology, coupled with a positive family his­ tory and an appropriate clinical presentation, can be enough to diagnose HS or HE. Laboratory confirmation is done using the osmotic fragility and autohemolysis tests. Direct assay of mem­ brane proteins by polyacrylamide gel electrophoresis is only necessary when the clinical picture is atypical. If fragility of the patient's red blood cells is measured, it is important to order an incubated osmotic fragility test to bring out the underlying defect (see Figure 1 1-4 ) . 4. Acanthocytosis-Acanthocytosis, another disorder of membrane structure, is seen in patients with abetalipoproteine­ mia (congenital absence of apolipoprotein- �) and as a compli­ cation of severe cirrhosis or pancreatitis. It results from accumulation of nonesterified cholesterol or sphingomyelin on the outer layer of the lipid membrane. This distorts the mem­ brane configuration and produces a characteristic spiculated­ spur shape of the acanthocyte (Figure 1 1- 1 5 ) . 5 . Stomatocytosis-Stomatocytosis (Figure 1 1- 1 6 ) i s seen in

patients with cirrhosis, neoplasms, cardiovascular diseases, and as an inherited defect characterized by marked reduction in the

FIGURE I 1 - 1 5. Acanthocytosis. The characteristic spiculated shape of the red blood cells is typical of acanthocytosis, typically seen with abetalipoproteinemia, and in patients with cirrhosis and/or pancreatitis.

FIGURE I 1 - 1 6. Stomatocytosis. Stomatocytes, cells with a mouth-shaped con­ cavity, are seen as an inherited defect, as well as in patients with liver disease, neo­ plasms, and cardiovascular disease.

expression of Rh antigen on the cell membrane. Congenital stomatocytosis has been associated with vasoocclusive events, especially pulmonary hypertension. Osmotic fragility is increased, reflecting a loss of red cell membrane.

C. Intracellular Metabolic Defects The principal metabolic pathways of the red cell are described in detail in Chapter 1 . Major functions of these pathways include maintenance of protein integrity, membrane structure, and cell shape; the continuous reduction of heme-iron to its ferrous state; and production of appropriate amounts of 2,3-diphosphoglycerate ( 2 ,3 - DPG ) . A deficiency in any one of the more than 20 enzymes involved in these pathways can result in a clinical abnormality. However, pyruvate kinase, hexokinase, glucose-6phosphate isomerase, and phosphofructokinase are the enzymes most ofren linked to a clinically significant hemolytic anemia. I . Pyruvate kinase deficiency-Pyruvate kinase deficiency (PK) is the most common of the Embden-Meyerhof pathway enzymopathies leading to defective glycolysis, adenosine triphos­ phate (ATP) depletion, and an increase in 2,3 -DPG. PK is inherited as an autosomal recessive, missense or nonsense, muta­ tion of a single gene (PKLR) on chromosome 1 . While more than 1 60 different mutations have been reported, the clinical phenotypes are quite similar. Homozygous or compound het­ erozygous patients can present with an anemia that varies from extremely severe to a mild well-compensated hemolytic anemia (nonspherocytic hemolytic anemia) . The more severe cases will present in childhood with a marked anemia and abnormal mor­ phology: marked anise- and poikilocytosis with red cell fragmen­ tation and severely dehydrated cells-xerocytes. The reticulocyte count tends to be unusually high (often >30%-40%) due to an apparent delay in the breakdown of reticulocyte RNA. The incubated osmotic fragility test (see Figure 1 1-4 ) will generally distinguish PK from HS, since the PK xerocytes actually have a decreased osmotic fragility. A simple, highly sensitive screening test is also available to test for PK deficiency.

CHAPTER I I 2. Glucose-6-phosphate

isomerase--G lucose-6-phosphate isomerase ( GPI) is the second most common enzymopathy responsible for a nonspherocytic hemolytic anemia. GPI defi­ ciency is inherited as an autosomal recessive trait; homozygous or compound heterozygous patients present with an anemia of variable severity and, on occasion, a hemolytic crisis. GPI defi­ ciency can also impact nonerythroid tissues, especially the cen­ tral nervous system. The gene responsible for GPI ( GPI ) is located on chromosome 19.

3 . Other enzymes in the Embden-Meyerhof pathway­ Hexokinase, aldolase, phosphoglycerate kinase, and triosephos­ phate isomerase have been reported as rare causes of nonspherocytic anemia often in combination with a myopathy and neurologic dysfunction. G6PD deficiency is the most com­ mon of the phosphogluconate pathway enzyme defects (see dis­ cussion in the section Drug-Induced Hemolysis) . Glutathione reductase and phosphogluconate dehydrogenase deficiencies are rare, but should be considered in circumstances of a well­ documented oxidant-induced hemolysis when tests of G6PD are normal (see earlier discussion in this chapter under Drug­ Induced Hemolysis) .

D. Disorders of the Environment Autoimmune hemolysis can also present as a chronic hemolytic anemia, the severity of which can be highly variable depending on the underlying disease process, the level of antibody produc­ tion, and the activity of the antibody. Although this condition in most patients can be detected using routine polyspecific and monospecific DAT measurements, some patients will evade detection since they have relatively small amounts of antibody on the cell surface. Detection in these patients will require the expertise of a laboratory that uses sophisticated serological test­ ing to detect very small amounts of cell-bound antibody. As discussed in the section on intravascular hemolysis, mechanical heart valves can be associated with chronic frag­ mentation hemolysis. Hemolytic anemia is also an integral com­ ponent of both hemolytic uremic syndrome and thrombotic thrombocytopenic purpura (see Chapter 3 1 ) . One clue to an environmental disorder is the presence of fragmented cells ( schistocytes ) on the peripheral blood film; another is the appearance of both intravascular and extravascular hemolytic components to the disease.

C A S E H I S T O RY

H E M O LY T I C A N E M I A S

T H E RA P Y The management of a patient with hemolytic anemia will vary according to the individual disease state. As a result, an accurate diagnosis is very important. There are also several therapeutic themes that apply to all hemolytic anemias, especially the chronic, well-compensated hemolytic states.

General G uidelines Whatever the cause of increased destruction of circulating red blood cells, the erythroid marrow has the capacity to compen­ sate by increasing production by more than 3- to 5-fold. This compensation is equal to a transfusion of a unit of red blood cells every 2-3 days. This fact, coupled with the innate ability of red blood cells to increase the oxygen delivery to tissues, allows patients to survive disease states where the red blood cell lifes­ pan is as little as 1 0-20 days. The capacity to compensate depends, however, on the ability of the marrow to respond and the patient's cardiovascular status. As with any anemia, an increase in red blood cell production depends on an adequate supply of essential substrates, a normal marrow structure, and an appropriate erythropoietin response. Patients who develop kidney or marrow damage as a part of their disease will be unable to respond and therefore will need trans­ fusion to survive. Adequate iron and folic acid supplies are extremely important. The patient with intravascular hemolysis who loses iron into the urine will be unable to increase red blood cell production. All hemolytic anemia patients have an increased requirement for folic acid and need to be chronically supplemented ( 1 mg of folic acid twice a day by mouth) . Other­ wise, erythropoiesis will become ineffective and red blood cell production will decrease.

I ntravascu lar Hemolysis The success of treating intravascular hemolysis depends on the cause. In the case of transfusion of ABO-incompatible blood, the severity of the reaction will depend on the nature of the mis­ match and the amount of blood transfused. The worst reactions are seen in type 0 patients who are mistakenly transfused with type A blood. If it is detected early and the transfusion is dis­ continued, little needs to be done other than providing suffi­ cient fluid to induce a diuresis and prevent glomeruli and tubular

Part 3

The finding of lgG on the patient's red cells (and poten­ tially also in excess amounts in the plasma) is diagnostic for a (warm-antibody) autoimmune idiopathic hemolytic anemia (AI HA). The low cold agglutinin titer and absence

151

of free hemoglobin in plasma ru le out cold-antibody AIHA or intravascular hemolysis.

Questions • How should this patient be managed ?

1 52

SECT I O N I

RED BLOOD CELL D ISORD E RS

damage. If there is a delay in detecting the reaction, the kidney is at risk for damage from both disrupted red blood cell mem­ branes damaging the glomeruli and the excess of free hemoglo­ bin that can result in acute tubular necrosis. In this situation, diuresis alone is not enough. The patient should also be treated with mannitol to encourage renal blood flow and decrease hemo­ globin reabsorption. If renal shutdown does occur, patients can recover function with time. Transfusion of ABO-incompatible blood can result in severe hypotension, ore, and the death of the patient. The treatment of acute intravascular hemolysis associated with bacterial or parasitic infections must focus on the treat­ ment of the primary infection. The hemolysis is usually not asso­ ciated with renal failure. Transfusion may be necessary if the hemolysis is severe and, in the case of heavy infiltration of cir­ culating red cells with malaria or babesia, exchange transfusion is indicated. Chronic intravascular hemolysis in patients with PNH or mechanical heart valves can result in iron deficiency and an iron-deficiency anemia (see Chapter 9 ) . This condition may respond to routine iron therapy or may require transfusion. Therapy with eculizumab is indicated for PNH, while evalua­ tion for a structural abnormality in a heart valve may reveal a correctable defect.

Extravascu lar Hemolysis Management of acute or chronic extravascular hemolytic anemia involves both evaluating the patient's ability to physiologically compensate for the anemia and treating the specific condition. For example, acute self-limited hemolysis in patients with G6PD deficiency rarely needs treatment. The anemia that results is rel­ atively mild, and the normal marrow production response will return the hemoglobin level to normal. The more important man­ agement issue is patient education regarding the drugs and chem­ icals that provoke hemolysis. On the other hand, patients with a more severe enzyme deficiency state or autoimmune disease can present with a life-threatening anemia. In this situation, transfu­ sion, aggressive chemotherapy, or both will be required. As with the diagnostic workup, patient management needs to be organized according to the mechanism causing the hemolysis.

A. Hemoglobinopathies The management of the patient with a hemoglobinopathy is discussed in Chapter 7. These patients require lifelong health care support and are at constant risk for both hemolytic and aplastic crises in association with various infections and sys­ temic illness. If they have a severe anemia and require long­ term transfusion therapy, they have to be simultaneously treated for iron overload. 8.

Membrane Structural Defects

Patients with relatively mild hereditary spherocytosis or hered­ itary elliptocytosis maintain near normal hemoglobin levels and are generally in good health. Patients with more severe heredi­ tary spherocytosis will be symptomatic. They are also at risk for recurrent hemolytic episodes in association with viral and bacterial infections and aplastic crisis with parvovirus ( B 1 9 )

infection. There i s a role for splenectomy t o improve red blood cell lifespan and decrease the severity of the anemia, since it almost always results in marked improvement. The patient feels better, the red blood cell lifespan returns to near normal, and the risk of gallstones and hemolytic crises is reduced. If possible, splenectomy should be avoided until after the first decade of life to decrease the risk of postsplenectomy sepsis. Partial splenec­ tomy has been used in some centers to improve red cell lifespan without total loss of spleen phagocytic and immune functions. After splenectomy, a sustained rise in the hemoglobin level and fall in transfusion requirement is observed, although the patients still demonstrate elevated reticulocyte counts. With partial splenectomy, the splenic remnant rapidly regrows, reaching normal splenic size by 1 year and twice normal size by 4-6 years. Because of this, a second total splenectomy is neces­ sary in one-third of patients. Any patient who receives a splenec­ tomy must receive H. lnfluenzae, meningoccal, and polyvalent pneumococcal vaccine prior to operation. If a total splenectomy is performed before age 10, the child should receive oral peni­ cillin prophylaxis ( 1 25-250 mg penicillin per day by mouth) . Because hereditary spherocytosis patients are a t risk for developing pigment gallstones, a prophylactic, laparoscopic cholecystectomy should be considered early in adult life. Elec­ tive cholecystectomy should definitely be performed if a patient has even one attack of cholecystitis or biliary colic because of the risk for recurrent disease.

C. Autoimmune Hemolysis Management of patients with autoimmune hemolytic anemia will vary according to the nature of the disease process. For example, autoimmune red blood cell destruction associated with drug ingestion eventually stops after withdrawing the offending agent. When the autoimmune process complicates a lymphopoi­ etic malignancy, control of the hemolysis will depend on effec­ tive treatment of the tumor. As for AIHA, the choice of therapy will depend on whether the hemolysis is owing to a warm- or cold-reacting antibody. I . Warm-antibody AI HA-Several therapeutic options are available to treat warm-antibody AIHA. The first choice is always corticosteroids or, in the case of severe disease, steroids plus an immunosuppressive drug such as cyclophosphamide or rituximab. a. Treatment with corticosteroids-Corticosteroids act by blocking the reticuloendothelial cell clearance of red blood cells coated with either lgG or C3 and the production of new lgG antibody. Cyclophosphamide and rituximab act as lympholytic agents to reduce antibody production. Oral prednisone in a daily dose of 60- 1 20 mg ( 1-1 .5 mg/kg) is a typical starting regimen. It should be continued at this level for at least 2 weeks with daily measurements of the CBC and reticulocyte count. The patient's response will vary according to the severity and nature of the disease process. More than half of patients will show an increase in reticulocyte index and hemoglobin level within the first 1-2 weeks. Patients with severe AIHA can show little response or even a worsening of their anemia, however.

CHAPTER I I

Subsequent management of the patient will depend on the observed response. If initial therapy is effective, the prednisone dose will need to be gradually tapered while closely monitoring the CBC. Warm-antibody AIHA will frequently relapse as the prednisone is tapered. Therefore, the taper should be gradual, reducing the daily dosage by increments of 10 mg or less at weekly intervals. As the dosage falls below 20 mg, there is a risk that severe hemolysis can recur suddenly, requiring an immedi­ ate return to a higher prednisone dose and the institution of other therapies. If the daily dosage can be brought below 1 5 mg/d, it may be possible to switch to an every-other-day schedule and thereby reduce the chance of significant side effects. b. Treatment with combined chemotherapy or splenectomy­ Patients who do not respond to steroid therapy or can't be tapered successfully are candidates for combined chemotherapy or splenectomy. Cyclophosphamide given in pulse doses of 1 ,000 mg intravenously on 1-3 occasions may be effective in some patients. It is very useful in patients who present with a severe hemolytic anemia that does not respond to prednisone therapy during the first 2-3 weeks. Rituximab, given in a dose of 3 7 5 mg/m 2 weekly for 3-4 weeks, has also been reported to reduce hemol­ ysis in steroid resistant patients. Splenectomy can help in the long-term control of autoimmune hemolysis in the prednisone­ refractory patient. It works both by removing the trapping func­ tion of the spleen and by reducing the level of antibody production. It should generally be performed after the patient is stabilized on chemotherapy. Splenectomy is not a cure by itself and will not eliminate the need for chemotherapy. It can, how­ ever, reduce the amount of prednisone, cyclophosphamide, or both needed to control the disease. c. Other therapies-Warm-antibody AIHA can present as a severe, life-threatening anemia. In this situation, other therapies must be considered. Transfusion with red blood cells is clearly indicated, regardless of the difficulties encountered in adequately crossmatching the patient. An attempt should be made to find units of red blood cells that have the minimum activity on the indirect DAT, since it is unlikely that truly "compatible" blood will be identified. Patients can be transfused with type-specific blood when transfusion is required to save the patient's life. lt can be anticipated that the survival of transfused red blood cells will be no better or no worse than the survival of the patient's

C A S E H I S T O RY

H E M O LY T I C A N E M I A S

own cells. In warm-antibody AIHA, there should be little or no risk of precipitating an intravascular hemolytic event. Both intravenous immunoglobulin and plasmapheresis have been used with limited success in the treatment of AIHA. hnmunoglobulin appears to work by acutely blocking the Fe recep­ tors on reticuloendothelial cells, and perhaps by downregulating antibody production or increasing the fractional clearance of the antibody. If therapy is attempted, at least 5 days of 400 mg/kg/d of one of the commercially available immunoglobulin preparations should be given. If there is a response, it may not be observed for several days and can be short-lived. Plasmapheresis or extracorpo­ real absorption of IgG using an anti-staphylococcal protein­ A-silica column may also be beneficial in the severely ill patient. 2. Cold-antibody

AI HA-The treatment of a patient with cold-antibody AIHA is significantly different. Little needs to be done for those patients who develop a high-titer cold agglutinin following an infection with Mycoplasma or EBV virus other than to monitor the severity of the anemia and, if necessary, transfuse the patient. Patients with de novo cold agglutinin dis­ ease or lymphopoietic malignancy with a high-titer IgM anti­ body may respond to treatment with an alkylating agent. Usually, corticosteroids are of little benefit. When a patient's anemia is very severe, plasmapheresis can be lifesaving, because the major portion of the patient's IgM antibody is intravascular. The response to conventional agents (alkylating agents, interferon­ a, purine analogs a is poor at best. Rituximab has been reported to be effective and well tolerated with an overall partial response rate of better than 50%. As with warm-antibody AIHA, patients with cold-reacting IgM antibodies can receive transfusions without risk of precipi­ tating a life-threatening hemolytic episode. However, any patients being treated or transfused at cold temperatures, such as those undergoing cardiac surgery, may be at risk for acute complement­ mediated intravascular hemolysis. It is also very important to rec­ ognize the essential role of complement in IgM-driven AIHA. In fact, the severity of hemolysis in a patient with cold-antibody AIHA may be suppressed by the depletion of complement in the patient's plasma. In this situation, fresh complement provided as part of a red cell or plasma transfusion can result in a dramatic increase in hemolysis. Such a patient should receive transfusions of washed red blood cells that are free of complement.

Pa rt 4

This patient exhibits a severe, even life-threatening hemolytic anemia that requires immediate intervention. Immunosup­ pression using high-dose corticosteroids and, if needed, cyclophosphamide/rituximab should be started immediately and maintained until the hematocrit and reticu locyte index have normalized. Only then should therapy be slowly

1 53

tapered while closely watching for signs of relapse. Transfu­ sion of type-specific red blood cells may also be called for if the patient is highly unstable, even though the lifespan of the transfused red cel ls may be little better than that of the patient's own red cells. In patients who are refractory to immunosuppressive therapy, splenectomy may play a role.

I 54

SECTI 0N I

RE D BL00D CE LL D I S0RD E RS

Patients with cold agglutinin disease and a high thermal amplitude lgM antibody can demonstrate dramatic cold sensi­ tivity. Even brief exposure of extremities to cold environments can result in an acute hemolytic episode. These patients need to learn how to avoid cold exposure. In addition, any blood prod­ uct or intravenous fluid must be warmed prior to transfusion. Cold agglutinin disease is generally manageable but not curable. With time, patients become refractory to chemotherapy and transfusion dependent. In addition, the survival of transfused red blood cells becomes progressively shorter. This progression does not respond to splenectomy or other therapeutic options used in warm-antibody AIHA.

P O I N T S TO R E M E M B E R Hemolytic anem ias can present as an intravascular process with hemoglobinemia and hemoglobinu ria, or a largely extravascular process where red cells are destroyed in the reticuloendothelial system (spleen, marrow, and liver). Intravascular hemolysis is often transitory, such that when hemoglo­ binemia and hemoglobinu ria are no longer present because of rapid free hemoglobin clearance, serial measurements of haptoglobin and methemalbumin levels, and the detection of hemosiderinu ria may allow a retrospective diagnosis. Extravascu lar hemolysis is associated with increases in LDH and indirect bilirubin levels and, when sustained, an impressive increase in red blood cell production as reflected in the reticulocyte count (reticulocyte index >3).

The differential diagnosis of a hemolytic episode/anemia is complex. Red cell morphology may provide a major clue (red cell fragmenta­ tion, spherocytosis, parasite infestation, etc). However, accurate diag­ nosis requires a number of laboratory tests to look for defects in hemoglobin stability, membrane structure, and metabolic pathways, as well as autoimmune disease and disorders of the environment. The most common causes of acquired extravacular hemolysis are d rug-induced hemolysis, especially the episodic h emolysis seen in patients with type A-G6PD deficiency who are exposed to oxidant d rugs, and autoimmune id iopathic hemolytic anemia (AIHA). Chronic (lifelong) extravascular hemolysis is the rule in patients with hemoglobinopathies (sickle cell anemia-see Chapter 7), membrane structural defects (hereditary spherocytosis, hereditary elliptocyto­ sis, etc), and metabolic defects (pyruvate kinase deficiency, etc). AIHA can be classified as secondary to an lgG antibody (warm­ reacting antibody) or an lgM antibody (cold-reacting antibody) according to the pattern of the routine direct antiglobulin test (DAT or Coombs test) and a measurement of the cold agglutinin titer (lgM). Treatment of warm-reacting antibody (lgG) AIHA patients depends in large part on the patient's primary diagnosis (ie, idiopathic AIHA or disorders such as lymphoma, chronic lymphocytic leukemia [CLL] , lupus erythematosis, etc). Aggressive immu nosuppression is usually effective, although chronic low-grade hemolysis may persist in some cases, requiring splenectomy. Except for the transient lgM-related hemolysis seen with EBV or mycoplasma infections, patients with cold-reacting antibody AIHA ten d to be much more resistant to therapy, even when associated with lymphoma.

B I B L I O G RA P H Y Tabbara IA: Hemolytic anemias: diagnosis and management. Med Clin North Am 1 992;76:649.

Palek J , Sahr KE: Mutations of the red blood cell membrane proteins: from clinical evaluation to detection of the underly­ ing genetic defect. Blood 1 992;80:308.

Drug-Induced Hemolysis

Enzyme Defects

Beutler E: Glucose-6-phosphate dehydrogenase (G6PD) defi­ ciency. N Engl J Med 1 9 9 1 ;324: 1 69. Membrane Structural Defects

Eber S, Lux SE: Hereditary spherocytosis: defects in proteins that connect the membrane skeleton to the lipid bilayer. Semin Hematol 2004;4 1 : 1 1 8 . Gaetani M et al: Structural and functional effects o f heredi­ tary hemolytic anemia-associated point mutations in the alpha spectrin tetramer site. Blood 2008; 1 1 1 : 5 7 1 2 . Gallagher PG: Hereditary elliptocytosis: spectrin and protein 4. 1 R. Semin Hematol 2004;4 1 : 142. Liu SC et al: Alteration of the erythrocyte membrane skele­ tal ultra-structure in hereditary spherocytosis, hereditary ellipto­ cytosis and pyropoikilocytosis. Blood 1 990;76: 1 98.

van Wijk R, van Solinge WW: The energy-less red blood cell is lost: erythrocyte enzyme abnormalities of glycolysis. Blood 2005 ; 1 06:4034.

Autoimmune Hemolysis

Berenstsen S et al: Rituxamib for primary chronic cold agglu­ tinin disease: a prospective study of 3 7 courses of therapy in 27 patients. Blood 2004; 1 03 : 2925. Besa EC: Rapid transient reversal of anemia and long-term effects of maintenance intravenous immunoglobulin for AIHA in patients with lymphoproliferative disorders. Am J Med 1 988;84:69 1 . Collins PW, Newland AC: Treatment modalities of autoim­ mune blood disorders. Semin Hematol 1 992;29:64. Engelfriet CP, Overbeeke MAM, vondem Borne AEGKR: Autoimmune hemolytic anemia. Semin Hematol 1 992;29:3 .

AN E M I A I N T H E E LD E RLY

n r--

A77

C A S E H I S T O RY

CBC: Hematocrit/hemoglobin - 33'YcJ I I g/dl MCV - 96 fL MCH - 34 pg MCHC - 33 g/dl RDW-CV - 1 4% Reticulocyte count/index - 1 .5'YcJ- I White blood cell count - 5, I 00/)ll Platelet count - 1 30,000/)ll 1-

12

l

Pa rt I

-year-old woman is brought to the Geriatric Center by her family for evaluation of increasing frailty, forget­ fulness, and decreased ability to live independently and care for herself. She has a history of at least 2 falls and has lost approximately I 5 lbs in the last 3 months. As part of her evaluation, she has a blood count with the following results:

•

• BLOOD SMEAR MORPHOLOGY Generally normocytic, normochromic red blood cells with slight anisocytosis. No polychromasia and both white blood cell and platelet morphology are normal. Lymphocytes are decreased in number but with normal morphology.

Questions •

•

Is this patient anemic or does she fal l into the appropri­ ate range of normal for her age group? If a further workup is in order, what additional labora­ tory tests should be ordered?

·------

Aging is associated with subtle physiologic changes in the hematopoietic system. Unlike the renal and reproductive sys­ tems, primary hematopoietic stem cell failure is very rare. Only the immune system demonstrates a predictable decrease in com­ petence in the elderly (see Chapters 20 and 2 1 ) . At the same time, the observed incidence of anemia, myelodysplastic disor­ ders, and thrombotic events (see Chapter 3 6 ) is progressively greater with each passing decade. This is a result of the conver­ gence of multiple factors, many of which are environmental in origin and are, therefore, reversible.

STEM C E LLS AN D T H E AG I N G P RO C E S S Hematopoietic stem cells (HSC) emerge early in embryonic development and, after residing in the fetal liver, spleen, and

thymus, populate the bone marrow and lymph glands. Fetal HSC differ from adult HSC in their rate of proliferation, differ­ entiation, cell surface markers, and regulatory control. While the majority of adult HSC are in the G 0 phase of cell division, they are capable of self-renewal and, despite a constant high level of differentiation needed to constantly repopulate the sev­ eral lineages of mature blood cells, appear to gradually increase in number. In fact, based on mouse model experiments, there is a 2-fold increase in adult HSC in aging mice. Moreover, as demonstrated by serial transplant studies, these adult HSC are able to repopulate the marrow through 1 5-50 lifespans. Adult HSC do age, although the mechanisms underlying the aging process are not well defined. Telomere length, DNA methylation, reactive oxygen species exposure, and accrued DNA damage have all been advanced as playing a role in this aging process. Because of this, individual HSC function

SECTI 0N I

I 56

RE D BL00D CE LL D I S0RD E RS

decreases with age, while total capacity is made up for by the increased number of HSC. Changes in the marrow microenvi­ ronment are also important. The ratio of marrow precursor cells to fat cells decreases in the aging marrow, although rapid expan­ sion of the erythroid marrow secondary to an increase in ery­ thropoietin stimulation is still possible. However, the stromal cells and associated cytokines of the older marrow do appear to be less able to support repopulation following stem cell trans­ plantation. The pattern of HSC differentiation also changes with aging. The decline of the lymphopoietic cell lineages, particularly B-cell proliferation and differentiation, is the most dramatic, reflecting thymic involution and reduced cytokine levels. At the same time, granulopoiesis increases with age. This may reflect different demands on the immune system in the elderly. While young individuals are busy programming their adaptive immune systems, older adults face a greater threat from bacter­ ial infections, and thus require a rapid granulocytic response.

A N E M I A I N T H E E L D E R LY The incidence of anemia and associated comorbidities (func­ tional disability, impaired cognition, increased episodes of hos­ pitalization, and death) are reported to increase significantly after age 65. The prevalence by decade, based on the Third National Health and Nutrition Survey (NHANES Ill phases I and II data, 1 988-1 994 ) , is illustrated in Figure 1 2- l . The over­ all incidence of anemia for community-dwelling adults over age 65 was 1 1 % for men and 1 0.2% for women, but progressively increased to levels exceeding 20% in individuals over age 80. Race/ethnicity also plays a role; the prevalence of anemia in non-Hispanic black men and women has been reported to be 2to 3-fold higher, but is much less if patients with a.-thalassemia, sickle cell trait, and iron deficiency are excluded. The prevalence of anemia depends, of course, on the defi­ nition of a lower limit of normal for the hemoglobin in elderly

men and women. Most survey studies have used the World Health Organization (WHO) definition of anemia-a hemo­ globin less than 13 g/dL in men and less than 12 g/dL in women ( Figure 1 2-2 ) . The use of the lower cutoff point for elderly women, however, may not be as appropriate as it is for pre­ menopausal women. It may, in fact, distort the incidence data, resulting in a falsely low estimate of anemic elderly women. If the less than 13 g/dL cutoff point is used for both sexes, the prevalence of anemia in women would be more than double and exceed levels in comparably aged men. There is a similar issue in regard to the criteria used for estimating anemia prevalence in African American and Hispanic populations. The traditional definition of "anemia" for the purposes of anemia evaluation and treatment is not necessarily the same as that for predicting functional impairments in elderly popula­ tions. Recent epidemiological studies have suggested an inde­ pendent association of lower hemoglobin levels with functional disabilities, including impaired mobility and cognitive function, as well as overall mortality. Moreover, the severity of the impair­ ment appears to be a continuous function as the hemoglobin level declines below 13 g/dL. Another argument for considering a higher hemoglobin level as the lower limit of normal is the observed increase in morbid­ ity and mortality in elderly individuals with hemoglobin levels as high as 13- 1 3 . 5 g/dL (NHANES Ill study) . This was true regardless of the etiology of the anemia. The same is true for nursing home patients, where 50%-60% of long-terrn residents are "anemic" and demonstrate a 2- to 3-fold increase in morbid­ ity and mortality as compared to non-anemic patients under similar circumstances. At the same time, there have been no organized studies of the impact of erythropoietin-induced higher hemoglobin levels on functional outcomes. Without such proof, the ability to convincingly separate the role of the hemoglobin level from the impact of other disease processes is lacking.

25 � 'Q) () c:

15

.s

10

�()

� 5i:::.

20

c:r

�

5

10 < 30

40

50

60

11

12

13

14

15 >16

Hemoglobin (g/dl) 70

80+

Age (years)

FIGURE 1 2-2. Frequency distribution of hemoglobin levels in men and women, aged 65 and older. Based on the N HANES I l l survey data, the recommended

FIGURE 1 2- 1 . Incidence of anemia by age.The incidence ofanemia in community-

lower limits of normal (shown as vertical bars) are I 3 g/dl in men and I 2 g/dl in

dwelling individuals increases progressively in the sixth, seventh, and eighth decades

women. The use of a lower limit of normal ( I 3 g/dl) in women would greatly

of life (based on the N HAN ES Ill survey data).

increase the anemia frequency.

CHAPTER I 2

rl

C A S E H I S T O RY

A N E M I A I N T H E E L D E R LY

l

I

Part 2

According to the NHANES I l l su rvey, this woman's hemo­ globin level is below the lower limit of normal (< 1 2 g/dl) for a community-dwelling woman in her 70s. At the same time, she has a very mild anemia with a hemogram that does not allow an accurate classification (see Chapter 2). 1 n light of this, further evaluation should begin with a battery of tests, including, as a minimum, iron studies (serum iron, iron-binding capacity, and serum ferritin), both serum folate and cobalamin (B 1 ) assays, renal and thyroid function assays, and indirect measures of inflammation (sedimentation rate and C-reactive protein [CRP]). These studies were drawn with the following results:

Serum folate - 5 ng/ml Serum cobalamin - 220 pg/ml Sedimentation rate - 60 mm/h (Westergren) C-reactive protein - 3 mg/dl Serum creatinine - 0.9 mg/dl BUN - 23 mg/dl Thyroid studies - within normal limits Fasting blood glucose - 1 20 mg/dl

Serum iron - 40 !lg/dl TIBC - 280 J.lg/dl Saturation - 1 4% Serum ferritin - 55 llg/L

•

TY P E S O F A N E M I A Anemia, as defined by the NHANES Ill study, is not a natural product of growing old, and therefore should not be ignored. As a practical matter, the "anemia of aging" is most often associated with 1 or more age-related illnesses, which helps guide the eval­ uation and treatment. The major types of anemia seen in the NHANES Ill survey of geriatric populations are listed with their relative frequencies in Table 1 2-1 . The apparently large proportion of elderly patients with anemia categorized as unexplained may be artifactual. The anemia of many individuals in this category may well represent an undiagnosed,

TABLE 1 2- 1

• Types of anemia seen in geriatric populations

(NHAN ES I l l) Etiology

Approximate Prevalence (%)

Anemia of chronic inflammation

20

Chronic renal disease

9

Renal disease with inflammation

5

Iron deficiency

17

Vitamin B 1 2 and/or folate deficiency "Unexplained" anemia

IS 34

1 57

Questions •

Given the age of the patient and the above results, what are the possible etiological factors behind her anemia? What additional workup is in order?

slowly evolving dysplastic or sideroblastic anemia. These are o ften difficult diagnoses to make, requiring repeated blood studies over several years and several bone marrow aspiration/biopsies for morphology and cytogenetic studies (see Chapter 9 ) . Therefore, a single time point survey could easily underestimate their prevalence.

Anemia of Chronic I nflammation (Anemia of C h ronic Disease) Patients with chronic inflammatory conditions predictably demonstrate a mild to moderately severe anemia (see Chapter 4 ) . The mechanisms involved include reduced red cell survival, impairment of the erythropoietin response, and a decrease in functional iron supply to the marrow secondary to upregulation of the liver protein hepcidin. Hepcidin and its response to inflammatory cytokines, especially interleukin 6 ( IL-6 ) , is the dominant mechanism. Increased blood levels of hepcidin are seen in association with many age-related illnesses--chronic infections, autoimmune disease, and some cancers. Still, even apparently healthy elderly patients can exhibit elevations of IL-6 and other proinflammatory cytokines and higher than nor­ mal hepcidin levels. Since the anemia of inflammation, even when relatively mild, can be an especially strong predictor of morbidity and mor­ tality in the elderly, a full workup is essential. This includes both proof of the nature of the anemia and a careful workup of asso­ ciated disease processes, in as much as an inflammatory-based anemia will generally resolve once an underlying condition is treated successfully. The approach to anemia workup is dis­ cussed in detail in Chapter 4. In essence, the hematopoietic

I 58

SECTI 0N I

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characteristics of an inflammatory anemia are a hemoglobin level of 1 0--12 g/dL (mild to moderately severe anemia) ; nor­ mocytic to slightly microcytic red blood cell indices (mean cell volume [MCV] 80-90 fL); low reticulocyte index; and iron stud­ ies typical of inflammation, that is, decreased serum iron and iron-binding capacity (percent saturation of 1 0%-20% ) and a normal to slightly elevated serum ferritin level. This pattern of iron studies distinguishes an inflammatory anemia (functional iron deficiency) from absolute iron deficiency where the iron­ binding capacity is high, the percent saturation falls below 10%, and the serum ferritin is less than 1 5 j..ig/L (see Chapter 5 ) . A s they become clinically available, direct measurements of blood IL-6 and hepcidin levels should increase the sensitivity and specificity for the differential laboratory diagnosis of an inflammatory-based anemia. It will also help distinguish com­ ponents of inflammation from those of concurrent absolute iron deficiency and/or renal disease. At present, measurements of C-reactive protein (CRP) and sedimentation rate must serve as indirect indicators of an inflammatory state. Even when none of these studies are definitive, the importance of looking for an associated illness with an inflammatory component can­ not be overemphasized. A patient with very mild inflamma­ tory-based anemia may never show the distinctive changes in serum iron, iron-binding capacity, and serum ferritin, but nev­ ertheless will respond to effective treatment of their primary disorder.

C h ronic Renal Disease and Progressive Renal Fai l u re Chronic renal disease and progressive renal failure are associ­ ated with increasingly severe anemia. The potential mechanisms involved are several and include reduced red blood cell survival, impaired erythropoietin production, stem cell resistance to ery­ thropoietin stimulation, and concurrent inflammation. Progressive loss of renal mass is recognized as a predictable part of the aging process. The major loss involves the cortex and is associated with a falling glomerular filtration rate (GFR) and creatinine clearance as glomeruli are obliterated. By age 70--80, renal mass has decreased by 30% or more and the percent of hyalinized glomeruli can exceed 30%. The GFR declines progres­ sively with aging, falling from approximately 140 mL/min/1 . 73m 2 at age 30 to 90--100 mL/min/ 1 . 73m 2 at age 80. At the same time, the serum creatinine level does not show a comparable increase, most likely related to the decrease in muscle mass in the elderly. Renal vascular disease, hypertension, and diabetes are addi­ tive factors in the decline in renal function with age and also in predicting the frequency and severity of the patient's anemia. The NHANES III survey identified nearly 1 4% of anemic indi­ viduals over age 65 as suffering from chronic renal disease or the combination of renal disease and inflammation. At the same time, correlating the loss of renal function with the severity of anemia in the aged is difficult. While there is an apparent lin­ ear correlation between hemoglobin levels and creatinine clear­ ance with aging, creatinine clearance by itself, once age is excluded, shows a relatively poor correlation with anemia inci­ dence and severity. ln fact, the creatinine clearance must fall to

e - Men - Women

70

� 'Q) () c:

�() s

50

30

10

< 30

3 1 -90

> 90

Creatinine clearance (mlfmin) FIGURE 1 2-3 . Incidence of anemia in elderly individuals with renal failure. The creatinine clearance must fall below 30 mUmin before the incidence of anemia in community-dwelling elderly is significantly increased.

levels below 30% of normal before the incidence of anemia is significantly increased (Figure 1 2-3 ) . Impairment of erythropoietin production has been advanced as the most likely mechanism responsible for renal disease­ associated anemia in the elderly. Diabetic patients often develop anemia well before advanced renal failure, based on their vascu­ lopathy and damage to the peritubular interstitial cells respon­ sible for erythropoietin production. However, measurements of blood erythropoietin levels in nondiabetic, nonhypertensive populations have, in fact, shown an incremental rise in the ery­ thropoietin level with advancing age, even in those who are thought to have the anemia of chronic renal disease. This would suggest the appearance of an age-related reduced sensitivity of the erythroid marrow to erythropoietin, cause unknown. This finding means that measurements of blood erythropoietin levels are of little value, but it does emphasize the need for greater dili­ gence in identifying concurrent diabetes, hypertensive vascular disease, or chronic inflammatory conditions as important etio­ logical cofactors. While the exact sequence of events leading to the anemia of chronic renal disease remains to be defined, patients with mod­ erate to severe anemia can be effectively treated with recombi­ nant erythropoietin. Resistance to therapy is observed in some patients but relates more to the coexistence of an inflammatory disease and/or absolute iron deficiency and their impact on iron delivery rather than an outright failure in stem cell response.

I ron Deficiency Iron deficiency was implicated as the sole etiological factor in up to 1 7 % of community-based individuals over age 65 in the NHANES Ill survey. Iron-deficiency anemia in older individu­ als is most often the result of chronic blood loss, usually occult gastrointestinal bleeding. Therefore, a careful search for a bleed­ ing site is mandatory (see Chapter 5 ) . Inadequate nutrition may contribute as diets change and daily caloric intake falls, but diet is rarely the sole cause of an iron-deficiency anemia. Marked mal­ absorption of iron is seen in patients with severe disruption of

CHAPTER 1 2

duodenal function, as, for example, in celiac sprue ( gluten­ sensitive enteropathy) patients. In this situation, concomitant malabsorption of folic acid may cloud the laboratory presentation. The diagnosis of an iron-deficient state is readily made from measurements of the serum iron, iron-binding capacity, percent saturation, and serum ferritin level. A visual assessment of mar­ row iron stores is possible using a Prussian blue stain of a mar­ row aspirate particle or biopsy specimen. Faced with negative iron balance, iron stores will be depleted first (absent stores on the marrow iron stain and a serum ferritin < 1 5 J.Lg/L ) , followed by a fall in the serum iron and an increase in the total iron-bind­ ing capacity, until the percent saturation is less than 10%. Changes in red cell morphology (microcytosis and hypochro­ mia) only appear with worsening anemia, usually when hemo­ globin levels are sustained below 10 g/dL. These several stages in the evolution of iron deficiency and iron-deficiency anemia are discussed in detail in Chapter 5. It is important to review this material, since iron-deficiency anemia can present either as a normocytic, normochromic (hypoproliferative) anemia or as a microcytic, hypochromic anemia depending on the severity and duration of the iron loss. Moreover, the classical changes in iron studies may be less definitive the milder the anemia. Another major issue is the presence of a concomitant illness. Iron deficiency and the anemia of inflammation often coexist, making the diagnosis even more difficult. Measurement of the serum transferrin receptor has been used to help separate the 2 conditions, but is ofren not readily available nor has it been proven to be more reliable than the ferritin measurement. Once available, a measurement of the hepcidin level may help iden­ tify an underlying inflammatory component. At this time, the coexistence of iron-deficiency and chronic inflammatory ane­ mia may only become clear when the patient fails to respond to iron therapy. Iron deficiency can also coexist with folate and/or vitamin B 1 2 deficiency, especially in patients with malabsorp­ tion. This presentation can be very confusing, since one or another of the deficiencies will tend to dominate clinically. Even in the presence of marked iron deficiency, the patient may pres­ ent with a macrocytic anemia secondary to folate or vitamin B 1 2 deficiency. The underlying iron deficiency will only be detected as the patient is treated and fails vitamin therapy (see Chapters 5 and 8 ) .

Vitami n B 1 2 and/or Folic Acid Deficiency

Vitamin B 12 and/or folic acid deficiency were implicated in up to 1 5 % of the NHANES Ill survey group. In the case of folate deficiency, poor nutrition, malabsorption, and alcohol abuse can all play a role (see Chapter 8 ) . The primary manifestation of folate deficiency is a macrocytic anemia. It can evolve quickly, especially in association with alcohol abuse, and can resolve just as quickly once a normal diet is reinstituted. The quickness of changes in serum folate levels in alcoholic patients, as a result of alcohol-induced metabolic blockade of the normal entero­ hepatic folate cycle, can make the diagnosis very difficult. Alco­ holic patients with blood alcohol levels exceeding 1 00 mg/dL will invariably (unless on folate supplements) have a serum folate level less than 4 ng/mL. This will rapidly return to normal

A N E M I A I N T H E E L D E R LY

1 59

in patients with residual liver folate stores once alcohol is with­ drawn and/or a normal diet is resumed. Macrocytosis with little or no anemia can be a relatively common finding in elderly individuals who suffer from a poor diet, with or without alcohol intake. Dietary folic acid is prima­ rily supplied by fresh vegetables and fruits in the diet; thus, sub­ sistence on a daily diet of highly processed foods puts patients at risk. Furthermore, unlike vitamin B 12 ' folate stores in the liver are relatively small, making it possible for a pure dietary defi­ ciency in folate to evolve within a few months of dietary restric­ tion. The classic "tea and toast" diet of the elderly widow( er) is cited as a prime example of this scenario. Add to this diet sev­ eral glasses of sherry each night, and low-grade macrocytosis, at times accompanied by a mild anemia, can be expected. Chronic liver disease has also been correlated with low-grade macrocyto­ sis and target cells on the blood smear due to changes in red blood cell membrane cholesterol metabolism. Elderly individuals are also at increased risk for vitamin B 12 deficiency as a result of gasrric/small bowel surgery, gastric atro­ phy with reduction in inrrinsic factor levels, immune suppres­ sion of intrinsic factor activity, or malabsorption (parasite infestation, small bowel diverticulosis, celiac sprue, or regional ileitis). Faced with a reduced dietary vitamin B1 2 intake and age­ related gastric atrophy, even the healthiest of elderly patients are at risk for negative vitamin B 1 2 balance, resulting in gradual ( over years) exhaustion of hepatic stores and a fall in blood cobalamin levels. The clinical manifestations of vitamin B 1 2 deficiency are diverse and involve both the hematologic and neurologic sys­ tems. Elderly individuals can present with a macrocytic anemia, a range of neurological abnormalities from early dementia to nonspecific neurological signs, or "combined systems disease" where a severe macrocytic anemia is accompanied by signs of dorsal column demyelination (positive Romberg, decreased posi­ tion and vibratory sense, and dysesthesias) . Much has been made o f measurement of blood cobalamin level as the gold standard for the detection and differential diag­ nosis of vitamin B 1 2 deficiency. To make it reliable, the serum cobalamin level should be ordered together with a serum folate level. Both tests should be drawn without delay in patients pre­ senting with a severe macrocytic anemia, prior to reinstituting a normal diet or, in the case of the alcoholic patient, before sig­ nificant alcohol withdrawal (see Chapter 8 ) . The normal range for serum cobalamin levels is said to be from 200-500 pg/mL. However, setting the lower limit of normal at less than 200 pg/mL has been challenged, based on the ability to detect "subclinical" cobalamin deficiency with the methylmalonic acid assay, a meas­ ure of functional metabolic deficiency (see Chapter 8). Because of this, the probability of a cobalamin level being abnormal may better be stated as follows: •

In the presence of a severe vitamin B 12-deficient macrocytic anemia, the serum cobalamin level will be less than 200 pg/mL 95%-97% of the time. From the opposite viewpoint, 60%--BO% of individuals with serum cobalamin levels less than 200 pg/mL will have anemia or metabolic evidence ( abnormal methylmalonic acid level) of vitamin B 12 deficiency.

1 60

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When the serum cobalamin level is between 200 and 350 pg/mL, there is still a considerable chance of a metabolic abnormal­ ity suggestive of a subclinical deficiency state. From 30%-35% of apparently normal individuals with cobalamin levels in this range will have an abnormal methylmalonic acid level with­ out hematologic abnormalities. • The negative predictive value of tests for cobalamin defi­ ciency is, however, a significant issue. In a single study of a group of ambulatory patients who appeared to improve hema­ tologically or neurologically when given pharmacological doses of vitamin Bw more than 50% had cobalamin levels greater than 300 pg/mL. Moreover, measurement of methyl­ malonic acid failed to identify apparently deficient patients 30%-45% of the time.

•

This raises major concerns regarding the use of the cobal­ amin level and/or the test for methylmalonic acid for screen­ ing elderly patients for vitamin B 12 deficiency. The sensitivity and specificity of the tests are clearly not up to the task. Whether this is due to a failure of the commercially available tests for vitamin B 12 deficiency or rapid changes in blood vita­ min levels is unclear. One contributing factor may be the differ­ ential binding characteristics of circulating transcobalamin proteins (see Chapter 8 ) . Whatever the cause, the end result is that many individuals will go undiagnosed and others will tum out to be false positives. This has resurrected the concept of per­ forming a therapeutic trial using pharmacological doses of vita­ min B 12 ( > 100 J.Lg daily by inj ection for several weeks) plus folic acid orally in elderly patients with a macrocytic anemia or a recent onset of dementia or unexplained neuropathy. It is not a welcome solution to a long-standing desire to have a highly sen­ sitive and specific test for vitamin B 12 deficiency in elderly patients. It also calls into question many past reports of the incidence and cause of neurological abnormalities in geriatric populations. The treatment of vitamin B 1 2 and folic acid deficiency is discussed in depth in Chapter 8. Proper management requires careful documentation of the patient's hematological and neu­ rological responses to the vitamin. All too often, the hematolog­ ical response can be dampened or defeated by the hidden presence of iron deficiency or inadequate iron stores. Any inflammatory illness will also inhibit the response. If 1 or both are not appreciated and dealt with judiciously, the whole basis of the diagnosis of vitamin B 12 deficiency can be called into question. This can lead to disaster, since lifelong maintenance therapy with vitamin B 12 is required to prevent irreversible neu­ rological damage. Elderly patients with a severe macrocytic anemia (hemoglo­ bin S.

Eosinophil morphology. The major fu nction of eosinophils

appears to be the defense against multicel lular parasites mediated by the release of the h ighly toxic major basic protein in their granules. In addition, they are capa­ ble of scavenging immune complexes and may play a role in the suppression of humoral immune reactions.

202

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ITE BL00D C E L L D I S0 RD E RS

Although the principal function of the eosinophil is to kill parasites, the cell also contains peroxidase and other enzymes similar to those of neutrophils. The production of eosinophils is stimulated by several cytokines, including IL- l , IL-3 , and IL- 5 , a s well a s b y GM-CSF, but IL-5 i s the most specific growth factor. Their production and function seems to be more closely tied to the immune system, helper T-cell and NK-cell activity, than the typical antibacterial response of neutrophils. Eosinophils are phagocytic and can kill organisms by phago­ some formation. At the same time, when the eosinophil must deal with an organism such as a helminth that is too large to engulf, it will release its granules directly onto the surface of the organism. Eosinophils also appear to be involved in immediate-type hyper­ sensitivity reactions . They are capable of neutralizing hista­ mine and may play a role in downregulating allergic reactions. When stimulated to excessive levels, eosinophils, perhaps by release of their granules, can give rise to tissue damage and endomyocardial fibrosis.

Basophils Basophils and marrow mast cells are equally distinctive morpho­ logically because of their basophilic granules ( Figure 1 6-9 ) . However, the granules o f basophils and mast cells are not iden­ tical and it is still unclear j ust how they are related. Circulating basophils are easily recognized on stained films as cells whose internal structure is largely occluded by a dense mass of large, deep-purple granules. The cells often appear somewhat smaller than neutrophils. In patients with basophilia, however, the gran­ ules may be relatively sparse, revealing a nucleus that resembles that of a monocyte more than a neutrophil. The size of the indi­ vidual granules is the tip-off; they are much larger than the pri­ mary granules of the neutrophils. Circulating basophils appear to play a major role in immedi­ ate-type hypersensitivity reactions both as triggering and effector cells . Their granules contain abundant proteoglycans and histamine. They express high-affinity Fe receptors for lgE and are triggered to release their granule contents by crosslinking of their surface-bound lgE by antigens. Basophils also produce other mediators of acute hypersensitivity such as leukotrienes. Clinically, basophil granule release is manifested as urticaria, rhinitis, asthma, and anaphylaxis. Ttssue mast cells also play a role in the hypersensitivity response. In addition, mast cells contain large amounts of heparin that may serve to maintain blood and extracellular fluid flow, especially in the marrow. Mast cells in the marrow are closely located to vessels and sinusoids.

Cytokines responsible for basophil production may be simi­ lar to those that stimulate eosinophil production. Basophils pro­ vide a useful marker for certain myeloproliferative disorders, parricularly CML. Leukemias restricted to basophils or mast cells are very rare. Marrow and tissue mast cells are increased in the benign disorder urricaria pigmentosa and the clonal malignancy progressive systemic mastocytosis. Symptoms of these disorders are related to the release of histamine and leukotrienes from the cells, resulting in angioedema, pruritus, and hypotension.

M Y E LO I D C E L L K I N E T I C S The kinetics of cell production, egress from the marrow, and sur­ vival in circulation is best illustrated by neutrophils. As with red blood cell production, marrow biopsy can be used to eval­ uate overall cellularity of the pool of leukocyte/monocyte pro­ genitors, whereas a marrow aspirate provides information regarding cell differentiation. Overall, there should be approxi­ mately 3 myeloid precursors or mature granulocytes for every recognizable erythroid precursor. The normal ratio of erythroid to granulocytic precursors ( E/G ratio ) is 1 :3 . Moreover, in the normal basal state, about one-third of all cells observed in a mar­ row aspirate are mature granulocytes that are being stored and awaiting release in response to an infection-related cytokine. Figure 1 6- 1 0 illustrates the relative sizes of the neutrophil precursor compartments, the transit times, and the storage pool

NORMAL PRODUCTION

INFECTION

Production Marrow pool ,...

,.::::. : - : : : ...... . - : .

Increased Decreased production marrow pool

. ,... . ._ . -.. · . .

!

Circulati n g and marginated pools Blood vessel

Bone

l

Increased ci rcul ation Decreased margination Blood vessel

Tissue

1

Increased transmigrati o n Si te of infl a mmati o n

Baso p h i l

Segmented nucl e us Cytoplasm fi l e d by large, dark granul e s

FIGURE 1 � 1 0.

Neutrophil kinetics in the basal state and in infection. There

are several distinct compartments of neutrophils within the body These are the proliferating and storage pools in the marrow, the marginated and circulating pools in the blood vessels, and finally those neutrophils in the tissues at the site of inflam-

FIGURE 1 69.

Basophil morphology. The major role of basoph ils and mast

mation. Infection triggers increased production, depletion of the marrow storage

cells is the release of vasoactive compounds in response to immunologic stimuli

and marginated pools, increase in the circulating pool, and increased transmigration

mediated by the crosslinking of lgE.

into the tissues.

C HA PT E R I 6

for both the normal and infected states. Approximately 1 X 1 09 neutrophils/kg/d are produced by the normal adult marrow, and the total time spent in proliferation, maturation, and marrow storage is estimated to be between 5 and 14 days. With a severe infection, however, the maturation time may be shortened to as little as 48-72 hours. This process reflects a shift of the marrow storage pool into circulation, a phenomenon that can be recog­ nized on inspection of the marrow aspirate as a disappearance of mature neutrophils from the specimen even while the E/G ratio shows an increase in the immature granulocyte compartment.

Factors Affecting the N u m ber of Circulating and Stored Neutrophils Once neutrophils enter circulation, they rapidly equilibrate with the marginated neutrophil pool of approximately equal size. The partition between the marrow storage pool, the circu­ lating neutrophils, and the marginal pool is in constant flux. The number of neutrophils in circulation can increase dramat­ ically in response to infection as a result of a shift of neu­ trophils out of the marrow storage pool that exceeds any increased egress of neutrophils from circulation into the tissues. Administration of glucocorticoids will also change the parti­ tion by releasing marrow granulocytes into circulation, chang­ ing the size of the marginal pool, and slowing the rate of egress into tissues. Sudden exertion with release of catecholamines will also change the pool partition and can double or even triple the blood neutrophil count. Finally, African American sub­ jects may have significantly lower neutrophil counts because of variations in the pool sizes, with otherwise normal neutrophil production and delivery into tissues. Circulating granulocytes leave circulation in a random fash­ ion with an average disappearance time of 6--7 hours . Once they enter tissue they do not return to circulation, and their sur­ vival depends on their reason for homing to that site. At best, it is less than 2-3 days. In response to an infection, they release cytokines, which encourage additional granulocyte migration.

Estimates of Myeloid Cel l Production Even though the kinetics of neutrophil production and survival in circulation are complex, it is possible clinically to estimate myeloid cell production from the count of mature and imma­ ture cells in circulation. Modern automated counters provide an accurate measurement of the total leukocyte count and a rela­ tively accurate differential count of neutrophils, metamyelocytes (bands ) , monocytes, eosinophils, basophils, and lymphocytes ( see Chapter 2 and Figure 2-2 ) . A white blood cell differential can also be performed by direct counting of a stained blood film. Since a smaller number of cells are counted, the error of this measurement is far larger than that of the automated differential. However, automated counters are often unable to accurately classify abnormal cell types, and such methodologic errors result in flags that must be taken into account before releasing differ­ ential results. Normal values for the leukocyte count and differential are summarized in Table 16-3 . Clinical laboratories generally report the absolute number of leukocytes and a percent differential of

N 0 RMA L MYE L0 P 0 I ESI S

203

TABLE 1 6-3 The normal leukocyte count •

Percent

Absolute Count

Neutrophils

45-75

9 5- 1 I ,000/j.!L (5- I I x I 0 /L) 9 4--6)00/ j.!L (� x 1 0 /L)

Metamyelocytes (bands)

0-5

Monocytes

5- 1 0

Eosinophils

0-5

Basophils

0- 1

Lymphocytes

1 0-45

Cel l l} 1 million/J..LL ) in the absence of any other cause of a reactive process. The ]AK2 mutation, which is present in 40%-5 0% of patients, greatly facilitates the diagnosis. For patients who are ]AK2 negative,

CHAPTER 1 9

M Y E L O G E N O U S L E U K E M I A A N D M Y E L O P R O L I F E R AT I V E D I S O R D E R S

C A S E H I S T O RY

237

Pa rt 2

A bone marrow aspirate is attempted but is not successful. A biopsy specimen shows marked increase in reticulin and fibro­ sis as well as increased numbers of dysplastic megakaryocytes. Cytogenetic and molecular genetic analyses show no evidence for a Philadelphia chromosome or the BCR-ABL translocation; however, molecular analysis shows the pres­ ence of the JAK2 V6 1 7F mutation. Based on these findings a diagnosis of primary myelofi­ brosis can be made. At the same time, the history of elevated

thrombocythemia is a diagnosis of exclusion, which means that any known cause of reactive or clonal thrombocytosis must be considered. This includes iron deficiency, chronic inflammatory disorders, chronic infectious diseases, hyposplenia, and solid malignancies, as well as the other stem cell myeloproliferative disorders such as polycythemia vera, CML, and idiopathic myelofibrosis. In the case of thrombocytosis secondary to inflam­ mation or neoplasia, IL-6 appears to be a primary mediator responsible for overexpression of thrombopoietin mRNA. From the perspective of relative incidence, more than 80% of patients presenting with a platelet count greater than 5 00,000/ j..tL will have reactive thrombocytosis. Primary thrombocythemia has been shown by G6PD isoen­ zyme studies, and more recently by the presence of the ]AK2 mutation, to be a clonal disorder involving all of the hematopoi­ etic cell lines in most patients. The underlying disease mecha­ nism involves a defect in the c-Mpl thrombopoietin receptor. This includes both a decreased expression and abnormal bind­ ing of thrombopoietin, resulting in higher than normal throm­ bopoietin levels and, because of this, increased megakaryocyte proliferation. Most patients with primary thrombocythemia are first detected on routine CBC while they are still asymptomatic. When the platelet count reaches very high levels , the most common symptoms are those associated with bleeding owing to platelet dysfunction or the appearance of a hypercoagulable state with thrombosis and microvascular ischemia. During the course of the disease, some 50% of patients will experience at least 1 venous or arterial thrombotic event, ranging from distal vessel thromboses to strokes and coronary artery occlusions to unusual presentations such as Budd-Chiari syndrome or skin necrosis. Patients with higher platelet counts will complain of vasomotor symptoms such as headaches, dizziness, syncope, visual distur­ bances, paresthesias , acrocyanosis, livedo reticularis, palmar burning, and digital erythromelalgia. These events are related to platelet activation and usually are responsive to treatment with aspirin and a reduction in the platelet count. Patients will have some splenic enlargement, but it is never as prominent as that seen in CML or idiopathic myelofibrosis. The very high platelet counts can result in splenic infarction and a loss

red cells and white cells in the past suggests the possibility that this cou ld represent evolution of a process that may have been active for many years, such as polycythemia vera. The finding of the JAK2 mutation is compatible with either diagnosis.

Questions • What are the therapeutic priorities for this patient? • What is the prognosis at this junctu re?

of splenic function. This will result in the appearance of Howell-Jolly bodies, nucleated red blood cells, and target cells on the peripheral film (see Chapter 2 ) .

Laboratory Studies A routine CBC and marrow examination may distinguish pri­ mary thrombocythemia from CML, polycythemia vera, and idiopathic myelofibrosis. The very high peripheral platelet count is not accompanied by maj or changes in the white blood cell or red blood cell lines , although an absolute basophilia is observed in some patients. The marrow may be normocellular or hypercellular, with a normal ratio of ery­ throid to granulocytic precursors and a normal display of mye­ locytic precursors. At the same t ime , the number of megakaryocytes should be dramatically increased. Their mor­ phology is usually normal, but it is common to see large aggre­ gates of megakaryocytes dispersed throughout the marrow aspirate and biopsy. An artifactual hyperkalemia is frequent, due to loss of potassium from the excess platelets in v itro fol­ lowing blood drawing. For JAK2-negative patients , a primary thrombocythemia diagnosis is reached after exclusion of other disease states. The laboratory evaluation should include iron studies to rule out iron deficiency or an inflammatory state; chromosomal analy­ sis to rule out CML and myelodysplasia, especially the 5q minus syndrome where elevated platelet counts are frequent; and a bone marrow biopsy to exclude a diagnosis of myelofi­ brosis. Polycythemia vera patients with marked thrombo­ cythemia can present with a normal hemoglobin level and red blood cell mass, or even anemia secondary to acute and chronic blood loss. These patients may be recognized because of the marked disparity between the severity of their microcy­ tosis and their mild degree of anemia ( see Chapters 5 and 1 0 ) . Rarely, polycythemia vera will not b e detected until after iron replacement is initiated and the hemoglobin level rapidly increases. Spontaneous in vitro formation of megakaryocyte colonies (CFU-MK) in the absence of added growth factors has been reported in patients with primary thrombocytosis. While this

238

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has been previously suggested as a diagnostic test for the disease, the phenomenon has also been observed in patients with other myeloproliferative disorders and has been largely replaced by the ]AK2 mutation evaluation.

have a protracted benefit with stabilization, regression, and some­ times disappearance of symptoms. In other cases, however, when tissue symptoms are present prior to instituting therapy, the dis­ ease quickly progresses to fatal heart failure or acute leukemia.

Disease Course The overall life expectancy of patients with essential thrombocy­ tosis is near normal (median survival 1 0- 1 5 years ) . However, older adults (over age 60) and patients with a history of thrombo­ sis and a platelet count greater than 1 .5 million/� are at a signif­ icant increased risk of thrombohemorrhagic complications and need to be treated. Transformation into polycythemia vera, myelofibrosis, or acute leukemia, even with prolonged chemother­ apy, is seen in fewer than 5 % of patients. There would appear, therefore, to be little downside to extended chemotherapy with hydroxyurea.

e

C H RO N I C E O S I N O P H I L I C L E U KEM IA

For a long time , cases presenting with very high eosinophil blood counts have been classified as hypereosinophilic syn­ dromes, as their specific cause remained elusive. Recently, chro­ mosomal data obtained in some patients with this presentation have revealed the presence of a recurrent translocation t { 1 ;4 ) (q44;ql 2 ) involving the gene for the receptor of the platelet derived growth factor a (PDGFR-a) with a hitherto unknown partner gene (FIP l L l ). The fusion protein that results from this rearrangement has tyrosine kinase activity. Patients are generally young adults, more frequently men. The presentation is often asymptomatic for a long period of time. The diagnostic criteria are persistent elevated eosinophil counts above 1 , 500/J..LL , absence of known cause of hypere­ osinophilia, and possible signs of organ damage related to toxi­ city of eosinophil granule constituents on tissues, the most severe being endomyocardial fibrosis, which can result in a restrictive cardiomyopathy and tricuspid insufficiency. Neuro­ logic manifestations, both central and peripheral; lung infil­ trates; skin lesions; and mucous membrane ulcerations are less prominent symptoms.

Laboratory Studies Blood hypereosinophilia is a constant, isolated, and prominent fea­ ture. Eosinophil values are generally above 5 ,000/�. Other cell lines are normal. Marrow aspiration shows isolated eosinophil hyperplasia, but a mild fibrosis is frequent on marrow biopsy. Serum tryptase is elevated. Cytogenetic studies have shown the most fre­ quent abnormality being the t( l ;4) ( q44;q 1 2 ) translocation and, less commonly, translocations involving chromosome 5 at the site of PDGFR-{3. In these latter forms, the disease often shares fea­ tures with chronic myelomonocytic leukemia (see below) .

Disease Course The course is highly dependent on stage and treatment efficacy. Patients responding to treatment with tyrosine kinase inhibitors

C H RO N I C M Y E LO M O N O C YT I C LEUKEM IA Overlapping the myeloproliferative and the myelodysplastic syndromes, chronic myelomonocytic leukemia (CMML) pres­ ents in adult ( especially elderly ) patients as an insidious dis­ ease, with manifestations including fatigue, easy bruising, and splenomegaly. The CBC and blood film show an admixture of immature myelocytes and monocytes ( > 1 0,000/ J..LL ) , together with quantitative and qualitative modifications of red cells, neutrophils, and platelets, as generally observed in myelodys­ plastic syndromes. The combined esterase stain ( see Chapter 1 6 ) clearly confirms the mixed population of myelocytes and monocytes, even when the cells are immature with few gran­ ules. Hyposegmented neutrophils (pseudo--Pelger-Huet abnor­ mality ) and mild eosinophilia are frequent. The marrow aspirate shows granulocytic and monocytic hyperplasia, and sometimes a mild increase in myeloblasts. Marrow karyotyping is abnormal in one-third of patients, mainly with translocations recombining 5q33 ( PDGFR-/3) with several gene parmers. The fusion products behave as tyrosine kinases and can display sen­ sitivity to TKis.

Disease Course and Prognosis CMML has a highly variable course. As discussed in Chapter 9 , CMML may have a relatively benign course. Some elderly patients can remain alive and asymptomatic for relatively long periods of time. On the other hand, some patients, especially those with chromosomal abnormalities, more rapidly develop pancytopenia, and 20% of cases evolve over time into an acute myeloid leukemia (AML ) -like picture.

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Juvenile myelomonocytic leukemia (JMML), observed in young children less than 4-5 years of age, has a presentation similar to adult CMML. However, its mechanism appears quite different as cells in vitro display a high sensitivity to granulocyte macrophage colony-stimulating factor ( GM-CSF), which is a hallmark of the disease. Several mutations involving RAS signaling pathways have been described. Infants present with failure to thrive, fever, recurrent infections, and mucous membrane bleeding. Spleen enlargement is almost constant, as well as maculopapular or xan­ thomatous skin lesions. Blood films show a picture similar to adult CMML. Cytogenetics is either normal or infrequently shows recurrent abnormalities, the most frequent being monosomy 7. The disease displays poor sensitivity to chemotherapeutic regi­ mens and the overall survival is generally less than 3--4 years, unless a stem cell transplant can be performed.

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T H E RA PY The most important elements of good management of a patient with a myeloproliferative disorder are the accurate diagnosis of the condition and a sense of when to treat the disease. Since many patients are elderly at the time of presentation, aggressive chemotherapy and marrow transplantation are often not feasible. Therefore, watchful waiting with blood product support and sin­ gle-drug chemotherapy are often more appropriate. The selec­ tion of drugs also varies according to the individual disease process. This is especially true for CML, for which TKI therapy has become increasingly effective.

Chronic Myelogenous Leu kemia Until the late 1 9 70s-1 980s, CML outcome was invariably lethal as treatment was limited to drugs such as hydroxyurea or busul­ fan that were unable to eradicate the Ph 1-positive malignant clone. During the last 20 years, 3 treatment modalities, that is, allogeneic bone marrow transplantation, interferon-a, and more recently the TKis have demonstrated their ability not only to reduce but even to eradicate the malignant clone. In fact, true remissions (Ph 1 negative) and durable disease-ftee survivals can be achieved when patients are treated with imatinib, interferon- a, or allogeneic marrow transplantation. Success depends on several factors including the patient's age, the timing of the treatment according to the phase of the disease, and the innate responsive­ ness of the CML. In essence, younger patients who are diagnosed and treated early in the chronic phase of their illness and who have a very responsive leukemic stem cell do the best. Control of BCR-ABL residual disease is most likely dependent on an effec­ tive immune response against the BCR-ABL clone. This is best illustrated by the presence of cytotoxic T cells directed against CML-specific epitopes in patients maintained in stable, complete molecular responses after interferon or allogeneic transplantation, as well as the graft versus leukemia effect that can be induced by donor lymphocyte infusions in allogeneic stem cell recipients.

A. BCR-ABL Tyrosine Kinase Inhibitors A specific inhibitor of the Ph1 chromosome BCR-ABL tyrosine kinase, imatinib mesylate (Gleevec ) , has shown significant activity in both the chronic and blast phases of CML and in the treatment of Ph 1 -positive ALL. A large multicenter trial has compared imatinib 400 mg/d to interferon plus cytarabine in previously untreated patients in chronic phase. Long-term results ftom this trial show that 87% of patients receiving ima­ tinib are in complete cytogenetic response at 60 months, and the estimated overall survival is 89%, reaching 95% when only CML-related deaths are considered. lmatinib has also been shown to be effective in patients who have failed interferon- a therapy. In addition, responses have been reported in more than 50% of patients with myeloblastic crises and 70% of patients with lymphoblastic crises or Ph 1-positive ALL. However, unlike chronic-phase patients, most blastic crisis patients relapsed while receiving therapy. Adverse side effects are described as minimal and include nausea, myalgias, edema, diarrhea, and in some patients, abnormal bleeding.

239

Because of its low toxicity and effectiveness in the early phases of CML, imatinib has now become the treatment of choice. Cur­ rent trials support the use of high-dose imatinib, 400 mg orally twice a day, both because of its greater efficacy in inducing a com­ plete molecular remission ( absence of BCR-ABL RNA) and as a way to reduce the development of resistance. When the response is incomplete or because of resistance to imatinib (Ph1-positive cells persist in the marrow or less than a 3 -log reduction in RNA product in blood) , higher-dose imatinib therapy may be more effective but yields poorer hematologic tolerance, which, in some patients, can be mitigated by the use of growth factors. A better approach to higher dose imatinib is the use of one of the newer tyrosine kinase inhibitors. Second-generation TKis have now reached the clinic. They offer improved efficacy and can overcome some of the resistance mechanisms resulting ftom mutation within the tyrosine kinase domain. Dasatinib, a "dual inhibitor" as it inhibits TKs together with src kinase, is roughly 300 times more active in vitro when compared with imatinib and displays activity against most of the resistant mutated clones, with the exception of T3 1 5I. In a piv­ otal study, patients insensitive or intolerant to imatinib experi­ enced 5 2 % maj or cytogenetic responses. The recommended optimal dosage is 1 00 mg once a day. Tolerance is good, although some patients have developed pleural effusions that resolved with stopping the drug or reducing its dose. Nilotinib is equally active on non- T3 1 5I resistant cells, and the results observed in imatinib-resistant patients compare with those of dasatinib. The recommended dosage is 400 mg twice a day. Both drugs are cur­ rently under study for first-line treatment of CML. Bosutinib is another "dual inhibitor" currently being tested in phase II/III trials. Finally, MK-045 7 , an Aurora kinase inhibitor, appears to be promising as it retains activity against T3 1 5I mutations. Patients can develop resistance to the effects of imatinib, especially when it is given at lower doses. Several mechanisms of resistance have been identified, with mutations within the tyrosine kinase activity site being the most frequent. Some of these mutations can be overcome with a dosage increase or switch to another TKI such as dasatinib, nilotinib, or bosutinib. However, a mutation in codon 3 1 5 induces an invariable resist­ ance to TKis, and therefore is associated with a poor response and prognosis. Long-term control of the malignant clone with imatinib is a maj or issue in as much as patients stopping imatinib while in complete remission ( Ph 1 -negative for 2 years) have experienced molecular relapse. This observation supports the concept of con­ tinuous TKI treatment, or combining it with other treatment modalities that are capable of suppressing residual disease, such as allogeneic bone marrow transplantation. Of note, previous treatment with imatinib does not alter the morbidity and out­ come of stem cell transplantation when patients switch to this procedure.

B. Interferon-a Prior to the success of imatinib, interferon- a was the preferred drug in the initial treatment of the chronic phase of CML. It now must be considered a poor second choice. Interferon

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therapy can improve overall survival by about 20 months when compared with hydroxyurea or busulfan therapy. Normalization of the CBC can be achieved in 70%-80% of patients and a Ph 1negative remission in up to 30% of patients. However, residual malignant cells can still be detected by polymerase chain reac­ tion ( PCR) measurement of the BCR-ABL translocation. Still, a complete cytogenetic response does predict a more durable remission. The effectiveness of interferon therapy correlates with the maximum dose tolerated by the patient. Lower-dose regimens ( 2 X 1 06 U/m2 given subcutaneously or intramuscularly 3 times per week) will improve the blood counts in most patients but will not produce a complete cytogenetic response. A dose of 5 X 1 06 U/m 2 given 3 times a week or, if tolerated, daily is needed to achieve a complete cytogenetic response. The rate of response is slow. If the initial granulocyte count exceeds 1 00,000/J..LL , the patient should be first treated with hydroxyurea (see below) to lower the count to below 20,000/J..LL . The hydrox­ yurea should then be continued during the first 2-3 months to prevent a count rebound. Interferon therapy is best started at a reduced dose, 3 x 1 06 U/d for 1-2 weeks followed by 5 x 1 06 U/d for another 1-2 weeks, before escalating to full dose. Otherwise, the patient will show poor tolerance for the interferon. Patients are slow to respond to interferon. Therapy must be given continually for 1 year or more because the maximum response may not occur for 1 2- 1 8 months. A maj or downside is when interferon is given for more than 6 months, the success rate of a subsequent marrow transplant may be significantly reduced. Therefore, a decision regarding transplantation needs to made in the first 6 months and the transplant completed during the first year. Transplantation should be seriously con­ sidered when a significant hematologic remission is not reached by 6 months. If a maj or cytogenetic remission is achieved, the interferon should be continued for 2-3 years. The patient should then be followed off therapy using a sensitive assay ( PCR or FISH assay) for the re-emergence of Ph1 -positive cells. The pro­ j ected 6- to 8-year survival rate for patients with maj or cytoge­ netic responses is better than 85%, and the 10%-20% mortality with transplantation is avoided. Interferon-a therapy is associated with several side effects. With each inj ection, patients experience a flu-like syndrome with fever, chills, and anorexia. Severe, persistent fatigue, depression, weight loss, and the appearance of autoimmune­ mediated organ damage (cardiomyopathy, collagen vascular dis­ orders, hypothyroidism, hemolysis, and thrombocytopenia) will require dose reductions. As a rule, the dose administered will need to be cut by 2 5 %-50% when there is evidence of organ damage or severe leukopenia or thrombocytopenia ( absolute leukocyte count below 2 , 000/J..LL or platelet count below 60,000/J..LL ) . Up to 20% of patients will not be able to tolerate the drug. Rarely, severe organ damage, especially cardiac disease with arrhythmias or congestive failure, will require discontinu­ ation of the drug.

C. Hydroxyurea Hydroxyurea has been used in the past to treat CML. However, it is now obsolete, and with few exceptions has little or no place

in the treatment strategies of CML. However, hydroxyurea con­ tinues to be used in the treatment of other myeloproliferative disorders, primarily for palliation and relief of symptoms due to splenomegaly and reduction of extremely elevated platelet and leukocyte counts, and therefore is briefly discussed here. Hydroxyurea is an inhibitor of DNA synthesis and acts by blocking cell division and marrow precursor maturation. It does not affect the malignant stem cells, and therefore does not pro­ duce a cytogenetic remission. Because hydroxyurea blocks mat­ uration of all hematopoietic cell lines, patients become markedly megaloblastic and develop a peripheral macrocytosis. It can be very effective in the treatment of patients with very high granu­ locyte counts ( > 1 00,000/J..LL ) in myeloproliferative disorders. Given as an oral dose of 2-8 g/d, hydroxyurea will rapidly reduce the granulocyte count, generally within 48-72 hours. In a sim­ ilar fashion, hydroxyurea will reduce the platelet count in pri­ mary thrombocythemia patients whose platelet counts rise to levels above 1 million/J..LL . Hydroxyurea in doses less than 2 g per day has few if any side effects, but its long-term use can be limited by its impact on red cell and leukocyte production.

D. Bone Marrow Transplantation ! . Al logeneic marrow transplantation Allogeneic mar­ row transplantation was recommended as first-line therapy for younger CML patients with a matched sibling donor before the era of TKis. It is not without risk; the procedure itself carries a risk of 5 %-20% acute mortality. In addition, survivors have to deal with some degree of GVHD in order to achieve the 50%-75 % chance of a prolonged disease-free survival when transplanted during the chronic phase. The best results are achieved when transplantation is carried out early in the chronic phase of CML. Once the disease pro­ gresses, the chance of an effective transplant decreases dra­ matically. When the patient has had the disease for more than 2 years, a positive result can be expected less than 50% of the time. If the disease enters the accelerated phase, the results fall to nearer 20%-40% , and patients in blastic crisis have only a 1 5 %-20% chance of achieving any significant remission. The preparative regimen also makes a difference; patients who achieved a Ph1-negative remission with TKl therapy do the best. -

2. U n related H LA-m atched donor transplants-Unre­

lated HLA-matched donors have been used extensively in the marrow transplantation of CML patients. In the ideal situation, unrelated donor transplants appear to be as or more effective than an HLA-matched sibling transplant: disease-free survival is 75% if the transplant is done in the first year. It is self-evident, however, that patients who use the unrelated donor pool for their transplant will often have progressed further in their dis­ ease, been exposed to more chemotherapy, and be somewhat older. Because of a higher rate of transplant-associated deaths, overall disease-free survival for patients receiving transplants from unrelated donors is approximately 30%-40% at 5 years, and there is a significantly higher incidence of severe GVHD. Late relapses are seen in CML patients with transplants, sug­ gesting that transplantation will never result in a guaranteed cure. This situation may reflect a persistence of the rare leukemic stem

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cell or an environmental factor that leads to reemergence of the clone. The antileukemic effect of acute and chronic GVHD also plays a role. Patients who receive T-cell--depleted marrow trans­ plants have a 5-fold increased risk of relapse. This is also true for twin transplants and for patients who receive immunosuppressive therapy for their GVHD. It is perhaps the best example of the graft-versus-leukemia (GVL) effect of donor lymphocytes. In patients who relapse following transplant, donor lympho­ cyte transfusions have been used successfully to reinduce remis­ sion. From 70%-90% of patients with a hematologic or cytogenetic relapse will respond, usually after a 2- to 3-month course of multiple transfusions of donor T cells. Patients who develop grade 2 or higher GVHD as a result of the therapy do best, demonstrating a better than 90% remission rate . The mechanism behind this effect is still unclear. Experimental data would suggest, however, that the T-cell GVL effect is distinct from the GVHD effect, and that infusions of CDS (suppressor) T-cell--depleted donor lymphocytes will give the GVL effect with far less GVHD. ) . Autologous marrow transplantation-Attempts to use autologous marrow transplantation have not been effective in CML. In this case, the inability to completely eradicate the malignant cell line with chemotherapy and the absence of a GVL effect may guarantee failure . However, it has been observed that during culture in vitro, the Ph 1 -containing stem cells may not survive as well as normal stem cells. 4. Non-myeloablative allogeneic transplantation-An

alternative approach to full allogeneic transplantation is being investigated. It consists of reduced doses of myelosuppressive drugs followed by relatively large infusions of donor stem cells. This results in partial engraftment of donor cells (mixed chimerism) with reduced severity of GVHD but preservation of the GVL effect of the donor immune cells. Another investiga­ tive approach is to follow allogeneic transplantation with infu­ sions of donor lymphocytes, the intent being to augment the GVL phenomenon without significantly worsening GVHD. Results with these approaches can compare with full myeloab­ lative stem cell transplants. They offer the opportunity to extend the indications for stem cell transplantation in CML for patients who are up to 65-70 years old. E.

Choice of the Appropriate Therapy

The TKis are now the recommended first-line treatment for management of CML. Patients treated with imatinib during the chronic phase of their illness achieve maximum control of their hematologic abnormalities with minimal side effects. Second­ generation TKis are suitable for patients with imatinib intoler­ ance or resistance with the exception of the T3 1 5I mutation. These TKls have completely replaced interferon and stem cell transplant as initial treatments in the chronic phase of CML. However, for patients in accelerated or blastic phase, allogeneic stem cell transplantation is recommended as soon as possible, after a short course of imatinib at a higher dose ( 600-800 mg/d) , with the aim o f improving hematological status before the trans­ plant procedure.

24 1

Myelofibrosis Patients with myelofibrosis are classically managed conservatively. Most ofren, the disease process follows a chronic, slowly progres­ sive course, and patients can simply be observed. Symptomatic anemia will respond adequately to periodic red blood cell trans­ fusion, unless the patient develops hypersplenism with an increased rate of red blood cell destruction. Patients who develop hypersplenism may be candidates for splenectomy. Splenectomy may also play a role in decreasing the rate of progression of the marrow fibrosis. It is difficult, however, to predict the outcome of a splenectomy. Often, the patient's condition is worsened both by a spread of the extramedullary hematopoiesis to the liver and other tissues and a post-splenectomy rise in the platelet count to levels in excess of 1 million/J..!.L Splenectomy is most successful in those patients with symptomatic splenomegaly, with overt portal hypertension, and progressive, transfusion-dependent anemia. Severe thrombocytopenia and a hypocellular marrow are adverse indicators for response to splenectomy. Splenic irradiation has been used effectively to control the splenomegaly and hyper­ splenism. Ninety percent of patients will respond to repeated irra­ diation. However, splenic irradiation is associated, at times, with severe myelosuppression, even aplastic anemia. Marrow transplantation has been used successfully in young patients with myelofibrosis. Of interest, the marked fibrosis of the marrow can be reversed if the patient's malignant cell lines are eliminated and a successful transplant is achieved. The num­ ber of patients who are reasonable candidates for transplanta­ tion is relatively small, however. Since myelofibrosis is an illness of middle-aged and older patients, the risk of procedural death and severe GVHD is also very high. It has been reported that 2-CDA therapy will also result in a decrease in marrow fibrosis. Non-myeloablative allogeneic transplantation may have some­ thing to offer to this older patient population. Very promising results have recently been observed with a novel ]AK2 inhibitor (referred to as INCB0 1 8424 ) and tipifarnib, a farnesyltransferase inhibitor, in both primary and secondary myelofibrosis, the lat­ ter including post-polycythemia vera or essential thrombo­ cythemia patients.

Primary Thrombocythemia Age greater than 60 years, a history o f at least 1 thrombotic event, or platelet counts greater than 1-1 . 5 X 1 cYi/J..!.L are adverse prognostic signs that dictate a need for trearment. Patients with primary thrombocythemia can usually be controlled with chemotherapy. Several single-agent drug regimens have been used, including hydroxyurea, anagrelide, interferon- a, and in selected cases, alkylating agents. Since the course of the disease can be prolonged, hydroxyurea may be considered the drug of choice. Although its use is associated with the development of both anemia and granulocytopenia, the fears of hydroxyurea­ induced acute leukemia or myelodysplasia in patients receiving long-term therapy have not been confirmed. The use of regi­ mens containing alkylating agents is discouraged because of the higher risk of secondary malignancies. Anagrelide can be effective in resistant patients. If one begins with a daily oral dose of 0.5 mg 2--4 times per day and

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Pa rt 3

The presence of cachexia and weight loss, as well as signif­ icant anemia and marked splenomegaly, suggest that this patient has severe myelofibrosis and a poor prognosis. Treatment priorities include red cell transfusions to allevi­ ate the anemia. However, the effectiveness of transfusion therapy may be in jeopardy since her low WBC and platelet counts suggest hypersplenism may be playing a role in her disease. As a result she should be evaluated for splenectomy

then escalating the dose by 0.5 mg/d at 1 - to 2-week intervals, the platelet count should fall below 600,000/J.IL within 1 month. Continuous maintenance is required, since like hydroxyurea, anagrelide interferes with platelet maturation, not megakary­ ocyte proliferation. Side effects are frequent and include headache , fluid retention, diarrhea, nausea, abdominal pain, and, in elderly patients, congestive heart failure. Patients with known heart disease should be given the drug with caution. In a recent trial comparing anagrelide plus aspirin to hydroxyurea plus aspirin, anagrelide was associated with a significant excess of arterial thrombosis, bleeding, and myelofibrotic transforma­ tion, and thus should be considered as second-line therapy. Interferon can be used in hydroxyurea or anagrelide failures, but at considerable cost and toxicity. Treatment is initiated with 3 million units subcutaneously 3 times a week. Use of antipiateiet agents other than aspirin in the treatment and prevention of thrombotic events is somewhat controversial. Aspirin is effective in patients with recurrent thromboses,

P O I N T S TO R E M E M B E R The rnyePop�ltferative dlsorde�

are

all donal disorders of the

hematopoietic stem cell. Although they usually present with disease expression in a single cell l i ne, all hematopoietic cell lines are affected to some extent. Over time, this can result in a variable dis­ ease course and considerable overlap of clinical findings. C M L is unique in that its pathogenesis depends upon the presence of the BCR-ABL fusion protein, which has tyrosine kinase activity. Based on this, treatment with the tyrosine kinase inhibitor imatinib has shown great clinical success. In fact, it has revolutionized the treatment of CML. A small proportion of C M L patients will become resistant to ima­ tinib. They may respond to an increased dose of imatinib or, even better, one of the newer tyrosine kinase inhibitors-dasatinib, nilo­ tinib, or bosutinib-- i f the T3 I 51 mutation is not present. Polycythemia vera (see Chapter 1 3), pri mary myelofibrosis, and p rimary throm bocythemia share the JAK2 mutati on. This is of

I with a careful consideration of her suitability as a surgical candidate. Splenic irradiation is a possible alternative. She is at the upper limit of the age range for allogeneic stem cell transplantation, but this could be considered once she has improved symptomatically. Of course, transplantation will depend on her overall medical evaluation and the avail­ ability of a matched donor or the possibility of a non-mye­ loablative transplant protocol.

especially arterial thrombi or microvascular ischemia. It is con­ traindicated in patients with a history of abnormal or gastroin­ testinal bleeding.

Chronic Eosinophilic Leukemia Steroids (prednisone ) have remained for a long time the effective treatment of hypereosinophilic syndrome. Responding patients are expected to have a 70% survival rate. However, steroid side effects or resistance lead to a need for alternative drugs including hydroxyurea, vincristine, methotrexate, or other cytotoxic agents. More recently, recombinant interferon-a , cyclosporine, and anti-IL-5 monoclonal antibodies have demonstrated efficacy. However, the recent discovery of ima­ tinib-sensitive cases, especially but not only in patients demon­ strating PDGFR-o: translocations, has led to trials of imatinib. Complete response, including molecular ones, can be achieved with moderate doses of imatinib ( 1 00-400 mg/d) , which now appears to be the treatment of choice in these cases.

considerable val ue in diagnosis and is a potential futu re therapeu­ tic target. When the JAK2 mutation is not detected, the diagnosis becomes largely one of exclusion. The differential diagnosis of polycythemia vera is discussed in detail in Chapter 1 3. Myelofibrosis is frequently seen with the progression of disease in polycythemia vera, C M L, and refractory anemia with excess blasts (RAEB) patients and in association with systemic tubercu losis and solid tumors (breast, lung, and prostate) metastatic to the bone marrow. There is a considerable overlap between the myeloprol iferative dis­ orders and the myelodysplastic disorders (see Chapter 9). Evolution from a dysplastic state (RAEB) to a myeloproliferative state, either C M M L or AM L, is a relatively common occu rrence. Treatment goals for all of the myeloproliferative disorders begin with preventing vascular events (thrombosis or bleeding) followed by relief of sym ptoms due to anemia, thrombocytosis, and organomegaly, and then to improving survival and possible cure. O n ly successfu l allogeneic stem cell transplantation is cu rrently known to be curative.

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Kroger N , Thiele J, Zander A, et al: Rapid regression of bone marrow fibrosis after dose-reduced allogeneic stem cell trans­ plantation in patients with primary myelofibrosis. Exp Hematol 2007;3 5 : 1 7 1 9.

Schafer AI: Thrombocytosis. N Engl J Med 2004;3 50: 1 2 1 1 .

Mesa RA, Camoriano JK, Geyer SM, et al: A phase II trial of tipifamib in myelofibrosis: primary, post-polycythemia vera and post-essential thrombocythemia. Leukemia 2007;2 1 : 1 964. Tefferi A: Pathogenesis of myelofibrosis with myeloid meta­ plasia. J Clin Oncol 2005 ;23:8520. Essential Thrombocythemia

Finazzi G, Harrison C: Essential thrombocythemia. Semin Hematol 2005;42:230.

Chronic Eosinophilic Leukemia

Bain B: Cytogenetic and molecular genetic aspects of eosinophilic leukaemias. Brit J Haematol 2003 ; 1 2 2 : 1 73 . Martinelli G , Rondoni M , Ottaviani E , Paolini S , Baccarani M: Hypereosinophilic syndrome and molecularly targeted ther­ apy. Semin Hematol 2007 ;44:S4.

N O RM A L LY M P H O PO I ES I S A N D TH E LY M P HATI C SYSTE M Normal lymphopoiesis is an essential component in host defense. It involves the proliferation and function of several types of lymphoid cells including B cells, which are the antibody­ producing cells; T cells , which carry out cell-mediated immune functions and are largely responsible for regulatory control of the immune system; and the natural killer (NK) cells, which function more in a macrophage-like role in host defense against infection and malignancy. An understanding of normal lym­ phopoiesis requires knowledge of individual cell characteristics and expected responses of these cells to disease states.

LY M P H O I D S T E M C E L L S The earliest lymphoid stem cell is derived from the totipotent stem cell pool of the marrow. However, both B cells and T cells then mature in other lymphoid tissues. The thymus plays a major role in developing T cells. Precursors leave the marrow and migrate to the thymus, where they develop into immuno­ competent cells. It is in the environment of the thymus that the T cell develops its critical ability to distinguish self from non-self and where errors in development form the basis for most, if not all, autoimmune disease. The stages of T-cell development in the thymus are well defined and form the basis for the clinical approach to the classification of T-cell malignancies. B-cell development takes place in the marrow and periph­ eral lymphoid tissues, the lymph nodes, and spleen. The stages of B-cell development are not as clearly defined as those of T cells, forming more of a continuum leading to the end stage plasma cell. In addition to their classical role in the production of antibodies, B cells also serve as antigen-presenting cells. They have the ability to localize and process antigens from the envi­ ronment and to present these antigens to other cells of the immune system just like macrophages. Regulatory T cells largely

•

20

control their development and function. Therefore, it is some­ times difficult when presented with a disease secondary to immune dysfunction to assign root cause to the B- or T-cell system simply because the 2 systems are so intimately intertwined.

The I mmune Network One important concept for disorders of the immune system is the "immune network." Cells of the immune system make no basic distinction between internal antigen ( ie, a component of self) and external antigen ( ie, a pathogen or molecule arising from mutation or transplantation). All chemical structures in the body, including proteins, carbohydrates, and to a lesser extent lipids, are recognized by immune cells. This includes the components and products of the immune cells themselves. The "immune network" is balanced in such a way, however, that those cells that recognize self-antigens are suppressed but not eliminated, and those cells recognizing foreign antigens are stim­ ulated but not allowed to become predominant. Thus, the immune system can be looked on as a balanced network of pos­ itive and negative interactions that is controlled by intertwined feedback systems (Figure 20-1 ) . Although w e understand the principles that control the immune network, and have some clear examples of how it func­ tions, it is too complex to describe completely. Autoimmunity is a necessary, even critical part of the immune system. Disease results from a disruption of the normal balance, that is, emer­ gence of uncontrolled autoimmunity, inappropriate suppression of the ability of cells to recognize a foreign antigen, or uncon­ trolled proliferation of 1 or more clones of lymphocytes. How­ ever, simple disease explanations, such as "too many suppressor cells" or "too few helper cells," are viewed with great skepticism because they do not present the complete clinical picrure of immune dysfunction.

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Antigen driven clonal maturati o n •

•

-

L •

•

Anti-id iotype resembles antigen

l

- , , _ • _ _ • _ -

Antigen independent clonal maturation

-�

Anti-anti - idi otype FIGURE 20- 1 . The Jlnmune network." The immune network consists of a cas­ cade of interacting cells with specificity for antigen and for each otherThe first cell that responds to antigen creates an antibody that is itself antigenic for other cells. The idiotype of this antibody stimulates production of "anti-idiotype" antibodies that resemble, antigenically, the original antigen. This series of interactions contin­ ues and results in a balanced network of stimulatory and suppressive interactions that control the immune system.

Time ---.-----·

Lymphoid Cell Development Another important concept in development of the immune sys­ tem is that it is not a linear process. Development of erythro­ cytes or neutrophils is normally characterized by a series of recognizable steps in maturation with no possibility of return to a more immature cell form or independent clonal expansion. This characteristic has served as the foundation for classifying myeloproliferative disorders. This is not true, however, for lym­ phoid cells. Both B cells and T cells develop in a 3 -dimensional manner (Figure 20-2 ) . This complex maturation can be simpli­ fied to a linear, recognizable morphologic pathway (Figure 20-3 ) . However, unlike myelocytes, developing lymphoid cells, b y the process of gene rearrangement, are able to program themselves to respond to a wide variety of antigens. This results in the appearance of clones of lymphocytes with the ability to recog­ nize and react to a specific antigen. Whenever these cells encounter that antigen, they are stimulated to begin a new round of proliferation and differentiation typical of the mature immune response, both cellular and humoral. This complex pattern of proliferation and differentiation makes it difficult to determine the history and future of a lym­ phoid cell simply from its morphology. For example, an acti­ vated, proliferating T-cell can be a cell that has never encountered antigen but is proliferating in the normal course of expanding the number of antigen-reactive cells. On the other hand, it may be a T-cell that has recently encountered antigen and is proliferating to give rise to programmed cytotoxic effec­ tor and memory cells. Or it may be a cell that has undergone an oncogenic mutation and is on the way to produce a lymphoma. In each case, we would call such a cell a blast, and the morpho­ logic, immunologic, and cytogenetic tools that we now have could not distinguish between the several possibilities. In order to clinically define the condition, whether benign or malignant, the entire pattern of the disease process must be examined.

FIGURE 20-2. Lymphocyte development. Both B and T cells develop along a mu ltidimensional pathway. On the first level is the continuous process of gene rearrangement, taking place i n lymphoid progenitors, which results in the genera­ tion of the diverse repertoire of the immune response. This process begins in the fetus and continues throughout life. As cells with new specificities arise. their devel­ opment moves to the level of antigen-independent clonal maturation, which results in the production of a clone of cel ls with the same specificity capable of recogniz­ ing a specific antigen. Although all of the cells of a given specificity will have the same antigen-receptor molecules, they may differ in other respects depending on their stage of maturation at this level. Finally, when the cells of a given clone encounter specific antigen, they begin to mature on a new level with the result that they give rise to both the fully differentiated cells of the immune system (plasma cells in the case of B cells, and effector T cells) and also to memory cells. As the antigen-driven clonal expansion fades, the memory cells survive and are capable of mounting a secondary response should antigen reappear

LY M P H O I D G ROWT H FAC TO RS Several growth factors (interleukins) that regulate the devel­ opment and function of lymphocytes have now been identified. The precise regulatory roles of each of the interleukins still need to be defined. It is apparent that they function in a complex and overlapping way to control lymphocyte development. In some cases, interleukins affect other cell lineages as, for example, the role of interleukin-3 in myelocyte and erythrocyte production. Thus, the descriptions that follow are not meant to be exhaus­ tive but simply to provide examples of the roles of some of these growth factors in cell development and function.

l nterleukin- 1 lnterleukin- 1 (IL- l ) is produced by several different cell types and has a wide range of effects as part of acute and chronic inflamma­ tion. For example, IL- l induces proliferation of thymocytes and

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Early B cell

Mat u re B cell

Early plasma cell

247

Plasma cell

N K cell CD?, (CDS), C D 1 6, CD56, (CD57)

CDS B cell C D 1 9, CD20, CD5

sl g(k!A.), dim

C D4 Peri pheral T cell

C D4 Thymocyte

C02, CD5 CD3, CD4,

TcR

CDS Peri pheral T cell

FIGURE 20-3 . Morphologic and phenotypic differentiation of B and T cells. The lymphocytic stem cell can differentiate along a B- or T-cell pathway, characterized by changes in morphology and cell phenotype. Surface markers can be helpful in diagnosing lymphoproliferative disorders, malignancies of the B- and T-cell lines, and immune deficiency states (slg, surface immunoglobulin; clg, cytoplasmic immunoglobulin) .

fibroblasts, activates osteoclasts to enhance bone reabsorption, increases levels of acute phase reactants, and activates neutrophils. It also stimulates the production of IL-2 by T cells and synergizes with myeloid growth factors to stimulate marrow stem cells.

l nterleukin-2 lnterleukin-2 (IL- 2 ) is the interleukin most clearly associated with lymphoid functions. It is produced by activated T cells and in tum stimulates the proliferation and differentiation of both T and B cells. It serves to amplify the immune response and is required for T-cell responses and the stimulation of NK cells. The measurement of IL-2 and its receptors has been used to monitor the activity of the immune system. Drugs and antibodies that inhibit IL-2 or block its receptors may play a role as immunosuppressive agents. On the other hand, IL-2 itself has been used therapeutically as an antitumor agent.

l nterleukin-3 lnterleukin-3 ( IL-3 ) i s a growth factor for B cells. It induces pro­ liferation of antigen-activated B cells, increases antibody syn­ thesis, and synergizes with IL-2 . It also stimulates the proliferation of T cells, predominantly of the CDS subtype. IL-3 plays a synergistic role in early myeloid and erythroid progeni­ tor proliferation and differentiation (see Chapters 1 and 1 6 ) .

Other l nterleukins Several other interleukins are now being investigated. lnter­ leukin-5 appears to induce B-cell maturation with its maj or

effect on IgA production. Its maj or clinical effect in humans is on eosinophil differentiation. lnterleukin-6 affects B-cell growth and differentiation but also stimulates the growth of hepatocytes and neurons. IL-6 plays a maj or role in regulating hepcidin expression as a part of the anemia of inflammation (see Chapter 4 ) lnterleukin-7 has stimulatory effects on early B cells and may affect lymphoid progenitors of both B- and T­ cell pathways. lnterleukin- 1 1 functions as a generalized hematopoietic growth factor and may have a role in throm­ bopoiesis. lnterleukin- 1 2 has potent stimulatory effects on lymphoid cells, especially cytotoxic T cells. It is being investi­ gated in the treatment of infectious disease, immunodeficiency, and autoimmunity. Both lymphocytes and myeloid cells are also capable of pro­ ducing interferons as a part of host defense. The interferons function as stimulators of T- and NK-cell function. At the same time, they have a suppressive effect on hematopoiesis, reducing red blood cell and white blood cell proliferation at the same time they stimulate cell functions such as cytotoxicity and phagocytosis. .

LY M P H O C Y T E A D H E S I O N MOLECU LES In addition to the growth factors, several adhesion molecules govern the migration, localization, and function of lymphocytes and other blood cells. These appear to fall into several families of related molecules (Table 20- 1 ) .

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TABLE 20- 1

•

Maj:>r families of adhesion molecules

Fami ly

Ligands

Functions

CD Numbers

Names

CD 56

N-CAM

CD 54

I-CAM I

CD3 1

PE-CAM

CD 58

LFA-3

LFA-2

T-cell signaling

C02

LFA-2

LFA-3

T-cell signaling

V-CAM

VLA-4

Cell-cell adhesion

Immunoglobulinlike

Cell-cell adhesion LFA- 1

Cell-cell adhesion On platelecs

lntegrins

pi family

CD29/49

VLA I -6

Collagen Fibronectin Laminin

Adhesion to matrix proteins

P2 family

CD I S/ I I

I-CAM I C3bi

Leukocyte adhesion Complement receptor

p3 family

LFA- 1 MAC- I p I 50,95

CD6 1 /5 I

Vitronectin

CD6 1 /4 1

Fibrinogen

Platelet-platelet adhesion

Selectins

CD62P

P-Selectin

Carbohydrate

Platelet-leukocyte adhesion

CD62E

E-Selectin

Carbohydrate

Leukocyte-endothelial cell adhesion

CD62L

L-Selectin

Carbohydrate

Lymphocyte-endothelial cell adhesion

I m mu noglobulin Super Fami ly The immunoglobulin (Ig) super family contains molecules that are structurally related to immunoglobulins. In general, these molecules appear to be involved with cell-cell adhesive inter­ actions, although in some cases they also serve as receptors for soluble complement components.

l ntegrins The integrins are a large family o f heterodimers with closely related structures. They derive much of their diversity from dif­ ferent combinations of the 2 component molecules, the a- and �-chains. They mediate interactions between cells and mole­ cules of the vascular subendothelium and serve as receptors for coagulation proteins such as fibrinogen and factor Vlll.

Selectins

cells within tissues. They play an essential role in the immune network, controlling lymphocyte circulation and their function in immune surveillance . They act as homing receptors to govern migration of lymphocytes into lymph nodes and Peyer patches. The L-Selectin molecule plays a role in the binding of lym­ phocytes to the high endothelial venules of lymph nodes. Another molecule, CD44, has been implicated in the preferen­ tial binding of gut-associated lymphocytes to the endothelium of Peyer patches. These molecules are expressed on mature migratory lymphocytes but not immature thymocytes or marrow lymphocytes.

B C E L LS

The selectins are molecules that are structurally related to lectins that bind to carbohydrates. They are involved in inter­ actions between leukocytes, platelets, and endothelial cells, playing a key role in granulocyte adhesion and egress from cir­ culation (see Chapter 1 6 ) .

Lymphocytes can b e characterized according t o their functional differentiation, surface phenotype, and gene rearrangement pat­ tern. Each of these needs to be considered when diagnosing an immune deficiency state or clonal malignancy.

Cad herins

A. Antibody Production

The cadherins are a family o f molecules that bind t o them­ selves. They appear to be involved largely in the interaction of

The principal role of the B cells in the immune system is to pro­ duce antibodies. Early in its development, the B cell acquires, by

Functional Differentiation

C HAPTER 20

N 0 R M A L L Y M P H 0 P 0 I E S I S A N D T H E LY M P H AT I C S Y S T E M

rearrangement of its immunoglobulin genes, the ability to make a specific antibody. It subsequently displays a small sample of this antibody on its surface ( about 1 00,000 molecules per cell ) . This antibody serves a s a n antigen receptor for the B cell. Whenever the cell encounters that antigen that binds to the receptor, it is stimulated to begin a process of differentiation leading to the conversion of the B cell into a plasma cell. The plasma cell is then a stable factory for manufacturing a constant amount of the same antibody for excretion. This capability of B cells to recognize antigen and respond with production of anti­ body is to some extent autonomous, although it is markedly influenced by interactions with T cells, which also recognize the same or closely related antigens. B-cell responses are augmented by the "helper" T cells and are suppressed by interactions with "suppressor" T cells.

B. Augmentation of the Immune Response Augmentation of the immune response involves several mech­ anisms. The antibody receptor of B cells can interact directly with antigen to trigger B-cell differentiation. B cells are also capable of internalizing some of the antigen and processing it in the same way that macrophages process antigen by digestion with proteases. The cell then re-expresses partially degraded and denatured antigen on the surface for recognition by T cells. Thus, B cells have an antigen-presenting function that stimu­ lates T-cell activity.

C. Maturation Sequence Once B cells are triggered by antigen, they undergo a maturation sequence leading to changes in class, but not specificity, of antibody they produce. Early in the immune response, B cells give rise largely to IgM antibodies. With maturation, there is an increase in the proportion of B cells producing IgG, IgA, and lgE. This occurs by a process called class switching that involves further alteration at the DNA level and by RNA splicing. The end result is production of memory B cells. These cells are capable of recognizing antigen upon re-exposure so as to give rise to an accelerated (secondary) immune response consisting of a mag­ nified production of lgG.

D. Tolerance to Antigens There are also defined mechanisms by which B cells fail to respond to a given antigen, that is, demonstrate "tolerance." A first mechanism is an active suppression of the response medi­ ated by T cells that recognize the same or similar antigen and actively suppress the response. A second mechanism is clonal deletion, in which all of the B-cell clones capable of interacting with antigen are destroyed. Suppression is the normal mechanism by which an organ­ ism prevents its immune system from responding to self-antigens. It is an active, continuous process that requires the proper func­ tioning of the immune network. A failure in network control gives rise to autoimmune disease. Immune deficiency or toler­ ance can also develop because of clonal deletion. It can result because of a lymphoid malignancy or following chemotherapy. This is not necessarily irreversible. The continuous process of regeneration of diversity by gene rearrangement at the level

249

of the lymphoid progenitor cells will eventually give rise to new clones capable of responding to specific antigens. Thus, no form of tolerance is likely to persist for the life of the patient.

Phenotypic Classification The normal sequence of maturation and phenotypic expression of B cells is illustrated in Figure 20-3. The listed antigenic mark­ ers are those that are most often used clinically in categoriz­ ing disease processes. There are many other markers that are not indicated because they are not unique or are of unknown significance.

A. Pre-8 Cell The earliest recognizable B cell, the pre-B cell, is recognized by the presence of cytoplasmic f.l heavy chain but no light chain, together with an absence of intact immunoglobulin on its surface. Its surface markers consist of CD 1 9 (but not CD20 ) , HLA-DR, CD34, and CD l O (CALLA ) . The cell also expresses the nuclear enzyme terminal deoxynucleotide transferase (TdT) , which may be one of the enzymes involved in the gene rearrangement process. This stage of B-cell maturation matches the level of cell development seen in the most common form of acute lymphoblastic leukemia.

B. Mature 8 Cell without Antigen As the B cell matures, it loses CD34 and TdT and acquires sur­ face immunoglobulin, first IgM alone and then lgM plus IgD. It also acquires CD 1 9 and then CD20. This process takes place in the marrow and in lymph nodes and spleen. It results in a mature B cell that has not yet been exposed to antigen with phenotypic markers of CD 1 9 , CD20, HLA-DR, sigM, and sigD. This is the most common B cell found in the lymphoid tissues of adults.

C. Mature 8 Cell with Antigen Once a B cell encounters antigen, it continues to express CD 1 9 and CD20, but expression o f surface immunoglobulin now includes IgM, IgG , IgA, or IgE. In addition, these cells can express any number of activation antigens. One antigen that has become of some importance in the classification of lym­ phomas (see Chapter 2 2 ) is CD23 , which serves as a receptor for the Fe portion of IgE and appears on some activated B cells. This variability in the normal response is reflected in the diver­ sity of phenotypes seen with B-cell lymphomas. For the pur­ poses of clinical diagnosis, the most consistent and reliable markers for mature B cells at any stage of development are CD 1 9 , CD20, and the expression of K- and A.-immunoglobulin light chains on the cell surface.

D. Plasma Cell Once B cells differentiate to become plasma cells, they devote nearly all of their synthetic energy to immunoglobulin produc­ tion and cease expression of other B-cell markers. Therefore, the best marker for plasma cells is the abundance of cytoplasmic immunoglobulin and the intense surface expression of CD38, an activation marker involved in signaling leading to activation and proliferation of lymphoid cells.

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COS-Positive B Cell

A maj or B-cell subset that does not fit easily into the sequence of B-cell development is characterized by the expression of CD5. This antigen is also expressed by T cells. CD5 -positive B cells are abundant in the fetus and represent 1 0%-20% of B cells in the adult. They express CD1 9 , CD20, sigM, and sigD much like conventional B cells. An expansion of this subset of B cells is associated with a production of autoantibodies in diseases such as rheumatoid arthritis and systemic lupus erythematosus. This is also the phenotype associated with chronic lymphocytic leukemia and mantle cell lymphoma.

Gene Rearrangement Pattern The lymphoid stem cell gives rise to the earliest recognizable B cell in the marrow, fetal liver, and spleen. This pre-B cell has already undergone the process of gene rearrangement of both its immunoglobulin heavy- and light-chain-variable regions. The rearrangement normally proceeds in an orderly fashion in which the cell rearranges each of its genes in sequence until it either produces a pair of functional heavy­ and light-chain genes or has failed. Because of the uncertain­ ties of splicing the rearranged DNA segments, there is a signif­ icant probability that some rearrangements will not give rise to functioning molecules. Even when it is successful, there is a good chance that the gene product will be slightly different from that encoded by the original germ-line gene sequences. This process of "generation of diversity" gives rise to an enor­ mous variety of different antibodies produced by the mature immune system. From a clinical point of view, studies of the gene rearrange­ ment pattern are important in diagnosing lymphoproliferative diseases. They can be used to answer 2 important questions: • •

Are the malignant cells B, T, or NK cells ? Do the cells belong to a single clone , which would strongly suggest malignancy ?

Although these questions can in part be answered using immunologic markers, they are more directly answered by ana­ lyzing the gene structure of the cells . Gene rearrangement is independent of the stage of maturation of the lymphocytes since it is the first defining event in a cell's life. In addition, gene rearrangement is unaffected by any of the later events in the life of the lymphocytes such as antigen exposure. Thus, it defines clonality in an irrefutable way. Recently, information about the genetic structure of malig­ nant B cells has begun to provide prognostic, as well as diagnos­ tic, information. It has been observed that some cases of chronic lymphocytic leukemia (CLL) have relatively un­ rearranged ( germ-line ) immunoglobulin heavy-chain genes ( 98%- 1 00% germ-line homology ) and thus most likely repre­ sent naive B cells that have not previously encountered antigen. This subset of CLL patients has a significantly worse prognosis than those patients in whom the heavy-chain genes have undergone significant somatic mutation (5 5 % ) in circulation are medium sized but are clearly larger than the typical small B lym­ phocyte, and each displays a prominent nucleolus. Such cells can be observed in advanced cases of CLL, but predominant pro­ lymphocytes in CLL signify transformation. The immunopheno­ type of de novo B-PLL cells differs from B-cell CLL by absence of CD23 , expression of FMC 7 , and strong expression of slg (Table 22-1 ) . Deletions of l l q23 and 13q14 with loss of the retinoblastoma gene are common. Treatment with combination chemotherapy, including alemtuzumab and purine analogs, gen­ erally result in incomplete and transient responses.

274

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C A S E H I S T O RY

Pa rt 3

The patient has the typical clinical and phenotypic presentation of B-cell CLL, compl icated by an associated autoimmune hemolytic anemia and, most likely, autoimmune thrombocy­ topenia In the absence of the associated autoimmune abnor­ malities, the patient would be categorized as Rai stage I or Binet stage B since the lymphocyte count is not greatly ele­ vated, nor is the lymphadenopathy striking. If the hemolytic anemia had not developed and brought this patient to medical attention, he might have had undiagnosed CLL for many years. However, in light of the anemia and thrombocytopenia, the patient is a Rai 3 or Binet C stage CLL with a poor prognosis. With typical findings in the blood, and evidence of a strong marrow response to the anemia, a bone marrow aspiration/biopsy is not necessary, but if carried out it would show extensive infiltration with small lymphocytes and likely erythroid hyperplasiaA lymph node biopsy is also not needed to confirm the diagnosis of CLL, unless transformation to a

T-Cell P rolymphocytic Leukemia T-cell prolymphocytic leukemia (T-PLL) presents in adults with very high counts of medium-sized lymphocytes, notable for their scanty cytoplasm, a convoluted nucleus with open chromatin, and a prominent central nucleolus. On examination, T-PLL patients typically have diffuse, bulky lymphadenopathy, hepatosplenomegaly, and skin infiltrates. Their immunopheno­ type is typical for a mature T cell (expressing CD3 , CD4, CDS , and CD7 ) . Most cases are CD4 +/CDS-, but some can express a CD4+/CD8+ or CD4-/CD8+ phenotype. Mutation in the ATM gene ( 1 1q23 ) is frequently observed, as well as TCLJ gene over­ expression. Clonality of the disease can be ascertained by study of the T-cell receptor genes or abnormal T-cell immunophenotyping. T-PLL is a very aggressive disease with median patient sur­ vivals of less than 10 months. Few treatments are effective. Among them, pentostatin, and more recently the monoclonal antibody, alemtuzumab, have provided high response rates, but unfortunately of short duration. Consolidation with high dose therapy and autologous stem cell support or allogeneic stem cell transplantation can improve the outcome in some patients.

A D U LT T- C E L L L E U K E M I A/ LY M P H O M A The adult T-cell leukemias share several clinical characteristics. Most striking is a propensity to involve the skin such that they are often included in a heterogeneous group of peripheral T-cell

more aggressive lymphoma is suspected because of rapid node enlargement or compression. If a node were biopsied in this case, the pathological diagnosis would be diffuse small cell lymphoma. This patient's immune hemolytic anemia and thrombo­ cytopenia should be treated with prednisone ( I mg/kg/d), transfusions if bleeding or cardiac failure is a problem, and folic acid supplementation. Simu ltaneous treatment of the CLL with chemotherapy is clearly indicated and shou ld help decrease the levels of anti-red cell/anti-platelet antibodies. I nitial therapy with chlorambucil alone or fludarabine in combination with cyclophosphamide to provide immuno­ suppression would be a good choice. Fludarabine as a sin­ gle agent is contraindicated due to reports of fatal exacerbation of hemolytic anemia. Combined therapy with rituxan can be effective, and in refractory patients splenec­ tomy can reduce both red cell and platelet destruction.

1ymphomas (see Chapter 23 ) . However, some of these cases will present with a leukemic picture and distinctive features.

C l i nical Features Adult T-cell leukemia/lymphoma (ATLL) was first described in Japan, where it represents the most common form of lymphocytic leukemia. Similar cases have now been recognized in the Caribbean, Great Britain, and worldwide. ATLL is associated with human T-cell leukemia virus- 1 (HTLV- 1 ) infection. Infection of T cells by this retrovirus results in a long period of latency, fol­ lowed by either their destruction or uncontrolled lymphocyte pro­ liferation in 1 %-3 % of infected patients. The clinical expression is highly variable. Some patients present with little more than lymphocytosis and/or chronic lymphadenopathy, while others fol­ low a more aggressive course with subacute leukemia, hypercal­ cemia, myeloma-like lytic bone lesions, and skin infiltrates. The morphology of the malignant cells in which the nuclear shape is typically "flowerlike" can make the diagnosis. Mycosis fungoides is due to an epidermal infiltration of mon­ oclonal CD4 + T cells, ofren with an associated leukemic T cell population. When the leukemia is prominent and the cells have a characteristic nuclear morphology ( ie, a folded or "cerebri­ form" nucleus ) , the disease is referred to as Sezary syndrome (Figure 22-4 ). Unlike ATLL, this cutaneous T-cell lymphoma is not associated with HTLV- 1 . Many patients with mycosis fungoides/Sezaty syndrome can present with exfoliative dermati­ tis or patchy plaque-like or nodular infiltration. Pruritis is a promi­ nent complaint and is usually constant and severe. Infection of

CHAPTER 22

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275

names, the most common of which are large granular lympho­ cytic (LGL) leukemia or T y-lymphocytosis. However, LGL lymphoproliferations constitute a heterogeneous group of disor­ ders, including transient or chronic benign LGL expansions and true T-cell LGL leukemias.

Cl i nical Features

FIGURE 22-4. Sezary cells. Lymphocytes with convoluted or cerebriform nuclei

(5ezary cells) in a patient with advanced mycosis fungoides/cutaneous T-cell lymphoma

the skin lesions is also common and can be life-threatening (see Chapter 23 ) .

Laboratory Studies Unlike B-cell CLL, there is no constant immunologic marker for ATLL T cells that indicates clonality. The cells express an activated mature T-cell phenotype, CD3/CD4/CD2S and are HLA-DR positive. One useful clue can come from examining sev­ eral different T-cell-associated markers. Normal mature CD4 • T cells also express C02, CDS , and CD7 , while a malignant T-cell population may lack one or more of these markers or express them in abnormal amounts. In addition, normal resting CD4 • T cells do not express HLA-DR or CD3S; intense expression of these acti­ vation markers may indicate that the cells are clonal. The defin­ itive test for clonality among the T-cell disorders is to examine for rearrangement of the T-cell receptor genes. Most malignant T cells will have a clonal rearrangement of the TCR-/3 and/or -y genes that can be detected either by restriction mapping and Southern blotting or by polymerase chain reaction (PCR).

Therapy The course of aggressive ATLL is almost always fatal, generally in the year after diagnosis. Some responses have been recorded with treatments combining recombinant interferon and zidovu­ dine. By contrast, cutaneous T-cell lymphoma with Sezary syn­ drome may respond to aggressive chemotherapy, photopheresis, or the combination.

e

LA R G E G RA N U LA R LY M P H O CYT I C L E U K E M I A

Occasionally, patients with what appears to be typical ATLL will prove to have a proliferation of CD3 • cos• T cells. These cases can be distinguished only by immunophenotyping, although leukopenia, especially neutropenia, may be clinically evident. This cos • T-cell disorder has been given various

LGL leukemia patients generally present with, at most, a mod­ est lymphocytosis together with granulocytopenia, aplastic ane­ mia, or pancytopenia. There is evidence that Cos• T cells are capable of directly inhibiting one or more aspects of hematopoiesis and that this gives rise to this unique clinical presentation. In contrast to B-cell CLL, where hematopoietic failure is not seen until there is extensive marrow infiltration with malignant cells, the offending cos• T cells may never be present in large numbers within the marrow during the course of LGL. Approximately 25% of LGL patients will also have pre­ existing systemic autoimmune disorders such as rheumatoid arthritis, lupus erythematosus, Sj ogren syndrome, or autoim­ mune cytopenias. In this setting, the presentation can be very similar to Felty syndrome.

Laboratory Studies The malignant cells ("large granular lymphocytes" ) resemble "atypical lymphocytes" of the type sometimes seen in infectious mononucleosis. They are larger than normal lymphocytes, with a more open chromatin pattern and a few prominent azurophilic granules in their cytoplasm. Marker studies show expression of the normal T-cell lineage markers CD3 and CDS. In addition, they typically express CDS 7 and activation markers such as HLA-DR and CD3S; some cases will aberrantly express the adhesion molecule CD 56. In some cases, cells have low or absent expression of the CDS that should be present on normal T cells. This morphology and phenotype are associated with acti­ vated cytotoxic T cells, which resemble and are sometimes con­ fused with CD3- NK cells because they share morphologic characteristics and markers such as CDS 7 . Gene rearrangement studies have shown definitively, however, that the cells are COY T cells. The entity of true natural killer NK-cell ( CD3CD16+ CD5 6 • ) leukemia is rare . Although morphologically very similar, NK leukemic cells do not show rearrangement of T-cell receptor genes and do not express CD3 . The presenta­ tion is much more acute, often with neurologic signs, and the course is much more aggressive.

Therapy The course of LGL leukemia is highly variable. Some patients appear to have little or no progression of the lymphoprolifera­ tive process and may only need to be treated for their anemia or granulocytopenia, whereas others have a more aggressive course resulting in progression to florid lymphoma and/or lymphocytic leukemia. Up to one-third of patients may require only support­ ive therapy, including hematopoietic growth factors, for anemia or recurrent infections owing to granulocytopenia. Others respond to single-agent treatment with methotrexate, cyclosporin, chlorambucil, or cyclophosphamide, with or without prednisone,

276

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or purine analogs. With transition to more aggressive disease, combination chemotherapy can be effective; however, the response rate is poor and brief in duration.

H A I RY C E L L L E U K E M I A Hairy cell leukemia (HCL) was named for its unusual cell mor­ phology. The malignant B lymphocytes have very long filamen­ tous cytoplasmic projections that are sometimes difficult to see in dried stained films but are prominent in wet mounts observed by phase microscopy. HCL has also been called "leukemic retic­ uloendotheliosis," perhaps because of the tendency for the malignant cells to infiltrate the marrow, liver, and spleen.

C l inical Features Like many of the chronic lymphoid neoplasms, this disorder occurs most commonly in adults and frequently has a unique clinical presentation characterized by extensive marrow involvement with pancytopenia and prominent splenomegaly. Lymphadenopathy is uncommon and should make the diagno­ sis of HCL questionable. It is more often seen in males than females ( 4 to 5 : 1 ) .

A

Laboratory Studies The so-called "hairy" cell has been the subject of considerable investigation. Some HCL cases have cells with properties of both lymphocytes and macrophages in that they can be mildly phago­ cytic and have markers associated with macrophages. Careful marker studies, gene rearrangement, and microarray studies have shown, however, that they are mature clonal B cells. A normal counterpart of hairy cells has not been identified, and the onco­ genic process that results in the development of the disease is unknown. The most useful markers for hairy cells, in addition to the usual lineage-specific B-cell markers (CD 1 9 , CD20, and a single light chain ) , are the absence of CDS , CDlO, and CD23 , and the strong presence of CD l l c, CD22, and CD 103 . Patients with HCL often present with mild t o moderate pancy­ topenia. The number of abnormal lymphocytes in circulation is often low, and automated cell counters class the cells as normal lymphocytes. A careful inspection of the blood film is, therefore, mandatory to detect the classic hairy cell (an intermediate-sized lymphocyte with a large nucleus and filamentous projections of cytoplasm; Figure 2 2-5 ) . Cytochemistry, specifically the tar­ trate-resistant acid phosphatase stain (see Figure 22-5 ) , can be used to confirm the presence of hairy cells in circulation, with characteristic polar brownish-red deposits surrounded by unstained cytoplasm. Cytochemistry, however, has largely been supplanted by immunophenotyping for clonal CD1 1c• CD 103 + B cells. Variant HCL is defined by its presentation with elevated white counts and large numbers of leukemic cells; variant disease is more aggressive. The diagnosis of HCL can also be made on the histology of the marrow or spleen. When the marrow is infiltrated by hairy cells, it usually cannot be aspirated because the cells tend to adhere to marrow structural cells. A marrow biopsy specimen will reveal a typical morphologic pattern, characterized by a

B

FIGURE 22-5. Hairy cell leukemia. A: Hairy cells in peripheral blood (clonal

CD I 03 • B cells) demonstrate their characteristic filamentous cytoplasm. B: Polar stai ning (red-brown) for acid phosphastase is seen i n the cytoplasm ofT-cell lymphoma cells; this staining is tartrate-resistant in hairy cell leukemia B cells.

diffuse infiltration with each cell nucleus separated by a large, clear cytoplasmic area, the so-called "fried egg" appearance. This is very different from the diffuse infiltration of small lympho­ cytes seen in B-cell CLL.

Therapy The outlook for patients with HCL has changed dramatically over the last 2 decades. Until the mid 1 980s, HCL was a lethal disease. Most of the patients experienced infectious complica­ tions from which they died within 5 years after diagnosis. Cur­ rently, when recognized early and rreated effectively, HCL is an indolent disorder with survival exceeding 80% at 5 years. HCL responds very well to therapy with interferon, with complete or partial response rates of about 80% but without evi­ dence for cure. Even higher complete remission rates and pro­ longed relapse-free survival are obtained with pentostatin ( deoxycoformycin) and with 2-CdA. Fludarabine has shown similar results and has been effective in patients who have failed

CHAPTER 22

LY M P H O C Y T I C L E U K E M I A & LY M P H O P R O L I F E R AT I V E D I S E A S E S

treatment with other agents. Anti-CD20 monoclonal antibody ( rituximab) has also demonstrated some efficacy in HCL. Purine analogues are now preferred to interferon as initial therapy, despite the depletion of CD4 cells, which can take as long as 1 year to replenish. Overall survival is 80%-90% at 5 years for each of these drugs, even with the variant form of HCL. Given the low incidence of the disease, and the reduced death rates with these treatments, it will be virtually impossible to determine if one of the agents can provide substantially longer survival. Moreover, patients who relapse or are refractory can successfully move from one drug to another or may respond to rituximab, obscuring the impact of each drug on survival. Prior to the use of these drugs, splenectomy was considered the initial therapeutic step owing to a high frequency of appar­ ent remissions. Splenectomy is now considered only as a pallia­ tive option in patients with massive splenomegaly or severe hypersplenism. If the patient is not a candidate for surgical splenectomy, splenic irradiation is an alternative.

P O I N T S TO R E M E M B E R B-cel l chronic lymphocytic leukemia (B-CLL) is the most common lymphoprol iferative disease in Western countries. B-CLL occurs predominantly in the elderly and frequently presents with little more than an elevated l ymphocyte count and modest lymphadenopathy. Diagnosis is relatively easy based on the clin ical picture and immunophenotype. With disease progression, B-CLL patients are at risk for autoim­ mune complications (hemolytic anemia, thrombocytopen ia) and recurrent infections secondary to hypogammaglobu linemia.

277

B-CLL can transform to a more aggressive large cell lymphoma with splenomegaly (Richter syndrome) or even to an aggressive prolym­ phocytic leukemia, with both entities preserving their CD 1 9 + cos• CD23+ dim surface lg immunophenotype. De novo B-cell prolym­ phocytic leukemia lacks CD23 and strongly expresses surface lg. Younger patients with CLL should be studied for lgV H ' CD38, and ZAP-70 expression to determine if their disease fits a more aggres­ sive genotype. B-CLL responds wel l to chemotherapy, although even a complete response/remission does not translate into a prolonged su rvival. Only allogeneic bone marrow transplantation can achieve cure and is reserved for young patients with a matched sibling donor. T-cell leukemias are much less common than B-CLL in the United States and Europe.ATLL is a CD4+ T-cell neoplasm with an aggres­ sive course and associated with HTLV- 1 infection. Other CD4 •T-cell malignancies most often present as a more indolent infiltrative skin disease (cutaneousT-cel l lymphoma/mycosis fungoides) without sig­ nificant lymphadenopathy, but patients can have leukemic presenta­ tions (Sezary syndrome). CD3+ CDB+ CDSJ+ T-cell (large granular lymphocytic) leukemia classical ly presents with pancytopen ia, secondary to marrow depression of other hematopoietic lines. LG L leukemia is often associated with preexisting autoimmune disease. Like all T-cell neo­ plasms, large granular lym phocytic leukemia is confi rmed to be clonal ifT-cell receptor studies show gene rearrangement. Hairy cell leukemia is a B-cell lymphoma that presents in the eld­ erly with pancytopenia and splenomegaly and relatively few hairy cells in the blood. Thus, a high degree of suspicion may be needed to make the diagnosis by classic CD I I c/CD I 03 immunophenotyp­ ing. Hairy cell leukemia responds very wel l to chemotherapy with purine analogues, making early diagnosis critical.

B I B L I O G RA P H Y Bartlett NL, Longo DL: T-small lymphocyte disorders. Semin Hematol 1 999;36: 1 64. Binet JL, Caligaris-Cappio F, Catovsky D, et al: Perspectives on the use of new diagnostic tools in the treatment of chronic lymphocytic leukemia. Blood 2006; 107:859. Catovsky D, Richards S, Matures E, et al: Assessment of flu­ darabine plus cyclophosphamide for patients with chronic lym­ phocytic leukaemia (the LRF CLL4 Trial ) : a randomised controlled trial. Lancet 2007 ;3 70:230. Diamandidou E, Cohe PR, Kurzock R: Mycosis fungoides and Sezary syndrome. Blood 1 996;88:2385. Dighiero G , Hamblin TJ : Chronic lymphocytic leukaemia. Lancet 2008;3 7 1 : 1 0 1 7 . Doehner H , Stilgenbauer S, Benner A , e t al: Genomic aber­ rations and survival in chronic lymphocytic leukemia. N Eng! J Med 2000;343 : 1 9 10.

Dungarwalla M, Matures E, Dearden CE: Prolymphocytic leukaemia of B- and T-cell subtype: a state-of-the-art paper. Eur J Haematol 2008;80:469. Eichhorst BF, Busch R, Hopfinger G , et al: Fludarabine plus cyclophosphamide versus fludarabine alone in first-line therapy of younger patients with chronic lymphocytic leukemia. Blood 2006; 107 :885 . Gale RP, Cozen W, Goodman MT, Wang FF, Bernstein L. Decreased chronic lymphocytic leukemia incidence in Asians in Los Angeles County. Leuk Res 2000;24:665 . Ghia P, Stamatopoulos K, Belessi C, et al: Geographic pat­ terns and pathogenetic implications of IGHV gene usage in chronic lymphocytic leukemia: the lesson of the IGHV3-2 1 gene. Blood 2005 ; 1 05 : 1 678. Golomb HM: Hairy cell leukemia: treatment successes in the past 25 years. J Clin Oncol 2008;28:2607.

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Hallek M, Cheson BD, Catovsky D, et al: Guidelines for the diagnosis and treatment of chronic lymphocytic leukemia: a report from the International Workshop on Chronic Lympho­ cytic Leukemia ( IWCLL) updating the National Cancer Guide­ lines Institute-Working Group (NCI-WG ) 1 996. Blood 2008; 1 1 1 :5446. Hamblin TJ et al: Unmutated IgVH genes are associated with a more aggressive form of chronic lymphocytic leukemia. Blood 1 999;94: 1 848. Hillmen P, Skotnicki AB, Robak T, et al: Alemtuzumab com­ pared with chlorambucil as first-line therapy for chronic lym­ phocytic leukemia. J Clin Oncol 2007 ; 2 5 : 5 6 1 6 . Hoffman M A : Clinical presentation and complications of hairy cell leukemia. Hematol Oncol Clin N Am 2006; 20: 1 065. Lamy T, Loughran TP: Clinical features of large granular lym­ phocyte leukemia. Semin Hematol 2003 ;40: 1 85 . Matutes E: Adult T-cell leukemia/lymphoma. J Clin Path 2007;60: 1373.

Matutes E: Immunophenotyping and differential diagnosis of hairy cell leukemia. Hematol Oncol Clin N Am 2006;20: 1 05 1 . Mayr C , Speicher MR, Kofler DM, e t al: Chromosomal translocations are associated with poor prognosis in chronic lym­ phocytic leukemia. Blood 2006; 1 0 7 : 742. Rawstron AC, Bennett FL, O'Connor SJ M, et al: Mono­ clonal B-cell lymphocytosis and chronic lymphocytic leukemia. N Eng! J Med 2008;3 5 9 : 5 7 5 . Shanafelt T D , Geyer SM, Kay NE: Prognosis a t diagnosis: integrating molecular biologic insights into clinical practice for patients with CLL. Blood 2004; 1 03 : 1 202. Taylor G: Molecular aspects of HTLV- 1 infection. J Clin Path 2007 ;60: 1392. Thomas DA et al: Rituximab in relapsed or refractory hairy cell leukemia. Blood 2003 ; 1 02:3906.

N O N - H O D G KI N LY M P H O M AS

rl ,.._.

A

C A S E H I S T O RY

The non-Hodgkin lymphomas (NHLs) are disorders charac­ terized by malignant proliferation of B or T lymphocytes. From a clinical standpoint, lymphomas generally present as tumors of the lymphoid system-the lymph nodes, Waldeyer ring, spleen, blood, and marrow. However, since lymphocytes by their nature are heterogeneous and have access to nearly every anatomic site, the NHLs may present with involvement of any organ, includ­ ing the central nervous system. With advances in clinical and pathological staging techniques, the ability to accurately diagno­ sis a specific NHL disorder and predict the course of the disease in an individual patient has greatly improved. It has also made it possible to plan an optimal course of treatment. The etiological mechanisms involved in lymphomagenesis are yet to be fully understood. Environmental factors, including radiation, chemical exposures, and both viruses and bacteria (human T-cell lymphotrophic virus type 1 [HTLV- 1), hepatitis C

2

J

Pa rt I

46-year-old man seeks evaluation of a non-tender mass that he recently d iscovered in his left axil la. H e notes that it seems t o have been enlarging rapidly over the past 3 weeks. He is otherwise feeling well, with no weight loss, fever, or c h i l ls, and has no sign ificant past medical history, nor any fam i ly h istory of hematologic disease. On examination, in addition to the 5-6 em mass that the patient noted, multiple 1 - to 2-cm lymph nodes are found in both axil lae and in the cervical region. All of these are

•

non-tender, mobile, and rubbery in textu re. There is no hepatosplenomegaly or palpable abdominal masses; the only other finding of significance is the presence of mild bilat­ eral pitting edema in the lower extremities. The patient's complete blood count (CBC) is entirely normal; no abnormal cells are noted on examination of the blood smear.

Question •

What diagnostic procedures are indicated/

virus [H CV) , Epstein-Barr virus, Helicobacter pylori, and Campy­ lobacter jejunii) clearly play a role in many of the NHL subtypes. Genetic predisposition is also a major factor. This is best illus­ trated by the recurrent genetic abnormalities observed in NHL disorders, including translocations or mutations involving proto­ oncogenes, signal transduction factors, cell cycle regulation, and apoptotic pathways. Epigenetic factors are almost certainly another important etiological mechanism in NHL. The importance of accurate diagnosis and effective manage­ ment of lymphomas has been heightened by their increasing incidence, the association of lymphomas with immune defi­ ciency states, and concomitant improvements in therapy. The incidence in Western countries has more than doubled in the last 20 years not only because of the association of B-cell lym­ phomas with AIDS, but also likely due to greater exposure to chemical agents in the environment.

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NHL in general is very responsive to therapy, and in most cases the physician can offer the patient with NHL both improved survival and quality of life. It is a paradox that the NHL patient with the most aggressive form of the disease can actually be offered the possibility of a cure, whereas the patient with indolent lymphoma may never be cured despite a relatively long survival. Because lymphoma cells tend to be very mobile, silently involving not only lymphoid organs but nearly every part of the body, the concepts of staging, remission, and relapse are far more fluid than with solid tumor malignancies. With increasingly sen­ sitive means of detecting lymphoma cells , it is frequently pos­ sible to demonstrate their presence throughout the body in patients previously thought to have localized disease. Similarly, it is frequently possible to detect lymphoma cells in patients who appear by usual criteria to be in complete remission. Patients with NHL will sometimes undergo prolonged periods of quies­ cent disease punctuated by periods of increased disease activity. In general these patients must be followed up carefully, with a constant suspicion that minor symptoms may indicate progres­ sion or relapse.

D I AG N O S I S Ultimately, a diagnosis of NHL depends on finding clonal lym­ phoid cells that are destroying the normal architecture of the lymphoid tissues or invading non-lymphoid tissues, or both. Detection of lymphoma in its early stages can be more of a chal­ lenge. lt is difficult, probably impossible, to recognize a single lymphocyte as malignant based on morphology alone, because normal lymphocytes are capable, through dedifferentiation, pro­ liferation, and differentiation in the course of a normal immune response, to display morphological changes mimicking malig­ nancy. A reactive lymph node contains activated lymphocytes that look as malignant as any lymphoma cell. Thus, in order for one to accurately diagnose lymphoma, an adequate tissue biopsy is absolutely required to display a large area of cells for collective morphology. Lymphoma can be suspected on the basis of cytologic examination of blood, marrow, effusions, and aspirates, but the physician should always make every attempt to obtain a good surgical biopsy of involved lymphoid or non-lymphoid tissue in order to be certain of the diagnosis. When multiple sites are available for biopsy, one should avoid those sites where nor­ mal reactive nodes are frequently found, such as the groin and the axilla. The surgical biopsy should always be considered as the first step of the pathology workup, in order to provide to the patholo­ gist optimal samples for an accurate diagnosis. With the availability of immunologic and genetic tests for clonality, one can make a strong presumptive diagnosis of lym­ phoma on the basis of the finding of clonal and immunopheno­ typically abnormal lymphocytes involving multiple sites, such as marrow and blood, but the finding of clonality does not absolutely prove malignancy, and clonality alone yields no infor­ mation regarding prognosis. Therefore, a diagnosis based solely on these criteria should be viewed with caution, and tissue con­ firmation should always be sought, if possible.

C LA S S I F I C AT I O N Over the years, several different classifications of lymphomas­ the Rappaport, Lukes-Collins, and Lennert classifications, and subsequently the International Working Formulation-have been proposed as guides to the classification and treatment of the non-Hodgkin lymphomas. These systems were based almost entirely on morphologic criteria. The Working Formulation was an advance because it emphasized the clinical behavior of the various lymphomas, grouping them into low, intermediate, and high grades based on their clinical aggressiveness. Inclusion of immunological and genetic characteristics have allowed better definition and revealed new entities, as described in the Revised European American Classification (REAL), and most recently in the consensus classification sponsored by the World Health Organization (WHO), which closely follows the REAL system. The WHO classification is summarized in Table 23- 1 .

TABLE 23- 1

•

Lymphoma classification

B-Cell Neoplasms

T-Cell and N K-Cell Neoplasms

Precursor B-cell neoplasms

Precursor T-cell neoplasms

B lymphoblastic leukemia/ lymphoma

T lymphoblastic leukemia/ lymphoma Blastic N K!T lymphoma

Mature B-cell neoplasms

Mature T-cell neoplasms

CLUsmall lymphocytic lymphoma B-cell prolymphocytic leukemia Lymphoplasmacytic lymphoma Splenic marginal zone lymphoma Hairy cell leukemia Plasma cell myeloma Solitary plasmacytoma of bone Extra-osseous plasmacytoma Extranodal marginal zone B-cell lymphoma of mucosa-associated tissue (MALT) Nodal marginal zone B-cell lymphoma Follicular lymphoma Mantle cell lymphoma Diffuse large B-cell lymphoma Mediastinal (thymic) large B-cell lymphoma Intravascular large B-cell lymphoma Primary effusion lymphoma Burkitt lymphoma/leukemia

T-cell prolymphocytic leukemia T-cell large granular lymphocytic leukemia Aggressive N K-cell leukemia Adult "f. cell lymphoma/leukemia Extranodal N K!T-cell lymphoma, nasal type Enteropathy-type T-cell lymphoma Hepatosplenic T-cell lymphoma Subcutaneous panniculitis-like T-cell lymphoma Mycosis fungoides Sezary syndrome Primary cutaneous anaplastic T-cell lymphoma Peripheral "f. cell lymphoma, unspecified Angioimmunoblastic "f.cell lymphoma

B-cell proliferations of

T-cell proliferations of

uncertain malignant

uncertain malignant

potential

potential

Lymphomatoid granulomatosis Post-transplant Jymphoproliferative disorder, polymorphic

Lymphomatoid papulosis

C H APT E R 2 3

N O N - H O D G K I N LY M P H O M A S

281

Frequencies of non-Hodgkin lymphoma subtypes in the United States

TABLE 23-2

•

Diagnosis

Frequency (%)

Diffuse large B-cell lymphoma

31

Follicular lymphoma

22

Marginal zone B-cell lymphoma, MALT type

8

Peripheral T-cell lymphoma Small lymphocytic lymphoma Mediastinal large B-cell lymphoma

7 6 6

Mantle cell lymphoma

6

Anaplastic T-cell lymphoma

2

Lymphoblastic lymphoma

2

Burkitt-like lymphoma

2

Paracortex

-T cells

Medullary cords

cells -Macrophages -Plasma cells -8

Marginal zone B-cell lymphoma Lymphoplasmacytic lymphoma Burkitt lymphoma

1 00,000/!!l•

Age 1 - 1 0 y

less than I y or > 1 0 y

Females

Males•

No or asymptomatic CNS

Overt CNS involvement• Mediastinal mass•

Pre-8 cell phenotype

T-cell phenotype (children)• Non-Caucasian

Hyperdiploidy, t( I 2;2 I ), t( I ; I 9), t(S; I 4) HOX I I overexpression

Hypodiploidy, t(9;22), t(4; I I )

•These factors are probably not independent because they tend to be seen together. Note: Of the risk factors listed, WBC count and age are clearly inde­

pendent and are by far the most significant.

FIGURE 25-2. lymphoblasts in All. A: Lymphoblasts in a patient with T-cell All; note the characteristic ''hand-mirror'' shape. B: Lymphoblasts in the marrow

therapy with rising counts, thereby declaring themselves as hav­ ing ALL. Even the best hematologist or hematopathologist cannot always distinguish ALL from AML by cellular morphology alone. Histochemical stains ( ie, peroxidase, combined esterase, PAS, and TdT stains ) can be very helpful. The ALL blast should be peroxidase and esterase negative; PAS positivity is constant only in the L3 subtype. Primitive blasts will show positive TdT staining. Histochemistry can be confusing or equivocal, how­ ever, especially in adults. Currently, a reliable distinction between ALL and AML depends much more on immunopheno­ typing and cytogenetics than on morphology or histochemistry.

of a B-ALL patient; note the prominent nucleoli in many of the cells.

C. lmmunophenotyping and Genetic Analyses cells, some of which may have the distinctive "hand-mirror" shape of a T-cell ALL (Figure 25-2A ) . Counts in excess of 1 00,000/J.lL, which are most often associated with T-cell ALL, can be seen (Table 25-3 ). At the same time, up to 30% of cases present with a normal or low total WBC count, again with a dif­ ferential comprised mostly of lymphocytic morphology. Neu­ tropenia is usually present and, in patients with very high lymphoblast counts, granulocytes may be undetectable. Anemia and thrombocytopenia are variable in degree but are nearly always present. 8.

Blood Film and Marrow Aspirate

The marrow aspirate is usually diagnostic, showing massive replacement of normal marrow by a uniform population of lym­ phoblasts (Figure 25-28 ) . The marrow can be so packed that aspiration is unsuccessful and a biopsy is required. Rarely, the ini­ tial marrow may show hypoplasia or aplasia, suggesting an aplas­ tic anemia. Usually, these patients will respond to glucocorticoid

Immunogenetic studies are absolutely essential in distinguish­ ing B- and T-cell ALL and in classifying the subtypes of ALL ( see Tables 25-1 and 25-2 ) . Cytogenetics and immunopheno­ typing must be obtained early in the diagnostic workup when blasts are abundant. Once therapy is initiated, these studies may be difficult to perform or impossible to interpret. Initial pheno­ typic and genotypic characterization of the malignant clone is also likely to be critical for the subsequent detection of minimal residual disease and possible relapse after induction and mainte­ nance therapy. Residual malignant cells can be detected with all of these highly sensitive procedures, including immunophenotyping and ploidy analysis, detection of fusion gene transcripts (eg, t[4; 1 1] ) , karyotyping, and immunoglobulin o r TCR gene rearrangement.

D. Other Laboratory Abnormalities The other laboratory abnormalities that are associated with ALL include hypogammaglobulinemia, elevated lactic dehydrogenase (LDH) and uric acid levels, and a variety of electrolyte abnormal­ ities such as hyperphosphatemia, hypocalcemia, and hyperkalemia.

C H APT E R 25

Both the hyperphosphatemia and hyperkalemia can worsen dra­ matically during initiation of therapy when large numbers of leukemic blasts are lysed (tumor lysis syndrome) . E.

Studies to Detect Tumor Growth

Although the level of the peripheral WBC count and the height of the LDH level provide a sense of the patient's tumor burden, a careful search should be made for node-based tumor masses. This search should include an examination of the patient for lymphadenopathy and splenomegaly and a chest x-ray to look for a mediastinal mass. Any ALL may demonstrate significant adenopathy, and in fact, most ALL is now classified (both B- and T-cell) as acute lymphoblastic leukemia/lymphoma since either presentation is considered to be similar in terms of management and prognosis. A large mediastinal mass is seen in up to 50% of cases of T-cell ALL. If a biopsy is done, it usually shows the presence of lym­ phocytes identical to those found in marrow and blood and most typical of the cell type seen in primary lymphoblastic lym­ phomas. In fact, some children will present initially with a medi­ astinal tumor, without evidence of leukemia in the blood or marrow. However, such patients will usually demonstrate overt ALL within a short period. Cerebrospinal fluid examination is usually performed as soon as the blast cells have disappeared from the peripheral blood, usually a week after starting the induction therapy. Although infrequent at presentation, CNS infiltration is more likely when patients display cranial nerve palsies or retinal infiltrates, what­ ever the results of cerebrospinal fluid examination. On the other hand, CNS infiltration can be found even in asymptomatic patients, when blast cells and/or elevated protein are observed in the cerebrospinal fluid. Recently, overexpression of IL- 1 5 has been shown to be predictive of CNS infiltration.

C A S E H I S T O RY

AC U T E LY M P H O C Y T I C L E U K E M I A

D I AG N O S I S A diagnosis of ALL is usually easily made in children. It is the dominant form of acute leukemia. When children present with a very high peripheral lymphoblast count, coupled with modest lym­ phadenopathy and splenomegaly, there is almost no chance that it can be confused with AML. If there is a question, histochemical stains and immunophenotyping studies will confirm the diagnosis. In adults where ALL is an unlikely diagnosis, it can be more difficult to distinguish ALL from AML. Immunopheno­ typic marker studies are essential because morphology and his­ tochemistry frequently do not clearly make the distinction. Some ALL cases will express a single aberrant myeloid antigen, and the occasional case of AML will have blasts that aberrantly express at least ! lymphoid marker, usually CD7 . The predomi­ nant antigenic markers will usually serve to classify the leukemia, but in the occasional case, the final diagnosis will require molecular or gene rearrangement studies. In addition, cytogenetic studies will often reveal abnormalities typical of either ALL or AML. Other forms of lymphoma, parricularly hairy cell leukemia, prolymphocytic leukemia, and Sezary cell leukemia, are unlikely to be confused with ALL. When the overall clinical picture of these diseases is considered, the morphology, clinical character­ istics, and the presence of mature lymphoid markers should make the distinction (see Chapter 2 2 ) . A few non-lymphoid tumors may be confused with ALL. Neuroblastoma and rhab­ domyosarcoma in children and Ewing sarcoma and small cell lung cancer in adults can have the morphologic appearance of ALL. ln each case, however, immunophenotypic markers should clearly show that these cells do not belong to either the lym­ phoid or myeloid lineages. Moreover, gene rearrangements typ­ ical of lymphoid cells will not be present.

Pa rt 2

This patient clearly has a leukemic process. The important decision to be made is the nature of the leukemia. Flow cytometric phenotyping of both blood and marrow is indi­ cated and a marrow sample should be collected for cyto­ genetics and molecular studies. Radiological examination should include evaluation of both the chest and abdomen by computed tomography (CT). The possibility of CNS involvement should be addressed by examination of cere­ brospinal fluid (CSF), including phenotyping any cells found. I n this patient, the bone marrow aspirate shows nearly total replacement of the marrow by a uniform population of blast cells (see Figure 25-2B), which when phenotyped are clearly early pre-B cells (CD34+, CD I 9+, C o l O+, CD2r, CD2o-, CD79a+, H LADR +, and negative for all T-cell

315

markers). Malignant pre-B cells may also demonstrate an abnormal CD38+/CD58+ phenotype that differs from nor­ mal hematogones. Cytogenetics shows hyperdiploidy (DNA index 1 .2 1 by flow cytometry) but with no specific translocation identified. The chest CT is normal. The abdominal CT confirms the presence of mild splenomegaly and suggests retroperitoneal adenopathy. The CSF shows increased numbers of large lymphocytes with the identical phenotype as the marrow blasts with nor­ mal protein and negative cultures. =

Questions • •

What risk category does this patient fit into? What initial therapeutic interventions are indicated?

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WHITE BLOOD CELL DISORDERS

Activated normal lymphoid cells can closely resemble leukemic lymphoblasts morphologically. Reactive lymphocyto­ sis, as seen in conditions such as infectious mononucleosis, can present with large numbers of atypical lymphocytes and, to the less sophisticated eye, be mistaken for ALL. If confusion arises, bone marrow examination and immunophenotyping will also show that reactive lymphoblasts consist of different cell types and have a mature phenotype. For example, the atypical lym­ phocytes of infectious mononucleosis are predominantly mature CDS T cells. If necessary, genetic studies will confirm that the gene rearrangements present in reactive lymphocytes are poly­ clonal, not monoclonal, thus ruling out leukemia.

e

T H E RA PY A N D C L I N I C A L C O U RS E

Soon after diagnosis, ALL must be treated with an intensive multidrug regimen that has a high probability of inducing remis­ sion. Several drugs have activity in this disease, and they are used in various combinations. Most institutions have treatment protocols that use varying drug combinations, doses, and treat­ ment schedules based on internationally accepted risk factors. Currently, the Children's Oncology Group recognizes 4 initial treatment groups based on age, WBC, and immunophenotype. They are T cell; infant; high-risk B precursor; and standard-risk B precursor. Treatment regimens specific to these groups are being studied. For example, T-cell ALL shows greater sensitiv­ ity to asparaginase and relative resistance to methotrexate, com­ pared with B-ALL. The drugs commonly used to treat ALL are listed in Table 25--4.

Rem ission I nduction Remission induction needs to be preceded by steps to avoid

hyperuricemia) , resulting from the rapid desrruction of a very large blast population. Hyperuricemia can result in acute renal failure, while hyperphosphatemia induces calcium precipitation with a risk of hypocalcemia and tetany. Prevention of hyper­ uricemia is accomplished by aggressive diuresis, alkalinization of urine, and allopurinol ( Smg/kg/d) usually for 8-1 0 days. Rasburi­ case (0.20 mg/kg/d) can help to reduce a threatening hyper­ uricemia even more quickly. The threat of hyperphosphatemia is reduced by hydration with large amounts of intravenous fluids. Treatment protocols often start with prednisone alone for a week. This will allow one to assess prednisone sensitivity, which is an important prognostic factor. For induction, the most potent chemotherapy agents are vincristine, daunorubicin, asparaginase, cytosine-arabinoside, and cyclophosphamide (see Table 25--4 ) . Induction therapy results i n myelosuppression with a pro­ longed period of pancytopenia, requiring intensive support (see Chapter 1 8 ) . Recovery of normal hematopoiesis cannot be expected for 3--4 weeks. Follow-up examination of marrow should be done at 2 weeks with careful evaluation of immunophenotypic markers, ploidy, and genetics to confirm the disappearance of malignant cells. Persistence of lymphoblasts in the bone marrow 1 -2 weeks after starting chemotherapy generally predicts a treatment failure, and is an indication to initiate salvage therapy without waiting for recovery of normal hematopoiesis. Hematologic remission is defined by full recovery of a normal blood and bone marrow. It is frequently difficult to assess remission in the bone marrow dur­ ing the early recovery phase because of the hypocellularity and the presence of variable numbers of immature but reactive nor­ mal cells. Therefore, the detection of even a few remaining blast cells by immunophenotyping is now considered of paramount importance in predicting long-term survival. Current induction treatments provide complete remission rates as high as 95% in children and 85% in adults.

tumor lysis syndrome (hyperphosphatemia, hypocalcemia, and TABLE 25-4

•

Chemotherapeutic regimens for ALL Usual Dose and Route

Major Toxicities

Vincristine

2 mg/m 2 IV weekly

Neuropathy

Prednisone

40 mg/m 2 PO daily

Psychosis, hypertension, ulcer

500 J U/m 2 IV daily JO d

Allergic reaction

Daunorubicin

30--60 mg/m 2 IV daily x 3 d

Myelosuppression, cardiotoxicity

Methotrexate

I 5-25 mg/m 2 various schedules

Myelosuppression

6-Mercaptopurine

90 mg/m 2 PO daily

Myelosuppression

Cyclophosphamide

1 00 mg/m 2 PO daily

Myelosuppression

Cytosine arabinoside

I 00 mg/m 2 IV or SC daily

Myelosuppression

Asparaginase

X

Prophylactic Treatment of the Central Nervous System Once remission has been achieved, it is important to treat sites potentially harboring previously undetected leukemic cells that may have escaped eradication. The most common site is the CNS. Although overt CNS involvement is unusual at pres­ entation, about 50% of patients will relapse in the CNS within 2 years if not specifically treated. Other sites include the testes and the ovary, although these are much less common. There­ fore, a second requirement of therapy is the prophylactic treat­ ment of the CNS. Prophylactic CNS irradiation delivering 18 Gy for standard­ risk patients and 25-28 Gy for high-risk patients has been proven to be very effective. However, irradiation has been asso­ ciated with early and late CNS toxicity, such as leukoen­ cephalopathy, meningioma, and neurocognitive defects. Thus, intrathecal therapy, most commonly with methotrexate, cytara­ bine, and hydrocortisone, is currently used with limited irradia­ tion aiming at a reduction of the CNS radiation dose. Boys must be followed with careful physical examination of the testes to

CHAPTER 25

detect any masses that may indicate relapse. If masses are sus­ pected, this should be confirmed with biopsy and then treated with local irradiation followed by reinduction chemotherapy.

Post-I nduction Therapy Further treatment once remission is obtained depends on the individual prognosis of the ALL subtype (see Table 25-3 ). Usu­ ally, patients receive an early intensification with high-dose treatments. For patients with very high risk of early relapse and failure, for instance, t(9;22 ) , t(4; 1 1 ) , hypodiploidy, inadequate early response to steroids in adults, and induction failure what­ ever the age, allogeneic hematopoietic stem cell ( HSC) trans­ plantation is an option provided that a histocompatible sibling or unrelated donor can be found, but its place will probably need to be redefined according to the results of ongoing trials. Incor­ poration of tyrosine kinase inhibitors in t(9;22) ALL as part of first-line therapy is currently being evaluated with encouraging results. Minimal residual disease assessment can help to tailor post- induction therapy and monitor patients for the earliest signs of relapse.

Maintenance Chemotherapy After completion of induction, prophylactic CNS treatment, and early intensification, a phase of maintenance chemother­ apy is started for those patients with low-risk characteristics. The details of this phase vary depending on the protocol. They may consist of continued administration of relatively low doses of agents such as 6-mercaptopurine and methotrexate or periodic "consolidation" treatments with higher doses of multiple agents. The total duration of treatment is usually 2-3 years.

Prognosis More than 80% of children who achieve complete remission and finish 2-3 years of maintenance therapy will be cured of

rl

C A S E H I S T O RY

Pa rt 3

This patient falls into an indeterminate risk category. Young children with early pre-B cell ALL have an excellent chance of cure. Adu lts, on the other hand, may ach ieve an initial complete remission but are rarely cured. When presented with a case such as this, it is often difficult to determine whether the patient fits into the childhood or adult cate­ gory of ALL. Positive factors in this patient include the B-cell ALL phe­ notype, hyperdiploidy, and female gender. Negative factors include her age, the high blast count, and evidence of CNS

A C U T E LY M P H O C Y T I C L E U K E M I A

317

their disease. The prognosis in adults treated with the conven­ tional ALL protocol is much worse, with only a 30%--40% chance of long-term survival. Patients who relapse 12 or more months following first remis­ sion will frequently achieve a second remission with a repeated course of conventional chemotherapy. However, second remis­ sions are usually shorter with a poor long-term survival. Patients who relapse during chemotherapy or within 6 months of first remission have a very poor prognosis. An improved outcome in adults, 40%-50% survival rates, has been reported with aggres­ sive chemotherapy, including CNS treatment, based on child­ hood protocols. The up-front CNS treatment reduced the rate of CNS relapse to less than 20%, versus 50% in conventionally treated patients. The genetic array profile of the malignant cell line may also help predict outcome. A limited set of genes has been shown to be expressed differently and correlates with sensitivity to pred­ nisolone, vincristine, asparaginase, and daunorubicin. It is antic­ ipated that this approach to predicting outcome, and thereby modifying therapy, will be used more and more in the future. Patients achieving long-term disease-free survival face some risk of a secondary malignancy, particularly gliomas in children. In addition, many patients will have decreased fertility, and this risk dictates offering male patients sperm preservation before treatment. There does not appear to be an increased incidence of birth defects in the offspring of ALL survivors.

Marrow/Stem Cell Transplantation Hematopoietic stem cell transplantation is of benefit in first remission for adults with high-risk features, and in children after induction failure. All patients who relapse should be considered candidates for marrow transplantation as soon as they achieve second remission. In these situations, allogeneic transplanta­ tion offers the best chance of long-term disease control.

1 involvement. Cytogenetics, while predictive of long-term su rvival, are not as yet useful in planning induction therapy. Due to the presence of several negative factors, this patient should probably be intensively treated with remission induction chemotherapy, including intrathecal chemotherapy, followed by consolidation and maintenance. She and her siblings should be tested for histocompatibility in anticipa­ tion of the need for an allogeneic HSC transplant, especially if remission is not immediately achieved or if early relapse occurs.

3 18

SECT I O N I I

WHITE BLOOD CELL DISORDERS

P O I N T S TO R E M E M B E R Acute 1)-mphceytle leukemia (All) t)'pleally presents In ehlldhood as

an acute illness, characterized by the sudden onset of some combi­ nation of fatigue, bone pain, abnormal bleeding, and fever. The bone marrow will usually show overwhelming infiltration by "blasts" and peripheral blast counts can be greater than I 00,000/!!l. Adenopathy can also be a presentation, confi rming this disease's cu rrent World Health Organization (WHO) designation as acute lymphoblastic leukemia/lymphoma. l mmu nophenotyping and cytogenetics are essential to the accu rate diagnosis of the cell type and as a guide to therapy and overall prog­ nosis. All can result from malignant transformation of either B-cell or T-cell precu rsors.

Due to the fact that lymphocytes are highly mobile, the concept of sanctuary disease in the CNS or testes has become an important concept in the treatment of All. Even in the absence of overt involvement, prophylactic treatment of sanctuary sites has greatly improved outcomes. All (especially B-cell All) in young children is highly curable by modern combination chemotherapy, but sti l l requires therapy tai­ lored to the risk of relapse. I n addition, laboratory studies for mon­ itoring relapse or residual disease are standard for guiding therapy. All in adults is uncommon but has a much poorer outcome than that seen in children, warranting an aggressive approach in adults who can tolerate intensive therapy and transplantation.

B I B L I O G RA P H Y Briiggemann M , Raff T, Flohr T, et al: Clinical significance of minimal residual disease quantification in adult patients with standard-risk acute lymphoblastic leukemia. Blood 2006; 107: 1 1 1 6. Holleman A, Check MH, den Boer ML, et al: Gene-expres­ sion patterns in drug-resistant acute lymphoblastic leukemia cells and response to treatment. N Engl J Med 2004;3 5 1 :533 . Lazarus HM, Luger S: Which patients with adult acute lym­ phoblastic leukemia should undergo a hematopoietic stem cell transplantation? Case-based discussion. Hematology (Am Soc Hem Educ Program) 2007 :444. Pui CH: Central nervous system disease in acute lymphoblas­ tic leukemia: prophylaxis and treatment. Hematology (Am Soc Hem Educ Program) 2006: 142. Pui CH, Behm FG , Crist WM: Clinical and biologic rele­ vance of immunologic marker studies in childhood acute lym­ phoblastic leukemia. Blood 1 993 ;82:343 . Pui CH, Evans WE: Treatment of acute lymphoblastic leukemia. N Engl J Med 2006;3 54: 166.

Pui CH, Reilling MY, Downing JR: Acute lymphoblastic leukemia. N Engl J Med 2004;350: 1 53 5 . Raff T, Gokbuget N , Liischen S , et al: Molecular relapse in adult standard-risk ALL patients detected by prospective MRD monitoring during and after maintenance treatment: data from the GMALL 06/99 and 07/03 trials. Blood 2007 ; 1 09:910. Szczepanski SZ: Why and how to quantify minimal residual disease in acute lymphoblastic leukemia? Leukemia 2007 ; 2 1 :622. Thomas DA: Philadelphia chromosome-positive acute lym­ phocytic leukemia: a new era of challenges. Hematology (Am Soc Hem Educ Program) 2007:436. Willemze R, Labar B: Post-remission treatment for adult patients with acute lymphoblastic leukemia in first remission: is there a role for autologous stem cell transplantation? Semin Hematol 2007 ;44: 267.

P LAS M A C E LL D I S O RD E RS C A S E H I S T O RY

A

•

Part I

65-year-old man presents with a 1 -month history of lower back pain, which began after he strained his back stacking fire wood. Despite rest and aspirin therapy it has not improved. He has not had similar back pain in the past and has been in good health.There are no neurological signs or symptoms on examination and he has no other com­ plaints except possibly increased fatigability, which he attrib­ uted to his age.The remainder of his examination is normal with the exception of some conjunctival pallor. CBC: Hematocrit/hemoglobin - 3 1 %/ I 0. 1 gm/d L MCV - 90 fL MCH - 32 pg MCHC - 3 1 g/dL WBC 8,500/!!L Differential - normal Platelet count - 230,000/!!L -

•

SM EAR MORPHOLOGY

Normochromic, normocytic red blood cells with promi­ nent rouleaux formation (stacking) and a vague bluish back­ ground on the slide.

Plasma cells are terminally differentiated cells of the B lympho­ cyte lineage. They are thought of as cellular factories whose entire energy and synthetic capacity is devoted to producing a single antibody protein. They are normally incapable of divid­ ing and are thought to have a relatively short lifespan of per­ haps several weeks. Plasma cells develop both in the lymph nodes, where they are found predominantly in the medullary cords, and in the marrow, although they represent a minority of cells in these tissues. They have a distinctive morphology and are easily identified in the marrow (Figure 26-1 ) .

Questions What feature(s) of this case might distinguish it from a routine lower back pain evaluation? · What fu rther evaluation is indicated? •

Plasma cell disorders, sometimes referred to as plasma cell dyscrasias, encompass several entities including monoclonal gammopathy of unknown s ignificance (MGU S ) , Walden­ strom macroglobulinemia (WM ) , amyloidosis, and multiple myeloma ( MM ) . The most common malignancy involv ing plasma cells is multiple myeloma, a multifaceted disease in which malignant plasma cells develop in bone marrow where they induce osteolytic les ions and produce monoclonal immunoglobulin components with humoral blood and urine repercussions.

SECTI0N

3 20

II

WH ITE BL00D CELL D I S0RDERS

Antigen receptor-immunoglobulin

8-l y mphocyte Tri g geri n g by specific antigen �

� Proliferation

�

plasma cells with marked overproduction of a single antibody that appears in the plasma as an M-component ( also termed monoclonal immunoglobulin or M-protein ) . Multiple myeloma (MM) i s a classic example of a malignant disorder that results primarily from the failure of mature cells to respond to apoptotic stimuli and die rather than from excessive proliferation of precursors. Nearly 1 billion ( 1 0 9) plasma cells need to accumulate before sufficient M-protein is produced to be detected clinically. Secondary mutations are seen later in the disease process and are associated with chemoresistance and tumor growth independent of IL-6. The most important of these are mutations of the ras oncogene on chromosome 13 and p53. As illustrated by animal models of multiple myeloma in mice and in human disease, clonal plasma cells develop preferentially in bones. The cause of the bone disease in MM is the local acti­ vation of osteoclasts (Figure 26-2A) by the clonal plasma cells. This involves the release of chemokines such as IL- l �, tumor necrosis factor-a, IL-6, and, most importantly, macrophage

Memory B cel l s Plasma Cell

_,

Eccentric nucl e us with cl u mped chromatin Promi n ent Gol g i apparatus Basophilic cytoplasm

r

Solubl e antibody production

FIGURE 26- 1 . Plasma cell differentiation and morphology. Mature B lympho­ cytes express on their surface the antibody that serves as the receptor for specific antigen.When they encounter this antigen, they are stimulated to proliferate and dif­ ferentiate, which leads to development of memory B cells and plasma cells. The plasma cell is highly specialized to produce and secrete large amounts of the same antibody.

T H E B I O LO G Y O F P LA S M A C E L L D I S O R D E RS After stimulation by specific antigen, the germinal center B cells differentiate to generate long-lived memory B cells on the one hand and plasma cells on the other (see Chapter 20). After then moving to the bone marrow, the plasma cell stops proliferating and manufactures large amounts ( 1 ng or more per cell per day ) of the same antibody that was initially displayed on the surface of the B cell. The normal plasma cell lives only for several weeks or months. Two cellular substances have been shown to play key roles in the regulation of apoptosis in plasma cells. These are the bcl-2 family of mitochondrial proteins (bcl-2, bel- XL, and mcl- 1 ) and interleukin [IL]-6. The level of expression of bel-2 and mcl- 1 on the mitochondrial membrane determines the response of the plasma cell to apoptotic stimuli, whereas lL-6 is an important regulator of bcl-2 activity. Therefore, to normally maintain the continued production of any antibody, new plasma cells need to be regenerated from programmed B-cell precursors. The development of a plasma cell malignancy is marked by loss of apoptosis, and thus involves the "piling up" of a clone of

A

B FIGURE 26-2. Marrow osteoclasts versus a diffuse plasma cell infiltrate. A: A solitary osteoclast (multinucleated cell that lacks the typical cytoplasm of a megakaryocyte). B: Diffuse plasma cell infi ltrate in the marrow of a myeloma patient (marrow aspirate, Wright stain).

CHAPTER 26

inflammatory protein (MIP) - 1 a and - 1 �. The latter are associ­ ated with an upregulation of RANKL (receptor activation of NF-K� ligand) and a downregulation of OPG ( osteoprotegerin, a natural antagonist of RANKL) . Overexpression of RANKL is associated with increased generation of osteoclasts from mono­ cyte precursors. It is an apparent paradox for a malignant clone to retain mature functionality together with a capacity for self-renewal. However, recent data have shown that myeloma stem cells exist and demonstrate self-renewal and transplantability properties. The challenge in this disease is to eradicate not only plasma cell progeny but also the myeloma stem cells.

Use of M-Component i n Diagnosis and Staging The M-component is a readily measured, quantifiable tumor marker and as such has been used extensively to diagnose, stage, and follow plasma cell disorders. By measuring the level of M-component in serum and estimating the turnover rate of immunoglobulin, it is possible to use the M-component to estimate the total body burden of malignant plasma cells. In addition, by making some assumptions about the rate of accumu­ lation of plasma cells, it is possible to estimate the amount of time that they have been accumulating and thus estimate the time of onset of the malignant process. These calculations have shown that the malignant transformation occurs at least 5 years before the onset of symptoms.

Cell Linea�e and I mmunologic Abnormal ities Since the M-component is a highly specific marker, the lineage of cells belonging to the clone has been traced from malignant B cells at the germinal center stage through the entire B-cell differentiation pathway to the plasma cell. One important clue to the possible etiology of plasma cell disorders comes from observations in the BALB/c mouse, which has a markedly increased propensity to develop myeloma after chronic anti­ genic stimulation. In humans, M-components have been recog­ nized in some patients to display specific antibody activity for an antigen known to have been encountered by the patient, such as human immunodeficiency virus (HIV ) , bacterial polysaccha­ rides, or natural self-antigens. It is likely, therefore, that clonal plasma cell proliferation results from the combination of a chronic B-cell antigenic stimulation and other cellular onco­ genic events that lead to clonal plasma cell disorders. The result­ ing clone fails to apoptose and reveals itself years later with clinical symptoms due to an accumulation of plasma cells and M-component. In addition to the clonal B and stem cells that lead to multi­ ple myeloma, many patients with MM will also have abnormal­ ities in the T-cell compartment. CD4 T cells are decreased and there is a concomitant increase in CDS T cells and sometimes natural killer (NK) cells. These changes may serve as additional explanations for the immunodeficiency state that accompanies myeloma. Intriguing recent observations, however, of increased numbers of isotype- and idiotype-specific T cells in myeloma

P LAS M A C E L L D I S O R D E RS

32 1

suggest a more active role for T cells in modulating B-cell func­ tion. There is some interest in the possible therapeutic exploita­ tion of this by immunizing the patient (or a prospective martow donor) with the patient's M-component in the hope of aug­ menting T-cell function against the malignant B cells. The role of the bone marrow microenvironment in MM has also been emphasized. The growth of myeloma cells appears to be highly dependent on exogenous IL-6 produced by bone mar­ row stromal cells. The production of IL-6 by these cells is stim­ ulated by myeloma cells, perhaps mediated by transforming growth factor-�. This paracrine role for IL-6 has generated inter­ est in designing therapies with antibodies against IL-6 and its receptor. Another factor produced by marrow stem cells that appears to be important in the growth of myeloma cells is vas­ cular endothelial growth factor (VEGF ) . Increased angiogen­ esis may play a role in promoting myeloma growth and anti-angiogenic therapies may have a role. Trials of thalidomide in MM have been very successful, supporting this proposition.

e

LA B O RATO RY D I AG N O S I S O F M O N O C LO N A L G A M M O PAT H Y

All plasma cell dyscrasias are characterized by an accumulation of a clone of plasma cells producing a unique homogeneous immunoglobulin product. This monoclonality can be demon­ strated either at the level of the soluble product, M-component, in serum/urine, or at the cellular level.

M-Components An M-component is detected in serum as a discrete single band on electrophoresis (narrow spike on the electrophoretic pat­ tern ) , and reaction of that band with specific antibodies to a single immunoglobulin heavy- (most commonly IgM, IgA, IgG , and rarely IgD or IgE) and light-chain forms: lambda ( A. ) or kappa ( K) (Figure 26-3 ) . As these M-components modify the physical interactions between red cells and plasma, their pres­ ence increases the erythrocyte sedimentation rate ( ESR) , which can reach more than 1 00 mm/h. Physicians should keep in mind that patients with unexplained rouleaux or high sedimentation rates require an electrophoresis to rule out an M-component. An inflammatory process, especially in non-febrile patients, should not be assumed as the cause of the increased ESR without a negative electrophoresis (serum protein and/or immunofixation ) . The special physical properties o f the M-component protein also play an important physiologic role in the disease process. For example, monoclonal IgM components, because they are pentameric, and IgA, which frequently dimerize, are much more likely to lead to hyperviscosity syndromes at lower concentra­ tions than IgG M-components. Monoclonal antibodies some­ times also have unusual binding properties, for example, cold agglutinin hemolytic anemia resulting from anti-I antibody specificity, and peripheral neuropathy resulting from anti­ myelin activity. The M-component may not be an intact immunoglobulin in a significant number of plasma cell disorders (Table 26-1 ) .

3 22

SECTI0N I I

WH ITE BL00D CELL D I S0RDERS

TABLE 26- 1

•

Monoclonal proteins produced by plasma cell

tumors %

Type

0

Normal serum

�

Anti - l a mbda light chai n 0 Myel o ma Serum

'-'I Anti-kappa light chai n --­ ....____

52 21

I gO

2

lgE

35 g/L of JgG or >20 gil of lgA A biopsy-proven plasmacytoma M inor criteria A < I 0% plasma cells in the marrow but with monoclonal

immunoglobulin expression B. An M-component quantitatively less than specified above Lytic bone lesions or unexplained osteopenia Depressed normal (polyclonal) immunoglobulins Unexplained normochromic, normocytic anemia Serum �2-microglobulin level of >3.5 mg/L Unexplained renal dysfunction Unexplained hypercalcemia Note: The diagnosis of myeloma requires at least I major and I minor

criterion or at least 3 minor criteria including both A and B.

CHAPTER 26

underestimates the percentage of plasma cells as compared with the marrow biopsy specimen. When the percentage of plasma cells in the marrow aspirate or biopsy is not greatly increased, it is diagnostically useful to deter­ mine if the cells are clonal using histochemistry or flow cytometry. This approach is especially important when a serum M-component cannot be demonstrated or is present in low concentration. Plasma cells can be specifically identified by their reactivity with mono­

clonal antibodies to CD 138 (immunohistochemistry) and CD38 (flow cytometry) . Because the plasma cell produces large amounts

of cytoplasmic immLmoglobulin, it is possible to label the individ­ ual cells with antibodies directed against specific immunoglobu­ lin heavy- and light-chain classes. Each plasma cell produces only one antibody, and therefore will label with only one heavy chain and/or one light chain reagent. The normal marrow contains plasma cells from many clones, and therefore cells will be found that label with antibodies to IgG, IgA, and IgM, in order of decreasing frequency, and the normal ratio of K light chain to A light chain expressing plasma cells will be about 2: 1 . In the case of a monoclonal gammopathy, plasma cells that express only a single heavy chain and a single light chain will predominate using immunohistochemistry on the biopsy specimen. Similarly, flow cytometry of the marrow aspirate can identify monoclonal plasma cells; the plasma cells can be distinguished from other marrow cells by their low level (or absence) of the leukocyte antigen CD45 and high expression of CD38. The plasma cells are permeabilized to permit entry of monoclonal antibodies directed against K and A light chain and, similar to detection of B-cell non-Hodgkin lym­ phoma, a predominance of one antibody's labeling makes the diag­ nosis of a plasma cell dyscrasia. Detection of a chromosomal abnormality is also proof of a clonal disorder. Even though plasma cell dyscrasias have a low proliferative potential, making convential cytogenetics difficult, the advent of interphase FISH (fluorescence in-situ hybridiza­ tion) methodology makes it possible to identify karyotypic abnormalities in nondividing cells. Using metaphase and FISH cytogenetics, it has now been shown that primary translocations involving either the IgH or IgL locus, including l l ql3 ( cyclin D l ) , 4p 1 6, 6p2 1 (cyclin D3 ) , 1 6q23 , and 20ql l , are present in 40%-50% of myeloma and monoclonal gammopathy patients. Other translocations-t(4; 1 4 ) , t{ 1 4; 1 6 ) , and t{ 1 1 ; 1 4 ) , and chromosomal abnormalities of 3, 5, 7, 9, 1 1 , 13, 1 5 , 1 9, and 21occur but are less specific and may reflect disease progression. The most frequent chromosomal abnormalities are del 1 3 , found in nearly half of myeloma patients, and translocations that dys­ regulate c-myc, which are seen in up to 20% of all MGUS and MM cases. With evolution of plasma cell disease, other cellular abnor­ malities can be appreciated. Early on, the growth fraction of the malignant clone is low; generally less than 1 % of the plas­ mablasts are dividing at any one time. This can increase dra­ matically to levels greater than 20% with disease progression, especially when a patient relapses afrer chemotherapy. The lat­ ter is associated with point mutations of the N-ras and K-ras oncogenes, as well as a point mutation of p53 in patients with extramedullary disease. Plasma cell phenotypic changes include the initial loss of CD 1 9 expression with CD5 6 overexpression,

P LAS M A C E L L D I S O R D E RS

323

as detected by flow cytometry. Flow cytometric CD1 1 7 expres­ sion is associated with a more favorable prognosis, while CD28 positivity is associated with a less favorable outcome.

M U LT I P L E M Y E L O M A ( P LAS M A C E L L M Y E L O M A) Multiple myeloma accounts for 1 0%-1 5 % of hematologic neo­ plasms and about 1 % of all cancer deaths.

Cli nical Features The manifestations of multiple myeloma are produced both by the tumor itself and the humoral factors it produces, as well as the spread of plasma cells throughout the skeleton. The most common clinical presentation of multiple myeloma is the recent onset of unexplained back pain; normochromic, normocytic anemia; or renal insufficiency/failure in an older patient. In recent times, however, up to 60% of new patients are first diag­ nosed when a serum or urine M-component is detected on rou­ tine laboratory testing, mainly because of an unexplained

increased sedimentation rate or excess globulin fraction . Approximately 70% of myeloma patients are over 60 years of age and 90% are over 50 years old. The diagnosis of multiple myeloma can easily be missed if the physician does not have a high degree of suspicion. In fact, the diagnosis is frequently missed on the first evaluation of a patient with back pain or anemia. This is even more of a problem in patients who have another disease, such as postmenopausal osteoporosis or rheumatoid arthritis, which may cause bone pain, anemia, or both. Therefore, it is important to include myeloma in the differential diagnosis of any older patient presenting with back pain or anemia, even when the history suggests a possible cause for the pain such as recent stress or trauma. Up to 80% of myeloma patients present with bone pain as the first clue and more than 70% of myeloma patients develop 1 or more pathologic fractures during the course of their disease. Spinal cord compression is the most serious complication. It should be anticipated when the patient presents with fixed, pro­ gressive back pain, most frequently in the dorsal region. This presentation should be quickly explored by magnetic resonance imaging (MRI ) , even if there is no evidence of any neurological deficit or paraparesis, because spinal cord compression with para­ plegia can be abrupt and irreversible. This complication is often the consequence of infiltration of the extradural space and com­ pression by the plasma cell tumor itself; pure mechanical com­ pression by a collapsed vertebra is another frequent etiology. Less commonly, myeloma may present not as a bony or marrow-based process but rather as an isolated extramedullary mass lesion, the so-called solitary plasmacytoma. These lesions may be found in the skin, the gastrointestinal (GI) tract, the nasopharynx, and elsewhere. They are not clinically distinc­ tive and can only be defined as plasmacytomas by biopsy. Most patients presenting with isolated plasmacytomas will also be found to have multiple myeloma on marrow examination; how­ ever, some patients will have an isolated tumor without signifi­ cant marrow disease and can be treated with local radiotherapy.

3 24

SECTI0N I I

WH ITE BL00D CELL D I S0RDERS

A. Renal Manifestations and Hypercalcemia

D. Hematologic Studies

Occasionally the myeloma patient will present with acute renal insufficiency/failure or sudden, symptomatic hypercalcemia. The cause of the hypercalcemia is primarily the rapid destruc­ tion of bone by osteoclast-activating factors secreted by plasma cells and/or bone marrow stromal cells. The cause of renal fail­ ure in MM is usually multifactorial, mainly related to acute tubular lesions resulting from light-chain deposition, dehydra­ tion, and hypercalcemia. Such tubular lesions are further exac­ erbated by nonsteroidal anti-inflammatory drug (NSAID) use; such drugs, therefore, are contraindicated in MM patients. Less common as a presenting symptom is amyloid nephropathy, which presents as glomerular dysfunction. The patient with resistant disease, however, is at risk for all of these problems. An episode of back pain requiring bed rest may result in hypercal­ cemia; similarly, an acute infection with fever may result in dehydration, which precipitates renal failure. With disease pro­ gression, renal failure can become a limiting factor in the design of an effective chemotherapy regimen.

The CBC can provide important clues to the diagnosis of myeloma. As the disease advances, the patient will almost cer­ tainly develop a normocytic, normochromic anemia secondary to inhibition of erythropoiesis by plasma cell cytokines or renal damage. Since the distinction is important for managing the patient, any anemia should be fully evaluated with marrow, iron studies, and renal function measurements. Differential diagno­ sis of a marrow damage anemia is discussed in Chapters 3 and 4. In contrast to the early appearance of anemia, changes in gran­ ulocyte and platelet count occur much later and are usually asso­ ciated with chemotherapy. It is impossible to identify the malignant plasma cell line from routine studies of the peripheral blood since the circulating B cells are polyclonal. Plasma cells or their progenitors are usually found in the circulation only with advanced disease. Rarely, patients will progress to plasma cell leukemia with circulating plasmablasts. Another important clue from the CBC relates to the amount and class of the patient's M-component. As the level of this monoclonal protein increases, there is an increased ten­ dency for red blood cell rouleaux formation. This tendency can be visually appreciated on the peripheral blood film, and when pronounced, can produce a false elevation in the mean cell vol­ ume ( MCV ) secondary to red blood cell agglutination. An ele­ vation of the sedimentation rate to levels above 1 00 mm/h (Westergren method) in an otherwise healthy individual is also suggestive of the presence of an M-component. With older pop­ ulations, where the incidence of plasma cell disorders is increased, a sedimentation rate can be a low-cost, high-yield screening test. At the same time, not all sedimentation rates above 1 00 mm/h tum out to be myeloma, and 10% of myeloma patients have only light chains in urine, without detectable M-component in blood. Vasculitis, arthritis, infections, and other malignancies are also associated with very high sedimentation rates. A golden rule is to consider every adult patient with a per­ sistent unexplained elevated sedimentation rate for SPEP/lFE.

B. Hematologic Manifestations Myeloma patients have an increased susceptibility to infection secondary to decreased production of normal immunoglobulins, possibly because of dendritic cell dysfunction or other abnor­ mality induced by the M-component. The maj or hematologic manifestation of myeloma is anemia, owing to decreased ery­ thropoiesis. The degree of anemia is not related to the degree of marrow involvement by plasma cells. In addition, patients who have begun chemotherapy may have severe myelosuppression. Less commonly, the M-component may interfere with platelet function or coagulation factor X, leading to bleeding, or with phagocytic cell function, leading to recurrent infection. Hyperviscosity of the blood, owing to large concentrations of IgG or dimerization of IgA at lower concentrations, is some­ times seen in myeloma, although it is much more common in macroglobulinemia with lesser concentrations of IgM. It is markedly worsened by dehydration. The clinical manifestations are fatigue and neurologic symptoms, including headache, blur­ ring or loss of vision, confusion, and ischemia. Serum viscosity will be at least 3 times normal before symptoms can be attributed to hyperviscosity. Treatment of this complication must be under­ taken promptly with hydration, plasmapheresis, and initiation of chemotherapy.

C. Laboratory Studies Any patient suspected of having a plasma cell disorder should have a serum protein electrophoresis (SPEP) and immunofix­ ation electrophoresis ( IFE ) for quantifying and typing the M-component, respectively, as well as quantitative measurement of albumin and polyclonal serum immunoglobulins. Additional important tests for staging and prognosis include electrophore­ sis of urine for light chains; a marrow aspirate and biopsy for morphology, flow cytometry, and karyotyping; a complete blood count (CBC ) ; tests of kidney function, serum Ca 2 + , albumin, and �2 -microglobulin; as well as x-rays of the skull and pelvis with careful inspection for excessive osteopenia or lytic lesions. Any area of localized bone pain should also be imaged.

E.

Immunoglobulin Studies

Eighty-five to ninety percent of patients will have an M­ component in serum, the most common being lgG . About 25% of patients will have an IgA or rarely an IgD or lgE M-compo­ nent, whereas 1 0 %- 1 5 % of patients have only light chain detectable (see Table 26- 1 ) . Both the amount and class of the protein are important in diagnosing myeloma (Table 26-2 ) . The presence of a high level of serum or urine M-component ( or both) or light chains, together with a significant plasma cell infiltration of the marrow, provide the maj or criteria for MM diagnosis. Even without evidence of other organ damage, the level of the patient's M-component generally correlates with tumor burden and will guide management decisions. The M-component may be first detected on routine serum protein electrophoresis as a narrow peak that deforms the nor­ mal symmetry of immunoglobulin electrophoresis pattern (see Figure 2 6-3 ) . Depending on the class of protein, the peak can appear at any point in the distribution of the immunoglobulins, from a2 to "( migration zones. The quantity of M-component is

CHAPTER 26

TABLE 26-3

•

Risk stratification of patients with multiple

myeloma High Risk (25%)

Standard Risk (75%)

FISH studies: del 1 7 p, t (4; 1 4), t( 1 4; 1 6) Karyotype: Monosomy or del 1 3,

All others. However, patients within this category and � -microglobulin >5.5 mg/L 2 without renal failure or elevated LDH are likely to be considered as high risk.

hypodiploidy

Plasma cell labeling index: 60%), which stain for lgG K; other blood lab­ oratories: reticulocyte index less than I ; normal serum iron, total iron-binding capacity (TI BC), and serum ferritin; nega­ tive stool guaiac; normal chemistries except for a modestly elevated BUN and serum calcium. K

Questions • What d iagnosis can be made from these resu lts? • Is treatment indicated and, if so, what strategy should be used? • Are there other tests that can help guide management?

3 26

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these abnormalities is difficult to appreciate since they can over­ lap in a single patient or appear during the course of the disease. Nevertheless, patients with a t(4; 1 4 ) , t( 1 4; 1 6 ) , 13q-, 1q+, del 1 7p do worse than patients with a t( 1 1 ; 1 4 ) or hyperdiploidy. Patients with l l ql3 and 6p2 1 translocations have a better prog­ nosis. These cytogenetic abnormalities are currently used in the risk stratification of multiple myeloma (Table 26-3 ) .

Therapy and Clinical Course The course of multiple myeloma is very heterogeneous. Some patients who present with a low tumor burden and stable or slowly growing disease are referred to as smoldering myeloma, whereas others evolve rapidly to full-blown symptomatic dis­ ease. Two staging methods of use in planning therapy and pre­ dicting survival have been described and validated in the last decades. The first, the Durie-Salmon Staging System, involves the calculation of tumor burden (number of plasma cells) based on the daily synthesis and turnover of the M-component. Together with the presence of anemia, the level of the M­ component in blood or urine , calcium and creatinine blood levels, and number of osteolytic bone lesions on skeletal x-rays, patients can be stratified (Table 26-4 ) according to a 3 - stage system-low, intermediate, and high tumor burden. The sec­ ond and more recent staging method focuses on the albumin and � 2 -microglobulin concentrations in serum. This Interna­ tional Staging System also appears to be highly predictive of overall survival ( Table 26-5 ) .

A. Traditional Therapy Unlike the lymphomas and leukemias, multiple myeloma responds poorly to traditional multidrug chemotherapy. As a result, chemotherapy results in, at best, a 1-2 log reduction in the plasma cell-mass but never leads to cure. Because of this and

The Durie-Salmon Staging System for multiple myeloma

TABLE 26-4

•

Stage I

Stage I I

Stage I l l

Plasma cell concentration 1 ( 1 0 2/m2)

1 .2

Hemoglobin g/dl

>12

1 0- 1 2

1 20 mg/L

M-component (giL)

lgA 70

Bence jones proteinuria

1 2 g/24 h

Osteolytic lesions

O- J visible lesion

2 visible lesions

� visible lesions

60 mo

45 mo

25 mo

Median overall survival0

'With standard (eg, melphalan/prednisone) treatment.

TABLE 26-5

•

The International Staging System for multiple

myeloma Stage

2

Criteria

Overall Survival

P 2m' 3.5 g/dl

62 mo

P 2m 5.5 mg/L

29 mo

'/32m, {3,-microglobulin.

depending on patient and MM characteristics, it may make sense to delay treatment as long as the disease remains stable and until the patient is at risk of progressive disease or organ damage. When myeloma is diagnosed before onset of symptoms, it may be years before the disease becomes symptomatic and early chemotherapy does not lengthen the time to progression. At the same time , asymptomatic patients should be followed carefully with quantitative serum immunoglobulins, CBC, and tests of renal function and serum calcium every 3-6 months, as well as periodic imaging to determine the rate of progression of bone disease. Early detection of complications is key; patients who are allowed to develop renal failure or severe marrow dam­ age may not respond to subsequent treatment. Until the past few years, the combination of melphalan ( 6-9 mg/m2 daily ) together with prednisone (40-60 mg/d for 4-7 days ) cycled every 4-6 weeks was the gold standard for treatment of myeloma. Although this regimen ( which began being used in the 1 960s ) provides a response as judged by a grad­ ual decrease in the quantity of the M-component in about 50%-60% of patients, few will achieve a "complete" remission as j udged by disappearance of the M-component. Moreover, the duration of the response is usually less than 1 year, and the median overall survival is about 3 years in clinically overt mul­ tiple myeloma. Attempts to improve these results with mul­ tidrug and high-dose regimens in the 1 980s and 1 990s, including combinations of vincristine, doxorubicin, and dexamethasone (VAD) or the M2 and C-VAMP protocols (vincristine, adri­ amycin, BCNU, melphalan, cyclophosphamide, and prednisone) have been of little benefit. Although these combinations can provide a more rapid induction response, they do not signifi­ cantly prolong overall survival. However, new treatment regimens have been introduced that demonstrate significant improvements in survival and even hold promise for complete remission in some patient subgroups.

B. Newer Therapies The efficacy of multiple myeloma treatment has been greatly improved during the last 2 decades by several maj or advances, including intensive chemotherapy with autologous stem cell support, and new drugs including thalidomide, lenalidomide ( Revlimid ) , bortezomib (Velcade ) , and bisphosphonates.

CHAPTER 26 I . I ntensive treatment with auto l ogous stem cell rescu e- Patients receiving intensive chemotherapy, mainly

high-dose melphalan ( 1 40-200 mg/m 2 ) with or without total body irradiation, followed by autologous stem cell rescue (ASCR) have a 1 2 - to 1 8-month gain in overall survival when compared with less intensive chemotherapy regimens. Subse­ quent trials have attempted to define the best intensive regimen schedule and timing of the ASCR. All of these trials have con­ firmed a clear-cut benefit regarding overall survival for patients eligible for this procedure. The failure of these regimens to cure the patient are due to the persistence of monoclonal plasma cells after induction chemotherapy, and possibly also because of the inevitable rein­ fusion of some tumor cells harvested from the patient as part of the ASCR procedure. Despite attempts to purge plasma cell pre­ cursors from peripheral blood collections of CDJ4+ progeni­ tor cells , a constant relapse rate is observed, suggesting that the failure to eradicate myeloma cells by chemotherapy is the pri­ mary cause for relapse. Nevertheless, the increase in median overall survival to 42-66 months makes this procedure the best choice for MM patients under age 65. Allogeneic transplantation has also been evaluated in selected patients, mostly those with relapsing or refractory dis­ ease. This procedure is of limited feasibility given the older age and general status of most MM patients, and the frequent lack of availability of a compatible HLA-matched donor. The few studies so far available show that some patients escaping the lethal complications of the procedure may expect to be cured. Non-myeloablative allogeneic transplantation following a single autologous transplantation has also been studied with some benefit in selected patients. 2. Newer chemotherapy drugs for M M-Three drugs have

demonstrated major efficacy in myeloma patients during the last decade . The first one is thalidomide, an immunomodulatoty drug, which has shown impressive results in myeloma patients when given alone or in combination with dexamethasone and/or traditional chemotherapy. The treatment-limiting toxi­ city is the development of a sensory neuropathy, and there is also an increased risk of thromboembolic episodes, but myelo­ suppression does not occur. A large, controlled trial has estab­ lished that the addition of thalidomide 200 g/d to the classical melphalan/prednisone regimen ( MPT) can improve the response rate and, more importantly, extend the median over­ all survival to 5 1 .6 months as compared to 33 months with melphalan/prednisone alone. Given these results, the MPT regimen is now considered the new gold standard first-line treat­ ment for elderly patients not eligible for intensive chemotherapy/ ASCR. Lenalidomide , an analog of thalidomide, and bortezomib, a proteasome inhibitor, have also shown significant efficacy in association with high-dose dexamethasone in advanced-stage myeloma patients. Based on current studies, lenalidomide ( Revlimid) is administered orally ( 2 5 mg/d on days 1 -2 1 each month) together with sequential dexamethasone (40 mg/m 2/d on days 1-4, 9-1 2 , and 1 7-20 ) . Compared with thalidomide, lenalidomide displays less neurotoxicity but a comparable risk

P LAS M A C E LL D I S O R D E RS

327

of thromboembolic events. Both drug dosages should be reduced in patients with renal failure. Bortezomib (Velcade ) can be administered at a dose of 1 .3 mg/m 2/d intravenously on days 1 , 4, 8, and 1 1 , in association with dexamethasone 40 mg/d on days 1-2, 4-5 , 8-9, and 1 1- 1 2 , for 2-8 three-week courses. Peripheral neuropathy and myelosuppression are the main lim­ iting toxicities. Both regimens display high efficacy in both relapsing/refractory and previously untreated patients. In the latter setting, current results with these regimens compare well with intensive treatments including autologous stem cell transplantation.

C. Management of Complications Among the hematologic malignancies, multiple myeloma stands out for its destructive action on bone resulting in severe pain and disability. During the course of their disease, most patients will have severe and sometimes intractable pain secondary to progressive osteolysis and pathologic fractures. Adequate pain relief should therefore be a very important aspect in caring for these patients. At the same time, the prevention, or at the very least inhibition, of lytic bone lesions is becoming more of a real­ ity. The bisphosphonates are potent inhibitors of osteolysis and are now widely used in the control of myeloma bone disease. The bisphosphonate, pamidronate, given in a dose of 90 mg as a 4-hour intravenous infusion every 4 weeks for 6 or more cycles, can reduce the incidence of bone fractures, prevent hypercal­ cemia, and decrease the patient's bone pain. The mechanism of action is unclear but may involve OPG stimulation and inhibi­ tion of RANKL activity. This has led to a search for other RANKL and MIP- 1 inhibitors for use as therapeutic agents. Fractures heal normally, and therefore their management does not differ from standard orthopedic procedures. Vertebral collapse should be treated as an emergency. In the absence of spinal cord or nerve root compression, high-dose steroid and local irradiation should be started immediately. However, any neurologic symptoms of spinal or nerve compression require a surgical consult for laminectomy or decompression. Hypercalcemia and acute renal failure usually improve rapidly with treatment. Patients with mild hypercalcemia (::;120 mg/L) can usually be managed with hydration, steroids, and antimyeloma chemotherapy. More severe hypercalcemia, levels of 1 20- 1 40 mg/L or higher, need to be treated as an emergency. Following aggressive hydration (3 or more liters of 0.9% saline over 1 2-24 hours) and a loop diuretic (furosemide 20-40 mg every 1 2 hours) , pamidronate or calcitonin or both should be administered. The dose of the bisphosphonate pamidronate is 60-90 mg and can be administered intravenously over 4-24 hours. The onset of effect is apparent within 3-4 days, with a maximal effect at about 10 days. The duration of effect can persist for 7-30 days. Repeated doses are effective for intractable hypercalcemic con­ ditions. Recent data suggest that pamidronate may also slow the progression of the underlying myeloma and increase survival. Calcitonin is a peptide hormone that rapidly inhibits bone resorption and decreases renal calcium reabsorption, perhaps through its effect on parathormone secretion. It is administered in a dose of 4 IU/kg body weight, subcutaneously every 1 2 hours.

3 28

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C A S E H I S T O RY

Pa rt 3

The patient clearly has mu ltiple myeloma with osteolytic lesions, a significant M-component in both serum and urine, a marrow damage anemia, hypercalcemia, and mild renal dysfunction. Based on these findings, he fits into the Durie-Sal men intermediate-stage II (see Table 26-4). A measurement of the �2-microglobulin level is indicated as another guide to staging and management. This was reported as 5.2 mg/L, a level indicating stage 2 disease, according to the International Staging System (see Table 26--5). Given his age, disease stage, and evidence of organ damage, he should be treated aggressively. Immediate hydration and diuretic therapy should correct his modest hypercalcemia as

The dosage can be increased to 8 IU/kg every 6-1 2 hours after a day or two if the response is unsatisfactory. Since tachyphy­ laxis is expected, calcitonin is only used to stabilize the hyper­ calcemic patient until pamidronate takes effect. Most myeloma patients develop a symptomatic anemia as their disease progresses. The underlying mechanism is multifac­ torial, involving both marrow damage and a relative failure of the erythropoietin response to the anemia. Both renal compro­ mise and overexpression of cytokines, especially IL-6 and tumor necrosis factor (TNF)-related apoptosis- inducing ligand ( TRAIL), inhibit hepcidin and suppress the erythropoietin response ( see Chapters 3 and 4 ) . Stem cell damage from chemotherapy only makes the situation worse. Fortunately, the anemia of myeloma will usually respond to pharmacologic doses of erythropoietin. Anemic patients should be treated with recombinant erythropoietin ( Epogen) 40,000 U once a week subcutaneously (SC) , or darbopoietin 200 J..l g every 2 weeks until the hematocrit rises above 36%. Symptomatic hyperviscosity with mucocutaneous bleeding, and ocular (retinal hemorrhages and papilledema) , neurologic (headache, dizziness, and somnolence ) , and cardiovascular (high-output cardiac failure ) manifestations may be seen in 2%-6% of myeloma patients, invariably those with higher lev­ els of serum immunoglobulin: greater than 40 g/L of lgG or greater than 60 g/L of lgA. These symptoms and signs resolve rapidly with a reduction in the level of serum paraprotein by plasmapheresis and chemotherapy.

D. Treatment of Plasmacytomas Patients with a solitary plasmacytoma involving soft tissue can be effectively cured with a minimum of 4.5 Gy of local irradiation. This is not true for solitary plasmacytomas of bone, most likely because the disease is already more widespread, although not detectable by standard staging procedures (bone imaging and mar­ row sampling) . These patients will eventually go on to develop full-blown multiple myeloma and should be managed as such.

well as lower his BUN. He should then be treated with lenalidomide/dexamethasone or M PT. H is management should include careful monitoring for any progression of his bone disease, changes in renal function, infection, or neuro­ logical complication. If his back pain becomes localized and is the major complaint, it should respond wel l to targeted radiation therapy. M PT or lenalidomide/dexamethasone therapy should give him an expected median survival of 4-5 years. Because of his age and renal function, high-dose chemotherapy with ASCR carries a considerable risk of early morbidity and mortality and does not offer a promise of longer survival.

S E C O N DA RY M O N O C LO N A L G A M M O PAT H Y A secondary monoclonal gammopathy is occasionally observed as an incidental laboratory finding in patients who have another disorder such as autoimmune disease; immunodeficiency, either primary or acquired; AIDS; chronic infections; carcinoma; and lymphoma. Approximately 2%-5 % of patients with B-cell non­ Hodgkin lymphoma (NHL) or lymphocytic leukemia will have a detectable M-component. The important clinical issue is to determine if the patient has occult NHL, carcinoma, or multi­ ple myeloma, and if the patient is likely to develop overt myeloma in the future. These patients should undergo the same diagnostic evaluation as the patient suspected of myeloma, including CBC, marrow examination for clonal plasma cells or NHL, renal function studies, and examination for lytic bone lesions. In addition, such patients should be followed at close intervals with quantitation of their M-component. It is unusual for the M-component to increase in cases of sec­ ondary gammopathy. Although these patients may have increased plasma cells in their marrow, they are usually poly­ clonal or oligoclonal by flow cytometry, and karyotypic abnor­ malities are rare. Anemia or osteopenia that cannot be explained on the basis of the underlying disorder should increase the level of suspicion that the patient may have myeloma rather than secondary gammopathy.

e

M O N O C LO N A L G A M M O PAT H Y O F U N K N OW N S I G N I F I C A N C E

Many older patients with a small M-component will, on com­ plete evaluation, be found to not fit the criteria for multiple myeloma, nor to have any underlying disorder associated with secondary gammopathy. They usually have less than 1 0% mar­ row plasmacytosis, no anemia, and no bone lesions, hypercal­ cemia, or renal dysfunction.

CHAPTER 26

Monoclonal gammopathy of unknown significance (MGUS) is a common finding in adults; its frequency increases from 2% in the fifth decade to more than 6% beyond 80 years of age. When this group of patients was first recognized it was questioned whether they had a different disease, perhaps one that was not malignant because they frequently remain free from progression for many years. Cytogenetic studies have shown, however, that transloca­ tions are common findings in MGUS, as they are in multiple myeloma. They typically involve 14q32 ( 46%) with most frequent gene partners being l lql3 (25%), 4p 1 6 (9% ) , and 1 6q23 ( 5 % ) . Other genetic abnormalities are hyperdiploidy and 1 3 q deletions, the frequency of which is similar in MGUS and multiple myeloma. Long-term follow-up of MGUS patients has shown that up to 26% of patients will progress to overt multiple myeloma, amy­ loidosis, Waldenstrom macroglobulinemia, or other B-cell lym­ phoproliferative disorders at a rate of about 1 % per year. Interestingly, the M-component disappears spontaneously in 2% of patients. Since it is not possible to predict which patients will convert to MM, all MGUS patients should be followed with yearly measurements of serum and urine M-component. No treatment is advised until the onset of symptoms or clear pro­ gression in terms of increased M-component or organ damage.

P LAS M A C E LL D I S O R D E RS

329

sclerotic bone lesion or a mixture of several sclerotic and lytic lesions; plasma cells in the marrow rarely exceed 20%. Trearment of POEMS syndrome is based on focal radiation therapy for localized osteosclerotic bone lesions; systemic ther­ apy similar to myeloma treatment is proposed for widespread dis­ ease. The median overall survival was 1 3 . 8 years in the largest cohort so far studied.

A M Y LO I D O S I S One dreaded complication of plasma cell dyscrasias is amyloidosis (AL). This clinical syndrome is caused by the tissue accumulation of large amounts of insoluble glycoproteins. The glycoprotein is usually a degradation product of larger proteins that have in com­ mon the ability to form �-pleated sheets. Several such proteins can give rise to amyloid deposits in a variety of clinical settings. The one most likely to cause amyloidosis in a patient with a plasma cell disorder is the immunoglobulin light chain (AL). Patients with overproduction of immunoglobulin light chains, especially A light chain, are at risk for the gradual accumulation of amyloid deposits that can cause a variety of signs and symptoms.

Clinical Features P O E M S SYN D RO M E The acronym POEMS refers to a monoclonal plasma cell disorder characterized by Polyneuropathy, Organomegaly, Endocrinopa­ thy, an M protein, and Skin changes. Less frequent symptoms are erythrocytosis or lymph node hyperplasia reminiscent of Castle­ man disease. POEMS patients, by definition, must have a serum ( and urine) M-component, usually of modest amount: 1-2 g/L of an IgG or IgA protein containing almost always a monoclonal A light chain. Most of these patients also present with a single

TABLE 26-6

•

In some cases, AL is discovered during the workup of a patient with a known plasma cell dyscrasia. The more difficult diagnos­ tic situation is when a patient with no previous plasma cell dis­ ease presents with symptoms related to amyloidosis. It requires a high degree of suspicion to make the correct diagnosis. Any patient found to have amyloid pathology should have a thor­ ough workup for a plasma cell disorder. The patient may have asymptomatic myeloma with a small M-component or only free light chains. Common clinical presentations and/or symptoms of amyloidosis are listed in Table 26--6. A severe bleeding tendency

Diseases frequently associated with amyloidosis

Classification

Diseases

Common Clinical Manifestations

Al amyloidosis (primary or lg light chain associated)

Multiple myeloma and other monoclonal gammopathy lymphoma

Macroglossia, cardiomyopathy, hepatosplenomegaly, nephrotic syndrome, carpal tunnel syndrome, peripheral neuropathy, purpura, and ecchymoses

Tuberculosis Hansen disease Bronchiectasis Chronic osteomyelitis Inflammatory bowel disease Rheumatoid arthritis Carcinoma

Usually: hepatosplenomegaly, nephrotic syndrome, adrenal insufficiency less frequently: Al manifestations

Familial Mediterranean fever

Recurrent fever, arthritis, pleuritis, and abdominal pain; glomerulonephritis, renal failure

A � 2m amyloidosis

long-term hemodialysis

Hepatosplenomegaly, nephrotic syndrome, adrenal insufficiency

ATTR (transthyretin) amyloidosis Other amyloid proteins (Apo Al/11, gelsolin, lysozyme fibrinogen, cystatin C.A� .AprP,ABri) A � amyloid (cerebral)

Senile systemic or familial amyloidosis Neuropathy, cardiomyopathy, nephropathy, vitreous opacities Hereditary amyloidosis Peripheral neuropathy, autonomic dysfunction, nephropathy, cardiomyopathy, dementia

AA amyloidosis

Alzheimer disease

Dementia

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is seen in up to 10% of patients with AL amyloid disease as a result of acquired factor X deficiency, secondary to absorption of factor X onto amyloid fibrils.

Diagnosis The best diagnostic amyloid test is a blind biopsy of subcuta­ neous fat that should be stained with Congo red and examined under a polarizing microscope. Amyloid deposits give a birefrin­ gent, green staining pattern that is diagnostic and can be observed in every tissue involved. If a patient has signs or symp­ toms in a region amenable to needle biopsy, it may be wiser to seek the diagnosis there. On echocardiogram, an interventricu­ lar septum thicker than 1 5 mm and with bright echogenicity is highly suggestive of amyloid cardiomyopathy. Amyloidosis can also arise from the deposition of proteins unrelated to a clone of plasma cells. AA amyloidosis is seen with chronic infections (especially tuberculosis and Hansen dis­ ease) , chronic inflammatory diseases, and carcinomas, though rarely to an extent that results in maj or organ damage, unlike AL. AA patients present with hepatosplenomegaly, nephrotic syndrome, or adrenal insufficiency (see Table 26-6 ) . A family history may reveal evidence of one of the familial forms of amy­ loid, especially in persons of Mediterranean heritage. A num­ ber of other proteins have been implicated in small numbers of patients with amyloidosis (see Table 26-6 ) and, infrequently, no underlying cause for the amyloid is found. In cases such as renal amyloidosis, it may be difficult to tell if the amyloid deposits are the cause or the result of chronic renal failure.

Therapy and Clinical Course Because of their insoluble nature, it is very difficult to remove amyloid deposits or to reverse their formation. Treatment of the underlying disease may slow or stop amyloid deposition with very slow improvement in symptoms. Thus, patients with amy­ loid related to a plasma cell disorder should be treated with high-dose melphalan and autologous transplantation, if cardiac status permits. Otherwise, they should receive lower dose mel­ phalan, together with high-dose dexamethasone. This is a rea­ sonably effective regimen with partial responses in more than 60% of patients. Patients with cardiac involvement or ortho­ static hypotension have a very poor prognosis, with median survival on the order of 6 months. By contrast, amyloid glomerulopathy, when isolated, is not associated with a poor prognosis and is amenable to treatment. Combination therapy using steroids with thalidomide (and also bortezomib ) have recently demonstrated impressive efficacy in overt AL amyloi­ dosis, including cardiac disease.

H E AVY A N D L I G H T C H A I N D I S EAS E S As mentioned earlier, about 20% of patients with plasma cell dis­

orders produce only monoclonal light chains. Such patients may have deposits of intact light chains, usually in the kidneys and other organs. These deposits are not amyloid and do not stain with

Congo red. Light-chain deposition disease (LCDD) can present with renal failure or nephrotic syndrome as the major clinical man­ ifestation, but it may be difficult to demonstrate monoclonal light chains in either serum or urine by electrophoresis. However, light­ chain analysis ( including ratio) in serum is usually diagnostic. Other organs are also vulnerable to LCDD, including the pul­ monary and cerebral parenchyma. Increased numbers of plasma cells with the appropriate light-chain expression can be demon­ strated in the marrow by flow cytometry. The approach to diagno­ sis and treatment is the same as for MM. Much less commonly, patients may produce only free heavy chains or fragments of heavy chains. The production of a chains is most commonly reported, although free A and f..1. chains have also been found. These abnormal proteins may be difficult to demonstrate in the serum or urine and may accumulate in the tissues in a manner analogous to light chains. a-Heavy chain disease most often affects the GI tract and is now referred to as Immune-Proliferative Small Intestine Disease ( IPSID ) . This dis­ ease follows a course that closely resembles a malabsorption syn­ drome evolving to a lymphoma affecting gut-associated lymphoid tissue, rather than a plasma cell dyscrasia.

WA L D E N S T R O M M AC R O G LO B U L I N E M I A Although usually discussed in connection with plasma cell dis­ orders, Waldenstri:im macroglobulinemia is more accurately clas­ sified as a lymphoplasmacytic lymphoma. The only feature that it shares with the plasma cell disorders is the presence of an M­ component. Unlike myeloma, this component is always of the lgM class. The presentation, diagnosis, staging, clinical course, and therapy of macroglobulinemia are similar to the non­ Hodgkin B-cell lymphomas (see Chapter 23 ) . Unlike myeloma, it does not present with bone pain, renal failure, lytic lesions, or hypercalcemia. The maj or organ involvement in macroglobu­ linemia is the marrow, spleen, and other lymphoid tissues.

C l i nical Features Macroglobulinemia is more common in older patients (median age 60 years) . Many patients remain asymptomatic, even with an M-component as high as 30--40 g/L. However, most patients present with fatigue, weight loss, anemia, mucocutaneous bleed­ ing, lymphadenopathy, hepatosplenomegaly, or symptoms related to hyperviscosity (Table 26-7 ) . Because of the higher molecular weight of lgM, the M-component is primarily con­ fined to the vascular space and does not cause renal failure. However, neuropathy and hyperviscosity are common complica­ tions of macroglobulinemia; up to one-third of patients will develop symptoms and signs of hyperviscosity as their serum M component rises to levels above 30 g/L. Some specific clinical presentations depend on the physical properties of the lgM antibody. Cold agglutinin disease is the consequence of anti-I specificity (see Chapter 1 1 ) , with some patients developing hemolytic anemia, often intravascular on exposure to cold. Antibody specificity against myelin-associated glycoprotein (MAG ) is associated with neuropathy, including

C H A P T E R 26

TABLE 26-7

•

Symptoms and signs of hyperviscosity

Organ System

Symptoms and Signs

Ocular

Retinal hemorrhage Papilledema Dilated retinal veins (boxcar changes)

Neurologic (central)

Headache Tinnitus Vertigo/dizziness Mental status changes

Neurologic (peripheral)

Neuropathy

Cardiac

High-output congestive failure

distal symmetric paresthesia, paresia, and tremor. Nerve con­ duction velocity is reduced, similar to demyelinating neuropathies. Some monoclonal lgM antibodies behave as cryoglobulins that precipitate when exposed to temperatures lower than 3 6 °C. These cryoglobulins are classified as mono­ clonal lgM without (type 1 ) or with anti-rheumatoid factor activity ( type 2 ) . Type 3 cryoglobulin is a separate entity of poly­ clonal lgM with rheumatoid activity. These cryoglobulins can present as vasculitis following cold exposure, with vascular pur­ pura, urticaria, Raynaud syndrome, glomerulonephritis, periph­ eral neuropathy, and arthritis. Interference of M-components with platelet adhesion or fibrin formation can induce bleeding.

Diagnosis Patients with Waldenstri:im macroglobulinemia will invariably have an lgM M-component, although it may not be quantita­ tively large. The pentameric nature of lgM may give rise to hyperviscosity phenomena at much lower concentrations than lgG or lgA. The typical lgM M-component in this disorder is between 10 and 30 g/L. The marrow is infiltrated by small lym­ phocytes with variable degrees of "plasmacytoid" features such as eccentric nuclei, basophilic cytoplasm, and prominent Golgi, and there is an increased number of mast cells. These plasmacy­ toid lymphocytes invariably express surface lgM, more often lC, and unlike typical plasma cells they express the monoclonal immunoglobulin both on their surface and in their cytoplasm. Abnormal, clonal lymphocytes are usually demonstrable in blood, in contrast with myeloma, where blood lymphocytes are polyclonal, and plasma cells are only observed in blood in the terminal phase. The CBC is usually normal as long as the M-component remains below 20 g/L. Above this value, a dilutional normo­ cytic, normochromic anemia due to plasma volume increase is frequent. Patients suspected of macroglobulinemia should have a marrow examination or biopsy of involved lymphoid tissues, and an evaluation identical to that performed in patients with other B-cell non-Hodgkin 1ymphomas (see Chapter 23 ) .

P LAS M A C E LL D I S O R D E RS

33 1

Hyperviscosity can be suspected when the fundoscopic examination shows clumping of red blood cells in the retinal veins ( so-called sausage or boxcar segmentation) , papilledema, or retinal hemorrhages (see Table 26-7 ) . The serum viscosity level can confirm the diagnosis of hyperviscosity. Compared to water ( 1 .4-1 .8 cp) , a serum viscosity that exceeds 4-5 cp is almost invariably associated with symptomatic hyperviscosity. However, this assay is not required for the diagnosis when symptoms of hyperviscosity are present, especially if the M-component is greater than 30-40 g/L.

Therapy Hyperviscosity should be treated promptly as it is life threaten­ ing. Hydration, with careful attention to the possibility of con­ gestive heart failure, plasmapheresis, and institution of chemotherapy, will usually control the syndrome. Because the lgM protein is confined to the intravascular space, plasmaphere­ sis can rapidly lower the concentration of M-component. For long-term control, cytotoxic chemotherapy must be added. Patients who have relatively small M-components and mild or no symptoms should be observed closely with repeated quan­ titation in order to determine the rate of disease progression. Some patients may be asymptomatic for several years. Patients with a progressive increase in their M-component or the onset of anemia or other symptoms should be treated with a single alky­ lating agent, usually chlorambucil or cyclophosphamide, or in combination with prednisone or the purine analog fludarabine-­ therapies appropriate for NHL. The goal of therapy is to control disease progression and decrease the M-component. The addi­ tional toxicity of multiagent chemotherapy is problematic in most older patients, and the outcomes for aggressive therapy have not justified its use. The median survival of patients with full-blown macroglob­ ulinemia is 5-10 years, but is worse in patients older than 65 or with the presence of lymphadenopathy or organomegaly.

P O I N T S TO R E M E M B E R Plasma cells are the end pro d u ct of stepwise dl«erentlatlon ef 6-ee41 progenitors. Each plasma cell is programmed to produce approxi­ mately I ngld of a single antibody with either A or K light chain, but never both. This fact is usefu l in identifying clonal popu lations of plasma cells where all of the cells show either A or K light chains instead of the normal 40:60 mix.

Plasma cell dyscrasia is defined as a clonal proliferation of plasma cells, with multiple myeloma being the most common malignancy, especially in older age groups where the incidence greatly exceeds that of other hematopoietic malignancies. Patients with multiple myeloma often present with common and/or minor complaints of back pain, fatigue, or anemia that have other ready explanations. Because of this, the diagnosis is often missed

332

SECTI0N I I

WH ITE BL00D CELL D I S0RDERS

until the patient presents with major organ damage. Therefore, a high degree of suspicion and careful investigation are necessary to reach a correct diagnosis. Accu rate diagnosis and staging requires a panel of tests including CBC; bone marrow aspi rate and biopsy for morphology, flow cytometry, and karyotyping; imaging of the skull, long bones, and spine; meas u rement of the M-component in blood and urine; stud­ ies of renal function; serum calcium; and �2-microglobulin level. Two staging systems can help in planning therapy. The Durie-Salman system uses the major and minor d iagnostic criteria (see Table 26-4) to classify patients as stage 1, 1 1 , or I l l , while the I nternational Stagi ng System (see Table 26--5) relies on the �2-microglobulin and albumin levels to derive a similar 3-level stage. Plasma cells are relatively resistant to standard chemotherapy. How­ ever, combinations of chemotherapy and autologous stem cell res­ cue plus the use of newer drugs-thalidomide, lenalidomide, and bortezomib--have shown the ability to diminish or even eliminate the M-component and to significantly increase su rvival times in MM. The complications of myeloma are related to the effect of the dis­ ease on the marrow, especially with rep lacement of normal medullary elements; bony changes with expansion of tu mor mass; and the properties of the monoclonal immunoglobulin itself. In the marrow, eryth ropoiesis is most commonly affected, pro­ ducing a normochromic, normocytic anemia. Studies to rule out i ron defi c iency are warranted, and the anemia of myeloma generally responds to erythropoietin until very late stages. Leuko­ cyte and platelet p roduction are not usually affected until chemotherapy. Bone disease is a frequent complication of multiple myeloma. Patients may present with widespread lytic lesions, hypercalcemia, or osteopenia, or a single large bony lesion, including plasmacytoma

B I B L I O G RA P H Y

of bone. Bone pain may be caused by pathologic fractures or by heavy invasion of the bone by the mal ignancy without fracture. Neurologic signs indicating nerve entrapment is a medical emer­ gency. Bone disease and hypercalcemia can be sign ificantly amelio­ rated by bisphosphonate therapy. The monoclonal paraprotein may cause pathology because of its specificity (causing hemolytic anemia or neu ropathy) or because of its predilection to organ involvement. The kidneys are commonly affected by myeloma, with both tubular and glomerular involvement. Light-chain deposition disease may occur in the parenchyma of the kidneys, brain, heart, and lungs. Large concentrations of lgG and lgA paraprotein may cause hypervis­ cosity, similar to smaller concentrations of the pentameric-capable lgM in Waldenstrom macroglobulinemia. Some light-chain parapro­ teins with !3-pleated sheet confirmation can precipitate in tissue parenchyma as amyloid, causing irreversible cardiac, mucosal, and r enal damage. Patients often have a small M-component without evidence of organ damage, thereby not meeting the diagnostic criteria for myeloma, so-cal led monoclonal gam mopathy of u n known significance (MGUS). This early-stage plasma cell dyscrasia progresses to myeloma at about I % per year and should be followed for organ damage or an increase in the paraprotein. Waldenstrom macroglobulinemia is a lymphoplasmacytic lymphopro­ liferative disease characterized by an lgM M-component but without the MM features of bony disease, hypercalcemia, and renal failure. It clinically resembles a B-cell non-Hodgkin lymphoma (NHL). Waldenstrom macroglobulinemia is sensitive to N H L chemother­ apy. Periods of remission can be suddenly interrupted by a dramatic increase in serum viscosity secondary to a rising lgM level. This is a medical emergency, requiring aggressive plasmapheresis and subse­ quent chemotherapy.

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

Diagnosis

Al-Saleem T, Al-Monclhiry H: lmmunoproliferative small intestinal disease ( IPSID ) : a model for mature B-cell neoplasms. Blood 2005 ; 1 05 : 2274. Blade J , Rosifiol L: Complications of multiple myeloma. Hematol Oncol Clin N Am 2007;2 1 : 1 23 1 . Dispenzieri A , Kyle RA , Lacy MQ, et al: POEMS syndrome: definitions and long-term outcome. Blood 2003 ; 1 0 1 :2496.

Huff CA, Matsui W: Multiple myeloma cancer stem cells. J Clin Oncol 2008;26:2895 . Kyle RA, Rajkumar SV: Monoclonal gammopathy of unde­ termined significance and smoldering multiple myeloma. Hema­ tol Oncol Clin N Am 2007 ;2 1 : 1 093 . Kyle RA, Rajkumar SV: Multiple myeloma. Blood 2008; 1 1 1 :2962.

Greipp PR, San Miguel J, Durie BGM, et al: International Staging System for multiple myeloma. J Clin Oncol 2005 ;23 : 1 .

Kyle RA, Remstein ED, Themeau TM, et al: Clinical course and prognosis of smoldering ( asymptomatic) multiple myeloma. N Engl J Med 2007;3 5 6:2582.

Guidelines Working Group of U K Myeloma Forum; British Committee for Standards in Haematology, British Society for Haematology. Guidelines on the diagnosis and management of AL amyloidosis. Br J Haematol 2004; 1 25:68 1 .

Lentzsch S, Ehrlich LA, G . Roodman D: Pathophysiology of multiple myeloma bone disease. Hematol Oncol Clin N Am 2007;2 1 : 1 03 5 .

CHAPTER 26

Mehta J, Singhal S: Hyperviscosity syndrome in plasma cell dyscrasia syndromes. Semin Thromb and Hemost 2003 ;29:467. Merlini G, Bellotti V: Molecular mechanisms of amyloido­ sis. N Engl J Med 2003 ;349:583 .

Mitsiades CS, McMillin DW, Klippel S , e t al: The role of the bone marrow microenvironment in the pathophysiology of myeloma and its significance in the development of more effective therapies. Hematol Oncol Clin N Am 2007 ;2 1 : 1 007. Stewart AK, Fonseca R: Prognostic and therapeutic signifi­ cance of myeloma genetics and gene expression profiling. J Clin Oncol 2005 ;23:6339. Tonon G : Molecular pathogenesis of multiple myeloma. Hematol Oncol Clin N Am 2007;2 1 :985 .

P LAS M A C E LL D I S O R D E RS

333

with multiple myeloma (IFM 99-06 ) : a randomised trial. Lancet 2007;3 70: 1 209. Kastritis E, Mitsiades CS, Dimopoulos MA, Richardson PG: Management of relapsed and relapsed refractory myeloma. Hematol Oncol Clin N Am 2007;2 1 : 1 1 7 5 . Rajkumar SV, Palumbo A : Management o f newly diagnosed myeloma. Hematol Oncol Clin N Am 2007;2 1 : 1 1 4 1 . San-Miguel J , Harousseau J L , D Joshua D , Anderson KC: Individualizing treatment of patients with myeloma in the era of novel agents. J Clin Oncol 2008;26:276 1 . Soutar R, Lucraft H , Jackson G , et al: Guidelines on the diag­ nosis and management of solitary plasmacytoma of bone and solitary extramedullary plasmacytoma. Brit J Haematol 2004; 1 24: 7 1 7 .

Dispenzieri A: Complications of myeloma therapy. Hematol Oncol Clin N Am 2007 ;2 1 : 1 247.

Treon SP, Gertz MA, Dimopoulos M, et al: Update on treat­ ment recommendations from the Third International Workshop on Waldenstrom's Macroglobulinemia. Blood 2006; 1 07 :3442.

Facon T, Mary JY, Hulin C, et al: Melphalan and prednisone plus thalidomide vs melphalan and prednisone alone or reduced­ intensity autologous stem cell transplantation in elderly patients

van Rhee F, Dhodapkar M, Shaughnessy JD, et al: First thalidomide clinical trial in multiple myeloma: a decade. Blood 2008; 1 1 2 : 1 03 5 .

Therapy

M O N O CYTE­ M AC RO P H AG E D I S O RD E RS

n lr-

A

C A S E H I S T O RY

Pa rt I

4frear-old man is referred by his orthopedic surgeon following the development of a pathological fracture of the neck of the femur after a fall on ice. X-rays taken at the time of the fracture show an abnormality of the ends of the long bones resembling an inverted Erlenmeyer flask. The patient has otherwise been in good health. He is of Ashkenazi j!wish descent with a small family and is unaware of any genetic disorders in his family. Examination is notable for an enlarged spleen, which is easily palpable several centimeters below the costal margin,

The mature cells that comprise the monocyte-macrophage sys­ tem function both as phagocytes and as antigen-presenting cells. Disorders of the monocyte/macrophage lineage are quite het­ erogeneous and include "benign" disorders such as Langerhans­ cell histiocytosis, reactive histiocytosis, and the lysosomal storage diseases, as well as monocytic and histiocytic malignant proliferations. In naming these disorders, the term "histiocyte" is used interchangeably with "macrophage" to describe the tissue­ bound phagocytic cells found throughout the body. The morphologic appearance of the tissue macrophage is key to the differential diagnosis of these disorders. For example, reac­ tive histiocytosis is characterized by prominent monocytosis and a tissue granulomatous reaction typical of the normal role of macrophages in host defense against infection. The so-called storage diseases are a manifestation of genetic deficiencies of

•

2

-,

1.------..

and hepatomegaly. The remainder of his physical examina­ tion is normal. His complete blood count (CBC) is normal with the excep­ tion of a moderately reduced platelet count of 80,000/J.LL

Questions -Given this limited amount of information, what diagnoses come to mind? •What additional tests and procedures are necessary to evaluate this patient?

certain enzymes responsible for the degradation of carbohy­ drates and lipids. Even though these enzyme deficiencies pre­ sumably affect all the cells in the body, the characteristic abnormality is an accumulation of degraded cellular debris within tissue macrophages. Primary malignancies of the tissue macrophages are quite rare ; marrow and tissue invasion by ery­ throphagocytic histiocytes is a primary distinguishing feature of such malignancies.

e

T H E N O R M A L M O N O C YT E ­ M AC RO P H AG E SYS T E M

As with the other hematopoietic cell lines, the monocyte­ macrophage cell lineage arises from the common hematopoietic stem cell. Cell differentiation and maturation to form mature

C H APT E R 2 7

M O N OCYT E - M AC RO P HAG E D I S O R D E RS

circulating monocytes is under the control of granulocyte macrophage colony-stimulating factor (GM-CSF), granulo­ cyte colony-stimulating factor (G-CSF), and monocytic colony-stimulating factor (M-CSF). Two distinct categories of blood monocytes are recognized according to their phenotypic expression. All monocytes display CD14, and the maj ority are CD 1 6-, whereas 1 0 % are more mature and express CD 1 6 + together with class Il major histocompatibility complex (MHC) molecules and adhesion molecules such as CCR2 and CX3CL1 ( see Chemokines and Their Receptors in Chapter 1 6 ) . These "mature" monocytes synthesize proinflammatory cytokines such as interleukin [IL] - 1 , lL-6, tumor necrosis factor [TNF] - a and IL- 1 2. When activated, monocytes also play a role in coagula­ tion and fibrin deposition at inflammatory sites, through expres­ sion of tissue factor and binding to activated platelets via P -selectin glycoprotein ligand- 1 ( PSGL- 1 ) ( see Chapter 2 8 ) . Monocytes migrate into tissues and transform into tissue macrophages/histiocytes, which are then named based on their distinctive morphology within individual tissues. These are then specifically referred to as alveolar macrophages, hepatic Kupffer cells, dermal Langerhans cells, and marrow reticuloendothelial cells. These tissue macrophages display many distinct membrane receptors. Pattern recognition receptors, also called toll-like receptors, are able to recognize highly conserved pathogen­ associated molecular patterns ( PAMP ) , which are highly con­ served motifs involved in innate immunity. Monocyte Fe receptors (see also Chapter 1 7 ) interact with the Fe portion of the immunoglobulin molecules, the best characterized being receptors for lgG referred to as FcyRI ( CD64 ) , II ( CD3 2 ) , and III (CD 1 6 ) . These monocyte receptors differ according to their immunoglobulin ( lg) affinity and the specific nature of subse­ quent signal transduction. Through this Fc-receptor binding, monocytes recognize immune complexes, as well as opsonized particles and pathogens. Complement receptors CR1 (CD3 5 ) and CR3 (CD1 1 b/CD 1 8 ) o n monocytes bind respectively to the C3b/C4b and C3b complexes fixed on opsonized pathogens. Monocytes are also involved in other complement pathways through their mannose receptors recognizing mannose oligosac­ charides on pathogens. Other important receptors are "scav­ enger" receptors for bacterial lipopolysaccharides and cholesterol from lipoproteins and atherosclerotic plaques; cytokine receptors for y-interferon, M-CSF, and TNF-a; and transferrin receptor (CD7 1 ) . Using the above receptors, the monocyte-macrophage sys­ tem has 4 principal functions: bacterial phagocytosis and killing, antigen presentation to T lymphocytes to initiate the immune reaction, modulation of the inflammatory response, and incorporation of monocytes into clots, where they play a role in fibrinolysis. Only the first 3 functions are clearly associated with clinical disease entities and will be discussed here.

Phagocytosis and Bacterial Ki lling Together with neutrophils, monocytes and macrophages actively phagocytize bacteria. With activation, these cells are then able to kill the ingested bacteria by superoxide generation. There are clear similarities and differences in the antimicrobial abilities of

335

T-CELL

Interferon

B

FIGURE 2-7 I .

CELLS

Monocyte-macrophage fu nction. The normal monocyte­

macrophage is capable of phagocytosis, ie, the killing of pathogens, and presenta­ tion of digested antigen toT cells to eventually promote the full immune response. Monocytes also release several cytokines to stimulate the T-cell response and pro­ mote the generalized inflammatory response.

the monocyte and macrophage as compared with the neu­ trophil. For example , the tissue-based macrophage contains much less myeloperoxidase than either the circulating neu­ trophil or monocyte. These differences are partly responsible for the clinical manifestations of some infections. The formation of granulomas in patients with certain infections, such as tubercu­ losis, reflects the inability of the tissue macrophage to lyse the mycobacterium. Patients with chronic granulomatous disease have an inherited defect in the ability of the monocyte­ macrophages to generate superoxide.

Role in I mmunity Monocytes and tissue macrophages play a key role in both the innate and adaptative immune systems. They process antigen and present it to T lymphocytes (Figure 2 7- 1 ) in a complex manner. The presentation of antigen involves a shared charac­ teristic of the macrophage and T cell, the expression of both class I and class II MHC molecules. The class I MHC mole­ cules are involved in CDS T-cell interactions, whereas the class II MHC molecules play a role in CD4 T-cell interactions ( see Chapter 20). According to the type of pathogen and the bal­ ance of secreted cytokines, macrophages and dendritic cells can elicit 2 types of T-cell responses. The TH 1 response is associated with stimulation of IL-2, y-interferon, and TNF-a secretion, which in tum results in activation of the cellular effectors of cytotoxicity. The TH2 response is associated with IL-4, IL-5, IL- 10, and IL- 1 3 secretion, which trigger mostly humoral responses.

336

SECT I O N I I

W H I T E BLOOD C E L L D I S O RD E RS

TABLE 27- 1

Role in the I nflammatory Response Monocytes and tissue macrophages also play a role in the gen­ eralized inflammatory response by the release of cytokines such as GM-CSF, G-CSF, M-CSF, IL- l , IL-8, TNF, and the interfer­ ons. They can also secrete proteases such as tissue plasminogen activator, collagenase, and elastase. These enzymes play a role in the tissue structural changes associated with the inflammatory reaction.

D I S O R D E RS O F T H E M O N O CYT E - M AC RO P H AG E SYST E M C li nical Features A. Blood Monocytosis Benign or reactive monocytosis is most often associated with impaired neutrophil production. Classical examples of reactive monocytosis are seen during the recovery phase of a drug­ induced agranulocytosis or cyclic neutropenia. In these cases, blood monocytosis is transient and usually mild, and is limited to the days immediately preceding the rebound increase in neu­ trophils. Chronic, mild monocytosis can be the first manifesta­ tion of myelodysplastic or myeloproliferative syndromes (see Chapters 9 and 1 9 ) , but reactive causes must first be ruled out. Severe, prolonged inflammatory responses (subacute bacterial endocarditis, tuberculosis ) , lymphoproliferative disease states ( Hodgkin disease ) , and collagen vascular diseases are frequently accompanied by a modest monocytosis, with counts of 500- 1 ,000/�. In any of these situations, the dominant clinical features are those of the primary illness, not the monocytosis.

'

• Underlying conditions and agents involved i n secondary hemophagocytic histiocytosis

Underlying Diseases

Triggering Agents

Malignant

Virus

Non-Hodgkin and Hodgkin lymphoma cancers Immunosuppression

Transplantation Chemotherapy AIDS IYer cirrhosis Asplenia

Sysemic diseases

lipus erythematosus Still disease Rheumatoid arthritis Ulcerative colitis !IWasaki disease Autoimmune thyroiditis Sarcoidosis Pyoderma gangrenosum Systemic sclerosis

HSVNll Adenovirus HHVf,HHV8 Hep A, B, C Dengue virus Epstein-Barr virus Cytomegalovirus Parvovirus B 1 9 Bacteria

Gram-negative bacillus Gram-positive cocci

Mycobacterium tuberculosis

Intracellular pathogens

Parasites

Leishmania donovani

Protozoans

Toxoplasma, Pneumocystis Fungal agents

Candida, Aspergillus, Cryptococcus

diseases, or malignancies (Table 27-1 ) . This complication is usu­ ally life threatening, depending on the underlying disease. 3. Mal ignant proliferations of monocyte-histiocyte l i ne­ age cells-Patients with malignancies of the monocyte­

macrophage lineage can present either as a leukemic state or as

B. Tissue Histiocytosis I . Langerhans cell histiocytic disorders--Langerhans cell

histiocytic disorders are non-malignant diseases characterized by histiocytic infiltrates of tissue but with a wide spectrum of clinical presentation. Hand-Schiiller-Christian disease pres­ ents in adolescents or young adults with diabetes insipidus, exophthalmia, and cranial bone defects. Letterer-Siwe disease affects children under 5 years of age and presents as a severe life-threatening hepatosplenomegaly with skin infiltrates and pancytopenia. Eosinophilic bone granuloma is usually localized to flat bones, mainly the skull, as well-circumscribed single or multiple osteolytic lesions. 2. Non-Langerhans histiocytic disorders--Non-Langerhans histiocytic disorders usually present as non-malignant, although

severe, histiocytic proliferations. The most striking feature in these disorders is hemophagocytosis by histiocytes in spleen, liver, or bone marrow, so that they are also referred to as hemo­ phagocytic syndromes. Common presentations include fever, hepatosplenomegaly, pancytopenia, hepatic dysfunction, and hypofibrinogenemia, all usually severe. However, the hemo­ phagocytic syndromes display a wide clinical heterogeneity. Reactive or secondary hemophagocytic histiocytosis, also referred to as Risdall syndrome, is often observed as a complica­ tion of severe infection in patients with immune defects, systemic

a wasting illness with marked fever, weight loss, and pancytope­ nia secondary to organ infiltration with malignant histiocytes. A small percentage of adult leukemias demonstrate pure mono­ cyte (M5 ) morphology ( see Chapter 1 8 ) . Chronic myelomono­ cytic leukemia is classified on the basis of the chronic monocytosis in blood and marrow (see Chapter 1 9 ) . Patients who present with a myelodysplastic syndrome may also have an increase in their absolute monocyte count, although patients with myelodysplasia (MDS ) with prominent monocytosis do not differ significantly from those with normal monocyte counts (see Chapter 9 ) . True malignant histiocytosis i s a very infrequent disease. For­ merly, it had been confounded with T-cell non-Hodgkin lym­ phoma (NHL), especially anaplastic large cell lymphoma, which can now be definitively defined by immunophenotyping and T cell-receptor ( TCR) gene rearrangement. However, true malignant histiocytosis, although extremely rare, is a definite entity. It usually presents in adults or elderly patients with hepatosplenomegaly, pancytopenia, lung infiltrates, and liver abnormalities. The diagnosis is made on biopsy, and the progno­ sis is poor. 4. Lipid-storage disorders--The storage diseases are typically diagnosed during childhood or early adult life based on distinc­ tive abnormalities of the liver, spleen, bone, and central nervous

C H APT E R 2 7

system, including blindness, deafness, and marked motor weak­ ness or spasticity. Dramatic expansion of tissue macrophages is responsible for the hepatosplenomegaly typically seen in patients with Gaucher and N iemann-Pick disease.

M O N OCYT E - M AC RO P HAG E D I S O R D E RS

337

the pinkish staining quality with periodic acid-Schiff stain and by examining an unstained preparation by phase microscopy. The sphingomyelin droplets within the cells are birefringent under polarized light. The diagnosis is definitively confirmed by the amount of sphingomyelinase in peripheral blood leukocytes.

Basic Laboratory Studies A. Complete Blood Count Diagnosis of a reactive monocytosis or leukemia may be made from the complete blood count (CBC ) . The normal absolute monocyte count is less than 5 00/!!L. Reactive monocytosis is associated with modest increases in the absolute count to 500- 1 , 500/!!L. Very high monocyte counts suggest an acute leukemia, myeloproliferative disorder, or leukemoid reaction.

B. Marrow Aspirate, Biopsy, and Other Tests Diagnosis of malignant histiocytosis or a lipid-storage disease can usually be made from the marrow aspirate and biopsy. The key finding is invasion of the marrow structure by morphologi­ cally abnormal macrophages. In patients with Gaucher disease, the marrow is infiltrated with large macrophages whose cyto­ plasm is filled with a characteristic pinkish, striated material (crinkled-paper appearance ) and a few vacuoles (Figure 2 7-2 ) . This material i s actually an insoluble glycolipid, glucocerebro­ side. Patients with Gaucher disease also show increases in acid

phosphatase activity, serum ferritin, and serum chitotriosidase, which parallel the disease activity. With increasing splenomegaly, most patients develop a normocytic, normochromic anemia; thrombocytopenia; or pancytopenia secondary to hypersplenism. In a small percentage of patients with Gaucher disease, serum elecrrophoresis discloses an M-component. It is now recognized that the risk of multiple myeloma is increased in this population. Patients with Niemann-Pick disease can also be diagnosed from the appearance of large, foamy macrophages in the mar­ row. The droplet-like material in these cells is sphingomyelin. Any confusion with Gaucher cells can be eliminated based on

D I F F E R E N T I A L D I AG N O S I S Lipid/Lysosomal-Storage D isorders A. Gaucher Disease Gaucher disease is the most common of the lipid-storage disor­ ders. It is an autosomal recessive disease caused by a defect in the production of the enzyme � -glucocerebrosidase, which is encoded by chromosome 1 q2 1 . This enzyme is required for the terminal step digestion of glycolipids in the lysosomes of all macrophages. When the enzyme is missing or defective, the extremely insoluble compound glucocerebroside accumulates within the cell's cytoplasm (Table 2 7-2 ) . Gaucher disease i s most common in the Ashkenazi Jewish population where carrier frequency is 8.9% and incidence of clinical disease is 1 in 450. The prevalence of homozygotes or composite heterozygotes in non-Jewish populations is estimated at approximately 1 /60,000. More than 200 mutations of the glu­ cocerebrosidase gene have been described. The 4 most common mutations encompass 94% of the Ashkenazi and 5 2 % of the non-Ashkenazi cases. The type of mutation affects the severity of the clinical manifestations, which range from severe disease presenting at infancy to almost asymptomatic forms diagnosed only in adults or the elderly. For instance, the presence of the N370S mutation, either as a homozygote or in combination with another mutation, is associated with mild forms of the disease, whereas mutations L444P, 84gg, or IVS2( + 1) are predictive of severe disease except when combined with N370S. I . C l i n ical subtypes-Three clinical subtypes of Gaucher dis­ ease have been identified (Table 27-3 ). Type 1 is the most com­ mon, representing more than 99% of cases. It also has the less severe presentation, with disease limited to the macrophages of the spleen, marrow, and liver. Type 2 disease is much more severe, presenting in early infancy with fulminating neurologic symptoms and early death, usually within 1 8 months of life.

TABLE 27-2 Most frequent mutations in Gaucher disease and their phenotypic counterpart •

M utation

N370S

Type of disease

FIGURE 272.

Gaucher cells. Giant histiocytes are noted to contain large

amounts of glucocerebroside. Note the abundant cytoplasm with a crinkled-paper or so-called onion-skin appearance.

Severity

Mild

Frequency (Yo Ashkenazi Non-Ashkenazi

lJ

18

4

L444P

84gg

IVS2(+ / )

1 , 2, 3

I,3

1,3

Severe

Severe

Severe

32

12

3

338

SECTJON I I

TABLE 27-3

•

W H I T E BLOOD C E L L D I SO R D E RS

Characteristics of Gaucher disease subtypes

Type I

Type 2

Type 3

Age at diagnosis

1 -70 years

< I year

2-20 years

Hepatosplenomegaly

++++

±

+

Bone lesions

+++

Lung disease

±

± ±

±

Encephalopathy

++++

±

Ocular apraxia

+

±

Corneal opacities Life expectancy (years)

60--9 0

±

±

1 .20) are consistent with a lupus anticoagulant. Up to 20% of patients presenting with VTE not associated with other disease, surgery, or trauma will demonstrate antiphospholipid antibodies. Therefore, along with factor V Leiden and the pro­ thrombin gene mutation, the presence of an antiphospholipid antibody must be considered as one of the top causes of throm­ boembolic disease in younger individuals and when thrombosis is unprovoked. Patients with lupus anticoagulant (LA) have shown an increased propensity to thrombosis , with 30%-60% of patients experiencing one or more thrombotic events during their lifetime. However, without a prior thromboembolic history, the mere pres­ ence of APLA or lupus anticoagulant does not justify prophylactic anticoagulation. Thrombotic events are mostly isolated VTE with a lesser incidence of cerebral thrombosis. Coronary, renal, retinal, subclavian, and pedal artery occlusions occur but are uncommon. Patients can also present with "catastrophic antiphospholipid syn­ drome" characterized by multiorgan failure secondary to widespread small vessel thrombosis, thrombocytopenia, acute respiratory dis­ tress syndrome, DIC, and, on occasion, an autoimmune hemolytic anemia. This clinical picture is indistinguishable from that of thrombotic thrombocytopenic purpura (TIP). Bacterial infections often appear to be triggering events for this syndrome. Women with antiphospholipid antibodies are susceptible to fetal death during the second or early third trimester, and repeated miscarriage is a major clue to the presence of APLAs. The incidence of pregnancy-associated hypertension (preeclamp­ sia and HELLP syndrome) and premature delivery secondary to placental insufficiency is also increased with APLAs.

C H APT E R 3 6

T H R0 M B 0T I C D I S 0 R D E RS

439

J. Coronary Artery Disease

A. Location and Extent of the Thrombotic Disease

Hypercoagulability plays a very limited role in coronary artery occlusion, especially since the relationship of genetic polymor­ phisms to arterial thrombosis is not as strong as that seen with venous thrombotic disease. Hyperhomocysteinemia has been cited as an independent risk factor for atherosclerosis. Increased fibrinogen levels have been associated with a higher risk for new coronary events, even in the absence of a lipidopathy. A genetic polymorphism in platelet function involving the glycoprotein Ilia polypeptide (HPA- 1 b ) has been reported to increase the risk of coronary thrombosis 6-fold, but its clinical implication is unclear. Fibrinolytic impairment secondary to an increase in t­ PA-PAI- 1 complex has also been advanced as a risk factor. Finally, elevated levels of factor VIII, as well as the appearance of an antiphospholipid/lupus anticoagulant, may be associated with myocardial infarction or arterial thrombosis in general (see Table 36-2 ) . The hs-C-reactive protein (CRP) (high sensitiv­ ity CRP-an assay that detects CRP levels in the normal range) predicts a higher incidence of coronary occlusion, and the com­ bination of a high hs-CRP level and increased total cholesterol/ HDL cholesterol ratio is associated with a 5- to 1 0-fold increased risk of a future coronary event, much greater than either risk factor alone. It is now standard practice to measure a metabolic risk panel in middle-aged individuals to gauge coronary artery risk and to recommend intervention for obesity, hypertension, high cholesterol, and high CRP.

In managing patients with a venous thrombosis, the location and extent of the thrombotic disease is a maj or guide to plan­ ning therapy. When the thrombus is limited to superficial veins of the leg or the deep veins of the calf, there is little risk of a pulmonary embolus. These patients can be managed with sim­ ple bed rest, a nonsteroidal anti-inflammatory drug, and support hose. At the same time, patients with symptomatic calf DVTs are at risk of developing chronic venous insufficiency, and it can therefore be of benefit to treat with anticoagulation. The avail­ ability of LMWH makes it feasible to give these patients 1 0-14 days of therapy at home, avoiding a costly hospitalization. When the thrombus resides in the deep veins of the thigh, the patient is at risk for PE and should receive full-dose antico­ agulation with heparin, either weight-adjusted LMWH, corre­ sponding to an anti-Xa level of 0.6-1.0 IU/mL for Lovenox or Fragmin, or unfractionated heparin, adjusted to achieve a ther­ apeutic PTT. This regimen is overlapped with beginning war­ farin to achieve an international normalized ratio ( INR) of 2.0-3 .0, such that heparin may be discontinued once the INR is therapeutic for 48 hours. In general, warfarin is then contin­ ued for at least 3-6 months or longer, and this interval determi­ nation is becoming more of an individualized decision based on the relative risks of recurrent VTE versus major hemorrhage (see Chapter 3 7 ) rather than on a population-based recommenda­ tion. The incidence of recurrent VTE and/or PE is highest dur­ ing the first 6-1 2 months after discontinuing anticoagulation, but the risk of a second VTE, depending on the patient's risk factors, can continue to be high for years. Population-based rec­ ommendations clearly favor prolonging anticoagulation; in tri­ als comparing 6 weeks versus 6 months of warfarin, the rate of recurrence was reduced by 50% by the latter. For a first-episode idiopathic VTE, warfarin for more than a year resulted in a 95% reduction in recurrence compared with a 2 7 % per patient year recurrence rate in those who stopped anticoagulation after 3 months. However, anticoagulation is continuously associated with the risk of a maj or bleeding episode of up to 3% per year. Based on these studies, recommendations regarding the length of therapy can be modified according to the relative risk of recurrence , whether high, moderate, or low. Patients who develop VTE in association with trauma, surgery, a fracture, or bed rest generally have a low risk of long-term recurrence ( < 5 % ) and can be treated for only 3 months. Patients who develop VTE without a provocative factor or who have a weak risk fac­ tor ( eg, estrogen use ) still have a less than 1 0% incidence of recurrence and can be conservatively anticoagulated for 6 months. New studies have recently suggested modifying the interval of treatment for such patients based on individual assessments of D-dimer levels and imaging of venous patency and recanalization. High-risk patients, however, are a different story. When a patient has had more than one VTE, a life-threatening PE, or suffers from VTE with an advanced malignancy, the risk of recurrence is greater than 1 0%-20%. These individuals deserve to be anticoagulated for an indefinite period unless they develop an increased risk for bleeding complications that clearly out­ weighs the thrombotic risk.

P R I N C I P L E S O F M A N AG E M E N T Good management depends on accurate diagnosis. Both the choice and duration of therapy differ greatly according to the nature of the thrombotic disease. As a general rule, patients with venous thrombosis or cardiac mural thrombi should immediately receive intravenous heparin and then change to full-dose war­ farin therapy. In contrast, patients at risk for coronary artery or cerebrovascular thrombosis are best managed with a platelet inhibitor such as aspirin and/or clopidogrel (see Chapter 3 7 ) .

Venous Thrombosis The best management of venous thromboembolic disease ( VTE) is prevention. This begins with a careful assessment of risk factors for DVT, including patient age , prior episodes of DVT or PE, paralysis, long-bone fractures, malignancy, obesity, congestive heart failure, estrogen use, and the presence of a pri­ mary hypercoagulable state. It also recognizes the thromboem­ bolic potential of trauma and surgery, especially orthopedic and neurosurgery. Hip and knee replacement surgery in patients who do not receive prophylaxis is associated with a greater than 50% incidence of VTE and a 6% fatal PE rate. This is reduced to less than 10% for VTE and less than 0.2% for PE mortality by pro­ phylaxis with low-molecular-weight heparin (LMWH) or low­ dose coumadin. Elastic stockings or intermittent pneumatic compression of the lower legs can also help reduce the incidence of VTE. Patients with a history of prior episodes of VTE or PE, or a hypercoagulable state, must receive prophylaxis, preferably with LMWH.

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B. lleofemoral Thrombosis Thrombolytic therapy has been used in patients with ile­ ofemoral venous thrombosis, where the risk of postphlebitic venous insufficiency is extremely high. Peripheral streptokinase use is effective less than 25% of the time, most likely because the thrombosis often completely occludes the vein, preventing the drug from reaching the clot surface. Catheter-delivered uroki­ nase can be more effective in this situation. Even when lysis is successful and venous patency is restored, it may still not prevent chronic venous insufficiency. This may reflect deep vein valves being irreversibly damaged early in the course of the thrombo­ sis. Since extension of this thrombosis retrograde, and also ante­ grade into the vena cava, is common, if catheter-delivered thrombolysis is not quickly successful, interventional radiologic consultation should be immediately sought for mechanical clot disruption and removal.

C. Vena Caval Filters In patients who have an absolute contraindication to anticoag­ ulation, or have had a maj or bleeding complication to thera­ peutic anticoagulation levels, the placement of a vena caval filter can be used to prevent recurrent PE. Available filters include the Greenfield filter, the bird's nest filter, the Simon nitinol filter, the Vena Tech filter, and the Gunther Tulip Retrievable Vena Caval Filter. The latter can be removed in 7-1 0 days if bleeding is controlled and anticoagulation can be reinstituted. The filters compare well in terms of efficacy, reduc­ ing the incidence of PE to less than 4% (median follow-up in most study series was 1 2- 1 8 months) , but are not more effec­ tive than long-term anticoagulation. In cancer patients who have recurrent VTE despite adequate anticoagulation, a vena caval filter combined with continued anticoagulation may pro­ vide greater protection. Complications include insertion site (20%--40% ) and inferior vena caval thrombosis, tilting or migra­ tion of the filter, damage to the wall of the inferior vena cava, and filter fracture.

D. Disease-Related Thrombosis Patients with malignancy and VTE can be a therapeutic chal­ lenge. Even with adequate warfarin to an INR of 2-3 , malig­ nancy is associated with a 1 5 %-20% recurrence rate and a similarly high risk of maj or bleeding complications. Moreover, it can be difficult to maintain a therapeutic INR because of changes in diet, drug interactions, periodic thrombocytopenia, and asso­ ciated liver disease. LMWH (eg, dalteparin 200 IU/kg once a day) has been shown to reduce the risk of both recurrence and bleeding by one-half, making it preferred over warfarin. Place­ ment of a vena caval filter may be necessary in refractory patients or patients who are actively bleeding. However, although vena caval filters reduce the short-term risk of PE, they can increase the long-term risk of DVT, especially forming on the filter itself. The duration of anticoagulation depends on the clinical status of the patient. Anticoagulation must be continued indefinitely in the face of active or metastatic malignant disease leading to thromboembolism. Even if a solid remission is achieved, treat­ ment should still be continued for at least 6 months.

FIGURE 36-3. Peripheral smear in essential thrombocythemia. Giant platelets, together with a marked increase in the platelet count, are seen in myeloprolifera­ tive disorders like essential thrombocythemia that are associated with increased thrombotic risk

Thrombosis associated with essential thrombocytosis ( ET) can present as an arterial event (stroke ) , venous thromboem­ bolism (VTE ) , or as microcirculatory insufficiency (erythrome­ lalgia) , the latter being especially noticeable in the distal extremities. The peripheral smear may demonstrate abnormal, giant platelets ( Figure 36--3 ), or only an elevated platelet count; platelet aggregometry is often abnormal. Unfortunately, predict­ ing thrombosis risk in ET using the platelet count or platelet function abnormalities has not succeeded; most patients are begun on anti-thrombotic therapy once they show signs or symp­ toms of thrombosis. Low-dose ( 8 1- 1 62 mg) aspirin has usually been combined with hydroxyurea or anagrelide to decrease the incidence of thrombotic events. Recent randomized studies have shown that the combination of anagrelide with aspirin, although decreasing the incidence of VTE, actually increases the rates of both arterial thrombosis and marrow myelofibrosis, despite equiv­ alent control of the platelet count. Thus, hydroxyurea and low­ dose aspirin should be the standard therapy for ET. When ET occurs in pregnancy, hydroxyurea cannot be administered; unfor­ tunately, low-dose aspirin alone is ineffective at preventing thrombosis or first-trimester fetal loss during pregnancy. E.

Pregnancy

Warfarin must be avoided in the treatment of venous thrombo­ sis during pregnancy because of its teratogenic potential. Unfractionated heparin and LMWH are both safe for therapeu­ tic anticoagulation since they do not cross the placenta. LMWH is preferred because it has reliable weight-based dosing and bioavailability such that it does not require constant monitor­ ing. A weight-adjusted dose of enoxaparin ( 1- 1 . 5 mg/kg) , dal­ teparin ( 200 U/kg ) , or tinzaparin ( 1 75 U/kg) administered once daily subcutaneously is the most convenient and can be given safely throughout pregnancy. In women who gain considerable weight, a periodic measurement of the anti-Xa level can be used to adj ust the dosage to achieve a therapeutic anti-Xa level of

CHAPTER 36

0.5-1 .0 U/mL measured 4-6 hours after dosing. Treatment with unfractionated heparin is a reasonable alternative, although monitoring ( PTT every 1-2 weeks ) is required. To avoid excessive blood loss at delivery, heparin therapy should be discontinued 24 hours before elective induction, and restarted 1 2-24 hours postpartum. For those patients who need extended anticoagulation, warfarin can be initiated in a similar timeframe. In the case of spontaneous labor, the risk of bleeding depends on the time between the last LMWH dose and the time of delivery. If unfractionated heparin was used, protamine sulfate can be used to reverse anticoagulation, but protamine does not reverse the LMWH anticoagulant effect. Caution also must be exercised in the avoidance of epidural anesthesia at delivery when women are receiving any heparin therapy, including LMWH. F.

TABLE 3 6-6

Risk Level

T H RO M B OT I C D I S O R D E R S

44 1

• Risk stratification for pediatricVTE therapy

Low

Standard

Definition

No predisposing conditions; transient trigger

1 -2 thrombophilic Factor 8 > I SO%; persistendy i traits D-dimer;APLA; �3 thrombophilic traits

High

Therapy

Anticoagulation only

Anticoagulation ± thrombolysis

Anticoagulation + thrombolysis

Duration

6- 1 2 weeks

3- 1 2 months

� 1 2 months

Cerebral Vein/Sinus Thrombosis

Thrombosis of the cerebral veins or sinus thrombosis mostly occurs in children and young adults. Cerebral vein thrombosis causes intracerebral edema, venous infarcts, and hematoma for­ mation, while sinus thrombosis often only demonstrates intracra­ nial hypertension with no other signs. Similar to any venous thromboembolism, risk factors include oral contraceptives, an adj acent procedure or trauma, and thrombophilic mutations; nearby infection is a unique risk factor for sinus thrombosis. Neu­ rologic symptoms may be nonspecific such as headache or seizures, but specific neurologic abnormalities occur, especially ocular. Diagnosis is best made using MRI with venography, but angiography may be required for definitive imaging. Immediate therapy is aimed at decreasing intracranial pres­ sures and anticoagulation, even if there is a hemorrhagic infarc­ tion; there is evidence that patients receiving unfractionated heparin prior to the transition to warfarin did no worse than those with warfarin alone. There are no data on the efficacy of thrombolysis. Warfarin should be adjusted to an INR of 2-3 for at least 6 months. Early mortality is about 6%, while long-term cumulative mortality reaches 9%. Nearly 90% of survivors make a full (or near-full) recovery; only 3 % of treated survivors have a recurrence.

is treated identically with removal of heparin exposure and use of direct thrombin inhibitors. Warfarin dosing, as in adults, can be variable in children, but the bleeding risk with oral antico­ agulation in children may be lower than in adults. As with adults, it is critical to monitor and maintain fibrinogen levels above 1 00 mg/dL and platelets above 50,000/J..LL in anticoagu­ lated children. Thrombolysis is recommended in high-risk children with VTE within 2 weeks of symptom onset, especially with an acute occlusive proximal DVT and an elevated factor VIII/0-dimer. Thrombolysis decreases the incidence of post-thrombotic syn­ drome at 1 8-24 months compared with anticoagulation alone. As in adults, the duration of therapeutic anticoagulation in high-risk children may require modification based on the pres­ ence of underlying diseases and risk factors. Risk factors that indicate a need for prolonged duration of therapeutic anticoag­ ulation include the presence of APLA syndrome or systemic inflammatory disorders (eg, systemic lupus erythematosus [SLE] , j uvenile rheumatoid arthritis ) . In the absence of specific risk guidelines, some studies suggest following levels of C-reactive protein, factor VIII, or D-dimer to determine if it is safe to dis­ continue anticoagulation.

G. Pediatric Thromboembolism

H. Thromboembolism in the Elderly

The diagnosis of pediatric VTE relies on similar methods used in adults, including ultrasound, magnetic resonance angiography ( MRA), and CT scans. Children with VTE have a similar rate ( 20%) of pulmonary embolism, and the diagnosis is made using the same techniques of helical CT or CT with angiography. Therapy for VTE in children, however, is somewhat different. For example, thrombolysis should always be considered in pedi­ atric VTE because of its generally excellent outcome (exceeding 90% patency in some studies ) . Stratification of children with VTE into low- , standard-, and high-risk groups may help in their management (Table 36-6 ) . Unfractionated heparin anticoagulation i n pediatric VTE is similar to that of adults and has the same complications, includ­ ing heparin resistance. As in adults, LMWH in children is easier to dose because of its superior bioavailability. Heparin-induced thrombocytopenia has an incidence of about 1% in children and

The rate of VTE begins to steadily rise after age 5 5 , and by age 80, the incidence of VTE is approximately 1 per 1 00 patient years, that is, 1 % per year; the rate of pulmonary embolism (PE) rises even faster with advancing age (Figure 36-4). The causes of this increased VTE incidence are multi-factorial. Clearly, co morbid conditions will enhance the risk of VTE, as well as the mortality rate from VTE and PE. Besides older age itself as a mortality risk from VTE, chronic diseases of the cardiac, pul­ monary, renal, and neurologic systems all promote the risk of death from VTE in older individuals. The rise in levels of thrombosis-related proteins with aging appears to be a VTE risk factor. Factor VIII and fibrinogen are increased with age, and higher levels may contribute to throm­ botic risk based on net thrombin generation. Interestingly, the regulation of plasminogen activator inhibitor- ! ( PAI- l ) is affected by aging itself, as well as several of the pathologic

442

1 200

s

g

c::i'

1 000

�

800

� �

��

D I S O R D E R S 0 F H E M O S TA S I S

SECTJON III

•

ALL VTE PE ± DVT

600

•

Q

.s

§

400

q:

200

§

80

Age group (years) F I G U RE 3 6--4. Annual incidence of venous thromboem bolism (VTE) and pulmonary embolism (PE) increases with age. VTE and PE rates are shown for

in older patients; indeed, the risk of VTE recurrence increases by 1 5 %-20% with each subsequent decade of age. As more of the population lives longer, the difficulty in deal­ ing with VTE in the elderly will become more critical, and spe­ cific studies are needed to determine risk and outcomes in order to make better-informed decisions. Currently, there are few data on the appropriate utilization of thrombolysis or inferior vena cava filters (temporary or permanent) in the elderly. However, studies on "personalized" medicine hold promise for individualiz­ ing therapy for older patients with VTE. For example, rather than discontinuing anticoagulation at a set interval (3 or 6 months) following a VTE episode, recent data suggest that following indi­ vidual patients with ultrasonography to determine recanalization and venous patency will better determine if anticoagulation can be stopped. Patients followed by the latter method had lesser recurrence rates of VTE than those who discontinued anticoagu­ lation at a set interval. This personalized approach may prove par­ ticularly useful in older patients with thrombosis.

the different age groups (adapted from Silverstein et al: Blood 2007).

Pulmonary Embolism processes that accompany aging, such that PAI- l activity is increased with age. This loss of fibrinolytic activity may pro­ mote thrombosis and vascular damage/atherosclerosis. Elevated D-dimer values in the elderly are also associated with thrombotic risk, but because the D-dimer level in blood normally increases with aging, this may affect the workup of elderly patients presenting with symptoms of VTE or PE. A "negative" D-dimer result is used to definitively exclude the risk for VTE/PE in patients who are classified as low probability based on widely used clinical algorithms. Since older patients have higher de novo D-dimer levels, there may be a higher incidence of false positives and older patients unnecessarily undergoing further VTE workup. An age-specific D-dimer cutoff value is not cur­ rently available. Other, perhaps independent causes of increased VTE inci­ dence in the elderly include obesity and both acute and chronic inflammatory diseases. The pathologic link between inflamma­ tion and thrombosis is well established, especially for arterial thrombosis risk; the laboratory investigation of the latter includes the "metabolic panel" and C-reactive protein. How­ ever, there is little knowledge of how inflammatory stimuli affect thrombosis risk with increasing age. Certainly the markers of the thrombosis/inflammatory link are increased with age, including the levels of factor 8, D-dimer, and fibrin generation. Hopefully, future studies will demonstrate the use of such assays for predicting VTE risk. Older individuals with VTE and/or PE show a higher morbid­ ity and mortality. This fact alone necessitates appropriate prophy­ laxis and aggressive diagnostic measures to determine VTE/PE occurrence in the elderly. However, the 30-day case fatality rates are still very high in older individuals, at 5% for deep vein throm­ bosis alone and 33% when VTE is associated with PE. Prophy­ laxis is critical for the latter category since at least 25% of older PE patients present with sudden death. Besides the acute event, the morbidity and mortality risk of VTE do not abate with time

The initial therapeutic approach t o a pulmonary embolus ( PE) will depend on the patient's hemodynamic status. Hemodynam­ ically unstable patients with massive or multiple pulmonary emboli should receive thrombolytic therapy (rt-PA 1 00 mg or urokinase infused over 2 hours) followed by full-dose unfraction­ ated heparin for 1 0- 1 4 days. Emergent thoracic surgery for embolectomy is dangerous but can be lifesaving in the patient with a large saddle embolus. Hemodynamically stable patients who demonstrate right ventricular hypokinesis on echocardio­ gram should also be considered for thrombolysis. The window of opportunity for thrombolysis is quite long, and patients will demonstrate a therapeutic response for up to 14 days. There is now good evidence that mortality is reduced and recovery is accelerated when thrombolytics are used in patients with large clot burdens. Otherwise, all patients who present with a high probability of PE, a positive lung scan, and/or ultrasound evi­ dence of a DVT with PE symptoms should receive heparin for 1 0-14 days followed by oral anticoagulation to an INR of 2-3 for at least 6 months. If the patient is clinically stable, the hos­ pitalization may be shortened by substituting LMWH, given as home therapy, after several days.

Cardiac Thromboembolic Disease Patients with unexplained atrial fibrillation or, even more important, atrial fibrillation with valvular disease, a dilated atrium, and evidence of heart failure or a previous systemic embolus should receive warfarin indefinitely with an INR target of 2-3 . Patients with acute anterior wall myocardial infarction who, because of a wall motion abnormality, are likely to form a mural thrombus need to receive warfarin for at least 2-3 months, after which anticoagulation should be guided by imaging results. Chronic anticoagulation is indicated in patients with artificial heart valves and dilated myocardiopathies, where valvular or mural thrombus formation, respectively, is likely. Acute antico­ agulation of patients with unstable angina with heparin and aspirin can reduce the incidence of acute myocardial infarction

C H APT E R 3 6

and death by 33%. Recent studies show a slight advantage of LMWH over unfractionated heparin, as well as a lower cost and a reduction in bleeding complications.

Primary Hypercoagulable States Management of the patient with a primary hypercoagulable state presents additional problems. First, the incidence of throm­ boembolic disease in patients with one of these conditions varies so much that therapy should only be considered for patients who exhibit a strong thrombotic tendency. Heterozygous factor V Leiden patients without a history of thromboembolism have a normal life expectancy and a low to normal risk of future throm­ boembolism. This is also true for family members of patients with clinical disease. They need not receive chronic anticoag­ ulation therapy. High-risk patients, who should be considered for lifelong anticoagulation, include those who have had more than 1 spontaneous thrombosis or a life-threatening throm­ boembolism, and any individual who is a double heterozygote. Asymptomatic carriers of factor V Leiden, lupus anticoagulant or antiphospholipid antibody, or an AT, protein C, or protein S defect should, however, always receive vigorous prophylaxis in situations that predispose them to thrombosis. In high-risk patients with the Leiden or G202 1 0A pro­ thrombin gene mutation or a deficiency of AT, protein S, or pro­ tein C, long-term anticoagulation with warfarin is recommended. Some caution must be taken in initiating warfarin therapy, espe­ cially in protein C- or S-deficient patients. These patients should receive full heparin anticoagulation prior to initiating the warfarin therapy, thereby preventing warfarin-induced skin necrosis. This rare complication is manifest by thrombosis of skin vessels within the first few days after beginning warfarin therapy. It is related to the rapid reduction of vitamin K--dependent pro­ tein C ( and perhaps protein S) levels by warfarin. Similarly, in patients with AT deficiency , heparin therapy may be unpre­ dictable. This situation reflects the lower than normal AT levels, or rarely, a defective AT protein. If full heparin anticoagulation is required, it may be necessary to provide the patient with exoge­ nous AT by administration of purified AT (Thrombate III ) , recombinant AT, o r transfusion o f fresh frozen plasma. Prophy­ lactic AT therapy can decrease the risk of thrombosis in defi­ cient patients undergoing surgery or during childbirth.

Antiphospholipid Antibodies Patients with antiphospholipid antibodies (APLA; especially lupus anticoagulants) and thromboembolic disease can repre­ sent a major therapeutic challenge. In women who have expe­ rienced recurrent fetal loss (but not other thromboembolic disease ) secondary to APLA or a lupus anticoagulant, heparin plus low-dose ( 8 1-162 mg/d) aspirin are recommended during pregnancy to prevent thrombosis of the placenta and loss of the fetus. Dosing with unfractionated heparin is suggested at 1 0,000- 1 5 ,000 U/d in divided doses, or daily LMWH can be substituted as prophylaxis (anti-Xa level of 0. 1-0.3 U/mL) for the duration of the pregnancy. However, women with APLA and a history of thromboembolic complications require more aggressive therapy during pregnancy, including therapeutic

T H R0 M B 0T I C D I S 0 R D E RS

443

LMWH ( 1 00 U/kg every 12 hours) subcutaneously (SC) or intravenous unfractionated heparin (aiming for a PTT 1 .5-2.5 times normal) . lf the PTT is prolonged by the lupus anticoagu­ lant and cannot be used to monitor heparin, the anti-Xa target level is 0.3-D.7 U/mL. When the APLA is a complication of active systemic lupus erythematosus (SLE ) , aggressive treatment of the primary dis­ ease can reduce the antiphospholipid titer and perhaps reduce the likelihood of thromboembolic complications. Indeed, severe SLE patients aggressively treated with hematopoietic stem cell transplant were shown to become lupus anticoagulant negative, and 80% of those with recurrent VTE were able to have their anticoagulant therapy discontinued after transplant. Patients with venous or arterial thrombosis with very clear lab­ oratory evidence of APLA and without other manifestations of autoimmune disease should receive therapeutic heparin, and then switch to long-term warfarin therapy with a target INR of 2-3. Most INR reagents are insensitive to APLA, but if the INR appears to be artifactually increased for the level of warfarin dosing, functional monitoring of factor II or X activity (20%-25% is the target value) can be substituted. One exception to the use of warfarin in APLA syndrome is when stroke is the only thromboembolic complication; in this circumstance, anti-platelet therapy with aspirin ± clopido­ grel appears to be the best therapy. Warfarin does not reduce the stroke recurrence rate more than aspirin. Anticoagulation should be continued indefinitely in APLA patients with a history of thromboembolism because the recur­ rence rate in such patients reaches 50%-60% per year when off anticoagulant therapy. The response to this treatment is variable. Some patients seem to do very well, whereas others continue to demonstrate a thrombotic tendency despite therapeutic antico­ agulation ( ie, INR of 2-3 on warfarin) . In refractory APLA patients, therapeutic options include increasing warfarin antico­ agulation to a target INR of 3-4, with or without low-dose aspirin; substituting therapeutic LMWH dosing; or immunother­ apy (eg, Rituxan or hematopoietic stem cell transplantion).

Arterial Thrombotic Disease Platelet inhibitors are of proven value in the prevention of coro­ nary artery and cerebrovascular thrombosis. Aspirin has been shown to decrease the incidence of myocardial infarction in patients with coronary artery disease, and the combination of clopidogrel and aspirin is routinely used for long-term treatment of ischemic cardiac disease. Dietary supplementation with folic acid, vitamin B12, and vitamin B 6 to lower homocysteine levels has not been shown to be effective in reducing the incidence of either cardiovascular or cerebrovascular disease in at-risk patients, and therefore should not be recommended for anti­ atherothrombosis therapy. In the treatment of acute arterial thrombosis, immediate throm­ bolysis, whether administered peripherally (rt-PA) or by catheter (urokinase), is key to successful recanalization and prevention of end organ damage. As demonstrated in coronary angioplasty patients (see below), agents such as the GPllb/llla inhibitors are effective in combination with clopidogrel and aspirin in the pre­ vention of rethrombosis following thrombolysis. Institution of

444

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heparin therapy is also strongly recommended in acute periph­ eral arterial disease ( PAD) , while warfarin with aspirin is used for chronic PAD.

Antithrombotic Therapy During Percutaneous Coronary Artery I nterventions Successful revascularization of the patient undergoing angio­ plasty/stents depends on effective anticoagulation to prevent acute and subacute thrombosis. Antithrombins (heparin, bivalrudin) and anti-platelet agents ( aspirin, clopidogrel, and the GPilb/Illa antagonists) are the mainstays of therapy dur­ ing the procedure. All patients should be preloaded with aspirin ( 3 2 5 mg) and clopidogrel ( 7 5 mg/d for 3 days or, for urgent cases, a single dose of 300 or 600 mg) . In the case of heparin, optimal dosing during angioplasty should increase the activated clotting time (ACT) to 250-300 seconds when used

C A S E H I S T O RY

Pa rt 3

The patient demonstrates several risk factors for throm­ bosis, including oral contraceptive use, a recent long air­ plane trip (venous stasis), and a presumptive family history of an inherited thrombophilia (father is on anticoagu lation therapy). This wil l require further testing but not as a pre­ requisite to beginn ing appropriate therapy. Based on the radiological studies, the patient has a deep vein thrombosis and bilateral pulmonary emboli with sig­ nificant clot burden in her lungs to lower her arterial 02 saturation. She is therefore a potential candidate for throm­ bolysis, especially in light of her presenting within 3 days of developing symptoms and the absence of comorbid condi­ tions that would increase her risk of bleeding. Following thrombolysis, she will need to be anticoagulated, beginning with heparin, and then transitioned to warfarin therapy with an I N R target of 2-3 for a prolonged period (>6 months). A search for other underlying thrombophilic defects is warranted in a young patient like this one. Without specific symptoms, an extensive workup for an occult malignancy is not efficacious. However, testing for an inherited/metabolic defect is in order. Therefore, a battery of coagu lation tests needs to be sent from the emergency room, prior to thrombolysis/anticoagulation, including tests for APC resist­ ance (APC-R/factorV Leiden), prothrombin G202 / OA muta­ tion, a lupus anticoagulant, and AT, protein C, and protein S levels. This patient's results are as follows: Prothrombin G202 / 0 mutation - not detected AT = 65% (SO'Yo- 1 20%)

alone, or 200-2 50 seconds when used together with a GPllb/llla antagonist. Once the procedure is over, the heparin can be discontinued and the sheath removed when the ACT falls below 1 7 0 seconds. Stent patients should then be main­ tained on both aspirin ( 8 1 mg/d) and clopidogrel ( 7 5 mg/d) for 4 weeks to 1 year after the procedure, to prevent subacute thrombosis until endothelialization of the stent has completed. The prominent role of platelets in the pathogenesis of throm­ bosis during standalone balloon angioplasty or when a stent is placed to maintain vessel patency has led to multiple trials look­ ing at the added effectiveness of a GPllb/Illa antagonist in com­ bination with heparin during the procedure. Three agents have been tried: abciximab (ReoPro), eptifibatide, and tirofiban. Each has shown a decrease in thrombosis and myocardial infarction at 3 months. The impact on long-term mortality is less clear. ReoPro has the longest duration of action and may have a greater pro­ tective effect, especially in ST segment elevation patients with myocardial infarction (MI).

l

I

Protein C = 60% (?O'Yo- 1 40%) Protein S = 35% (50'Yo- 1 50%) APC-R = 1 .80 (>2.20) d RVVT = 1 .22 ( < 1 .20) These coagu lation panel resu lts point out the difficulty in evaluating studies d rawn duri ng an acute th rombosis episode.AII of the natu ral anticoagulants-AT, protein C, and protein S-are slightly lower than the normal range, a fin ding that is common due to consumption of factors with an acute clot. When repeated once the patient fin­ ished her anticoagu lation, they are found to be normal. S i m i larly, testi ng for the l u pus anticoagu lant with the d i l ute RVVT can also be affected by acute stress or thrombosis. The most common inherited causes of thrombophilia are the factor V Lei den and proth rombin 2 02 1 0 muta­ tions; the latter was not detected in this patient, but the screening APC-resistance test for Leiden was abnormal. Unlike the natural anticoagulant activities, APC-R is not affected by acute th rombosis or anticoagu lation. When the APC-R result was confi rmed by mutational analysis, the patient was found to be heterozygous for the V Lei den mutation, as was her father on subsequent analysis. The heterozygous V Leiden mutation, by itself, does not increase the incidence of recu rrent thrombosis in other­ wise healthy i n d ivid uals. Therefore, the d u ration of her anticoagulation need not be extended and lifelong therapy is not indicated.

C H APT E R 3 6

P O I N T S TO R E M E M B E R Nel"ft''a l heme�ta�r� afl4: Withhold 1 day's dose and decrease weekly dose by 1 0%-20%

For very high INRs, 1 or 2 oral doses of vitamin K ( 2.5-5 mg) can be given, while continuing the warfarin therapy. This will speed the correction of the INR without completely reversing the patient's anticoagulation. Recommended target ranges for anticoagulation are listed in Table 3 7-2. For most situations, an INR range of 2-3 is recommended. Higher- intensity anticoagulation has been reported to provide protection against recurrent myocardial infarction and stroke in patients following acute myocardial infarction. However, high- intensity regimens are associated with an increased incidence of bleeding complications. The same is true for patients receiving chronic anticoagulation to prevent embolism from mechanical heart valves. This situa­ tion has led to recommendations for less intense regimens, INRs of 1 .5-2 . 5 , and regimens that combine lower-dose war­ farin with low-dose aspirin. The efficacy of these low-dose regimens appears to be comparable to that of the higher-dose approach in most instances, and bleeding complications are considerably less. Very low-dose warfarin, 1 mg/d, can signifi­ cantly reduce the incidence of catheter-related thrombosis in cancer patients.

CHAPTER 37

TABLE 37-2

•

A N T I C O A G U L AT I O N I N T H E M A N A G E M E N T O F T H R O M B O T I C D I S O R D E R S

Target ranges for warfarin therapy

Condition

INR

Duration

Venous thrombosis Treatment Prevention

2.0--3 .0 1 .5-2.5

3--{) months Chronic

Atrial fibrillation Embolus prevention

2.0--3 .0

Chronic

Myocardial infarction Embolus prevention postinfarction Prevent reinfarction

2.0--3.0 3.0--4 . 5

2-3 months Chronic

Mechanical heart valves Tissue valves Mechanical valves

2.0--2 .5 3.0--4 .0

Chronic Chronic

Arterial thrombosis Stroke prevention

2.0--4.0

Chronic

453

However, in patients at high risk for thromboembolism, bridging therapy with either unfractionated heparin or LMWH should be considered. Patients at increased risk of a periopera­ tive VTE include those who are within 3 months of a venous or arterial thromboembolism; have a history of recurrent VTE, an inherited factor deficiency (antithrombin, factors C and S ) , or an underlying thrombogenic illness (metastatic cancer, diabetes, severe hypertension, congestive heart failure) ; or patients in whom cardioembolism is likely ( mechanical heart valves and atrial fibrillation with valvular disease) . Bridging therapy involves treating with heparin immediately before and after sur­ gery to cover the gap in oral anticoagulation. Bridging studies of LMWH in mechanical heart valve patients have demonstrated a thromboembolism rate of less than 1 % and major bleeding of about 3 % , suggesting that bridging is safe in most surgeries. However, when a surgery is considered to be high risk for bleed­ ing, the bleeding rate for heparin bridging can increase to as high as 6%. In this situation, it may be prudent to delay heparin in such patients for at least 24 hours postoperatively or with­ hold bridging anticoagulation completely.

B. Management of Anticoagulated Patients during and after Surgery

C. Duration of Anticoagulation

The management of anticoagulated patients in the periopera­ tive period depends on the reason for the warfarin therapy and the duration of anticoagulation. Without full-dose anticoagula­ tion, patients with venous thromboembolism (VTE) run a risk of recurrence of greater than 1% per day in the first month fol­ lowing the event. Therefore, maj or surgery should be avoided when feasible for at least 1 month following a venous or arterial thromboembolism. If early surgery is required, the patient should probably receive heparin (either unfractionated or low molecular weight) perioperatively while the INR is less than 2-so-called bridging therapy. Unfractionated heparin has some advantage over LMWH. It can be discontinued 6-8 hours prior to surgery and restarted 1 2-18 hours later, minimizing the period of throm­ boembolic risk. Once-daily treatment with low-molecular­ weight heparin ( LMWH ) is also an option for perioperative anticoagulation. If a patient cannot receive heparin because of the higher risk of bleeding, a vena caval filter should be considered. The situation is very different for patients with a remote his­ tory of VTE without recurrence. These patients are at low risk of recurrent VTE in the perioperative period when oral antico­ agulation is interrupted. They are best managed by simply dis­ continuing the daily warfarin dose 4-5 days before surgery and then restarting it as soon as possible following the operation. Because it takes 3-4 days for an INR in the range of 2-3 to fall below 1 .5 and another 3 or more days to rise above 2.0, once the warfarin is restarted, the patient is subtherapeutic generally for only 4-8 days. If the INR has been maintained at levels above 3, the warfarin should be stopped 5-6 days earlier or a small subcutaneous dose of vitamin K ( 1 mg) can be given the day before surgery. Bridging anticoagulation with heparin is not warranted in low-risk patients because the bleeding risk with heparin ranges from 2%-4% in the postsurgical period and the case-fatality rate for a major bleed is about 8%-9%.

How long to continue oral anticoagulation in patients with VTE is a topic of intense debate. Population studies have provided an overall estimate for the frequency of recurrent VTE, but it is important to evaluate each individual patient's risk. Patients with VTE have an overall incidence of recurrent disease, once anticoagulation is discontinued, as high as 1 5 % per year. However, when patients with malignancy, long-term immobilization, certain factor deficiencies, and thrombophilia are excluded, the incidence is much lower. Relatively healthy patients followed after a 6-month course of oral anticoagulation in one study had only a 1 in 200 patient-year chance of a fatal pulmonary embolism. Moreover, the case-fatality rate was 9% for recurrent VTE, exactly matching the case-fatality rate for anticoagulation-induced bleeding; long-term oral anticoagula­ tion for VTE prevention carries about a 2% annual bleeding incidence. Some studies suggest that treated VTE patients can be fol­ lowed for recurrence risk on an individualized basis, for example, using the 0-dimer. If the 0-dimer result is prolonged ( > 500 ng/mL by enzyme-linked immunosorbent assay [ELISA] ) 1 month after stopping anticoagulation for a first unprovoked VTE, those patients were at increased risk of VTE recurrence (9% annual rate) compared to those with a normal 0-dimer (3.5% annual rate ) . Utilizing this approach may help in decision making with bleeding risk, but would require 0-dimer cutoff values to be val­ idated across multiple labs with different methods. Another "personalized medicine" approach to optimizing the duration of anticoagulation for VTE is to determine thrombus resolution (vein recanalization) with serial venous ultrasonog­ raphy. When compared to patients on fixed duration of therapy ( >6 months) , evidence for recanalization in one study was asso­ ciated with a reduced incidence of recurrent VTE, permitting a shorter course of therapy in that subset. However, these data are too preliminary to justify changing clinical practice. Perhaps, in

454

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D I S 0 R D E R S 0 F H E M 0 S TA S I S

the future, measurements of vein recanalization and 0-dimer levels, together with the age of the patient, bleeding risk, and complicating illness, can be incorporated in a decision-making algorithm that will help guide the duration of therapy.

Laboratory Monitori ng Although several laboratory tests can be used to monitor anti­ coagulation, the one-stage PT is the most popular. The test is quick and quite sensitive to reductions in the levels of prothrom­ bin and factors VII and X. The PT is not significantly prolonged by heparin given in therapeutic amounts. Therefore, it can be used to monitor coumadin therapy without interrupting a con­ tinuous heparin infusion. The sensitivity of the PT depends, however, on the type of thromboplastin used to initiate the reaction. Different commer­ cial thromboplastins have different sensitivities, varying over a 2- to 3 -fold range. This situation requires normalizing the pro­ thrombin time ratio for different sensitivity thromboplastins ( Figure 3 7-2 ) . By knowing the relative sensitivity of a commer­ cial thromboplastin, the international sensitivity index (lSI), the nomogram in Figure 3 7-2 can be used to calculate the inter­ national normalized ratio (INR). There is some evidence that the use of PT reagents with lower lSI values improves INR reporting by lowering its coefficient of variation by about two­ thirds; for this reason, many manufacturers are moving to lower lSI reagents. Traditionally, the PT has been measured on a venous blood sample by a local reference laboratory. However, instruments

designed to do a PT on capillary whole blood, collected by fin­ ger stick, are now available for office use and patient self-testing. The CoaguChek, ProTime Monitor, and Avocet instruments have all been approved for home use. Care needs to be taken to standardize the instrument's results to those of the local labora­ tory to guarantee appropriate dosing. Success keeping any patient within a therapeutic range will also reflect the frequency of PT testing and the attention given to following up the patient. Many medical centers now offer an anticoagulation management service dedicated to tracking patients who receive warfarin or heparin. Studies suggest that these services do much better maintaining patients within an appropriate therapeutic range, with a significantly lower incidence of bleeding.

Adverse Events A. Abnormal Bleeding Abnormal bleeding is the principal adverse effect of oral antico­ agulation. Risk factors that increase the likelihood of a bleed include advanced age; a preexisting medical condition, espe­ cially congestive heart failure or cancer, or bleeding diathesis; concomitant use of heparin or aspirin; and the intensity of the regimen. Generally, an INR below 3 should not by itself result in an abnormal bleed, while higher INRs are associated with a significant bleeding incidence of 20%-40% per year. The rela­ tive risk of bleeding can be, in part, predicted using the Blythe model, which uses various risk factors (age, recent stroke, cardio­ vascular disease, renal failure, diabetes mellitus) to derive a bleeding risk index. If a bleed occurs, the patient should be care­ fully worked up for an underlying medical condition. In the case of gastrointestinal bleeding, a full evaluation for ulcer disease or an occult neoplasm in the large bowel is required.

B. Contraindication ofWarfarin during Pregnancy Warfarin is contraindicated during pregnancy , especially during the first trimester. The drug freely crosses the placenta and can cause skin, bone, and central nervous system abnormalities in the fetus. Risk estimates for first trimester exposure are as high as 30%. Warfarin therapy at term will effectively anticoagulate the fetus with the possible risk of a significant fetal hemorrhage at delivery. If anticoagulation is required during pregnancy, heparin is a better alternative, especially the low-molecular­ weight heparins ( LMWH) .

C . Reversal ofWarfarin Anticoagulation

lSI

FIGURE 37-2. Nomogram for determining the I N R. The prothrombin time (PT) must be corrected for the sensitivity of the thromboplastin reagent in use i n t h e laboratory. B y knowing the published sensitivity o f the commercial thrombo­ plastin (lSI). the nomogram is used to convert the measured PT ratio (patient's PT/control PT) to

an

I N R The figure shows the example of converting a PT ratio

of 1 .7 for a thromboplastin with an lSI of 2.2.

Warfarin anticoagulation can be reversed completely with vita­ min K or transiently by the administration of fresh frozen plasma (FFP) to directly replace vitamin K--dependent coagu­ lation factors. The latter should be reserved for emergency sit­ uations such as, for example, an anticoagulated patient who must undergo immediate surgery. To reverse an INR of 3 or greater in preparation for emergency surgery, the patient should receive 1 0-20 mL/kg of FFP ( at least 1 ,000 mL) to increase lev­ els of factors II, VII, IX, and X to at least 30% of normal. Vita­ min K should also be given to correct factor production; otherwise, the PT will again rise as the infused factors, especially factor VII, which has a half-life of only 3-4 hours, are cleared.

CHAPTER 37

rl

A N T I C O A G U L AT I O N I N T H E M A N A G E M E N T O F T H R O M B O T I C D I S O R D E R S

C A S E H I S T O RY

1

Part 2

A surgical procedure requires reversal of oral anticoagula­ tion to guarantee adequate hemostasis during and after the operation. This does not generally apply, however, to low­ dose (8 1 mg/d) aspirin therapy since, unl ike high-dose anti­ platelet d rug therapy, it is not associated with increased perioperative bleeding. The key to management of a patient on long-term war­ farin therapy is to minimize the "unanticoagulated" interval and the associated risk for a thromboembolic event. Patients maintained at an I N R of 2-3 can usually be man­ aged by discontinuing their oral anticoagulant 4 days prior to their surgery to reach an I N R below 1 .5 on the day of surgery. This time interval wil l allow a return of depressed coagulation factors, in patients with normal liver function, to levels above 30%. If the patient has a higher chronic I N R range ( >3 ) , then warfarin should b e discontinued 5-6 days prior to the procedu re. If surgery is u rgent, the time delay to "normal izing the I N R" can be shortened by the administration of vitamin K or an infusion of fresh frozen plasma. However, while the I N R may appear to rapidly shorten with vitamin K therapy, this is largely a result of a rapid retum of factor VII, not factors

When there is less urgency, vitamin K given orally will effec­ tively reverse the warfarin effect within a few days. An INR greater than 4 can be brought into the therapeutic range within 2�8 hours by withholding the warfarin for that time and orally administering a single vitamin K dose of 2 . 5 mg. Several days of vitamin K therapy plus withdrawal of warfarin are required to completely reverse anticoagulation. Patients who have liver dis­ ease or have taken an overdose of warfarin can be resistant to therapy. Vitamin K 1 (phytonadione) is the recommended preparation. It is available as 5 -mg tablets, a liquid formulation containing 5-10 mg/mL for oral use, and a viscous liquid for inj ection ( AquaMEPHYTON ) . A dose of 2. 5-5 mg ( 2 . 5 mg if INR is between 6 and 10 or 5 mg if lNR > 10) of vitamin K 1 given orally is usually sufficient to decrease the INR to therapeutic levels of warfarin anticoagulation. Larger or multiple doses not only normalize the PT but also will make the patient resistant to reinstitution of warfarin therapy. Therefore, when a small dose of vitamin K is used to bring an elevated INR ( > 5 ) into the desired range of 2-4, warfarin need not be interrupted. With marked overdose or ingestion of rat poisons containing coumarin derivatives with extremely long half-lives, much larger

455

I

IX, X, and II (prothrombin), which still require several days to recover. In addition, vitamin K therapy can make it extremely difficult to reinstitute warfarin therapy after sur­ gery. Fresh frozen plasma must be given in volumes up to 1 - 1 .5 L (one-th ird of the estimated plasma volume in a patient with an I N R >2 and factor levels 1 02°F/39°C) or persistent fever fol­ lowing transfusion should be reason to draw blood cultures and, if available, culture the remnant of the transfused unit. It is now a US Food and Drug Administration (FDA) requirement that all platelet units be tested for bacterial contamination prior to transfusion; this policy has decreased the rate of post-platelet transfusion sepsis.

C OAG U LAT I O N FAC TO R C O M P O N E NTS As an integral part of blood component therapy, blood centers prepare fresh frozen plasma (FFP) and cryoprecipitate as respec­ tive sources of coagulation factors at physiologic levels, and a concentrated product containing fibrinogen, von Willebrand factor ( vWF), and factor XIII. FFP is most often used in patients with liver disease or those who require immediate reversal of warfarin anticoagulation. Both products are used for massive blood loss, where low factor and fibrinogen levels can result from dilution by the combination of colloid or electrolyte infusions, and large volume red cell transfusions. Low levels of coagula­ tion factors, especially fibrinogen and the common pathway fac­ tors, can also result from the consumptive coagulopathy associated with trauma.

Fresh Frozen Plasma FFP is harvested from donated whole blood as part of the prepa­ ration of platelet concentrates. Using a 3-bag system, the excess plasma/ACD solution lefr after the platelet concentrate centrifu­ gation step (- 200-250 mL) is transferred to the third bag, sepa­ rated, and frozen within 8 hours of collection. FFP can then be stored for up to 1 year at -20°C. At the time of transfusion, it is thawed at 3 7 °C, a process that takes 30-60 minutes. Once thawed, FFP should be transfused within 12 hours to guarantee adequate coagulation factor levels and sterility. FFP should be ABO compatible with the patient's red blood cells. Many blood centers also now provide a similar product known as plasma frozen within 24 hours of collection. As the name suggests, this product, unlike FFP, must be processed and frozen within 24 hours of initial collection. Plasma frozen within 24 hours is used because an 8-hour restriction ofren means that many whole blood dona­ tions cannot be used for FFP preparation. Thus, plasma frozen within 24 hours can help to alleviate or curb potential shortages of FFP. Studies have shown that the levels of coagulation factors in these products are virtually equivalent to FFP. Plasma transfusion may be used in several clinical situations (Table 38-5 ) . In all cases, FFP should be reserved for patients demonstrating coagulopathy by tests like the prothrombin time (PT) or partial thromboplastin time ( PTT). A common miscon­ ception with FFP use is that the higher the PT/PTT, the larger the dose of plasma is needed. This is not necessarily the case. Like any pharmaceutical product, the dose of plasma depends primarily on the weight of the patient receiving transfusion. To sustain a baseline factor level of 2 5%-30% ( ie, that which is

B L O O D C O M P O N E N T T H E RA P Y

TABLE 3 8-5

•

473

Indications for coagulation factor replacement

Fresh frozen plasma

Massive blood loss/transfusion Emergency reversal of warfarin therapy Factor replacement in DIC Treatment of hereditary coagulopathies (if purified factor unavailable) Liver disease C ryoprecipitate

Treatment of factor XIII deficiency Fibrinogen replacement, particularly in DIC Bleeding associated with uremia Purified and recombinant factor preparations

von Willebrand disease Inherited factor deficiencies

necessary to maintain adequate coagulation function), a plasma dose of 1 0- 1 5 mL/kg is often sufficient for most coagulopathic patients. In the setting of trauma, as a general rule, transfusions for massive blood loss should follow a 1 : 1 : 1 ratio of red cells:FFP:platelets as closely as possible; this ratio has resulted in improved hospital survival for combat injuries. Thus, a pool of platelets and 6 U of FFP should be transfused for every 6 U of red blood cells transfused, with additional FFP or platelets given according to the clinical situation (see Chapters 3 1 and 3 5 ) . When FFP i s used t o treat a PT greater than twice the con­ trol value in an adult patient weighing 70 kg or more, an appro­ priate plasma dose of 4-6 U ( - 800- 1 , 200 mL) must be given to achieve factor levels of greater than 30%. Each FFP unit increases coagulation factor levels by only 2%-3 % . Thus, attempting correction of the PT may involve the transfusion of close to 1 ,500 mL of plasma/ACD solution, and unless the patient is actively bleeding, can result in volume overload and congestive heart failure. Certainly, subsequent FFP infusions may be limited by the large volumes required for an appreciable incremental impact on factor levels. In addition, any sustained benefit from transient FFP correction of the PT requires a nor­ mal level of coagulation factor production by the liver. Patients with severe liver disease will benefit only briefly, often for only a few hours, before the transfused coagulation factors, especially factor VII, decline and the PT rises once again. In this regard, it is also important to remember that the effects of plasma infu­ sion induce only a temporary correction of coagulation tests. For instance, the duration of the correction of the PT following plasma infusion correlates with the half-life of factor VII, which is about 4-6 hours. Thus, the timing of plasma infusion is an extremely important aspect of FFP therapy. For the non-bleeding patient with a prolonged baseline PT who is receiving plasma transfusion to prevent complications from invasive procedures, the plasma should be infused as close as possible to the start time of the procedure. Provision of plasma more than 4-6 hours before the start of a procedure will only result in a return to a coagulopathic state at the time when the patient's procedure is

474

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to begin ! One good strategy for prophylactic reversal of a pro­ longed PT prior to an invasive procedure is to infuse 1 U of FFP immediately before the procedure and 1 U during the procedure. In this way, the patient will attain maximal coagulation status precisely when it is most needed. Like red cells and platelets, plasma can induce virtually all types of transfusion reactions. In fact, antibody-mediated reac­ tions like TRALI are most common with plasma products because of the opportunity to encounter high-titered antibody ( red cells and platelets have a much smaller plasma fraction) . Allergic reactions are also quite common following plasma infu­ sion. Finally, because of the large volumes sometimes necessary to replace coagulation factors in large patients or those with per­ sistent, ongoing bleeding, plasma infusions may also commonly be associated with circulatory overload. Adverse events to plasma infusion are treated in the same way as those following transfusion of red cells or platelets, as discussed above.

C ryopreci pitate Cryoprecipitate ( cryo) is prepared by flash freezing fresh plasma and then thawing it at 4°C. This process leaves a residual pre­ cipitate, once the plasma/ACD supernatant is removed, of cry­ oproteins, including fibrinogen, fibronectin, vWF, and factors VIII and XIII. The procedure recovers 1 50-200 mg of fibrinogen and 80--100 U of factor VIII/vWF in 1 5 mL of residual plasma, a 1 0-fold concentration over FFP. Cryoprecipitate units can then be stored for up to 1 year at 4 oc. The greatest advantage of cryo is its small volume-large amounts of fibrinogen can be replen­ ished with only a few hundred milliliters of fluid. As with plasma infusions, cryoprecipitate is dosed by weight and is based, in part, on a patient's underlying fibrinogen levels. Since this calculation can be complicated and not easily performed in the acute set­ ting, as a general rule, an adult patient with hypofibrinogenemia should receive a pool of 10 U of thawed cryo, which should be infused within 4 hours of pooling. Indications for cryoprecipitate therapy are listed in Table 38-5 . Each unit of cryoprecipitate will raise a patient's fibrinogen level by only 5-10 mg/dL. Thus, when it is used to treat hypofib­ rinogenemia (fibrinogen levels < 1 00 mg/dL) , a minumum of 10 U need to be pooled, which is sufficient to increase the cir­ culating fibrinogen level in an average-sized adult by at least 100 mg/clL. Following transfusion, the fibrinogen level should be monitored and repeated infusions given to maintain levels above 1 00 mg/clL. The amount required will vary with the rate of fib­ rinogen consumption. Cryo can also be used as a low-volume therapy to replete factor XIII levels in the setting of congenital or acquired deficiencies. There is also growing evidence to sug­ gest the use of cryo for bleeding associated with uremia. In this condition, circulating platelets do not function properly, often leading to microvascular oozing and bleeding. Although the mechanism of action of cryo in this setting remains unclear, it is theorized that the high levels of vWF attained post-infusion promote platelet adhesion and activation, helping to overcome acquired functional defects. The treatment of von Willebrand disease ( v WD) itself is often empirical and depends on the disease subtype. In the past, doses

of cryoprecipitate ranged from 20--30 pooled units per day in an adult with severe type 1 or 3 disease to fewer than 10 U/d for those with mild disease ( see Chapter 3 2 ) . However, with the development of virally inactivated, intermediately purified factor VIII concentrates containing large amounts of vWF (eg, Humate-P), cryoprecipitate is no longer the product of choice in the treatment of vWD and should only be used for this indication if no virally inactivated factor VIII or vWF concentrates are read­ ily available. Cryoprecipitate is also used in the operating room for the preparation of fibrin glue for topical surgical hemostasis.

Purified and Recombinant Factor Preparations The treatment of the inherited coagulopathies has changed dra­ matically, first with the purification of individual factors from pooled plasma, then with viral inactivation methodology, and now with the synthesis of recombinant coagulation factors and growth factors, the latter including erythropoietin and now pos­ sibly useful thrombopoietin mimetics. Recombinant technology has opened the door to a highly sophisticated approach to the management of both bleeding disorders and some thrombotic pathologies. See Chapters 3 1 , 33, 34, and 36 for a full discussion.

IPOI NTS TO

REMEMBER

Transfusions and the choice of the most appropriate blood compo­ nent(s) should always be targeted to a specific clin ical problem whether blood loss, thrombocytopenia, or coagulopathy. Leukodepleted red blood cells are the units of choice for transfu­ sion therapy for anemia, blood loss, or both. Frozen red blood cells are used for patients with rare blood types or alloantibodies to high frequency antigens. I rradiated and CMV-negative/leukodepleted red cells are preferred for transplant and other immunocompromised patients. Washed red cells are reserved for rare patients who requ i re removal of plasma to deplete lgA (lgA deficiency) or those at risk of hyper­ kalemia (dialysis dependence). All blood products are tested for transmissible diseases, includ ing viral hepatitis (H BV, HCV), H IV- 1 and -2, and West Nile virus. Nucleic acid ampl ification testing (NAT) has greatly reduced the incidence of transfusion-transmitted viral i nfections. Testi ng of platelet units for bacterial contami nation (because platel ets are stored at room temperature for 5 days) has reduced the incidence of post-transfusion sepsis. As a routine, patients should only receive ABO and Rh type-specific blood. In response to a "type and crossmatch" order from the physi­ cian, the blood bank determines the recipient's ABO and Rh type and screens for serum antibodies to minor blood group antigens. Selected units are then crossmatched (test of donor cells against patient serum for ABO compatibil ity). This procedure can take 30 minutes or more.

CHAPTER 38 When patients requ i re immediate red cell transfusion, u ncross­ matched type 0, Rh-negative, or ABO type-specific red cells can be used. FFP should also be type specific, but unless there is alloimmu­ nization, platelet transfusions do not require typi ng. Transfusion of incom patible (ABO mismatched) blood is most often the result of clerical and identification errors at the bedside, not a crossmatching error in the laboratory. Therefore, strict adherence to transfusion policies cannot be emphasized enough. An ABO-mismatch hemolytic transfusion reaction (usually a unit of type A blood given to a type 0 patient) is characterized by fever, chills, chest and low back pain, and hypotension. If any of these signs are present, the transfusion must be disconti nued immediately. Other compl ications of transfusion include a delayed hemolytic transfusion reaction (due to a minor blood group incompatability), an lgE-driven allergic reaction, and TRALI, an infrequent but severe compl ication that must be aggressively treated with respi ratory support.

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475

Platelet transfusions are given either a s pools combined from 4-6 random single donors or as a cytapheresis unit prepared from I donor. Patients receiving chronic platelet transfusions have a high rate of alloimmunization, resulting in refractoriness to subsequent platelet transfusions. Platelet "crossmatching" for H LA-compatible platelets is used to improve platelet recovery in such patients. Fresh frozen plasma (FFP) contains all of the coagulation factors at physiologic levels and is most often used to replace factors I I,V,VII, X, and XI when there is l iver disease or vitami n K deficiency ind uced by warfarin. Because of the short half- life of factor V I I , correction o f the P T i s short-lived i f these underlying abnormalities are not remedied. Cryoprecipitate, an en riched product from plasma, has very high concentrations of fibrinogen, factor X I I I , and vWF. Cryoprecipitate transfusion is used to treat bleeding associated with low fibrinogen levels, such as acquired with disseminated intravascular coagulation (DIC), and uremia, and congenital factor XI I I deficiency.

Platelet transfusions are one of the mainstays of supportive care for thrombocytopenic patients receiving intensive chemotherapy where they are transfused prophylactically for severe thrombocy­ topenia and for any bleeding symptoms. Platelet transfusion is also indicated for bleeding caused by acquired (drug-induced) or congen­ ital platelet dysfunction.

B I B L I O G RA P H Y Borgman MA et al: The ratio of blood products transfused affects mortality in patients receiving massive transfusions at a combat support hospital. J Trauma 2007;763 :805 . Kerkhoffs JLH et al: A multicenter randomized study of the efficacy of transfusions with platelets stored in platelet additive solution II versus plasma. Blood 2006; 1 08:3 2 10. Marks PW: Thrombocytopenia and platelet transfusion. In: Simon TL, Snyder EL, Solheim BG, Powell CP, Strauss RG, Petrides M, eds: Rossi's Principles of Transfusion Medicine. Wiley Blackwell, 2009; 1 99-210.

Pomper OJ : Febrile, allergic, and nonimmune transfusion reactions. In: Simon TL, Snyder EL, Solheim BG , Powell CP, Strauss RG, Petrides M, eds: Rossi's Principles of Transfusion Medicine. Wiley Blackwell, 2009;826-846. Silliman CC, Ambruso DR, Boshkov LK: Transfusion-related acute lung injury. Blood 2005 ; 1 05 :2266. Tormey CA, Snyder EL: Transfusion support for the oncology patient. In: Simon TL, Snyder EL, Solheim BG , Powell CP, Strauss RG, Petrides M, eds: Rossi's Principles of Transfusion Medicine. Wiley Blackwell, 2009;482-497 .

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I N D EX Note: Numbers followed by f and t denote figures and tables, respectively. A

Abbott Cell-Dyne instrument, 1 7 Abciximab, 447, 463 adverse effects, 45 1 clinical applications, 449 pharmacokinetics of, 449 therapeutic guidelines, 450 Abdominal pain, 1 1 7, 1 79 upper quadrant, 1 85 VP and, 1 79 Abelson proto-oncogene, 230 Absolute lymphopenia, 259 ABVD regimen, 307, 307t Acanthocytosis, 1 50, 1 50f ACD. See Plasma/acid citrate dextrose Acquired anemias, 1 88 Acquired angioneurotic syndrome, 262 Acquired coagulation defect, 4 14-41 5 , 445 Acquired coagulation factor abnormalities, 4 1 6-4 1 7 Acquired deficiencies of single factors, 4 1 4, 4 1 4t Acquired disorders of platelet function, 387f, 388-389 Acquired factor IX inhibitors, 400 Acquired factor VIII inhibitors, 400 Acquired immune deficiency, 258 Acquired immune deficiency syndrome. See AIDS Acquired immunodeficiency disorders, 262-265, 262t Acquired single-factor deficiencies, 4 1 9 Acquired von Willingham disease, 3 6 1 ACT. See Activated clotting time Actin, 2 Activated clotting time (ACT), 457 Activated partial thromboplastin time (aPTT), 347, 350-35 1 , 350f, 353, 355 heparin therapy and, 45 7-458 vascular purpura, 358 Activated protein C (APC), 345, 345f, 425, 46 1 Activated protein C (APC) resistance, 429f, 433-434 Activated protein C-resistant test for Leiden, 444 Activated prothrombin complex concentrate. See FEIBA Active kinase mutation, 3 1 2-3 1 3 Acute anemia, 8, 8t

Acute arterial thrombosis, 443 Acute blood loss, 7, 1 1 , 1 24, 134 Acute chest syndrome, 86, 91, 92 Acute coronary syndrome, 460 Acute Epstein Barr virus, 1 46 Acute extravascular hemolysis, 143-147 Acute hemodialysis, 426 Acute hemolytic event, 1 39, 1 44, 1 45t Acute inflammatory anemia, 46 Acute inflammatory disease, 45 Acute inflammatory states anemia and, 46-4 7 ferritin studies, 1 86, 1 86f Acute intermittent porphyria (AlP), 1 77 hormones and, 1 79 therapy, 1 80--1 8 1 Acute intravascular hemolysis, 139 diagnosis, 1 43-144, 1 44t measurements of, 138, 138f Acute lymphocytic leukemia (ALL), 3 1 1-3 1 8 case history, 3 1 1 , 3 1 5, 3 1 7 classifications, 3 1 1-3 1 3 genetic, 3 1 1-3 1 2, 3 1 2t immunophenotypic, 3 1 1 , 3 1 1 t morphologic, 3 1 1 , 3 1 1 t diagnosis, 3 1 5-3 1 6 laboratory abnormalities, 3 1 4-3 1 5 points t o remember, 3 1 8 risk factors, 3 1 4t therapy and clinical course, 3 1 6-3 1 7, 3 1 6t central nervous system, 3 1 6--3 1 7 remission induction, 3 1 6 tumor growth studies, 3 1 5 Acute mononucleosis-like syndrome, 263 Acute myeloid dysplasias, 2 1 0, 220 Acute myeloid leukemia (AML), 8, 36, 1 1 0, 2 1 5-228, 3 1 3 case history, 2 1 5 , 22 1 , 223 , 226 clinical features, laboratory studies, 220--22 1 cytotoxic chemotherapy, 1 2 1 diagnosis, 222 with genetic abnormalities, 222 genetic mutations, 2 1 9-220, 2 1 9t incidence of, 2 1 5-2 1 6, 2 1 6f with multilineage dysplasia, 222 not otherwise categorized, 222 points to remember, 227 relapse and, 226 secondary to therapy-related myelodysplasia, 222

Acute myeloid leukemia (AML) (Cont . ) : therapy, 223-22 7 allogeneic stem cell transplantation, 225-226 autologous marrow transplantation, 226 emerging, 226-227 empiric antibiotic, 224 guidelines, 223-224 postinduction and maintenance, 225 relapse, 226 remission induction, 224-225, 325f Acute myocardial infarction, 1 85 Acute normovolemic hemodilution, 133 Acute promyelocytic leukemia (M3 ), 222 Acute tubular necrosis, 152 Acyclovir, 223 ADA. See Adenosine deaminase deficiency ADAMTS 1 3 , 345, 358, 366, 369, 377, 3 8 1 , 385, 392, 424 protease activity, 426 Adaptive immune system, 335 Addison disease, 49 Adenosine 5'-diphosphate (ADP), 1 50, 342, 349, 357, 420-42 1 Adenosine deaminase deficiency (ADA), 260 Adenosine triphosphate (ATP), 1 , 386 ADH. See Inappropriate antidiuretic hormone ADP. See Adenosine 5 '-diphosphate Adriamycin, 296 Adsol, 469 Adult globin gene expression, 66 painful sickle crises, 88 Adult autoimmune thrombocytopenia, 379-380 Adult hematopoietic stem cells, 1 55-156, 162 Adult leukemias, 336 Adult sickle cell anemia, 81, 91 Adult T-cell leukemia/lyrnphoma (ATLL), 274-275 Affinity-purified Vlll, 407 Affymax. See Hematide African Americans iron overload in, 1 89 neutrophil counts and, 203 sickle cell trait, 92 Age anemia by, 1 56, 1 56f factor VIII and, 44 1-442, 442f

478

I N DEX

Age (Cont . ) : globin gene expression and, 66 oral anticoagulation, 452 Aggregometer, 386 Aging process. See also Elderly; Older patients hematopoietic cell lines and, 28 immune system and, 252 stem cells and, 1 55-156 AIDS (Acquired immune deficiency syndrome) , 258, 266, 279, 358. See also HAART; Zidovudine B-cell lymphoma, 289 consumptive thrombocytopenia, 368 course of infection, 263, 263f drugs for, 265-266, 265t erythropoietin therapy, 5 1 hematologic manifestations, 263-264 hemophilia and, 401 hypoproliferative anemia and, 48 staging classification, 263, 264t AIDS-associated thrombocytopenia, 373, 3 79 AIDS-defining illnesses, 263 , 264t AIDS-related lymphoma, 264, 296 AIHA. See Autoimmune idiopathic hemolytic anemia AlP. See Acute intermittent porphyria AITP. See Autoimmune idiopathic thrombocytopenic purpura Albumin, 1 26-1 27 Albumin solution, 1 29 Alcohol ingestion, 1 04, 105, 1 1 5, 1 59, 1 79, 1 80, 1 87, 2 1 1 Alcoholic liver disease, 1 89 Alcoholism, 97, 1 02 Alemtuzumab, 295 Alkalosis, 5 Alkylating agents, 1 52, 24 1-242, 3 3 1 ALL. See Acute lymphocytic leukemia Allergic reactions blood transfusions and, 4 70 RBC transfusion, 1 3 1 Alloantibodies to factor VIII, 400 painful sickle crises and, 89 Allogeneic blood transfusion, 135 Allogeneic bone marrow transplantation, 52, 277 AML and, 226, 226f anemias, 1 1 9 CML, 240 RAEB- 1 , 1 2 1 i n thalassemia, 78 Allogeneic hematopoietic stem cell transplantation (Allogeneic !-ISCT) , 242, 296-297 AML, 225-226 CLL, 273 1-IL relapse and, 309 Allogeneic 1-ISCT. See Allogeneic hematopoietic stem cell transplantation Allogeneic transplantation, 3 1 7 Alloimmunization, 36, 475 I-ILA, 3 76, 465-466, 469, 472 All-trans retinoic acid (ATRA) , 2 1 9, 223, 224-225, 226

Alport syndrome, 368, 368f Amenorrhea, 1 84 Amicar, 406 vascular purpura and, 361 vWD and, 395 Amino acid sequencing, 4 1 3 Aminocaproic acid (EACA), 406 hemophilia and, 404 liver disease, 4 1 7 Amiodarone, 45 1 AML. See Acute myeloid leukemia Ampicillin, 389, 389t Amyloid glomerulopathy, 330 Amyloid test, 330 Amyloidosis, 3 1 9, 329-330, 329t, 361 clinical presentations/symptoms, 329t Anabolic steroids anemia and, 48-49 warfarin and, 45 1 Anagrelide, 241-242 Analgesics, 2 1 1 Anaplastic large cell lymphoma, 290 Androgen therapy, 40 Anemia(s), 6, 1 2f, 72, 96, 98, 220, 23 1 , 3 70. See also Drug-damage anemia; Severe anemias; Severe aplastic anemia; Sideroblastic anemias; stJecific anemias

acute inflammatory states and, 46-47 age, 1 56, 1 5 6f approach to patient, 23-25 blood loss and, 1 26 case history, 1 0, 25 of chronic disease, 44t, 45 , 47-48, 52, 1 5 7-158 of chronic renal disease, 158 classification of, 24, 24f, 24t clinical approach to, 1 0-26 clinical evaluation, 1 1-23 diagnosis, 1 88 E/G ratio and, 8 in elderly, 1 1 1 , 1 55-1 62 case study, 1 5 7 , 1 6 1 functional implications, 1 60-1 6 1 points to remember, 1 62 therapy, 1 6 1-162 endocrine disorders, 48-49 environmental exposures, 1 1 erythropoietic profiles, inflammatory disease and, 44, 44t erythropoietin production and, 7f hypometabolic states, 48-49 of inflammation, 52 laboratory tests, 1 2-23 management guidelines, 25 MM, 324, 328 myelofibrosis, 24 1 points to remember, 25-26 postoperative, 133 pregnancy and, 49 preoperative, 1 27 with reduced erythropoietin response, 42-52, 44t, 46t case history, 4 2, 46 clinical features, 4 2-46 diagnosis, 46-49

Anemia(s), with reduced erythropoietin response (Cont. ) : differential diagnosis, 49 points to remember, 52 therapy, 49-52 of renal disease, 25, 48 therapy, 5 1 screening tests, 1 2, 1 2t severity of, 44 sudden onset, 3 1 types of, 1 5 7-1 60, 157t unexplained, 1 60, 1 62 Anemia-related exercise limitation, 1 60- 1 6 1 Angiography, arterial thrombus, 433 Angio-immunoblastic lymphadenopathy, 290 Angiotensin II, 7 Anglo-immunoblastic T-cell lymphoma, 290 Aniline dyes, 1 46 Anisocytosis, 1 7f, 58, 72 Ankyrin, 148 Ami-Bd2 antisense nucleotides, AML and, 227 Anti-CD45 radio labeled antibodies, AML and, 227 Anti-D IgG, severe autoimmune thrombocy­ topenia, 3 79, 3 79£, 380 Antibiotics, 1 1 5 neutrophil dysfunction, 2 1 2 platelet function and, 389, 389t sickle cell anemia, 9 1 Antibody production defects, 266 screening, 468 Antibody-heparin-PF4 complex, ELISA assay, 366 Antibody-toxin conjugates, 227 Anticoagulant factors, 346 Anticoagulant pathways, 427, 428, 429 Anticoagulants, 4 1 4, 4 1 4t, 427. See also Oral anticoagulants circulating, 353-354 venous thrombosis and, 445 Anticoagulation therapy, 433 , 44 1 monitoring, 4 1 8 points t o remember, 463 sickle cell anemia, 9 1 for thrombotic disorders, 4 47-464 case history, 447, 455, 462 Anticonvulsants, AlP and, 1 79 Anti-D antibody (RhoGAM), 1 3 1 Ami-D therapy, AIDS-associated thrombocytopenia, 379 Antifibrinolytics, hemophilia and, 406 Antifungal therapy, 223, 324 Antigenic assays, 434 Antigen-presenting cells, 245 Antigens. See specific antigen Antihistamine/1-!2 blockers, 2 1 1 Antihistamines, anaphylactoid reaction, 395 Anti-l-ILA antibodies, 3 7 Anti-IL-5, chronic eosinophilic leukemia, 242 Anti-intrinsic factor antibody, macrocytic anemias, 1 00 Antileukemic allogeneic effect, 225

I NDEX

Antimyeloma chemotherapy, mild hypercalcemia, 327 Antiparietal cell antibody, 100 Antiphospholipid antibodies (APLAs), 434, 435, 44 1 , 443, 445 hypercoagulability and, 438 Antiphospholipid syndrome, 427 a2-Antiplasmin, 345, 352, 422 deficiency, 358 levels, 4 1 5 Anti-platelet agents, 46, 396 clinical applications, 449 during percutaneous coronary artery interventions, 444 pharmacokinetics of, 448-449 primary thrombocythemia, 242 thrombotic disorders, 447-45 1 Anti-platelet antibody assays, for ITP, 374 Anti-thrombin (AT), 345 , 42 1 , 463 deficiency, types, 436-43 7 levels, 4 1 5 DIC, 422 therapy, 443, 444 Anti-thymocyte globulin (ATG) , 1 2 1 GVHD and, 38 horse-derived, 39 pure red blood cell aplasia, 40 Antithyroid medications, occasional idiosyncratic neutropenia, 2 1 1 Antiviral therapy, 223 Anti-vWF antibody, lVIG and, 395 Anti-Xa agents, 463 Anti-Xa inhibitors, 460 APC. See Activated protein C Apheresis, 4 7 1 APLAs. See Antiphospholipid antibodies Aplastic anemia, 7, 32, 3 2t, 33, 40, 1 89, 367. See also Severe aplastic anemia ferritin studies, 1 86, 1 86f radiation and, 32 therapy selection, 39f of unknown etiology, 33-34 immunosuppressive therapy and, 38 Aplastic crisis, 1 48, 1 49f aPTT. See Activated partial thromboplastin time AquaMEPHYTON, 455 Arachidonic acid metabolism, abnormal, 390 Argatroban, 46 1 HIT, 378 Arginine butyrate, painful sickle crises and, 90 Arsenic trioxide, 225 Arterial system clots, 445 Arterial thromboembolism, 443, 445 . See also Venous thromboembolism Arterial thrombosis, 1 65. See also Acute arterial thrombosis; Venous thromboembolism diagnosis, 433 Arterial thrombotic disease, 443-444 Arthritis, differential diagnosis, 1 84 ASCT. See Autologous hematopoietic stem cell transplantation Aseptic necrosis adult sickle cell anemia, 8 1 of femoral head, 9 1

Aseptic necrosis (Cont . ) : o f hip, 9 2 o f humeral head, 9 1 Aseptic vasculitis, 3 6 1 Ashkenazi Jewish population, 337, 409 Asparaginase, ALL, 3 1 6, 3 1 6t Aspirin, 349, 377, 386, 390, 395, 396, 443, 447 , 449, 452, 462, 463 adverse effects, 450-45 1 clinical applications, 449 ET and, 440 laboratory monitoring, 450 during percutaneous coronary artery interventions, 444 pharmacokinetics of, 448 platelet function and, 385, 386t primary thrombocythemia, 242 therapeutic guidelines, 449-450 Aspirin-induced platelet dysfunction, 385, 386, 386t Assays antigenic, 434 anti-platelet antibody assays, for ITP, 374 for antithrombin, 434 cell marker assays, 298-299 of coagulant activity, 402 erythropoietin, 1 69 fibrinogen, 350f, 35 1 , 353 high-grade DIC, 422 of fibrinogen concentration, 4 1 3 genotypes, 298-299 humeral effects, 285 inherited hypercoagulable state, 433-434, 434t PAlg assay, 366 PCR amplification assays, 407 PFA, 355, 402 for platelet structure, 386 for protein C, 434 for protein S, 434 reticulated platelet assay, 3 7 1 serum erythropoietin level, 1 6 7 serum methylmalonic acid, 98, 98f, 1 0 1 thrombin time, 347 dysfibrinogenemias, 4 1 3 von Clauss kinetic assay, 35 1 von Willebrand factor {vWF), 386 Asthenia, 1 84, 1 84t AT. See Anti-thrombin Ataxia-telangiectasia, 26 1 ATG. See Anti-thymocyte globulin Atherosclerosis, 44 7 ATLL. See Adult T-cell leukemia/lymphoma ATM gene mutations, 261 ATP. See Adenosine triphosphate ATRA. See All-trans retinoic acid Atrial fibrillation, warfarin and, 452 Atrophic gastritis, B 1 2 malabsorption and, 1 00 Audiometry examinations, iron chelation therapy, 77 Auer rods, 2 1 6-2 1 7, 2 1 7f Autohemolysis tests, 1 4 1 , 1 4 l f HS/HE, 150 Autoimmune disease, 2 1 1 , 368 immune response suppression and, 250 Autoimmune disorders, 40, 3 73-374

479

Autoimmune hemolysis, 1 5 1 , 1 5 2 Autoimmune hemolytic anemia, 1 42, 1 4 7 cephalosporins, 1 46 therapy, 1 5 2 Autoimmune idiopathic hemolytic anemia (AIHA), 147, 1 47t Autoimmune idiopathic thrombocytopenic purpura (AITP), 366, 374-3 75 Autoimmune neutropenia, 2 1 1 Autoimmune-related thrombocytopenia, 366, 3 7 1 f, 372, 373-3 74 in children, management, 378 diagnosis of, 3 7 lf types of, 3 7 1-375, 3 7 1 t Autologous blood storage, 1 27, 1 3 2-133, 470-47 1 Autologous hematopoietic stem cell transplantation (ASCT) clinical applications, 298 HL relapse, 309 outcome, 297-298 procedure, 297 protocol, 297, 297f Autologous marrow transplantation, 226 CML, 241 Autologous stem cell rescue CLL, 273 MM, 326, 327 Automated cell counters, 103, 203 , 204 Automated HPLC testing, 69 Autoplex, 407 Autosomal dominant thrombocytopenia, 368, 368f Avocet instruments, 454, 454f Axillary nodes, HL and, 303 Azathioprine, 1 1 5 AZT. See Zidovudine B

B cell(s}, 248-250, 252, 256, 259 antigen tolerance, 249 COS-positive, 250 development, 245, 246, 247f functional differentiation, 248-249 gene rearrangement pattern, 250 immunodeficiency state, 269 malignant, 250 maturation sequence, 249 mature with antigen, 249 without antigen, 249 phenotypic classification, 249-250 tumor, 285 B 1 9 parvovirus, 407 Babesiosis, 1 43-1 44, 144t Back pain, 323 Bacterial infections, 37, 46-47, 145-146, 152, 2 1 3, 438, 473 Bacterial killing, 335 Bacterial sepsis, 208, 3 78 Bactrim, 2 1 2-2 1 3 , 3 24 Barbiturates, 1 79 Bart hemoglobin, at birth, 7 1 Bartonellosis, 1 43-144, 1 44t Basal erythropoiesis, 8-9 Basal state, 202f Basophil count, 233, 233t

480

I N DEX

Basophilia, 203, 2 1 3 Basophils, 202, 202£ Bayer Advia, 58 B-cell ALL, 3 1 8 B-cell chronic lymphocytic leukemia, 269, 277, 284 clinical features, 269 differential diagnosis, 27 1-272 laboratory studies, 269-272 �2 -microglobulin, 2 7 1 cytogenetic analysis, 2 7 1 immunoglobulin gene, 270-2 7 1 serum LDH, 2 7 1 uric acid levels, 2 7 1 therapy, 2 72-2 73 B-cell lymphomas, 282, 284, 289 in AIDS patients, 289 characteristic phenotypes, 286£ individual, 285-290 B-cell prolymphocytic leukemia ( B-PLL) , 273 B-cell tumors, 285 BCL-1 proto-oncogene, 283t, 288 BCL-2, 282 family, 320 inhibitors, 29 5 proto-oncogene, 283t, 288 BCNU regimen, 309 BCR-ABL fusion gene, 230, 230f, 242 translocation, 233 translocation product, 234 tyrosine kinase inhibitors, 239 BDS. See Blackfan-Diamond syndrome BEACOPP regimen, 307t, 308 BEAM combination therapy, 297, 309 Beam irradiation, 296 Bebulin, 408, 408t Bendamustine, 294t, 295 Benign hyperglobulinemic purpura, 361 Benign monocytosis, 336 Benzene, 32, 367 Bernard-Soulier syndrome, 389-390 Beta carotene, 1 8 1 Bethesda assay method, 401-402, 405 BFU-E colonies. See ]AK2 mutation Bile acids, 1 Bilirubin, 24f, 58 Binet staging system, 272, 272t Biopsy. See also Marrow aspirate; Marrow biopsy chorionic villus biopsy, prenatal diagnosis, 82 Hodgkin lymphoma, 303 liver, 1 7 7 , 1 85f, 1 86 lymph nodes, 254-255, 298, 339 posterior iliac crest, 19, 1 9f skin, 300 of subcutaneous fat, 330 BioRad instrumentation, 69 Bisphosphonate pamidronate, 327 Bisphosphonates, 3 2 7 MM, 326 therapy, 332 Bivalirudin, 46 1 Blackfan-Diamond syndrome ( BDS) , 40. See also Diamond-Blackfan anemia Blast crises, 234

Blastic cell growth, 3 1 3, 3 13t Blasts, 1 1 2, 1 1 2f, 220, 234, 3 1 8 Bleeding, 36, 1 1 7, 403-404, 460. See also Bleeding disorders; Blood loss; Platelet-based bleeding; specific blood disorders

abdomen, 403-404 abnormal, 352, 40 1 AlTP patients, 374 anticoagulation therapy and, 454 of chest, 403-404 DDAVP, 394 diathesis, 354 episode, timing of, 1 28-1 29 excessive, 409 factor-deficient, 433 late-onset, 462 management guidelines, 403 patient, 352-354, 352t sudden and severe, 458 types of, 1 28-1 2 9 Bleeding disorders. See also Hemophilia(s); Porphyria cutanea tarda; Porphyr­ ias; sJJecific bleeding disorder clinical evaluation, 34 7 laboratory studies, 347-352 points to remember, 354-355 Bleeding time ( BT), 347, 348t, 352 platelet count, 349, 349f thrombocytopenia and, 349f in vivo, 349 in vivo template bleeding time, 385-386 Bleomycin, 296 Blood. See also Blood type; Complete blood count; Donor blood; Donor recipi­ ent matching; Recipient blood; Transfusion(s) alcohol level, 1 08 chemistries, 255 copper levels, 1 60 flow, 85 lead level, 1 80 monocytosis, 336 plasma volume, 1 27 procoagulant function, 357, 357t salvage, 1 33 screening, 468 testing, 284-285 uric acid levels, 236 Blood component therapy, 465-476 anemias, 1 20- 1 2 1 clinical problem and, 465 , 466t points to remember, 474-475 preparation, 4 7 1 Blood film, 15-16, 1 6f, 386 ALL, 3 1 4 genetic disorders, 2 1 2 JMML, 238 morphology, 8 1 normal, 1 1 0-1 1 1 Blood gas measurements, 1 66 Blood loss, 474. See also Blood loss anemia; Transfusion(s) cardiovascular response, 1 24-1 25 catastrophic, 1 3 5 chronic, low-grade, 1 29 days after, 1 2 7

Blood loss (Cont . ) : erythroid marrow response, 1 25 gastrointestinal, 1 27, 404, 426, 463 gradual, 1 25 laboratory studies, 1 27 large volume, 1 26 lower volume/slower, 1 26 perisurgical, 1 27, 1 3 2-133 RBC oxygen delivery, 1 25-1 26 severity and rate, 1 30-130 Blood loss anemia, 45, 1 24-136 case history, 1 24, 1 28, 134 clinical features of, 1 26-1 28 diagnosis, 1 28-1 29 points to remember, 134-135 therapy for, 1 29-1 34 Blood smear, 72, 204, 348f Blood type, 1 3 1 , 467-469 ABO, 1 3 1 , 145, 466, 467, 467t, 468 antigens, 467 compatible platelets, 375 incompatible hemolyric transfusion reaction, 469 incompatible platelets, 4 72 mismatch hemolytic transfusion reaction, 4 7 5 type-specific blood, 474 blood group antigens, 466-467 0, 1 3 1 , 145, 3 9 1 , 467, 467t Rh, 466, 467t, 474 Rh blood group system, 467, 467t, 468 surgical procedures, 468 transfusions, 1 5 2 uncrossmatched type ABO type-specific, 475 Blood urea nitrogen (BUN), 44, 48 Blood vessel, 356-358 Blood vessel wall, 34 1 , 357-358, 357f Blood viscosity, 6 Blood volume loss, 1 24-1 25, 1 25t, 1 27f normal erythropoiesis and, 1 64-1 67 Body iron content, 54, 54t, 1 86, 1 86f Bohr effect, 5, Sf, 1 26 Bone disease, 3 20, 3 20f, 332, 336 Bone marrow. See Marrow Bone marrow aspirate. See Marrow aspirate Bone marrow biopsy. See Marrow biopsy Bone marrow transplantation. See Allogeneic bone marrow transplantation; Marrow transplantation Bone pain, 332 MM and, 323 pamidronate, 327 Bortezomib, 295 , 326, 330 Bortezomib with dexamethasone, 327 Bosutinib, 239 Bowel hemorrhage, 360, 360t B-PLL. See B-cell prolymphocytic leukemia Brilliant crystal blue, 83f Bronze diabetes, 1 84 Bruising, 1 1 1 , 358-359, 36 1-362 BT. See Bleeding time Budd-Chiari syndrome, 1 1 7, 435 BUN. See Blood urea nitrogen Burkitt lymphoma, 282, 289, 296

I NDEX

Burst-forming unit-erythroid ( BFU-E), 28, 28f Burst-forming unit-erythroid colonies. See ]AK2 mutation Bypass grafting, 433 , 449. See also Coronary artery bypass grafting c

CABO. See Coronary artery bypass grafting Calcitonin, 327-328 Calcium disodium versenate, 1 8 1 Campylobacter jejuni, 279 Cancer, 52, 3 1 5, 424. See also European Organization for Research and Treatment of Cancer classification system; Metastatic cancer; Neo­ plasms; Tumor(s); st>ecific cancers marrow megakaryocyte mass and, 367 warfarin and, 452 Cancer-related anemia, 52 Candida species, 223 Carbimazole, 2 11 Carbonyl iron, 6 1 , 6 1 t, 62 Cardiac arrhythmias, 1 90 Cardiac damage, 192 Cardiac decompensation, 96 Cardiac disease studies, 1 67 Cardiac failure, 1 84, 1 84t Cardiac thromboembolic disease, 442-443 Cardiopulmonary bypass, 388 CBC. See Complete blood count CD4+ counts, 296 CD13, 1 99 CD34, 1 99 CD38, 323 CEBPA mutations, AML, 2 1 9, 2 1 9t Cefamandole, 4 1 4, 4 1 4t Cefoperazone, 4 1 4, 4 1 4t Cell lineage, immunologic abnormalities and, 3 2 1 �-cell proliferation, 1 5 6 Cells. See also B cell(s); Blasts; Effector cells; Endothelial cells; Fat cells; Gaucher cells; Gaucher-like cells; Helper T cells; Hematopoietic cell lines; Hematopoietic stem cells; Kidney sensor cells; Lymphoid cells; Lymphokine-activated killer cells; Lymphoma cells; Marrow cell; Marrow stem cells; Metaphase cells; Mucosal cells (of small intes­ tine); Myeloid stem cells; Natural killer cells; Plasma cells; Popcorn cells; Red blood cells; Stromal cells; T cell(s) differentiation, 1 98, 334 function defect, 2 1 1-2 1 3 , 2 l l t marker assays, 29S-299 maturation defects, 1 1 1 morphology, hemoglobinopathies and, 8 1 , 82f phenotypes, follicular lymphomas, 285 , 286f surface markers, 290 turnover, high rates, 1 04 Cellular immunity, 250 Cellular mitochondria, 2 1

Cellulitis, 60 Cellulose acetate electrophoresis, 69, 83f Central nervous system (CNS) ALL, 3 1 3, 3 1 3t irradiation, 3 1 6, 3 1 6t prophylactic treatment, 3 1 6-3 1 7 B 1 2 deficiency and, 96 head trauma, bleeding after, 403 lead poisoning and, 1 79 Cephalosporins autoimmune hemolytic anemia, 1 46 vitamin K metabolism, 4 1 4, 4 1 4t CERA. See Continuous erythropoietin activator Cerebral vein thrombosis, 44 1 Cerebrovascular thrombosis, 8 1 Ceredase, 339 Cerezyme, 339 Cervical nodes, 303 CFU-E. See Colony-forming unit-erythroid CFU-GM. See Colony-forming unit-granulocyte, monocyte COD. See Chronic granulomatous disease a-chains, 248 �-chains, 248 Chediak-Higashi syndrome, 2 1 2, 390 Chelation therapy, 1 8 1 , 1 90 Chemicals. See also Histochemical stains; Toxic chemicals anemia and, 32 exposure, 1 78 hemolysis and, 146 Chemokines, and receptors, 1 97-198 Chemotherapeutic agents. See Chemotherapy Chemotherapy, 40, 1 03, 1 2 1 , 2 1 2-2 1 3 , 284, 295, 327. See also Antimyeloma chemotherapy; lmmunochemotherapy; Induction chemotherapy; Maintenance chemotherapy; Multi-drug chemotherapy (regimen) ; Systemic chemotherapy anemias, 1 2 1 ATLL, 275 autoimmune thrombocytopenia, 379 B-cell CLL, 272 high-dose, 347 HL, 307-309, 307t platelet transfusion therapy and, 475 postinduction and maintenance therapy, 225 primary thrombocythemia, 241-242 remission induction, 324, 325f T-cell lymphomas, 296 Chest x-ray, ALL, 3 1 5 Childhood ALL, 3 1 3, 3 1 3t, 3 1 8 DBA and, 35 EPP, 1 7S-1 79 Childhood autoimmune thrombocytopenia, 378 Children, 209-2 1 0, 378 C-deficient, 425 congenital defective T-cell function, 265 drug-induced thrombocytopenia, 372 EPP and, 1 8 1

48 1

Children (Cont . ) : ferritin levels, 5 5 hemoglobin E/�-thalassemia, 7 1 t, 74 hemophilia A, 400 HUS, 370 internal bleeding, 403-404 iron chelation therapy, 7 6 ITP, 380 maternal AITP, 372 neutropenia in, 209-2 10, 209t postviral thrombocytopenia, 372 prophylactic transfusion, painful sickle crises and, 89 sickle cell anemia, 80, SOt, 85 thalassemia major, clinical course, 77-78 vasoocclusive infarction and, 88 vitamin C, 425 VTE in, 44 1 , 44 1t Chimeric p2 1 0 proteins, 233 Chlorambucil, 3 3 1 CLL, 273 large granular lymphocytic leukemia, 275 low-grade lymphomas, 294, 294t Chloramphenicol occasional idiosyncratic neutropenia, 2 1 1 toxicity, 3 2 2' chlorodeoxyadenosine, 294 Chloromas, 234 Chloroquine, 1 80 Chlorpromazine, 1 80 Cholangitis, 9 1 Cholecystectomy, 9 1 Cholecystitis, 9 1 Cholestyramine, 1 8 1 CHOP (cyclophosphamide, adriamycin, vincristine, prednisone) , 295 , 296 Chorionic villus biopsy, prenatal diagnosis, 82 CHr. See Hemoglobin content of reticulocytes Christmas factor, 399 Chromatin, 2 1 7 Chromosomal abnonnalities CML and, 233, 233t dysplastic anemias, 1 1 2-1 1 3 , 1 1 2f Chromosomal studies, 236 of dysplastic syndromes, 1 1 2-1 1 3 myeloproliferative disorders and, 23 1 t, 232-233 Chromosomal translocation, 285, 286f Chronic blood loss, 1 3 2 small volume, 1 26-1 2 7 Chronic eosinophilic leukemia, 23 1 , 238 cytogenetic analysis, 230-23 1 therapy, 24 2 Chronic (lifelong) extravascular hemolysis, 147-1 5 1 , 1 54 Chronic graft-versus-host disease, 263 Chronic granulomatous disease (COD), 2 1 2 Chronic hemolytic anemia, 8 Chronic hypoxia, 1 64 Chronic infections, 330 Chronic inflammatory diseases, 45, 60 anemia and, 43 Chronic inflammatory states, 1 86, 1 86f Chronic intravascular hemolysis, 152 Chronic ITP in pregnancy, 380

482

I N DEX

Chronic juvenile myelomonocytic leukemia, 1 96 Chronic lead toxicity, 1 79 Chronic low-grade disseminated intravascu­ lar coagulation (DIC), 422 Chronic lymphocytic leukemia (CLL), 154, 268-278, 373. See also B-cell chronic lymphocytic leukemia case history, 268, 274 complications, 273 lymphocytes, 270f malignant B cell, genetic structure, 250 marker studies, 2 ?Of morphology in, 272f Chronic myelogenous leukemia (CML), 199, 229-245 , 338 BCR-ABL tyrosine kinase inhibitors, 239 case history, 229 classification, 230 cytogenetic analysis, 230-23 1 disease course, 236 interferon-a, 239-240 laboratory studies, 233, 233t phases of accelerated, 234 blast crises, 234 chronic, 234 genetic factors and, 234-235 genetic tests, 234-235 survival curves, 234f Chronic myelomonocytic leukemia (CMML), 1 1 4, 1 1 6, 1 1 9, 230, 238 Chronic obstructive pulmonary disease, 1 65 Chronic renal disease, 158 Cigarette smoking, 13-14, 208 Cigar-shaped red cells, 58, 60f Cimetidine, 45 1 Ciprofloxacin, 223 Circulating inhibitor, 369 Cirrhosis, 1 84, 1 84t, 1 86, 1 92 liver iron loading, 1 77 with portacaval shunt, 1 89 in thalassemia, 7 7 Citrate agar electrophoresis, 69 Cladribine, 1 46 Class I MHC molecules, 335 CLL. See Chronic lymphocytic leukemia Clofarabine, 227 Clonal deletion. See Terminal deoxynucleotide transferase Clonal malignancies aplastic anemia and, 34 diagnosing, 290-293 Clonal myeloproliferative disorders, 368 Clonal plasma cells, 322, 322f Clonality B-cell lymphoma, 282 among T cells, 256 Clopidogrel (Plavix) , 447, 462, 463 clinical applications, 449 drug-induced TIP, 370 laboratory monitoring, 450 during percutaneous coronary artery interventions, 444 pharmacokinetics of, 448 therapeutic guidelines, 450 Clopidogrel and aspirin combination, 443

Clostridial sepsis, 1 45 Clostridium perfringens, 1 44 Clot, 4 1 3 , 445. See also Activated clotting

time; Fibrin clot formation, 34 1 , 344, 346, 427, 445 inhibition, 344-345 lysis, 344-345, 422, 422f, 462 CML. See Chronic myelogenous leukemia CMML. See Chronic myelomonocytic leukemia CMV. See Cytomegalovirus CMV-negative red blood cells, 466 c-myc, 283t, 288 CNS. See Central nervous system CoaguChek, 454 Coagulation cascade, 343-344, 343f, 344f, 346 inhibitors of, 345 cell factors regulating, 357, 35 7t defect, 34 7, 348t factor-deficient bleeding, 433 factors, 43 7, 445, 475 common pathway activation, 343-344, 344f components, 473-474, 473t deficiency, 4 1 2 replacement, 1 27 DIC, 424-425 turnover, 4 1 6f inhibitor deficiency, 429f, 433-434 panel, 444 pathways, 347-352, 421 screening tests, 436 tests, 355, 4 1 7 Coagulopathy, 474. See also Common pathway coagulopathies evaluation, 222 management, 133 Cobalamin, 97-98, 106, 1 08, 1 59, 1 60, 167. See also Serum cobalamin levels; Vitamin B 1 z deficiency, subclinical, 1 0 1 levels, misleading, 98 vitamin B 1 z deficiency and, ! 59 Cobalamin-IF complex, 95, 1 00 Cold agglutinin disease, 1 54, 330 Cold agglutinin hemolytic anemia, 147, 32 1-322, 3 22f Cold agglutinin titer test, 1 42, 1 43 Cold-antibody AIHA, 152, 153 Cold-reacting AIHA, 147, 154 Collagen vascular disorders, 46, 14 7, 2 1 1 , 336, 362 Colloid solutions, 1 29-1 30, 1 29t Colony-forming unit-erythroid (CFU-E), 28 Colony-forming unit-granulocyte, monocyte (CFU-GM ) , 1 95, 1 96f Colony-stimulating factors, 36 Combination anemias, 73 Combination therapies BEAM, 297 busulfan, Cytoxan and antithymocyte globulin combination therapy, 90-9 1 CHOP, 295 clopidogrel and aspirin combination, 443 CVAD combination therapy, 295

Combination therapies (Cont . ) : low-grade lymphomas, 294 R-CHOP, 295 recombinant interferon and zidovudine combination, 275 Riruximab combination therapy, 295 T-cell lymphomas, 296 Combined deficiency of factors V and Vlll, 400 Combined esterase stain, 221 Combined hemoglobinopathies, 71 t, 153 Common pathway coagulopathies, 4 1 1 -4 1 9 case history, 4 1 1 , 4 1 5 , 4 1 8 points t o remember, 4 1 8-4 1 9 Common pathways defects, 4 14, 4 1 4t normal, 4 1 1-4 1 2 , 4 1 2f Common thymocyte, 25 1 Common variable immunodeficiency (CVID), 262 Complete blood count (CBC), 1 1 , 1 2, 25, 3 1 , 36, 44. 72, 1 39, 1 65 , 1 9 1 ALL, 3 1 3-3 1 4 AML and, 220, 223 anemia, 1 02 B-cell chronic lymphocytic leukemia, 269 chronic lead toxicity, 1 79 CML and, 233, 233t CMML, 238 epoetin alfa and, 5 1 EPP, 1 77, 1 77t hemoglobinopathies, 81 HL, 304 myeloproliferative disorders and, 23 1-232 painful sickle crises, 88 platelet function and, 386 porphyria, 1 77 primary myelofibrosis, 235, 235t primary thrombocythemia, 23 7 reactive monocytosis and, 337 results, 13f sickle cell anemia, 9 1-92 thalassemia, 68, 68t Compound hemoglobinopathies, 8 1 , 92 Computed tomography (CT) arterial thrombus, 4 33 iron overload and, 187 lymphomatous infiltration of non-lymphoid organs, 285 Congenital coagulation factor abnormalities, 4 1 2-4 1 4, 4 1 8 therapy for, 4 1 5-4 1 6 Congenital coagulopathy, 34 7 Congenital defects, 1 05 Congenital disorders of platelet function, 389-393, 390£ aggregometry studies, 387f Congenital dyserythropoietic anemia (CDA), 1 1 8- 1 1 9, 1 1 9t Congenital dysfibrinogenemia, 4 1 5 Congenital dysplastic anemias, 1 1 8-1 1 9 Congenital erythropoietic porphyria (CEP), 179 Congenital factor Vlll deficiency, 475 Congenital heart disease, 1 65 Congenital hemolytic anemia, 256

I NDEX

Congenital hypogammaglobulinemia, 26 1-262 Congenital immunodeficiency disorders, 260--262, 26 l t therapy, 265 Congenital sideroblastic anemias, 1 1 8-1 1 9 Congenital TIP, 369 Congestive heart failure, 1 1 1 Conjugated estrogens, 388 Consumptive coagulopathies, 354, 420--427 case history, 420, 426 clinical features, 42 1--422, 42 l t differential diagnosis, 423--424, 424t points to remember, 426--4 27 Consumptive thrombocytopenia, 368 Continuous erythropoietin activator (CERA), 5 1 Contrast venography, 43 1 Controlled hypotension, intraoperative blood loss, 1 33-1 34 Cooley anemia. See Thalassemia major Coproporphyrinogen, 1 79 Coronary angiography, and bypass grafting, 433 , 449 Coronary artery bypass grafting (CABG) , 449 Coronary artery disease, 1 85 hypercoagulability and, 438 Coronary artery thrombosis, 4 33, 462 Corticospinal tract lesions, 96, 96t Corticosteroids, 1 5 2 aplastic anemia, 39f severe autoimmune thrombocytopenia, 379-380, 3 79f vasculitis, 361 Coumadin. See Warfarin sodium Coumarin adverse events, 454--455 clinical applications, 452 laboratory monitoring, 454 pharmacokinetics, 45 1--452 therapeutic guidelines, 452--454 COX- I isoform pathway, 342 COX-2 (Cyclooxygenase-2), 3 6 1 C-reactive protein, 4 5 , 4 9 , 1 5 7, 158 Creatine level, 1 5 8 Creutzfeldt-Jakob disease, 401 , 407 Crohn disease, 1 27 Cryoglobulins, 33 1 , 4 74 Cryoprecipitate, 396, 4 1 6, 4 1 9, 427, 474, 475 DIC, 425 dosage schedule, 394, 394t hemophilia A, 406 Crystalline cyanocobalamin, 1 00-- 1 0 1 CT. See Computed tomography Cutaneous CD30+ lymphomas, 292 Cutaneous lymphomas, classification system, 292t Cutaneous photosensitivity, porphyrin metabolism disorders, 1 8 1 Cutaneous T-cell lymphomas, classification, 291-292, 29 1 t CVAD. See Cyclophosphamide, vincristine, adriamycin and dexamethasone C-VAMP protocols, 326 CVID. See Common variable immunodeficiency

CXCR4, 1 97-1 98 Cyanocobalamin. See also Vitamin B 1 2 dosing and administration, 1 06-107 Cyclic neutropenia, 209-2 10, 209t Cyclooxygenase-2. See COX-2 Cyclophosphamide, 152, 153, 3 3 1 ALL, 3 1 6, 3 1 6t Burkitt lymphoma, 296 GVHD and, 38 intravenous, 380 large granular lymphocytic leukemia, 275 low-grade lymphomas, 294, 294t Cyclophosphamide, vincristine, adriamycin and dexamethasone (CVAD) combination therapy, 295 Cyclophosphamide-vincristine-prednisone regimen, low-grade lymphomas, 294, 294t Cycloserine, 1 1 5 Cyclosporine, 40 with ALG, 39 chronic eosinophilic leukemia, 242 drug-induced TIP, 370 GVHD and, 38 large granular lymphocytic leukemia, 275 long-term, 39 with methyl prednisolone, 39 oral, 380 Cytarabine-methotrexate, 225 ALL, 3 1 6 Burkitt lymphoma, 296 Cytogenetic abnormalities, 3 1 2-3 1 3 Cytogenetic analysis, 1 13 , 227 AML and, 221 B-cell chronic lymphocytic leukemia, 27 1 Cytogenetic studies, 30 Cytokine(s), 205-206 levels, 156 secretion, 250 Cytomegalovirus (CMV) , 223-224 Cytometric assay, of red cell CD59/CD55, 117 Cytoplasm, 1 98 Cytoplasmic immunoglobulin. See Terminal deoxynucleotide transferase Cytosine-arabinoside, 3 1 6, 3 1 6t, 3 24 Cytotoxic agents AML, 1 2 1 chronic eosinophilic leukemia, 242 Cytotoxicity, 250 D

Dabigatran, 460 Dalteparin, 440, 460 Danazol, 380 Dapsone, 1 46 Darbepoetin alfa, 50, 52 Darbopoietin, 328 Dasatinib, CML, 239 DAT. See Direct antiglobulin test Daunorubicin, 3 1 6, 3 1 6t DBA. See Diamond-Blackfan anemia DC. See Dyskeratosis congenita DDAVP. See Desmopressin D-dimer, 453--454 assay, 422 fragment, 345

483

D-dimer ( Cont . ) : level, 3 5 5 measurement, 43 2, 434 tests, 35 1 values, age and, 442 D-dimer assay, fibrin clot lysis, 422, 422f Decitabine, painful sickle crises and, 90 Deep venous thrombosis (DVT), 432, 433 , 439, 445, 462 clinical features, 429--430 primary hypercoagulable states and, 436t recurrent, 43 1 Deferasirox therapy, 76-77, 78, 1 90, 1 92, 1 93 Deferiprone, 1 92 Deferoxamine therapy, 76-77, 78, 187, 1 93 PCT and, 1 9 1-192 Deficiency state, 1 62 DeGuglielmo anemia, 1 1 8 Dehydration, sickle cell anemia and, 85 Delayed-release iron preparations, 62 Demethylating agents, AML and, 227 Dendritic cells, 201 , 20 lf Dense granule ADP, 386 Dental extraction, hemophilia and, 404 Deoxycoformycin. See Pentostatin Deoxygenated hemoglobin S, 80 Deoxyuridine suppression test, anemia and, 99 Desmopressin ( DDAVP), 45 1 contraindications for, 394 hemophilia A, 406 as intranasal spray, hemophilia A, 406 platelet dysfunction and, 393-394 uremia, 388 Desoxynucleoside analogs, AML and, 227 Dexamethasone, 330 amyloidosis and, 330 severe autoimmune thrombocytopenia, 3 79, 3 79f DexFerrum, 62 Dextrose, 469 Diabetes, 77, 1 58, 1 84, 1 90 Diamond-Blackfan anemia ( DBA) , 35 growth factors and, 3 7-38 Diazepam (Valium}, 1 80 DIC. See Disseminated intravascular coagulation Diego antigens, 467 Diet caloric intake, 1 79 high-carbohydrate, AlP, 1 8 1 meat, 96 western, 64, 1 90 folate/B 1 2 nutrition, 96 iron and, 1 83 Diffuse abdominal pain, 1 79 Diffuse large B-cell lymphoma, 283t, 288-289, 294, 294f staging studies, 288 Diffuse plasma cell infiltrate, marrow osteoclasts versus, 3 20f Diffuse polyclonal hypergammaglobulinemia, 361 Dimercaprol, lead poisoning, 1 8 1 2,3-DPG (Diphosphoglycerate) , 1 , 80, 1 26

484

I N DEX

Dipyridamole clinical applications, 449 pharmacokinetics of, 448 Direct antiglobulin test ( OAT) , 1 42, 1 46 Direct DNA testing, hemophilia, 403 Direct thrombin inhibitor ( DTI ) , 460 HIT, 378-379 Disease. See Disseminated disease; Transmissible diseases Disease of small intestine, 1 05 Disease-free survival, 2 1 9 Disease-related thrombosis, 440£ Disseminated disease, follicular lymphomas, 285 Disseminated intravascular coagulation (DIC), 220, 223, 35 1 , 352, 355 , 362, 368, 4 1 0, 420, 42 1 , 42 l t, 475 case history, 426 differential diagnosis, 423-424, 424t fibrinolytic component of, 422 laboratory studies, 422, 426 less severe, treatment of, 4 25 screening for, 354 therapy and clinical course, 424-426 Disulfiram, 45 1 DNA, 284f aneuploidy, 3 1 2 index, 3 1 2 methylation, 1 55-156 synthesis, 95, 96 abnormal, 101 test, 403 Dohle bodies, 367, 368f Donath-Landsteiner test, 1 43 Donor blood transmissible diseases and, 468, 468t typing and crossmatch, 467-469 Donor platelets, 3 7 5 Donor recipient matching, 38 Doppler flow study, 433, 445 Double heterozygotes, 87 Doxorubicin, 296 D-penicillamine, 1 1 5 Drug-damage anemia, 3 1-32, 32t Drug-induced disorders, 2 1 4 Drug-induced hemolysis, 1 46, 1 46t Drug-induced immune hemolytic anemia, 1 46, 1 46t Drug-induced platelet function, 349 Drug-induced thrombocytopenia, 372, 3 78-380 Drug-induced TIP, 3 70 Drugs. See also Combination therapies; Sj)ecific drugs

for AIDS, 265-266, 265t AlP and, 1 79 antifolate action of, 1 05 cardiovascular, 389, 389t CLL, 273 exposure, 36 inhibition, platelet function and, 389, 389t interactions, warfarin kinetics and, 45 1-452 neutrophil dysfunction, 2 1 2-2 1 3 occasional idiosyncratic neutropenia, 2 1 1 porphyrin metabolism and, 1 1 5, 1 1 5f toxicity, 3 1-32, 32t

DTI. See Direct thrombin inhibitor Duffy system, 467 Durie-Salmon Staging System, 326, 326t, 332 DVT. See Deep venous thrombosis Dysfibrinogenemias, 358, 4 1 2-4 1 3 , 4 1 8 amino acid sequencing, 4 1 3 hypercoagulability and, 438 Dyskeratosis congenita ( DC), 34, 40 Dysplastic anemias, 1 88. See also Myelodysplasia case history, 1 1 3 , 1 1 9 chromosomal abnormalities, 1 1 2-1 13 , 1 1 2f diagnosis, 1 1 3-1 1 6 differential diagnosis, 1 1 6-1 1 9 elderly, 1 6 1 patient survival, 1 20, 1 20£ points to remember, 1 22 Dysproteinemias, 357t, 360-3 6 1 , 388 E

EACA. See Aminocaproic acid EBV. See Epstein-Barr virus infection Echocardiography, 432, 433 Eculizumab, 1 22 Edema, 1 1 EDTA. See Ethylenediaminetetraacetic acid Effector cells, 202 E/G ratio, 9, 1 9-20, 20f, 24, 45, 202 anemia, 8 iron-deficient marrow and, 69 Ehlers-Danlos syndrome, 358, 359 Elderly, 362. See also Older patients anemia in, 1 1 1 , 1 55-162 B-CLL, 277 chemotherapy, 1 2 1 fatigue and weakness, 1 6 1 folic acid deficiency, 1 59-1 60 follicular ( nodular) lymphomas, 285 Gaucher-like cells, 338 iron deficiency anemia, 1 58-159 macrocytic anemia and, 1 60 microcytosis with no anemia, 159 mortality, 442, 442f senile purpura, 361 serum cobalamin levels, 101 serum methylmalonic acid assay, 1 0 1 sideroblastic anemia, 1 6 1 thromboembolism in, 44 1-442, 442f transfusions, 1 20 vitamin B 1 2 deficiency and, 1 59-1 60 injection, 1 06 Electrolyte solutions, 1 29, 134 Electrophoresis, 69 ELISA. See Enzyme-linked immunosorbent assay Elliptocytosis, 149-1 50, 1 49f Eltrombopag autoimmune thrombocytopenia, 380 chronic AITP, 374 Emboli. See also Arterial thromboembolism; Fat embolism; Pulmonary embolism; Thromboembolism; Venous thromboembolism cardiac source, 433

Emergency crossmatch, 468 Empiric antibiotic therapy, 324, 324t Endocrine disorders. See also Sj)ecific endocrine disorder

anemia and, 48-49 in thalassemia, 7 7 Endomyocardial fibrosis, 208 Endothelial cells, 346, 357 clot formation and, 341 plasma vWF, 385 Endothelial protein C receptor (EPCR), 429 Endothelin receptor blockade, 9 1 Endothelium, damaged, 445 End-stage renal disease, 44 Enoxaparin, 460 pregnancy and, 440 Enteric-coated iron, 62 Enteropathy-like T-cell lymphoma, 293 Environment B-cell chronic lymphocytic leukemia, 269 marrow and, 1 62 Environmental disorders, 1 5 1 Environmental exposures, 1 1 , 1 48, 1 5 1 , 1 62, 269 Enzymatic defect, 437, 437f Enzyme-linked immunosorbent assay ( ELISA), 366, 435 antibody-heparin-PF4 complex, 366 complete Xlll, 4 1 8 sTfR and, 5 7 vWD, 3 9 1 Enzymes, 142, 1 78-1 79, 1 8 2 , 1 83t, 340. See also Enzyme-linked immunosorbent assay in Embden-Meyerhof pathway, 1 5 1 Eosin, 29 Eosinophilia, 203, 208, 208t, 2 1 3 Eosinophilic bone granuloma, 336 Eosinophilic leukemia. See Idiopathic hypereosinophilic syndrome Eosinophils, 20 1-202, 201£ EPCR. See Endothelial protein C receptor Epigenetic therapy, 1 2 1 Epoetin alfa, 50 anemia of renal disease, 5 1 Epoetin beta, 50 Epoetin delta, 50-5 1 Epogen, 328 EPP. See Erythropoietic protoporphyria Epstein-Barr virus infection (EBV), 147, 1 52, 263 , 264, 265, 266, 279, 289, 290, 3 0 1 , 302 marrow-damage anemia and, 32 Eptifibatide, 44 7 , 448, 463 clinical applications, 449 pharmacokinetics of, 449 therapeutic guidelines, 450 Erythrocyte zinc protoporphyrin, 5 7-58 Erythrocytes, 1, 54 Erythrocytosis, 1 63-1 75, 1 67f case history, 1 63 , 1 68 diagnosis, 167 laboratory studies, 1 65-167 Erythroid marrow, 1 34, 1 5 1 , 1 64 CDA and, 1 1 8- 1 1 9, 1 1 9t maturation, 2 l f, 43f defects in, 24

I NDEX

Erythroid marrow (Cont . ) : production, 7-9, 1 3 2 measurement of, 7--8 proliferation, 43f, 1 0 1 response, 1 25 Erythroid precursor cells, 8 Erythroid progenitors, 1 1 0 Erythroleukemia, 1 07, 1 1 8 Erythromycin, 4 5 1 Erythron iron turnover, 7 Erythropoiesis, 43f, 332. See also Severe ineffective erythropoiesis normal, 1-9, 1 64-167 regulation of, 6-7 Erythropoiesis-stimulating agents (ESAs), 50-5 1 Erythropoietic abnormality, 24, 24t. See also Serum erythropoietin level Erythropoietic profile, 46, 14 7 anemia of renal disease, 48 of chronic hemolytic anemia, 1 39, 1 39t hemoglobin S/�-thalassemia, 75 hypoproliferative anemia of protein deprivation, 48 sickle cell anemia, 92 Erythropoietic protoporphyria (EPP), 1 77 diagnosis, 1 78-1 79 therapy, 1 8 1 Erythropoietin, 3 7-38, 40, 55 AIDS and, 264 assay, 169 full marrow response and, 6 level, 6-7 measurements, 167, 1 67f production anemia and, 7f impaired, 1 5 8 response, 43, 43f, 44t, 4 7 measuring, 6 , 7f studies, 38 therapy, 4 71 AIDS, 5 1 anemia and, 50-5 1 cancer-related anemia, 5 2 elderly, 1 6 1 ESAs. See Erythropoiesis-stimulating agents Escherichia coli, hemochromatosis and, 1 85 Essential thrombocytosis (ET) , 440, 440f Estrogens following menopause, 435 vWO and, 395 ET. See Essential thrombocytosis Ethacrynic acid, 452 Ethylenediaminetetraacetic acid ( EOTA), 1 79, 1 99 Ethylenediaminetetraacetic acid ( EOTA)-pseudothrombocytopenia, 45 1 Ethylenediaminetetraacetic acid (EOTA)-sensitive antibody, 348, 348f Etoposide AML relapse and, 226 Burkitt lymphoma, 296 Euglobulin lysis time, 3 5 1 -352 European Organization for Research and Treatment of Cancer classification system, 29 1-292, 292t

Ewing sarcoma, 3 1 5 Exchange transfusion, painful sickle crises and, 89 Exocytosis, 198 Exogenous IL-6, 3 2 1 Extranodal T-cell lymphomas, 292-293 Extravascular destruction (of red blood cells), 1 3 7 , 1 3 7f Extravascular hemolysis, 154 detection of, 140-1 4 1 , 14lt therapy, 1 5 2-154 Extrinsic pathway coagulopathies, case history, 4 1 1 , 4 1 5 , 4 1 8-4 1 9 Extrinsic pathways, normal, 4 1 1-4 1 2, 4 1 2f Eye examinations, 7 7 F

FA gene mutation, 34 Factor antigen, 402 Factor deficiencies tests, 40 1-402 Factor depletion, 427 Factor infusions, 4 1 0 Factor IX, 399, 400 Factor IX deficiency. See Rosenthal disease Factor IX-prothrombin complex concentrate ( FIX-PCC), 405 , 408, 408t Factor replacement, self-infusion, 403 , 404t Factor V Leiden, 429f, 433-434, 436, 437 Factor VII deficient patients, 408 hereditary deficiency of, 4 1 2 Factor Vlll, 354, 399, 405 age and, 441-442, 442f concentrates, 405 inhibitor titers, 409 levels, 404 HIT, 378 protein, 409 vW0, 3 9 1 Factor X , 409, 4 1 1 , 4 1 2, 4 1 8 Factor X deficiency. See Recombinant activated factor VII Factor X Ill levels, 4 7 4 Factor Xlll-deficiency, 358, 4 1 3 , 4 1 8 therapy, 4 1 6 Falciparum malaria, 1 43-1 44, 1 44t Famciclovir, 223 Familial Mediterranean fever, 262 Familial PCT patients, 1 78 Family history, thalassemia, 66 Fanconi anemia (FA), 34, 3 7-38, 40 Fanconi syndrome, 367 Farnesyltransferase, 226 Fat cells, 28 Fat embolism, 9 1 FOPs. See Fibrin degradation products FEIBA (Activated prothrombin complex concentrate), 405, 407, 4 1 0 Felty syndrome, 2 1 1 Ferrireductase ( STEAP3 ) , 54 Ferritin. See also Serum ferritin level levels, 54-55, 55 porphyria, 1 7 7 studies, hemochromatosis, 1 86, 1 86f synthesis, 1 82-1 83 Ferrlecit. See Sodium ferric gluconate Ferrous sulfate, 6 1 , 6 1 t

485

Fetal death, APLAs and, 438 Fetal hemoglobin, 66, 66f, 67 arginine butyrate and, 90 production, 77 thalassemia and, 7 7 Fetal platelet counts, 3 72 FFP. See Fresh frozen plasma Fibrin clot, 4 1 1 formation, 42 1 , 429 lysis, 422, 422f Fibrin degradation products (FOPs), 4 1 5 , 422, 422f Fibrin generation, 346 Fibrinogen age, 44 1-442, 442f assays, 350f, 35 1 , 353 concentration measurement, 4 1 3 , 4 1 4, 4 1 4t defects, 4 1 8 production abnormal, 4 1 2 hereditary deficiency of, 4 1 2 replacement, DIC, 425 Fibrinolysis, 429 impaired, 438 tests, 3 5 1 -352, 4 1 4, 4 1 4t, 427 Fibrinolytic disorders, 358 Fibrinolytic pathways, 427, 428 Fibrinolytic system, 133, 345 Fibrinopeptide chain analysis, 4 1 3 Fibrogammin P., factor Xlll-deficiency, 4 1 6, 4 1 6t Fibrosis, 1 86, 234 Fine needle aspiration, 255 FISH. See Fluorescence in-situ hybridization FIX Leyden, 400 Fixed schedule narcotic regimen, 88 FIX-PCC. See Factor IX-prothrombin complex concentrate FLIP!. See Lymphoma International Prognostic Index Flippase, 1 Flow cytometric immunophenotyping, 269 Flow cytometry, 323, 386 FLT3 , 227 Fludarabine autoimmune hemolytic anemia, 1 46 CLL, 273 with cyclophosphamide, mitoxantrone, and rituximab, 273 HCL and, 276-277 low-grade lymphomas, 294, 294t Fluid expander, 1 29 Fluorescence, 1 79 Fluorescence in-situ hybridization ( FISH), 271 Folate, 97. See also Serum folate deficiency, 8 1 , 3 7 6 enterohepatic cycle of, 96 macrocytic anemias, 97 nutrition, 96 Folic acid, 1 01-103, 107 absorption and distribution, 95-96, 96f deficiency, 95, 107-108 case history, 1 05 causes of, 1 04-1 0 5, 1 04 t diagnosis of, 1 0 1-103

486

I N DEX

Folic acid, deficiency (Cont . ) : elderly and, 1 59-1 60 laboratory tests, 97- 1 0 1 therapy for, 1 05-106 metabolism, normal, 95-96, 95f pregnancy and, 49, 97 prophylactic administration, 107 studies, 48 supplement, 1 9 1 supplies, 1 5 1 therapeutic response to, 1 03f unstable hemoglobins, 92 Folic acid deficiency anemia, 97, 101-103 Folic acid tablets ( Leucovorin), 107 Follicular (small cell) lymphoma, 294, 294f Follicular (nodular) lymphomas, 285-286 Follicular non-Hodgkin lymphoma, 295 Fondaparinux, 460, 463 Foods additives, 389, 389t cobalamin and, 1 00--101 platelet function and, 389, 389t Fortified anticoagulant solutions, 469 Fragility tests, HS/HE, 1 50 Fresh frozen plasma (FFP), 1 30, 1 34, 4 1 9, 468, 473, 475 clinical situations for, 4 73t congenital coagulation factor abnormalities, 4 1 5 DIC, 424-425 hemophilia, 400 hemophilia A, 406 liver disease, 4 1 7 Rosenthal disease, 405 TIP and, 369 Full marrow response, 6 Fungal infection, 208 G

G6PD deficiency, 152 dye decolorization screen test, 142 Gait, unsteady, 96, 96t Gallstones, 8 1 , 86, 9 1 Gamma globulin, 265 Gastrectomies, 1 04 Gastric intolerance, 62 Gastric MALT lymphoma, 286--287, 287f Gastrointestinal lymphomas, 284 Gaucher cells, 33 7f Gaucher disease, 256, 367 Cerezyme, 339 clinical subtypes, 33 7-338 prenatal and genetic diagnosis, 338 therapy, 339 Gaucher-like cells, 338 G-CSF. See Granulocyte colony-stimulating factors Gemcitabine, 370 Gemtuzumab ozogamicin, 226 Gene(s), 1 1 6, 250. See also BCR-ABL fusion gene; �-globin gene; Genetic analysis; Genetic defects; Genetic mutations; Hemojuvelin gene; HFE gene; J anus kinase gene; Kidd gene c282Y, 187

Gene(s) (Cont . ) : expression, 66 profiling, 220, 283, 284f globin, 65, 66f rearrangement pattern, 25 1 sickle cell, 84, 84t TFR2 , 189 therapy, 410 hemophilia and, 408 for thalassemia, 7 7 Generation of diversity, 250 Genetic analysis, 1 66-167, 250 hemophilia, 403 lymphomas, 284 Genetic defects, 26 Genetic mutations, 187 Genetics B-cell chronic lymphocytic leukemia, 269 testing, 1 87, 234-235 Genotypes assays, 298-299 C282Y/C282Y, 1 93 MTHFR 677TT, 43 7, 437f for thalassemia minor, 73 Genotyping, 234 GFR. See Glomerular filtration rate Giant band forms, 99, 99f Glanzmann thrombasthenia, 389, 390 Gleevec. See lmatinib mesylate Globin. See also a.-globin chains; �E-Thalassemia; �-globin chain mutants; �-globin chains; �-globin gene; Impaired globin chain syn­ thesis; Non-alpha-globin genes chain production, and development, 66, 66f chain synthesis, 65 normal, 65-66 chemistry, normal, 79-80 gene expression, 66 genes, 65, 66f production defects, 1 86 structure, inherited defects, 79 types of, 65-66 a-Globin chains, 65-66, 78, 80, 80f, 87 �-Globin chain mutants, 87 �-Globin chains, 74, 78, 80, 80f, 92 �-Globin gene deletion, 67 therapy, 7 7 Globulin fraction, 323 Glomerular filtration rate (GFR), 158 �-Glucocerebrosidase, 338 Glucocerebroside, 33 7 Glucocorticoid therapy, 208 Glucose-6-phosphate isomerase (GPI ) , 151 Glycine synthesis, 95 Glycoproteins, 329 Glycosylphosphatidylinositol anchor protein, 31 GM-CSF. See Granulocyte macrophage colony-stimulating factor Gold salts, 2 1 1 Gonadal failure, 1 84, 1 84t GPL See Glucose-6-phosphate isomerase

GPIIb/IIla antagonists, 444 GPIIb/Illa inhibitors, 463 Graft rejection, 38 Graft-versus-host disease (GVHD), 263, 295, 297 AML, 226 bone marrow transplantation, 38 CML, 240, 241 in thalassemia, 78 Graft-versus-leukemia effect, 225, 241 a.-Granule deficiency, 390 a.-Granules, 386 Granulocyte colony-stimulating factors (G-CSF), 37-38, 40, 1 2 1 , 1 96--197, 205-206, 295, 297, 324, 335 elderly, 1 6 1 HL, 307t, 308 Granulocyte macrophage colony-stimulating factor (GM-CSF), 28, 3 7-38, 1 96, 205-206, 324, 335 Granulocytes. See Neutrophils Granulocytopenia, 2 1 1 , 220 Gray platelet syndrome, 390 Growth factor therapy elder!y, 1 6 1 neutrophil dysfunction, 2 1 2-2 1 3 Growth factors, 28, 28f, 40 clinical role of, 1 96 long-term administration, 1 2 1 severe aplastic anemia and, 3 7 Growth retardation, 85 GSH deficiency test, 142 Guanidinosuccinic acid, 388 Gum lead line, 1 80 GVHD. See Graft-versus-host disease H

H. influenzae, 9 1 , 92 HAART (Highly active antiretroviral treatment), 265, 296

Haemophilus influenzae

sickle cell anemia and, 8 1 vaccines, 76, 380 Hageman factor, 398 Hairy cell leukemia (HCL), 276--2 77, 276f Haldane effect, 5 Ham-acid hemolysis test, 1 1 8 HAMP. See Hepcidin HAMP gene loci, 187 Haptoglobin, 138 HAS. See Hereditary sideroblastic anemia HCL See Hairy cell leukemia HCP. See Hereditary coproporphyria Hct. See Hematocrit HE. See Hereditary elliptocytosis Head trauma, 403 Heart disease, 1 84 failure, 77, 1 90 Heat, stability test, 83f Heavy metals, 1 1 5, 1 1 5f a.-Heavy chain disease, 330 Heinz bodies, 82, 83f, 87, 1 4 1 , 1 46 Helical CT scan with contrast, 432 Helicobacter pylori, 2 79, 287 HELLP syndrome, 368, 3 70-3 7 1 , 3 7 7 , 438 Helper T cells, 25 1

I N D EX

Hemapheresis, 9 1 Hemarthrosis, 403 Hematide (Affymax), 5 1 Hematocrit (Hct) , 6 , 1 2-14, 1 8 blood loss, 1 28 depression, 25 elevated, 1 65 sudden reduction in, 1 25, 1 25t Hematoma, 400 Hematopoietic cell lines, 28 Hematopoietic disorders, 2 1 4 iron overload secondary to, 1 8 7 laboratory measurements for, 2 3 , 23t Hematopoietic growth factors, 37, 1 2 1 , 275 Hematopoietic malignancies, 29, 2 1 2-2 13, 367 Hematopoietic profile, 1 62 Hematopoietic stem cell transplantation (HSCT), 296 follicular NHL, 295 Hematopoietic stem cells (HSC) , 28, 242-243, 334 and aging process, 1 55-156 hemophilia, 408, 408t malignant transformations, 33 Hematoxylin, 29 Hematuria, 400 hemophilia and, 404 sickle cell trait and, 84 Heme biosynthetic pathway, 1 76, 1 77f Heme groups, 2 Heme iron, 55 Heme synthesis, 54 Heme synthetase enzymes, 1 78, 1 79 Hemochromatosis, 1 82-1 94 case history, 1 82, 1 90, 192 clinical course, 1 92 clinical features, 1 84-187 differential diagnosis, 1 87-1 89 Escherichia coli, 1 85 genotypes/phenorypes, 1 89 iron balance, 1 82-1 84 laboratory studies, 1 85-187 points to remember, 1 92-1 93 therapy, 1 90-192 unusual presentations of, 1 85 Hemochromatosis rype 4, 189 Hemodialysis, 5 1 , 426 Hemoglobin, 1, 2-3 , 9, 66, 70-7 1 , 70t, 75, 77, 90, 92, 140, 1 82, 1 83t. See also Bart hemoglobin; Deoxygenated hemoglobin S; Fetal hemoglobin; Hemoglobin Constant Spring; Hemoglobin content of reticulocytes; Hemoglobin Lepore; Hemoglobinopathies; Hemoglobin-oxygen affiniry; Hemoglobin-oxygen dissociation curve; Intracellular hemoglobin concentration; Intracellular hemoglobin F; Mean cell hemoglo­ bin; Mean corpuscular hemoglobin concentration; Paroxysmal cold hemoglobinuria; Paroxysmal nocturnal hemoglobinuria; Plasma hemoglobin; Serum hemoglobulin; Sickle hemoglobin; Unstable hemoglobin molecule; Unstable hemoglobins

Hemoglobin (Cont. ) : A, 66 A 2 , 66 analysis dysplastic syndromes, 1 1 3 and quantitation, 69 W-thalassemia, 75 C disease, 8 1 , 82-83 , 92 diagnosis, 87 D disease, 87 depression, 25 E, 7 1 , 78 E/�-thalassemia, 74 electrophoresis, 82-83 hemoglobinopathies and, 8 1 , 8 1 t electrophoresis pattern, hemoglobin S/[3-thalassemia, 75 F, 66, 66f, 70, 8 1 Kleihauer-Betke acid elution test, 69 F induction, painful sickle crises and, 90 H, 1 1 3 H disease, 68, 70-7 1 , 78 test for, 74 increased, hemoglobinopathies and, 1 66f inherited defects of, 2-3 levels, 1 2-14, 162 acute bleed, 1 27f age, 50, 156, 156f altitude and, 1 64, 1 64f decrease in, 43, 43f elevated, clinical features, 1 65 epoetin alfa and, 5 1 iron therapy, 62 older patients, 50 oxygen delivery and, 1 64, 1 64f pregnancy and, 49 sickle cell anemia, 91 molecule, 79 normal versus abnormal values, 1 4f normal values, 1 4t quantity of, 66 respiratory motion of, 2 reticulocyted, 58 S, 74, 92 S disease, Sf, 8 1 diagnosis, 84-87 S/�-thalassemia, 75, 8 1 , 86-87, 92 S/C disease, 8 1 , 92 diagnosis, 86f screening/measuring, 69 stabiliry tests, 1 4 1 structure, 80f synthesis, 28 types, 66 variants, 80 Hemoglobin Constant Spring, 67, 69, 7 1 , 73 Hemoglobin content of reticulocytes (CHr), 58 Hemoglobin Lepore, 75 Hemoglobinemia, 154 Hemoglobinopathies, 79-93, SOt, 152 case history, 79, 84, 87 clinical features of, 80-83 diagnosis, 83-88, 148 geographic distribution of, 66, 66f laboratory studies, 8 1 LDH, 8 1 points t o remember, 92 therapy, 88-92

487

Hemoglobin-oxygen affinity, 8 1 Hemoglobin-oxygen dissociation curve, 5, 6, 9, 1 1 , 1 26 Hemoglobin-oxygen saturation, 1 3 Hemoglobinuria, 1 27, 1 3 9 , 1 54 Hemojuvelin gene (HJV gene), 1 84, 189 mutation, 187 Hemolysis, 138, 1 45 aniline dyes and, 1 46 Hemolytic anemias, 7, 9, 1 03 , 1 1 7, 1 36-1 54 case history, 1 36, 143, 1 5 1 , 152 clinical features, 139-143 diagnosis, 1 43-1 5 1 HL, 3 1 0 with microcytosis, 74 points to remember, 1 54 RBC morphology, 148t therapy for, 1 5 1-154 Hemolytic crises, 1 48, 1 49f Hemolytic episode/anemia, differential diagnosis, 1 54 Hemolytic transfusion reactions, painful sickle crises and, 89 Hemolytic uremic syndrome (HUS), 48, 368, 370, 382, 427 management, 377 treatment, 426 Hemopexin clearance pathways, 138 Hemophagocytic histiocytosis, 336 Hemophagocytic syndromes, 336, 339 Hemophilia(s), 354, 398-410, 408t. See also Hemophilia A; Hemophilia B; Severe hemophilia-like syndrome acquired inhibitors, 405 case history, 398, 402, 409 desmopressin, 393 genetic analysis, 403 hematuria, 404 immunosuppressive therapies, 4 1 0 intron 22 inversion, 403 IVIG, 405 laceration, 404 liver failure, 40 1 mouth laceration, 404 older patients, 4 1 0 points to remember, 409-4 1 0 prednisone and cyclophosphamide, 405-406 prophylactic therapy, 404 recombinant factor VIII, 407 replacement therapy, 403 sex-linked inheritance pattern, 402, 402f therapeutic preparations, 406-408 therapy and clinical course, 403-406 treatment, 4 1 0 Hemophilia A, 394, 394t, 399-400, 402, 406-408, 409, 41 1 purified factor VIII, 406-407, 407t surgery, 404 Hemophilia B, 399, 400, 409, 4 1 1 carriers of, 402 therapeutic preparations, 408 treatment, 404-405, 404t Hemophilic pseudotumor, 400 Hemorrhage, 9, 1 29, 133, 352, 360, 360t, 380, 400, 408, 4 1 0, 42 1 , 426 excessive, 34 7 massive, 465

488

I N DEX

Hemorrhage (Cont . ) : severe autoimmune thrombocytopenia, 379, 3 79f Hemorrhagic anemia, 7, 1 1 , 26, 1 03 Hemosiderinuria, 154 Hemosiderosis, 30 Hemostasis. See Normal hemostasis Hemostatic system, 346 HEMPAS, 1 1 9, 1 1 9f Henoch-Schiinlein purpura, 360, 360t, 36 1 , 362 Heparin, 353, 3 73 , 402, 409 , 4 1 8 , 444, 447, 448. See also Low-molecular weight heparin; Unfractionated heparin adverse effects of, 458 anticoagulation, reversal, 458 aPTT, 457-458 dysfibrinogenemias, 4 1 3 hypoaldosteronism with hyperkalemia, 458 PE, 442, 442f during percutaneous coronary artery interventions, 444 plus aspirin, clinical applications, 449 pregnancy and, 44 1 Heparin-induced platelet aggregation, 366 Heparin-induced thrombocytopenia (HIT), 366, 3 72-373 , 424, 459, 460, 463 management, 378-379 and platelet thrombosis, 458 type II, 458 Hepatic cirrhosis, 1 84 Hepatic iron content, 1 88 Hepatic uroporphyrinogen decarboxylase enzyme ( URO-D), 1 7 8 Hepatic vein thrombosis, 430 Hepatitis A virus, 407 Hepatitis B virus, 403, 407, 410, 468, 474 hemophilia and, 40 1 Hepatitis C virus, 33, 1 78, 403, 407, 410, 468, 474. See also Thrombocy­ topenic hepatitis C hemophilia and, 401 iron overload and, 187 Hepatocellular carcinoma (Hepatoma), 1 84, 1 85f Hepatoma. See Hepatocellular carcinoma Hepcidin (HAMP), 47, 47f, 54, 55, 1 5 7 , 1 58, 1 83 , 1 83f, 328 Hereditary angioedema, 262 Hereditary coproporphyria (HCP), 1 77, 1 79 Hereditary elliptocytosis (HE), 1 49-1 50, 149f Hereditary hemochromatosis, 182, 1 86 clinical features, 1 84, 1 84t untreated, 1 92 Hereditary hemorrhagic telangiectasia (HHT), 132, 356, 358, 360, 362 therapy, 361 Hereditary hyperferritinemia-cataract syndrome, 1 89 Hereditary pyropoikilocytosis (HPP), 1 50 Hereditary sideroblastic anemia (HAS), 1 1 9, 1 22 clinical fearures, 1 1 1 Hereditary spherocytosis (HS), 1 48, 1 5 2 diagnosis, 1 48-149 microspherocytes and, 1 49f

Hereditary spherocytosis/Hereditary elliptocytosis (HS/HE), 1 50 Hermansky-Pudlak syndrome, 390 HES. See Idiopathic hypereosinophilic syndrome Hespan, 130 Hetastarch, 1 30 HFE gene, 1 83-1 84, 1 83t, 1 8 7 defect, 1 82 genotype analysis, 1 88-1 89 hemochromatosis, 1 90, 1 92, 1 93 mutations, 1 84, 1 92 Caucasian population, 1 88 iron overload and, 1 85, 1 85t HFE protein, 1 83 , 1 83f HHT. See Hereditary hemorrhagic telangiectasia HIE See Hypoxia-inducible factor High-grade disseminated intravascular coa&rulation ( DIC), 422 High-grade lymphomas, 294, 295-296, 298 Highly active antiretroviral treatment. See HAART High-molecular-weight kininogen (HMWK) , 398 High-performance liquid chromatography (HPLC), 8 1 , 82 Histiocytic medullary reticulosis (HMR), 339 Histochemical stains, 200£, 2 1 7, 2 1 7t, 221 Histone deacetylase, 226-227 HIT. See Heparin-induced thrombocytopenia HIV infection, 48, 2 1 1 , 258, 266, 284, 3 2 1 , 365, 403, 407, 474 cryoprecipitate, 406 hemophilia and, 40 1 marrow-damage anemia and, 32 primary effusion lymphoma, 288 thrombocytopenia and, 373 HIV- 1 red cell transmission, 468 HIV-2 red cell transmission, 468 HIV-associated thrombocytopenia, 3 79 HIV-positive hemophiliacs, 40 1 HJV gene. See Hemojuvelin gene HL. See Hodgkin lymphoma HLA. See Human leukocyte antigen HMR. See Histiocytic medullary reticulosis HMWK. See High-molecular-weight kininogen Hodgkin lymphoma (HL), 52, 254, 264, 301-3 1 0, 373 advanced disease, 308 autoimmune thrombocytopenia, 379 biopsy, 303 case history, 301 , 306, 309 clinical features, 303 diagnosis and classification, 302 early favorable disease, 308 early unfavorable disease, 308 histopathologic types, 302-303 lymph node histopathology, 302-303f prognosis, 305, 305t salvage therapy, 308-309, 309f staging, 304-305, 304f, 3 1 0 therapy and clinical course, 306 chemotherapy, 307-309 radiation therapy, 306-307, 307f tumor, 302

Holo TC II, 99 Holo TC II level, 101 Homocysteine elevation, 98, 1 08 metabolism pathways, 437, 437f Homozygous hemoglobin C disease, 81 Homozygous sickle cell disease, 84 Hormones, 1 79 Host challenge, 198 Host defenses, 22 7, 259 Howell-Jolly body, 83f, 256 HPLC. See High-performance liquid chromatography HPP. See Hereditary pyropoikilocytosis HPV B 1 9, 34 HS. See Hereditary spherocytosis HSC. See Hematopoietic stem cells hs-CRP levels, 439 HSCT. See Hematopoietic stem cell transplantation HS/HE. See Hereditary spherocytosis/ Hereditary elliptocytosis HTLV- 1 . See Human T-cell lymphotrophic virus- 1 Human herpesvirus 8, 289 Human leukocyte antigen (HLA) , 1 20, 296 alloimmunization, 3 76, 465-465 , 465-466, 469, 472 identical siblings, 90 platelet disorders and, 3 75-3 76 typing, 36 Human T-cell lymphotrophic virus- 1 (HTLV- 1 ), 274, 376. See also Non-Hodgkin lymphoma Humate, 394, 395, 396, 407 Humoral growth factors, 1 95 HUS. See Hemolytic uremic syndrome Hydration, 33 1 Hydrocortisone ALL, 3 1 6 Burkitt lymphoma, 296 Hydrops fetalis, 68, 7 1 , 73 Hydroxyethyl starch solution, 1 29, 1 29t, 130 Hydroxyurea, 1 03 chronic eosinophilic leukemia, 242 CML, 240 ET and, 440 painful sickle crises and, 90 primary thrombocythemia, 24 1 , 24 2 Hypercalcemia, 324, 327 Hypercoagulability, 438 Hypercoagulable state, 429, 429f, 434t, 435 Hypereosinophilia, 208 Hyperglycemia, 1 04 Hyperhomocysteinemia, 43 7 Hyper-IgD syndrome, 262 Hyperlipidemia, 436 Hyperparathyroidism, 49 Hyperphosphatemia, 3 1 6, 3 1 6t Hypersegmented polymorphonuclear leukocytes, 99, 99f Hypersensitivity reactions, 202, 458 Hypersplenism, 1 20, 24 1 , 256 Hypertransfusion, 89 Hyperuricemia, 3 1 6, 3 1 6t Hyperviscosity, 33 1 , 33 1 t Hyperviscosity syndromes, 3 2 I-322, 322f

I NDEX

Hypoalbuminemia, 436 Hypoaldosteronism with hyperkalemia, 458 Hypochromia, 72 Hypodiploidy, 3 1 2 Hypofibrinogenemia, 223 Hypogammaglobulinemia, 262-263, 273 Hypoparathyroidism, 77 Hypoproliferative anemias, 24, 25, 26 clinical features, 4 2-46 diagnosis, 46-49 differential diagnosis, 49 iron studies and, 35-36 of protein deprivation, 48 case history, 50 therapy, 49-52 Hyposplenism, 83f, 256 Hypotension, 130 Hypothyroidism, 49 Hypovolemic shock, 1 1 , 1 25 , 1 26, 1 3 1 Hypoxia, 6 , 8 , 1 1 , 1 64, 1 64f Hypoxia-inducible factor (HIF), 6, 5 1 Hypoxic erythrocytosis, 1 67 Idiopathic aplastic anemia, 29, 3 1 , 33-34, 38 Idiopathic hypereosinophilic syndrome (HES), 208 Idiopathic neutropenia, 2 1 1 Idiopathic thrombocytopenic purpura (ITP) , 338, 365, 373, 3 74-375 plasma infusion, 3 74f Idiopathic TIP, 369 Idraparinux, parenteral, 460 IF. See Intrinsic factor IgA-deficient patients, 4 70 IgA-immune complex, 360, 360t IgE immune- mediated allergic reaction, 130 IGF- 1 . See Insulin-like growth factor- 1 IgG antibodies, 467 lleofemoral thrombosis, 440 Illness severity, anemia versus, 44 Imatinib mesylate (Gleevec), 239 Immature cells. See Blasts Immediate factor replacement, 4 1 7 Immune deficiency, 258-267, 284. See also Severe combined immunodefi­ ciency disease Immune destruction tests, 14 2 Immune globulin, 3 72 AIDS-associated thrombocytopenia, 3 79 pure red blood cell aplasia, 40 Immune network, 245-246, 246f Immune neutropenia, 209, 209t Immune response, 248-249 Immune response suppression, 250 Immune system, 245-246, 246f, 250, 256 aging process and, 252 defects, 262 T cells, 250-25 1 Immune vasculitis, 360, 360t Immune-mediated aplasia, 28f Immune-mediated HIT, 373 Immune-related disease, 1 1 1 Immunity, 335 Immunoaffinity purified products, 407 Immunoassay, total fibrinogen protein, 4 1 3

Immunochemotherapy follicular NHL, 295 MCL, 295 Immunocompromised patients, 299 blood transfusions and, 4 70 irradiated platelets and, 4 72 Immunodeficiency, 266 secondary to lymphoproliferative disease, 264 Immunodeficiency syndromes, 260-26 1 Immunoglobulin, 1 53 childhood autoimmune thrombocytopenia, 378 gene rearrangements, 285, 286f B-cell chronic lymphocytic leukemia, 270-2 7 1 production, 261-262 severe autoimmune thrombocytopenia, 380 studies, 324-3 25 Immunoglobulin light chains, 329 Immunoglobulin super family, 248 Immunohistochemistry, 323 Immunologic markers, 1 99, 20 1 monoclonal antibodies and, 2 1 7-2 1 8 Immunomodulatory therapies, dysplastic anemias, 1 2 1 Immunophenotypic marker studies, 3 1 5 Immunophenotyping, 284, 3 1 8 ALL, 3 1 2t, 3 13t, 3 1 4 AML and, 221 B-cell chronic lymphocytic leukemia, 269 Immuno-proliferative small intestine disease (IPSIO), 330 Immunosenescence, 252 Immunosuppression, 39-40 Immunosuppressive agents, 284 Immunosuppressive therapies, 28, 34, 40, 154, 3 6 1 AIHA, 1 5 2 dysplastic anemias, 1 2 1 hemophilia, 4 1 0 myelodysplasia, 40 Impaired globin chain synthesis, 79-80 Impedance plethysmography, 430-43 1 Inappropriate antidiuretic hormone (ADH), 179 Inborn errors of cobalamin metabolism, 98, 108 Inborn errors of folate metabolism, 1 05 Inborn errors of serum homocysteine, 98 Incubated autohemolysis tests, 1 4 1 , 1 4 1 f Indirect antiglobulin test, 467 Indirect bilirubin levels, 139 Indirect Coombs test, 1 42 Indirect serum LDH levels, 139 Induction chemotherapy, 227, 3 1 6, 3 1 6t Ineffective erythropoiesis, 7, 69, 1 86, 1 86f Ineffective hematopoiesis, 1 1 0 Ineffective thrombopoiesis, 367 Infection, 1 1 7, 223. See also AIDS; Bacterial infections; Chronic infections; Epstein-Barr virus infection; Fungal infection; HIV infection; Parasitic infections; Viral infections; Yeast infections granulocyte response, 206f hemochromatosis and, 1 85

489

Infection (Cont . ) : hemodialysis and, 5 1 marrow-damage anemias, 32-33 MM, 324 neutrophil kinetics, 202f, 203 neutrophils, normal response, 205-206 prognosis and survival, 1 20-1 2 1 recurrent, 1 1 1 Inflammation, 49, 250, 25 1 Inflammatory anemias, 57, 1 6 1 Inflammatory cytokines, 7 Inflammatory disease, 44, 44t Inflammatory disorders, 1 1 5 Inflammatory response, 336 Inherited coagulopathy, 353, 445, 474 Inherited hypercoagulable state, assays for, 433-434, 434t Inhibitor alloantibodies, 407 Inhibitor mixing assay-PTT, 402 Inhibitors of platelet function, vascular purpura and, 362 Injury, vessel structure and, 358 INR. See International normalized ratio Insecticides, 367 Insulin-like growth factor- 1 ( IGF- 1 ), 7 Integrin blockers, 44 7 Integrins, 248 Intensive therapy, 2 73 Interferon, 25 1 y therapy, 2 1 2 CML, 240 side-effects of, 240 HCL and, 276 primary thrombocythemia, 242 therapy porphyria cutanea tarda, 1 80 thrombocytopenic hepatitis C, 376 Interferon-a CML, 239-240 primary thrombocythemia, 241-242 Interleukin(s), 203-204, 246--247 Interleukin 2 (Neumega), 247, 260, 376 Interleukin 2 receptor, 25 1 Interleukin 3, 205-206 Interleukin 6, 1 5 7 , 320 Interleukin- 1 , 246--24 7 Interleukin-3 , 28, 1 97, 247 Interleukin-5 , 1 97, 247 Interleukin-6, 4 7, 1 97, 24 7 Interleukin-7, 24 7 Interleukin- 1 1 , 1 97 , 247 Interleukin- 1 2, 247 Intermediate/high-purity products, 407 International normalized ratio ( INR) anticoagulation therapy, 454, 454f PT and, 349-350 PT reagents, 4 1 8 vitamin K deficiency, 4 1 6, 4 1 6t warfarin dosing, 443 International prognosis index (IPI), 288, 288t International Prognostic Scoring System (IPSS), 1 1 3 myelodysplastic anemias, classification system, I 20, 1 20t International Staging System (for multiple myeloma), 326, 326t, 332

490

I N DEX

Intracellular hemoglobin concentration, reduction, 90 Intracellular hemoglobin F, sickle cell anemia, 9 1 1ntracellular inclusion bodies, 83f Intracellular metabolic defects, 150 Intracellular pathogens, 201 , 20 1f Intracerebral hemorrhage, 426 Intracranial hemorrhage, 400, 408, 4 1 0 Intracranial pressures, 44 1 Intraoperative blood loss, controlled hypotension, 133-134 Intrathecal therapy, 225, 3 1 6--3 1 7 Intravascular destruction (of red blood cells) , 1 3 7 , 1 3 7f Intravascular hemolysis, 1 38f, 1 39-140, 140f, 154 therapy for, 1 5 1-152 Intravascular hemolytic event, 1 38-139 Intravascular lymphoma, 288 Intravenous immunoglobulin ( IVIG) anti-vWF antibody, 395 autoimmune thrombocytopenia, 3 79, 3 79f, 380 chronic ITP in pregnancy, 380 hemophilia, 405 Intrinsic factor (IF) deficiency, 1 00, 1 04 synthesis, 1 04 Intrinsic pathway, 409 coagulation factors of, 398-399, 399f defects, 398--4 1 0 case history, 398 normal, 398-399 lntron 22 inversion, 409 hemophilia, 403 Ionized calcium, 343 Ionizing radiation, 284 !Pl. See International prognosis index IPSID. See lmmuno-proliferative small intestine disease IPSS. See International Prognostic Scoring System IRE/IRP regulatory system, 55 Iron, 43f. See al.so Body iron content; Oral iron preparations; Parenteral iron therapy; Serum iron; Total iron­ binding capacity absorption, 1 82-1 83 genetic control of, 1 83-1 84, 1 83t mucosal cells, 1 83 , 1 83f balance, normal, 1 82-1 84, 1 83t childbearing, 1 83 dietary content of, 1 83 dosage regimen, 62-63 for patient tolerance, 62, 62f hypoproliferative anemias, 35-36 intake, monitoring, 1 90 loss, 54 cause of, 58, 60 metabolism, normal, 53-55 metabolism abnormalities, 1 89 nutrition, 55 overload arthropathy of, 1 84 clinical features, 184 painful sickle crises and, 89

Iron, overload (Com . ) : prognosis and survival, 1 20 in thalassemia, 7 7 therapy, 1 90-192 overload states, 1 87 , 1 88t RBC production and, 8-9, Sf removal effects of, 1 90 measurement of, 1 9 1 studies, 29, 44-45, 49, 49t, 50, 60, 167' 188 anemia and, 4 7 hypoproliferative anemia and, 35-36, 35t hypoproliferative anemia of protein deprivation, 48 polycythemia vera criteria, 1 69-1 70 primary thrombocythemia, 23 7 renal disease anemia, 48 thalassemia, 68-69 supplementation, 55, 58, 60 pregnancy and, 64 supplies, 9, 1 5 1 RBC production and, 8 tests of, 22-23 therapy dosage guidelines, 62-63, 1 3 1 response to, 1 3 1-13 2 unloading, 1 90 Iron chelation therapy, 36, 3 7 in children, 76 deferasirox/deferoxamine, 76-- 7 7 monitoring, 76 PCT and, 1 9 1 Iron deficiency, 9 , 1 1 , 1 3 , 2 1 , 2 1 f, 44, 52, 1 27' 134 clinical features, 55-58 smear morphology with, 59f thalassemia minor versus, diagnosis of, 72 Iron dextran, 62-63, 1 32, 132f, 362 administration and complications, 63 clearance, 63 Iron loading, 1 85f. See al.so Hemochromatosis Iron overload. See al.so Tissue iron overload African Americans, 189 heart disease and, 1 84 hepatitis C virus, 187 organs and, 1 92 TIBC and, 1 85, 1 85t transfusions, 2 1 Iron store depletion, 56, 64, 1 03f diagnosis of, 58 Iron stores, 1 82-1 83. See al.so Total body iron stores marrow, 5 7 reticuloendothelial cell, 5 7 Iron sucrose (Venofer ) , 62, 63 Iron transport genetic control of, 1 83-1 84, 1 83t pathways, 54, 54f, 1 82-183 Iron-binding proteins (IRP), 1 83 Iron-containing enzymes, 1 82, 1 83t Iron-deficiency anemia, 1 1 , 45, 49, 53-64, 72, 1 6 1 , 361 case history, 53, 59, 63 causes of, 56t clinical features, 55-58

Iron-deficiency anemia ( Cont . ) : diagnosis, 58-60 differential diagnosis, 60-6 1 elderly and, 1 58-159 Laboratory studies, 56-58, 56t points to remember, 64 therapy, 6 1 -63 Iron-deficiency thalassemia, 64 Iron-deficient erythropoiesis, 55, 58, 64 Iron-deficient marrow, 69 Iron-deficient state, 6 1 Iron-Loading hematopoietic diseases, 1 85t, 187 IRP. See Iron-binding proteins Irradiated platelets, 4 72 Irradiated red blood cells, 466, 474 Islet cell function, 1 90 Isolated aplasia of erythroid progenitors, 34 Isolated platelet consumption (Platelet DIC), 420, 424, 424t, 426 Isoniazid, 1 1 5, 45 1 Isopropanol stabi I ity test, 83 ITP. See Idiopathic thrombocytopenic purpura ltraconazole, 223 IVIG. See Intravenous immunoglobulin

J

]AK2 mutation, 1 67, 1 68, 1 69, 236-- 2 37,

238, 242 ]AK2 V6 1 7F. See Janus kinase gene Janus kinase gene UAK2 V6 1 7F), 23 1 JMML. See Juvenile myelomonocytic

Leukemia Juvenile myelomonocytic leukemia (JMML), 238 Juvenile rheumatoid arthritis, 48 K

Karyotypic abnormalities, 23 1 , 23 1 t Karyotyping, 23 1 t, 232-233 Kell system, 467 Ketoconazole, 452 Kidd gene, 467 Kidney, 1 5 2 erythropoiesis and, 9 platelet thrombi, 369, 369f Kidney sensor cells, 48 Kleihauer-Betke acid elution test, 69 Kogenate, 407 Kostmann syndrome, 2 1 0 K-ras oncogenes, 323 L

LA. See Lupus anticoagulants �-Lactam, 3 24 Lactic acid dehydrogenase (LDH), 1 9 ALL, 3 1 4-3 1 5 hemoglobinopathies and, 8 1 TIP and, 369 LAD. See Leukocyte adhesion deficiency Langerhans cell histiocytic disorders, 336 Large cell B-cell Lymphomas, 284, 298 Large cell Lymphoma, 294, 294f Large cell tumor mass, 282f, 288 Large granular lymphocytic Leukemia, 275-276, 277

I NDEX

Large intestine bleeding, 1 28 Large joints, 1 84, 400 Latex particle agglutination method, 35 1 , 422 LCDD. See Light-chain deposition disease LDH. See Lactic acid dehydrogenase Lead poisoning, 1 77, 1 79, 1 8 1 case history, 1 80 diagnosis, 1 77, 1 78f heme synthetase enzymes, 1 79 treatment, 1 8 1 Lecithin cholesterol acyltransferase, 1 Leg ulcers, 9 1 Lenalidomide, 1 1 9, 1 2 1 , 326, 327 Lennert lymphoma, 291 Lennert lymphoma classification system, 280 Lepirudin, 3 78, 461 Lethal defect, 7 4 Lethal midline granuloma, 293 Letterer-Siwe disease, 336 Leucovorin. See Folic acid tablets Leukapheresis, 296 Leukemia, 33f, 1 1 1 , 367. See also specific leukemic diseases

molecular genetics, 2 1 9-220 thrombocytopenia in, 3 76 Leukemia classification, 2 1 6-220, 2 1 6t cytogenetic abnormalities, 2 1 8--2 1 9 immunologic, 2 1 7-2 18, 2 1 8t molecular genetics, 2 1 9-220 morphologic, 2 1 6-2 1 8 Leukemic lymphoproliferative diseases, 268-278 case history, 268, 274 Leukemic monocytosis, 338-339 Leukemic T-cell lymphomas classification, 290 Leukocyte adhesion deficiency ( LAD), 2 1 2 Leukocyte adhesion molecule (L-selectin) , 1 98, 1 98f Leukocyte alkaline phosphatase, 1 99 Leukocyte count, 203 Leukocyte-reduced red blood cells, 50, 1 20 Leukodepleted red blood cells, 465-466, 470, 474 Leukofiltered red blood cells, 1 30 Leukopenia, 3 7 Leukopenia associated with aplastic anemia, 37 Leukostasis syndrome, 220 Levamisole, 2 1 1 Lewis antigens, 467 L&H cell, 302, 303f Liebow-Carrington disease, 293 Flt3 ligand, 197 Light-chain deposition disease (LCDD) , 322, 330 Lipid/lysosomal-storage disorders, differential diagnosis, 337-338 Lipid-storage disorders, 336-33 7 Liste1·ia, 1 85, 201 Lithium salts, granulocytosis and, 208 Liver, 1 84 biopsy, 1 77, 1 85f, 1 86 chemistries, 285 damage, 1 92 failure, 40 1

Liver ( Cont . ) : folate and, 96 with iron deposition, 187 iron loading, 1 77 neoplasm, 1 92 porphyrin synthesis, 1 7 7 toxicity, 1 84, 1 85f Liver disease, 55, 73, 368, 4 1 4, 4 1 4t. See also Severe liver disease alcoholic, 1 89 aminocaproic acid, 4 1 7 bleeding and, 4 1 7 DIC and, 424 ferritin studies, 1 86, 1 86f platelet function in, 388 PT and, 349-350 Liver function studies, 1 78 HL, 304 porphyria, 1 77 LMWH. See Low-molecular weight heparin Loeffler syndrome. See Idiopathic hypereosinophilic syndrome Long-term hematopoietic stem cells ( LT-HSC), 28, 1 1 0 Low-dose heparin, 457 Low-dose heparin with warfarin, 457 Low-grade disseminated intravascular coagulation ( DIC), 422, 424 Low-grade lymphomas, 294-295, 294t, 298 Low-molecular weight heparin (LMWH), 425, 453, 458-460, 463 adverse effects, 460 cardiac thromboembolic disease, 442-443 clinical applications, 459 cost-effectiveness, 460 HIT and, 378 pediatric thromboembolism, 44 1 , 44 1 t pregnancy, 440, 44 1 , 454, 45 7 therapeutic guidelines, 459-460, 459t L-seiectin. See Leukocyte adhesion molecule LT-HSC. See Long-term hematopoietic stem cells Luebering-Rapaport pathway, 5 Lukes- Butler classification, 302, 303t Lukes-Collins lymphoma classification system, 280, 28 1 Lung function, 6 Lung scan, 43 1-432 Lupus anticoagulants (LA), 353, 402, 434-435, 438 Lupus erythematosus, 14 7 Lymph nodes, 252, 252f, 253 architecture, 253, 253f biopsy of, 254-255, 298, 339 distribution, 253, 253f enlarged, 283-285 histology, phenotype, 28 1 f palpable, major sites of, 304f Lymphadenopathy, 253-254, 253f causes, 253-254, 253f, 254t diagnostic procedures with, 254 Lymphangiography, 255 Lymphatic system, 245-257, 252f points to remember, 256 Lymphatic vessels, 252 Lymphoblastic lymphoma, 290 Lymphoblasts, 3 1 3-3 14, 3 14f

49 1

Lymphocyte adhesion molecules, 247, 248t Lymphocyte kinetics, normal, 258, 259t Lymphocyte-rich classical Hodgkin lymphoma, 303 Lymphocytes, 256, 3 1 8 aspirate marrow and, 1 1 1 development, 245-246, 246ff dysfunction, clinical features, 259-260 MCL, 287f, 288 Lymphocytic/histiocytic cells, 302-303 Lymphocytopenia. See Myelodysplasia Lymphoid cells development, 245-246, 246f normal, 3 1 6 Lymphoid growth factors, 246-247 Lymphoid stem cells, 245-246 Lymphoid tissues, enlargement, 283-285 Lymphokine-activated killer cells, 252 Lymphoma, 8, 1 1 1 , 1 54, 256, 368. See also Lymphoma International Prognostic Index; specific lymphomas clinical features, 283-285 follicular/nodular versus diffuse histologic patterns, 282f imaging studies, 255 multifocal versus localized disease, 284 REAL classification, 280, 280t staging, 298 Staging classification systems, 280, 280t, 3 1 0 survival curves, 294f vaccine therapy, 295 Lymphoma cells, 279 circulating, morphology in, 272f Lymphoma International Prognostic Index (FLIP! ), 286, 286t Lymphomatoid granulomatosis, 290 Lymphomatoid papulosis, 292 Lymphomatous infiltration of non-lymphoid organs, tests for, 285 Lymphopenia, 258--267 case study, 258, 260, 266 clinical features, 259-260 Lymphoplasmacytoid variant, 286 Lymphoproliferative disease, 2 1 1 , 266 Lymphoproliferative disorders, 3 73-374 Lymphoproliferative process, 256 Lysozyme, 1 99 M

M3. See Acute promyelocytic leukemia Macrocytic anemias, 94-1 08, 1 1 2, 1 1 2t, 1 59. See also Severe macrocytic anemia case history, 94, 1 02, 105 diagnosis of, 1 0 1-103 differential diagnosis, 1 03-105 laboratory studies, 97-1 0 1 , 97t anti-intrinsic factor antibody, 1 00 homocysteine levels, 98 methylmalonic acid levels, 98 Schilling test, 1 00-- 1 0 1 serum cobalamin level, 97-98 serum folate level, 97 serum gastrin, 1 00 vitamin-deficient erythropoiesis, 99 points to remember, 1 07-1 08 secondary to folic acid deficiency, 1 02

492

I N DEX

Macrocytosis, 14, 1 7f, 60, 6 1 , 72, 99, 103-104, 1 03t, 105, 1 67 with little anemia, 73 a2-macroglobulin, 345 Macroglobulinemia, 330-33 1 Macroovalocytes, 99, 99f Macrophages antigen presentation by, 20 1f morphology, 200f MAG. See Myelin-associated glycoprotein Magnetic resonance imaging (MRI ) arterial thrombus, 433 iron overload and, 187 marrow cellularity and, 30 Maintenance chemotherapy, 3 1 7 Major basic protein, 20 1 Major histocompatibility complex (MHC) molecules, 250 Malabsorption, 6 1 , 62-63, 64, 97, 1 00-- 1 0 1 , 1 08 Malabsorption syndrome, 23 Malaria, 145, 145f Malignancies, 1 1 8, 1 90, 209, 2 1 1 , 2 14, 222, 255, 284, 424. See also Clonal malignancies; Hematopoietic malignancies; Metastatic malignancies; Staging classification systems hematologic, 445 lymphadenopathy and, 253-254, 253f lymphokine-activated killer cells, 252 marrow aspirate, 255 marrow damage and, 33 of monocyte-macrophage lineage, 336 staging, 255 thrombotic tendency and, 435 of tissue macrophages, 334 venous thrombosis and, 445 Malignant cell infiltrates, 220 Malignant cell line, 2 1 7 , 2 1 8 Malignant histiocytosis, 336, 339 Malignant lymphadenopathy, 254 Malignant proliferations of monocytehistiocyte lineage cells, 336 Malignant state, reactive granulocytosis versus, 207 MALT rumors (Mucosa-associated lymphoid tissue rumors), 286. See also Gastric MALT lymphoma Mantle cell lymphoma ( MCL) , 287-288, 295 Marginal zone lymphomas, 286-287 Marrow, 8, 30, 69. See also Allogeneic bone marrow transplantation; Autologous marrow transplantation; Erythroid marrow; Marrow aspi­ rate; Marrow biopsy; Marrow cell; Marrow E/G ratio; Marrow megakaryocytes; Marrow stem cells; Marrow transplantation; Marrow-damage anemias; Marrow-damage specimens anemia response, 8 cellularity and distribution, 1 1 0 core biopsy, 29 damage, 134 platelet production and, 367

Marrow (Cont . ) : environment, 1 62 examination, 19-20, 26 ALL, 3 1 6, 3 1 6t B-cell chronic lymphocytic leukemia, 269 primary myelofibrosis and, 1 1 8 primary thrombocythemia, 23 7 failure, 3 1 3 , 3 1 3t function, 1 8 histology, HCL and, 276 iron stain, 5 7 , 5 7f stores, 5 7 studies, 1 86 iron-deficient, 69 MM and, 332 morphology distortions, 1 0 1-103 normal, 1 1 0-1 1 1 , 1 1 0t myelodysplastic anemia, 1 1 3 normal adult, 203 osteoclasts, 3 20f diffuse plasma cell infiltrate versus, 320f proliferation, normal, 43, 43f reticulocytes, 24 structure, anatomical distribution, 27-28, 28f studies CML and, 233, 233t hypoproliferative anemia, 45 thalassemia, 68-69 testing, 284-285 Marrow aspirate, 29, 202 ALL, 3 1 4, 3 1 4f AML and, 220 biopsy, 167 dysplastic syndromes, 1 1 1-1 1 2 examination, 167 granulocytosis and, 207 myeloproliferative disorders and, 23 1 , 232 polycythemia vera, 1 69 reactive monocytosis and, 33 7 Reed-Sternberg cells, 305 , 305f specimen, 20--2 1 , 20f, 29-30 staging and, malignancy, 255 thrombocytopenia, 366 Marrow biopsy, 2 1 -22, 22f, 29-30, 3 1 , 167, 202 AML and, 220 dysplastic syndromes, 1 1 1-1 1 2 myeloproliferative disorders and, 23 1 , 232 polycythemia vera, 1 69 posterior iliac crest and, 1 9, 1 9f primary myelofibrosis, 1 1 8, 1 1 8f, 235-236, 235t primary thrombocythemia, 23 7 reactive monocytosis and, 337 staging and, malignancy, 255 thrombocytopenia, 366 Marrow cell, differentiation and proliferation, 28f Marrow E/G ratio, 7, 99, 1 2 7 , 147 Marrow erythroid precursors, 1 86 Marrow megakaryocytes, 3 7 1 cancer and, 367 Marrow red cell precursor, measurements of, 9

Marrow stem cells, 252 Marrow transplantation, 24, 32, 34, 36, 40, 265, 324 in aplastic anemia, 38-40, 38f autoimmune thrombocytopenia, 379 CML, 240--24 1 myelofibrosis, 24 1 thalassemia and, 7 7 Marrow-damage anemias, 27-4 1 , 36t case history, 27, 3 1 , 40 causes, 3 1 t clinical features, 28-3 1 diagnosis of, 3 1-35 differential diagnosis of, 35-36 infection and, 32-33 marrow structure and, 27-28 points to remember, 40 therapy for, 3 6 Marrow-damage specimens, 30f Massive blood transfusion, 1 34, 135 MAST. See Military antishock trousers Mast cell disease, 2 1 3 Mast cell leukemia, 236 Mast cells, 1 1 1 Maternal death, 435 Matures scoring system, CLL versus leukemias, 270, 270t May-Hegglin anomaly, 367, 368f MCH. See Mean cell hemoglobin MCHC. See Mean corpuscular hemoglobin concentration M-component, 33 1 , 332 for diagnosing and staging, 3 2 1 identification of, 321-322, 322f MGUS, 328-329 MM, 324 M-CSF. See Monocyte colony-stimulating factor MCV. See Mean cell volume MDR- 1 reversing agents, 22 7 MOS. See Myelodysplasia MDS-U. See Undifferentiated myelodysplastic syndrome Mean cell hemoglobin ( MCH), 1 5 , 58 Mean cell volume (MCV), 1 2, 14-1 5 , 14f, 16, 1 6f, 139 anemia and, 99, 99f iron deficiency and, 58 Mean corpuscular hemoglobin concentration (MCHC) , 1 2, 1 5 , 139 Mechanical heart valves, ! 5 2 Mechanical purpura, 3 5 9 Mechanism o f regulation, 6 Mediastinal (thymic) large B-cell lymphoma, 288, 288t Mediastinal nodes, HL and, 303 Megakaryocyte colonies, primary thrombocythemia, 237-238 Megakaryocytes, 1 1 0--1 1 1 , 1 1 2, 365, 365f abnormalities, 367 HIV, 373 Megaloblastic anemias, 149, 1 49f Megaloblastic marrow, 2 1 Megaloblastosis, 99, l OOt Melphalan/prednisone therapy, MM, 326, 327 Membrane phospholipids, 1

I NDEX

Membrane skeletal proteins, 1 48 Membrane structural defects, 148-150, 1 5 2 Membrane structure tests, 1 4 1 Menorrhagia, 409 Menstruating women, ferritin levels, 55 Meperidine, 88 Mesenteric venous thromboembolism, 430 Metabolic diseases, 2 1 1 Metabolic machinery tests, 1 4 1-142 Metaphase cells, karyotyping, 23 1 t, 232-233 Metastatic cancer, 33, 36, 236f, 254 Metastatic malignancies, 36 marrow damage and, 33 Methemalbumin, 1 38f, 1 40 Methionine synthase, 95, 98, 98f Methotrexate, 1 03. See also Folic acid tablets ALL, 3 1 6 antifolate action of, 1 05 Burkitt lymphoma, 296 chronic eosinophilic leukemia, 242 GVHD and, 38 large granular lymphocytic leukemia, 275 T-cell lymphomas, 296 Methyl violet stain, 83f a-Methyldopa, 1 46 Methylene-tetrahydrofolate reductase polymorphisms, 1 05 variant, 437 , 437f Methylmalonic acid levels, 98, 1 08 vitamin B 1 2 deficiency and, 1 60 Methylmalonyl-CoA mutase, 98, 98f Methylprednisolone platelet DIC, 426 severe autoimmune thrombocytopenia, 3 79, 379f Metronidazole, 45 1 Mezlocillin, platelet function and, 389, 389t MGUS. See Monoclonal gammopathy of unknown significance MHC molecules. See Major histocompatibility complex molecules Microangiopathic hemolytic anemia, 3 70 Microcytic/hypochromic anemias, 60, 78 Microcytic/hypochromic red cell morphology, 64 � 2-Microglobulin, B-cell chronic lymphocytic leukemia, 2 7 1 Microspherocytes, H S and, 149f Microvascular hemorrhage, 426 Miglustat, 339 Mild anemias, 1 1 , 36 Mild hypercalcemia, 327 Mild marrow-damage anemia, 27-4 1 Miliary tuberculosis, 3 2 Military antishock trousers (MAST), 1 29 Sq Minus syndrome. See Myelodysplasia with deletion of Sq Mitochondria, 58 Mitochondrial function synthesis, 1 1 5f Mitomycin C-associated TTP-HUS, 370 Mitoxantrone, AML relapse and, 226 Mixed cellularity and lymphocyte-depleted Hodgkin disease, 303 Mixed cellularity Hodgkin lymphoma, 303 Mixed cryoglobulinemia, 360-361 Mixed TTP-HUS, 426

MM. See Multiple myeloma MNSs system, 467 Moderate anemia, 1 0 1 - 1 03 with marked microcytosis, 73-74 Modest neutropenia, 2 1 3 Modified Bethesda assay, 405 "Modified" whole blood, 465 Molecular genetics analysis, 227 leukemia, 2 1 9-220, 2 1 9t Molecular pathology, polycythemia vera, 1 69 CD44, 248 Monoclonal antibodies, immunologic markers and, 2 1 7-2 18, 2 1 8t Monoclonal gammopathy of unknown signif­ icance (MGUS) , 3 1 9, 328-329 laboratory diagnosis, 3 2 1 -323 Monoclonal lgM antibodies, 33 1 Monocyte colony-stimulating factor (M-CSF), 1 97, 205-206 Monocyte-macrophage disorders, 334-340 case history, 334, 339 Monocyte-macrophage system function, 335f normal, 334-336 Monocytes, 335 functions of, 20 1 morphology, 200f Monocytic colony-stimulating factor (M-CSF), 335 Monocytosis, 203, 2 1 3 Monosomy 7, 33-34, 1 2 1 MOPP protocol, 307, 307t Morphine therapy, 88 Morphine-6-glucuronide, 88 Motor neuropathies, 1 79 Mouth, sore, 97 Mouth laceration, hemophilia and, 404 M-protein, 320 MRI. See Magnetic resonance imaging Mucosa-associated lymphoid tissue tumors. See MALT tumors Mucosal bleeding, 354, 396 Mucosal cells (of small intestine) , iron balance and, 1 83 , 1 83f Mucosal hemorrhage, 426 Mucous membrane bleeding, 404 childhood autoimmune thrombocytopenia, 378 Multi-drug chemotherapy (regimen) . See also st>ecific chemotherapy

ALL, 3 1 6, 3 1 6t high-dose, 32 MM, 326-327 platelet consumption and, 423 Multiorgan damage, sickle cell anemia and, 86 Multiple myeloma (MM), 3 1 9, 323-328, 33 1 , 36 1 , 362. See also Antimyeloma chemotherapy anemia, 324, 328 bone disease in, 320, 320f case history, 3 25 complication management, 327-328 cytogenetic studies, 3 25-326 diagnosis criteria, 322t

493

Multiple myeloma (MM) ( Cont . ) : hematologic manifestations, 324 organ function studies, 3 25 risk stratification of, 325t T-cell compartment and, 321 therapy and clinical course newer therapies, 326-327 traditional therapy, 326 Mycobacteria, 20 1 Mycocytosis with no anemia, 159 Mycoplasma pneumoniae, 1 45-1 46, 1 5 2 Mycosis fungoides, 274, 287f, 291-300 Myelin-associated glycoprotein (MAG), 330-33 1 Myelodysplasia (MDS), 1 1 , 29, 33, 35, 107, 109-1 23, 1 60 case study, 1 09 clinical features, 1 1 1-1 1 3 differential diagnosis, 1 22 immunosuppressive therapy, 40 pathophysiology of, 1 1 0 Myelodysplasia with deletion of 5q (Sq minus syndrome), 1 1 6, 1 1 9 Myelodysplastic syndrome, 2 1 6, 2 1 6t. See also Myelodysplasia Myelofibrosis, 23 1 , 232, 232f, 368, 3 76-377. See also Primary myelofibrosis therapy, 241 Myelogenous leukemia, 2 1 3 Myeloid cell(s), 203 function, 198, 1 98f histochemical stains for, 200f kinetics, 202-203 neutrophilic precursors versus, 199, 199t, 200f production, 203 Myeloid growth factors, 1 95-202 Myeloid leukemias, 340. See also Acute myeloid leukemia Myeloid metaplasia. See Primary myelofibrosis Myeloid progenitors, 1 96 Myeloid stem cells, 1 95 Myeloma stem cells, 3 2 1 Myelopoiesis normal, 195-204 points to remember, 203-204 Myeloproliferative disease, 29, 1 96, 435 clinical features, laboratory studies and, 23 1-233 platelet function in, 388 therapy, 239-242 Myeloproliferative disorders, 202, 229-245, 230t, 338, 340 case history, 229 classification of, 230, 230t differential diagnosis, 233 molecular diagnosis, 23 1 morphologic patterns, 230t points to remember, 242-243 treatment goals, 24 2 Myelosuppression, 327 Myoglobin, 1 82, 1 83t N

NADPH. See Nicotinamide adenine dinucleotide phosphate Nafcillin, 389, 389t

494

I N DEX

Narcotics painful sickle crises, 89 porphyria cutanea tarda, 1 80 Nasal T/NK lymphoma, 293 NAT. See Nucleic acid amplification testing National Kidney Foundation, 5 1 Natural killer cells (NK cells), 25 1-252, 256, 259 Necrosis of femoral head, 86 Necrosis of humeral head, 86 Necrotizing pancreatitis, 426 Neonatal sepsis, 209 Neonatal thrombocytopenia, 3 6 1 £, 3 7 1 -372, 378 Neoplasms, 1 1 5, 1 92, 277 CD4 T-cell, 277 Nephrotic syndrome, 435-436 Neumega. See lnterleukin 2 Neuroblastoma, 3 1 5 Neurologic abnormalities, 1 08, 1 77, 1 7 8f, 1 79 Neuropathy, 96, 98, 1 60, 1 8 1 , 330-33 1 Neuropsychiatric disorders, 97 Neutropenia, 208 in adults, 2 1 0-2 1 1 , 2 1 0t clinical features, 208 diagnosis, 209-2 1 1 laboratory studies, 209 in newborns and children, 209-2 1 0 Neutropenic syndromes, 209, 209t Neutrophilia, 206-208 clinical features, 207 diagnosis, 207-208 etiology of, 206t Neutrophilic precursors, myeloid cells versus, 1 99' 1 99t, 200f Neutrophils (Granulocytes) , 1 1 7, 1 98-1 99, 335 counts, African Americans and, 203 differentiation, 1 96f differentiation- immunologic markers, 200f dysfunction, 2 1 1-2 14, 2 1 1 t case history, 205, 2 1 3 diagnosis, 2 1 2 therapy for, 2 1 2-2 1 3 factors affecting, 203 function, congenital defects in, 2 1 4 granule contents of, 1 98--1 99, 1 99t kinetics, 202f mature, 1 1 0 monocytes versus, 1 99, 1 99t proliferation, 204 quantitative and qualitative disorders, 205-2 1 4 case history, 205 , 2 1 0, 2 1 3 points t o remember, 2 1 3-2 14 Newborns, neutropenia in, 209-2 1 0, 209t NHANES studies, 1 58, 1 60, 1 62 anemia, 1 3 , 156, 1 56f by age, 1 56, 1 56f iron deficiency anemia and, 1 58-- 1 59 NHL. See Non-Hodgkin lymphoma N icotinamide adenine dinucleotide phosphate (NADPH), 2 1 2 Niemann-Pick disease, 3 3 7 , 338 N ight sweats, 1 1 Nilotinib, CML, 239

N itrous oxide, 420-42 1 oxidation, B 1 2 metabolism and, 1 04 painful sickle crises and, 9 1 NLPHL. See Nodular lymphocyte-predominant Hodgkin lymphoma NMP1 gene mutation, AML and, 2 1 9, 2 1 9t Nodal marginal zone lymphomas, 286 Nodal T-cell lymphomas, classification, 290-29 1 Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL), 302-303 Nodular sclerosis, 303 Nodular sclerosis Hodgkin lymphoma, 309 Non-alpha-globin genes, 65 NonHeme vegetable iron, 55 Non-Hodgkin lymphoma (NHL), 52, 254, 279-300 autoimmune thrombocytopenia, 379 case history, 2 79, 289, 292, 298 classification, 280, 280t clinical features, 283-285 cytogenetic features, 282 cytologic features, 28 1-282 diagnosis, 280 frequencies of, 28 1 , 281 t gene-expression profiling, 283 , 284f histologic features, 281 immunologic features, 282 points to remember, 298--2 99 therapy and clinical course, 293-298 Nonimmune destruction disorders, 368--3 7 5 , 369t Non-Langerhans histiocytic disorders, 336 Non-lymphoid tumors, 3 1 5 Non-myeloablative allogeneic transplantation, CML, 241 Nonrandom chromosomal trans locations, 282, 283t, 286t Normal hematopoiesis, ALL, 3 1 6, 3 1 6t Normal hemostasis, 341-346, 364, 445 points to remember, 346 Normal lymphopoiesis, 245-257 points to remember, 256 Normal saline, 1 29 Normochromic anemia, 1 3f Normochromic insufficiency, 323 Normocytic anemia, 13f, 323 NovoSeven. See Recombinant activated factor Vll N-ras oncogenes, 323 NSA!Ds (Nonsteroidal anti-inflammatory drugs), 349, 386, 390, 396 platelet function and, 389, 389t Nucleic acid amplification testing (NAT), 474 Nucleoli, 2 1 7 Nucleoside reverse transcriptase inhibitors plus efavirenz, 266 Nutrients, to marrow, 8 Nutritional imbalance, 64 Nutritional supplements, vitamin B12, 1 06-107

0

Occasional idiosyncratic neutropenia, drugs and, 2 1 1 Occupational exposure anemia, 1 1 benzene, 3 2 lead poisoning and, 1 7 9 Occupational Safety and Health Administration (OSHA) , chronic lead toxicity, 1 80 Older patients, 44 anemia and, 1 1 fluids and, 1 29 hemoglobin levels, 50 hemophilia and, 4 1 0 transfusion and, 36 Omenn syndrome, 260 Omeprazole, 45 1 Optic fundus, polycythemia vera and, 1 65f Oral anticoagulants, 45 1-455, 463 adverse events, 454-455 clinical applications, 452 pharmacokinetics, 45 1-452 therapeutic guidelines, 452-454 Oral chelator, 1 92 Oral contraceptives, 36 1 , 444 thrombotic tendency and, 435 Oral fluoroquinolone, 223 Oral GPllb/Illa inhibitors, therapeutic guidelines, 450 Oral iron preparations, 61-62, 6 1 t, 64, 362 absorption, 62f dosage guidelines, 62-63 gastrointestinal intolerance to, 61 lack of response, 6 1 Organ(s) blood flow, 1 64-1 65 damage, 1 86-1 87, 423 iron overload, 192 Orthochromatic normoblasts, 1 1 4 Orthostatic hypotension, 330 OSHA. See Occupational Safety and Health Administration Osler nodes, 360, 360t Osmotic fragility test, 1 4 1 , 1 4 1 f H S and, 1 48, 1 49f Osteoporosis, heparin and, 458 Over-the-counter medications, vitamin B 1 2, 1 06-107 Oxygen delivery, blood loss and, 1 26 Oxygen sensor, in kidney, 9 Oxygen supply, 6 Oxygen transport regulation, 5-6, Sf hemodynamic factors, 5-6 normal erythropoiesis and, 1 64, 1 64f p

P antigen, 467 PAI- l . See Plasminogen activator inhibitor- ! PA!g assay. See Platelet-associated antibody assay Pain relief, MM, 327 Painful sickle crises, 88-9 1 adult severe crises, 88 exchange transfusion and, 89 fluid intake, 88-89 Palpable purpura, 358

I NDEX

Pamidronate, 327 Pancreas, 1 84, 192 Pancytopenias, 1 1 , 3 1 , 32, 32t, 33, 36, 40, 105, 23 1 , 276 PAR. See Protease activated receptor Parasites, eosinophils and, 202 Parasitic infections, 1 5 2 Parathormone, anemia and, 48-49 Parenchymal tissues, iron-transport pathway to, 54, 54f Parenteral fluid therapy, 88 Parenteral glucocorticoids, childhood autoimmune thrombocytopenia, 3 78 Parenteral iron therapy, 62-63 Paroxysmal cold hemoglobinuria (PCH ) , 143 Paroxysmal nocturnal hemoglobinuria (PNH), 33, 1 16-1 1 7 , 1 52, 435, 445 therapy, 1 22 Partial thromboplastin time (PTI), 220, 343, 409, 4 1 3 , 41 3t, 4 1 8, 433, 434, 438, 45 7 hemophilia and, 40 1 high-grade DLC, 422 plasma transfusion and, 4 73 Parvoviruses, 34, 46, 92, 149f marrow-damage anemia and, 32 sickle cell anemia and, 85 Patient, 452, 470, 472. See also lmmunocompromised patients; Older patients AIDS, 289 anemia, 23-25 approach to, bleeding, 352-354, 352t, 374 compliance, 191 DVT, 436t history, anemia, 1 1 HlV, 288 immunocompromised, 299 iron dosage, 62, 62f prednisone-refractory, 153 spinal cord from, 96f survival, 1 20, 1 20f tailored to, platelet transfusions, 375-3 76 teenage, painful sickle crises, 88 transfusion dependent, 1 20 Pattern recognition receptors, 335 Pautrier microabscesses, 287f, 292 Pawn-ball nuclei, 1 1 2 PBSCs. See Peripheral blood stem cells PCC. See Prothrombin complex concentrate PCR. See Polymerase chain reaction PCT. See Porphyria cutanea tarda PE. See Pulmonary embolism Pediatric thromboembolism, 44 1 , 44 l t, 445 Pelger-Huet anomaly, 235, 236f Penicillamine, lead poisoning, 1 8 1 Penicillin G, platelet function and, 389, 389t Pentostatin (Deoxycoformycin), HCL and, 276 Percutaneous coronary artery interventions, anti thrombotic therapy during, 444 Periodic acid-Schiff stains, 29 AML and, 22 1 Peri-operative erythropoietin therapy, 1 2 7 Peripheral blood film, 1 48 morphology, 1 1 1 RBCs on, 1 49, 1 49f thalassemia and, 68

Peripheral blood stem cells (PBSCs) , 297 Peripheral neuropathies, 97, 321-322, 322f, 327 Peripheral T-cell lymphoma, unspecified, 290-29 1 Peri-surgical blood loss, 1 27, 1 32-133 Peritonitis, 2 1 1 Pernicious anemia, 1 03 diagnosis, 1 03 laboratory tests, 97t Pernicious anemia patient, spinal cord from, 96f Peroxidase staining, 1 99, 1 99t, 200f AML and, 22 1 Persantine, 463 TTP and, 3 7 7 PET scan HL and, 304, 309 lymphomatous infiltration of non-lymphoid organs, 285 Petechiae, 356, 360, 360t Petechial bleeding, 354 Petechial eruptions, 23 1 , 360, 360t Petechial hemorrhage, 352, 380, 421 PF4 complex, 373 PFA. See Platelet function assay; Whole blood platelet function analysis pH, hemoglobin-oxygen affinity and, Sf Phagocytosis, 1 98, 335 Phagosome formation, 202 Phenacetin, 2 1 1 Phenothiazine, 2 1 1 Phenotypic studies. See also lmmunophenotypic marker studies; lmmunophenotyping marrow-damage anemia and, 30 Phenylbutazone, 45 1 Phenylbutazone toxicity, 3 2 Phenylhydrazine, hemolysis and, 146 Phenytoin, 45 1 Philadelphia chromosome, 230 Phlebotomy therapy, 190-1 9 1 , 1 93 patient compliance, 1 9 1 porphyria cutanea tarda, 1 80 Phosphofructokinase, 5 Photopheresis ATLL, 275 T-cell lymphomas, 296 Photosensitivity, 1 7 7 , 1 78, 1 78f Phototherapy, T cell lymphomas, 296 Physical examination, anemia, 1 1-12, 1 2f Physiologic anemia of pregnancy, 49 pig-A gene, 1 1 6 Pigmented gallstones, 1 48, 149f Pituitary deficiency, anemia and, 49 PK. See Prekallikrein Plasma, 465 homocysteine, 437 infusion, ITP, 3 74f level, 1 64 volume, 1 1 measurements, 1 65-1 66, 1 66t restoration, 1 26-1 2 7 Plasma cells, 249, 33 1 differentiation and morphology, 3 1 9, 320f

495

Plasma cells (Cont . ) : disorders, 3 1 9-333, 329, 330 biology of, 320-321 case history, 3 1 9 M-component and, 32 1-322, 322t points to remember, 33 1-332 dyscrasias, 3 1 9, 329, 3 3 1 phenotypic changes, 323 tumors, 3 22f Plasma exchange, drug-induced TIP, 370 Plasma hemoglobin level, 139-140, 1 40f quantitation of, 140 Plasma/acid citrate dextrose (ACD) , 465 Plasmacytomas, 328 Plasma-derived factors, 4 1 0 Plasma-labeling index, 325 Plasmapheresis, 152 AIDS-associated thrombocytopenia, 379 with FFP, 370 with plasma exchange, 426 Plasminogen activator inhibitor- I (PAl- l ), 345, 35 1-352, 42 1 , 44 1-442, 46 1 Platelet(s), 352, 47 1-472. See also Donor platelets; Platelet transfusions; Single-donor platelets; Whole blood platelet function analysis abnormality, differential diagnosis, 388-393 activation, 342, 346 activation/aggregation measurement, 386 adhesion, 342, 346 aggregation, 236 second wave of, 387f, 390 aggregation inhibitors, 44 7 aggregometry, 396 bacterial infections, 4 7 3 clumping, 348f coagulators, 343-344, 343f counts, 347-348, 348t, 352 abciximab, 45 1 BT and, 349, 349f heparin and, 373 high-!,rrade D!C, 422 primary myelofibrosis, 235, 235t primary thrombocythemia, 23 7-238 thrombocytopenia, 365-366 transfusion therapy and, 3 75, 3 75f vascular purpura, 358 degranulation, 342-343, 342f destructive disorders, 366, 3 7 7-380 disorders of distribution, 368, 376-3 7 7 , 380 disseminated intravascular coagulation, 368 dysfunction, 352, 354, 384-397 case history, 387, 395 congenital causes, 396 points to remember, 395, 396 therapy and clinical course, 393-395 factors, 343 function, 1 1 7, 341-342, 342f, 384-385, 385f aspirin, 385, 386t defects clinical features, 385-386 long-term management, 393 inhibitors, 443, 445, 447

496

I N DEX

Platelet(s) (Cont . ) : function analysis, 349, 385-386, 396 antiplatelet drugs and, 450 template bleeding time and, 348-349 growth factors, 3 7 6 kinetics, 365 monocytes and, 20 1 myeloproliferative disease, 388 procoagulant activity, 390 production disorders, 367-368, 375-377, 380 long-term management, 376 replacement, 1 27 satellitism, 348f, 366f secretion/release defects, 390 thrombus formation, 385 Platelet function assay (PFA), 355, 402 Platelet rich plasma ( PRP) , 47 1 , 4 7 1 f Platelet transfusions, 1 20- 1 2 1 , 1 3 1 adverse reactions, 3 76 chemotherapy and, 475 childhood autoimmune thrombocytopenia, 378 chronic AlTP, 3 74-3 75 complications, 4 72-4 73 DIC, 424-425 liver disease, 4 1 7 order, 375 patient, tailored to, 375-376, 3 75t platelet administration, 472 platelet dysfunction and, 393 platelet production disorders, 3 75-3 76, 375f prognosis and survival, 1 20 prophylactic, 3 7 repeated, 3 7 typing and crossmatch, 472 Platelet-associated antibody assay (PAig assay), 366 Platelet-based bleeding, 355 Platelet-rich plasma aggregation, 386 Plavix. See Clopidogrel PML-RARa oncogene, all-trans retinoic acid and, 2 1 9 Pneumococcal vaccine, 7 6 Pneumocystis carinii pneumonia, 39 Pneumonia, 39, 60, 8 1 , 9 1 , 92, 1 45-1 46, 1 5 2 Pneumovax, 9 1 PNH. See Paroxysmal nocturnal hemoglobinuria POEMS syndrome, 329 Poikilocytosis, 1 6, 58 Polyacrylamide gel electrophoresis dysfibrinogenemias, 4 1 3 HS/HE, 1 5 0 Polychromasia, 1 8 Polychromatic macrocytes (shift cells), 1 6, 1 25 Polycythemia vera, 72, 1 63- 1 75 , 165f, 435 case history, 1 63, 1 68 laboratory studies, 1 65-167 major versus minor criteria, 1 68-1 69, 1 69t WHO criteria, 1 69, 1 69t Polymerase chain reaction (PCR) amplification assays, 407 CML, 240 malignant T cells, 275

Polymerase chain reaction (Cont. ) : pure red blood cell aplasia and, 3 4 thalassemia, 7 2 Polymorphic reticulosis, 293 Polysaccharide iron complex, 6 1 Polyspecific direct antiglobulin test, 142, 142f Popcorn cells, 302, 303f Population screening, HFE genotype analysis and, 188 Porphobilinogen, 1 80 Porphyria cutanea tarda ( PCT), 1 77, 1 8 1 , 189 diagnosis, 1 78 therapy, 1 80 treatment, 1 9 1 Porphyrias, 1 76, Porphyria cutanea tarda (PCT). See also Erythropoietic protoporphyria; Hereditary coproporphyria; Porphyria cutanea tarda; Variegate porphyria clinical features, 1 77 diagnosis, 1 77-1 80, 1 78f therapy, 1 80 Porphyrin precursor excretion, 1 78 precursors, 1 7 7 i n urine and stool, 1 77, 1 77t synthesis, 1 1 5f, 1 76-1 77 normal, 1 76-1 77 Porphyrin metabolism disorders, 1 76-1 8 1 case history, 1 76, 1 80 neuropathy, 1 8 1 points t o remember, 1 8 1 therapy, 1 80 Posaconazole, 223 Posterior iliac crest, bone marrow biopsy and, 1 9, 1 9f Post-induction therapy, ALL, 3 1 7 Post-phlebitic venous insufficiency, 462 Post-transfusion purpura, 3 7 1 f, 372 Post-transplant immunodeficiency, 265 Post-transplant lymphoproliferative disorders (PTLD) , 289-290 Postviral thrombocytopenia, 372 Potassium chlorates, hemolysis and, 146 Pre-B cell, 249 Prednisone, 35, 40, 1 52-1 53 ALL, 3 1 6, 3 1 6t autoimmune thrombocytopenia, 380 chronic ITP in pregnancy, 380 and cyclophosphamide, hemophilia, 405-406 granulocytosis and, 208 hemophilia, 405 platelet DIC, 426 severe autoimmune thrombocytopenia, 379, 3 79f Prednisone-refractory patient, 153 Pregnancy, 14, 55, 438, 443 AlP and, 1 79 anemia and, 49 cobalamin levels, 98 enoxaparin, 440 folic acid, 49 folic acid deficiency anemia, 97 iron supplementation and, 64

Pregnancy (Cont . ) : LMWH, 440, 44 1 , 454, 457, 459 prenatal screening, 73 serial testing, 435 sickle cell anemia, 86 thromboembolic disease during, 435, 457 thrombotic tendency and, 435 TTP, 377 vitamin prophylaxis, 1 06 VTE and, 440-44 1 warfarin and, 454 Pregnancy-associated hypertension, 438 Prekallikrein (PK), 398 Prenatal screening, thalassemia, 73 Prevnar, sickle cell anemia, 9 1 Priapism, 86, 9 1 Primary cutaneous anaplastic large cell lymphomas, 292 Primary cutaneous B-cell lymphomas, 288-289 Primary disease, DIC and, 426, 427 Primary effusion lymphoma HIV patients, 288 human herpesvirus 8 and, 289 Primary hypercoagulable states, 436-439, 443 in DVT patients, 436t Primary illness, hypoproliferative anemia and, 46, 46t Primary myelofibrosis (Myeloid metaplasia), 1 1 7-1 1 8, 1 1 7f, 235-236 causes of, 1 1 8 Primary thrombocythemia, 23 1 , 236-238 disease course, 238 laboratory studies, 23 7-238 therapy, 241-24 2 Procoagulants, 345 Profilnine, 408, 408t Profound neutropenia, 2 1 1 Progesterone, AlP and, 1 79 Progressive renal failure, 158 Proliferative retinopathy, 86 Prolonged red blood cell aplasia, 34 Prolymphocytic leukemias, 273-274 Promyelocytic leukemia, 2 1 6-2 1 7 , 2 1 7f, 227 ALTA and, 2 1 9 Prophylactic therapy bleeding, 403 red blood cell transfusion, 9 1 Proplex T, 408, 408t, 4 1 5 , 4 1 6t Prostacyclin, 357, 420-421 Protamine sulfate, LMWH, 459 Protease activated receptor (PAR) , 342 Protectin, 1 1 6 Protein C activation, 429, 434 deficiency, 43 7 Protein precipitation technique, 4 1 3 Protein S, 334, 345, 345f, 434 Protein S deficiency, 43 7 Protein solutions, 1 29t, 1 30, 1 9 1 Prothrombin. See also Factor IX-prothrombin complex concentrate; FEIBA; Prothrombin complex concentrate; Prothrombin gene mutation; Prothrombin time hereditary deficiency of, 4 1 2

I NDEX

Prothrombin complex concentrate (PCC), 41 1, 419 commercially available, 4 1 5 , 4 1 6t congenital coagulation factor abnonnalities, 4 1 5 hemophilia, 407 Prothrombin gene mutation, 436 Prothrombin time (PT), 220, 347, 350f, 35 1 , 353, 355, 4 1 3 , 4 1 3t, 4 1 8, 433 , 463 factor VIla, 408 hemophilia and, 40 1 high-grade DIC, 422 and INR, 349-350 plasma transfusion and, 473 prolonged, prophylactic reversal, 4 74 test, anticoagulation and, 454 vascular purpura, 358 ProTime Monitor, 454, 454f Proto-oncogene, BCL- 1 , 283t, 288 Proto-oncogene mutations, 3 1 2-3 1 3 Protoporphyrin, 58, 1 79 PRP. See Platelet rich plasma Pruritus, 1 65 Pruss ian blue stain, 1 86 iron store depletion, 58 of marrow aspirate, 29 marrow iron stores and, 57, 5 7f polycythemia vera criteria, 1 69-1 70 P-selectin, 357 P-Selectin glycoprotein ligand (PSGL- 1 ) , 1 98 Pseudo von Willebrand disease, 392 Pseudothrombocytopenia, 348, 348f causes, 365, 366f Pseudoxanthoma elasticum, 359 PSGL- 1 . See P-Selectin glycoprotein ligand PT. See Prothrombin time PT mixing study, 4 1 8 PTLD. See Post-transplant lymphoproliferative disorders m See Partial thromboplastin time m mixing study, 409 Pulmonary angiography, 432 Pulmonary embolism (PE), 434, 440f, 445, 462 diagnosis, 43 1 , 43 1 t diagnostic workup, 432 high clinical probability, 432 intermediate clinical probability, 432 low clinical probability, 433 management, 442, 442f Pulmonary hypertension, 85 Pulmonary thrombosis, sickle cell anemia, 91 Pure red blood cell aplasia, 34-35 therapy for, 39-40 Purified factor Vlll, hemophilia A, 406-407, 407t Purified plasma protein fraction, 1 29, 1 29t Purified recombinant factor preparations, 474 Purified thromboplastins, 349 Purine analogues HCL and, 277 large granular lymphocytic leukemia, 275 .

Purpura, 23 1 , 358, 360, 360t. See also Autoimmune idiopathic thrombocytopenic purpura; Henoch-Schonlein purpura; Idio­ pathic thrombocytopenic purpura; Mechanical purpura; Post­ transfusion purpura; Spontaneous purpura; Thrombotic thrombocy­ topenic purpura; Vascular purpura Purpura fulminans, 360 Purpuric eruptions, 360, 360t Purpuric lesion, nature of, 358 Pyrazinamide, 1 1 5 Pyridoxal-5-phosphate, RARS and, 122 Pyridoxine therapy, sideroblastic anemia and, 1 2 1-122 Pyruvate kinase deficiency (PK), 150

Q Quinidine autoimmune hemolytic anemia, 1 46 thrombocytopenia and, 372 warfarin and, 45 1 Quinine, thrombocytopenia and, 372 R

RA. See Refractory anemias Race, anemia, 1 1 Racial background, thalassemia, 65, 66 Radiation therapy, 40 autoimmune thrombocytopenia, 379 NHL, 294 Radiation-damage anemia, 3 1-3 2 Radioimmunoassay, 386 Radiotherapy ports, HL, 306-307, 307f RAEB, allogeneic bone marrow transplantation, 1 2 1 RAEB- 1 . See Refractory anemia with excess blasts Rai staging system, CLL, 272, 272t Random donor platelet concentrates, storage, 47 1-472 RANKL, 3 2 1 , 327 Rappaport lymphoma classification system, 280, 28 1 RARS. See Refractory anemia with ringed sideroblasts RBCs. See Red blood cells R-CHOP (rituximab, cyclophosphamide, adriamycin, vincristine, prednisone) follicular NHL, 295 high grade lymphomas, 295-296 RCMD. See Refractory cytopenia with multi lineage dysplasia RCMD-RS. See Refractory cytopenia with multilineage dysplasia and ringed sideroblasts RDW. See Red blood cell distribution width RDW-CV, 1 5 , 1 5f RDW-SD, 1 5 Reactive granulocytosis, malignant state versus, 207 Reactive histiocytosis, 334 Reactive monocytosis, 336, 338-339 Reactive oxygen species (ROS), 1 , 155-156 c-Mpl receptor, 365

497

Recipient blood, 468 Recombinant activated factor Vll (NovoSeven), 405, 407-408, 410, 4 1 7 , 4 1 9 congenital coagulation factor abnormalities, 4 1 5 hemorrhage and, 1 33 thromboembolic complications, 4 1 7 Recombinant enzyme therapy, Gaucher disease, 340 Recombinant erythropoietin therapy, 50-5 1 , 162 anemia of renal disease, 5 1 elderly, 1 6 1 perisurgical, 1 33 Recombinant factor VIII, hemophilia, 407 Recombinant factors, 4 1 0 Recombinant G-CSF, 2 1 2-2 1 3 Recombinant interferon and zidovudine combination, ATLL, 275 Recombinant interferon-a, chronic eosinophilic leukemia, 242 Recombinant products, 407 Recombinant tissue factor pathway inhibitor, 46 1 Recombinant t-PA ( rt-PA), 46 1 , 462 Recombinant VIla (NovoSeven), 408, 4 1 0 Recombinate, 407 Recurrent venous thromboembolism, prophylaxis, 463 Red blood cell distribution width (RDW), 1 5 , 1 6, 25 Red blood cell mass, 1 64, 1 65-166, 1 66t depletion, 1 26 Red blood cell unit, 465 Red blood cell volume (MCV), 25 Red blood cells (RBCs), 465-4 7 1 abnormal, 138 administration of, 469 destruction clinical indicators, 7t, 8 clinical measurements of, 138, 1 38t increased, 24-25 pathways of, 1 3 7-138, 1 3 7f research measurements, 8 spleen and, 137, 1 3 7f filtration of, 130 folate, 97 frozen, 466 fully crossmatched, 468 growth, 28 hemolysis, 136 indices, 81 lifespan, 138, 1 38t maturation disorder, 26 membrane of, 1-2 inner/out layers, 1-2 structure, 3f mixed populations of, 1 4f morphology, 1 , 2f, 46-47, 52, 99, 99f, 1 48 anemia severity and, 60f anemia versus, 58 hemolytic anemia, 1 48t thalassemia and, 68f normal morphology, 1 6f nucleated, 33f, 232f oxygen delivery, blood loss, 1 25-1 26

498

I N DEX

Red blood cells (Cont . ) : pathways, 150 on peripheral blood film, 149, 1 49f points to remember, 9 primary myelofibrosis and, 1 1 7, 1 1 7f production, 48-49, 1 5 1 , 1 64 rate of, 6 production and destruction, 7t salvage, 4 7 1 shape, 2f size and shape, abnormalities, 1 7f size-distribution curve, 14f structure, 1 -5 turnover, normal, 136-1 3 7 uncrossmatched/type-specific, 468-469 zinc protoporphyrin levels, 1 7 8- 1 79 Red cell agglutination, 1 44f Red cell fragmentation, 144f Red cell poikilocytosis, 1 03 Red cell substitutes, 4 7 1 Red cell volume distribution curve, 1 5 , 1 5f Red thrombus, 344 Reed-Sternberg cells, 302-303, 305, 305f Refractory anemia with excess blasts (RAEB)- 1 , 1 1 6, 1 22 chemotherapy, 1 2 1 prognosis and survival, 1 20 therapy, 1 19 Refractory anemia with ringed sideroblasts (RARS), 1 14-1 1 5 , 1 14f, 1 20, 1 22, 1 88 Refractory anemias (RA), 1 22. See also Acute myeloid leukemia diagnosis, 1 14 prognosis and survival, 1 20 Refractory cytopenia with multilineage dysplasia (RCMD), 1 1 5- 1 1 6, 1 22 Refractory cytopenia with multilineage dysplasia and ringed sideroblasts (RCMD-RS) , 1 14, 1 22 Regional lymph nodes, 253, 253f Regulatory T cells, 245 Relapse ALL, 3 1 8 HL, 309 Relative erythrocytosis, 1 63 Remission ALTA and, 2 1 9 anemia and, 3 6 Renal disease, 2 5 , 44, 45f, 48, 5 1 , 134, 158. See also specific renal disease

serum erythropoietin level, 45f Renal disease anemia, 48 Renal failure, 52, 460. See also Progressive renal failure BUN and, 48 workup, 44 Renal function, 9 Renal insufficiency, sickle cell anemia and, 86 Renal insufficiency/failure, 323 Renal transplantation, 370 Renal vascular disease, 158 Renal vein thrombosis, 430 Replacement therapy, hemophilia, 403, 404t Reptilase time, 4 1 8 dysfibrinogenemias, 4 1 3

Research measurements, red blood cell destruction, 8 Reticular protein network, 2 Reticulated platelet assay, 3 7 1 Reticulin stain, primary myelofibrosis and, 118 Reticulocyte(s) count, 1 7-19, 1 8f, 44, 47 formula for, 18 hemoglobin content, 58 RNA, 1 7 shift, 1 8f Reticulocyte index, 8, 9, 19, 25, 138 blood loss, after week 1 , 1 2 7 hemoglobinopathies and, 8 1 Reticuloendothelial cell iron storage, 5 7 , 5 7f, 182, 1 83t Reverse organ damage, 1 90 Reverse transcriptase polymerase chain reaction (RT-PCR) , 23 2-235 Revised European American Classification (REAL), of lymphomas, 280, 280t Rh antigens, 467 Rh status, 1 3 1 Rhabdomyosarcoma, 3 1 5 Rheumatoid arthritis, 44 RhoGAM. See Anti-D antibody Riboflavin, 1 42 Ribosomal protein genes, 35 Richter syndrome, 272, 277 Ringed sideroblasts, 21, 11 4, 1 1 5, 1 1 5f chronic lead toxicity, 1 80 Ringer's lactate, 1 29 Ristocetin, 386, 387f Riruxan autoimmune thrombocytopenia, 380 childhood autoimmune thrombocytopenia, 378 Rituximab, 1 5 2, 4 1 0 HCL and, 2 7 7 low-grade lymphomas, 295 Riruximab combination therapy, 295 Rivaroxaban, 463 Romberg test, 96, 96t Romiplostim autoimmune thrombocytopenia, 380 chronic AITP, 3 74 ROS. See Reactive oxygen species Rosenthal disease (Factor XI deficiency), 40 1 , 405 Roth spots, 360, 360t rt-PA. See Recombinant t-PA RT-PCR. See Reverse transcriptase polymerase chain reaction Rubella, 32 Russel viper venom time (RVVT) , 434-435, 438 s

S . aureus, 1 92 S . jmeumoniae, 9 1 , 92

Salicylate overdose, 4 14, 4 1 4t Salmonella, 8 1 , 86, 9 1 Salvage therapy, 308-309, 309£ Schilling test, 1 00- 1 0 1 , 1 08 Schistocytes, 1 5 1 Schistocytosis, 369

SCID. See Severe combined immunodeficiency disease SCPTCL. See Subcutaneous panniculitis-like T-cell lymphoma Scramblase, 1 Screening programs excess porphyria, 1 77 prenatal, 435 thalassemia gene and, 73, 7 7 Screening tests anemia, 1 2, 1 2t antibody, 468 APC resistance, 429f, 433-434 coagulation, 436 DIC, 354 dysfibrinogenemias, 4 1 3 hemoglobin, 69 population, 1 88 prenatal, 7 3 vitamin, 1 60 vWD, 391 Scurvy, 3 6 1 , 362 Scurvy lesion, 360 SDS. See Shwachman-Diamond syndrome Sea-blue histiocytes, 338 Secondary malignancy, 222 Secondary monoclonal gammopathy, 328 Secondary mutations, 320 Secondary myelodysplasia, 1 1 1 Secondary polycythemias, cardiac disease studies and, 167 Sedimentation rate, 1 5 7 , 1 58, 323 Sedormid, 372 Selectin, 248 Senile purpura, 3 6 1 , 362 Sepsis, 37, 92, 1 46, 208, 365-366, 3 78, 380, 425. See also Bacterial sepsis; Neonatal sepsis; Severe sepsis deferoxamine therapy, 1 92 granulocytopenia, 2 1 1 sickle cell anemia, 8 1 , 9 1 Septic shock, 425 Serotonin release assay, 366 Serotonin syndrome, 88--89 Serum bilirubin, 1 9 Serum cobalamin levels, 1 0 1 , 1 08, 1 60 Serum complement levels, 14 3 Serum erythropoietin level immunoassay, 1 6 7 measurements, 45 in renal disease, 45f Serum ferritin level, 23, 29, 44-45, 49, 55, 55£, 56-5 7, 58, 64, 1 67, 1 85, 1 85t, 1 9 1 , 1 93 Serum folate, 1 0 1 Serum gastrin, 1 00 Serum haptoglobin, 1 40 Serum hemoglobulin, 2 1 2 Serum iron (SI), 58, 6 7 , 1 6 7 , 1 9 1 level, 2 2 , 44-45 toxicity and, 37 porphyria, 1 77 studies, 44, 52, 56, 1 86, 1 86f Serum lactic dehydrogenase ( LDH) AML and, 22 1 B-cell chronic lymphocytic leukemia, 27 1 Serum methylmalonic acid assay, 98, 98f, 1 0 1

I NDEX

Serum protein electrophoresis, 2 7 1 Serum TfR/ferritin ratio, 55, 58 Serum transferrin-receptor (sTfR), 23, 44--45, 55, 5 7 Serum uric acid level, 221 Serum vitamin B 1 2 binding proteins, 98-99 level, 1 67 Severe anemias, 27-4 1 , 101-103 , 1 1 1 , 139, 1 8 7 life-threatening, 106 Severe aplasia, 3 2, 32t Severe aplastic anemia, 40 therapy, 36 with TIBC, 35 Severe autoimmune thrombocytopenia, 3 79, 3 79f Severe combined immunodeficiency disease (SCID), 260, 265 Severe DIC, 427 Severe fibrinogen deficiency, 4 1 8 Severe hemophilia-like syndrome, 40 1 Severe ineffective erythropoiesis, 1 1 5 Severe liver disease, 354 Severe macrocytic anemia cyanocobalamin and, 1 06 treatment, 107 Severe macrocytosis, 1 03 Severe pancytopenia, 33 Severe sepsis, 424, 4 25 Severe thalassemia, 69 Sezary syndrome, 274, 275, 275f, 287f, 29 1-300 Shear rates, 358 Shift cells, 18 Shotgun therapy, 24 Shwachman-Diamond syndrome (SDS), 35 SI. See Serum iron Sickle cell anemia, 1 1 , 79, 85-86, 1 04--1 05, 256 acute chest syndrome, 86 children, 80, SOt, 85 clinical features, 80-8 1 , SOt complications, 85-86, 9 1 disease course, 86 gallstones, 86 late complications of, 92 prenatal diagnosis, 82 routine health maintenance, 91-92 severity, 85 survival, 85, 86f symptoms and signs, 85 therapy, 88-9 1 Sickle cell trait, 84-85 Sickle hemoglobin, 89 Sidenafil, 9 1 Sideroblastic anemias, 6 1 , 1 09-123, 1 6 1 , 1 86. See also Hereditary sideroblastic anemia case history, 1 09, 1 1 3 causes, 1 1 5t clinical features, 1 1 1-1 1 3 diagnosis, 1 13-1 1 6 differential diagnosis, 1 1 6-1 1 9 elderly, 1 6 1 points t o remember, 1 22 pyridoxine therapy, 1 2 1-1 22

Sideroblasts, 2 1 , 57 Siderocytes, 2 1 Silver stain, 29, 1 1 8 Single-donor apheresis, 4 7 1 -4 72 Single-donor platelets, 4 7 1 Single-factor deficiency, 3 5 3 , 354, 4 1 5 Sinus histiocytosis with massive lymphadenopathy, 339 Sinus thrombosis, 441 Skeletal defects, 40 Skin biopsy, 300 heparin and, 458 pigmentation, 1 85 staining, 63 testing, 259 warfarin-induced skin necrosis, 443 SLE. See Systemic lupus erythematosus Small bowel disease, 23 Small cell lung cancer, 3 1 5 Small cell lymphocytic lymphoma, 286 Small intestine bleeding, 1 28 Small-cell lymphocytic lymphoma, 269 Smoking. See Cigarette smoking SMZL. See Splenic marginal zone lymphoma Sodium chlorates, 146 Sodium ferric gluconate, 62, 63 Solid tumors imaging studies, 255 staging, 254 Solitary lgA deficiency, 262 Solitary plasmacytoma, 323 Somatic mutation ]AK2 V6 1 7F, 1 68, 1 69 Southern blotting, 275 Spectrin, 2, 148 Sphingomyelin, 337 Spinal cord bleeds, 460 compression, 323 from pernicious anemia patient, 96f Spleen, 252, 252f architecture of, 255, 255f enlargement, 283 histology, 276 RBC destruction, 1 3 7 , 1 3 7f Splenectomy, 1 52, 1 53, 376-3 7 7 autoimmune thrombocytopenia, 3 78, 380 EPP and, 1 8 1 HCL and, 277 myelofibrosis, 241 Splenic infarction, 80 Splenic irradiation, 277 Splenic marginal zone lymphoma (SMZL), 287 Splenomegaly, 1 65 , 2 1 1 , 255, 256, 368, 368f Spongiform encephalopathy, 407 Spontaneous abortion, 92, 4 1 3 , 4 1 8 Spontaneous purpura, 40 1 Sporadic PCT, 1 78 Sporadic TIP, 370 Staging classification systems, 332. See also European Organization for Research and Treatment of Cancer classification system; WHO classification system; WHO/FAB classification; Working Formula­ tion lymphoma classification system

499

Staging classification systems (Cont . ) : AIDS, 263 , 264t ALL, 3 1 1-3 1 3 Binet staging system, 272, 272t cutaneous lymphomas, 292t diffuse large B-cell lymphoma, 288 Durie-Salmon Staging System, 326, 332 MM, 326, 326t HL, 304--305 Hodgkin lymphoma, 304--305 , 304f, 3 1 0 International Staging System, 326, 3 26t for multiple myeloma, 332 leukemia classification, 2 1 6-220 leukemic T-cell lymphomas classification, 290 lymphoma, 280, 280t, 298 malignancies, staging and, 255 Matures scoring system, 2 70 M-component, 3 2 1 myelodysplastic anemias, 1 20, 1 20t Rai staging system, 272, 272t solid tumors, 254 tumor markers, 255

Staphylococcus aureus

osteomyelitis, 86 septicemia, 1 85 STEAP3 . See Ferrireductase Stem cell. See also Hematopoietic cell lines; Hematopoietic stem cells damaging factors, 28 disorder, 168 factor, 1 97 radiation and, 32 response, 158 Stem cell assay, polycythemia vera, 1 67 , 169 Stem cell transplantation, 92, 2 1 2-2 1 3 , 225. See also Autologous hematopoietic stem cell transplantation; Hematopoietic stem cell transplantation painful sickle crises and, 90 platelet consumption and, 423 Stepwise approach, thalassemia, 72-73, 72f Steroid therapy anaphylactoid reaction, 395 anemia and, 36 Steroids, 225, 3 2 7 sTfR. See Serum transferrin-receptor Stibophen, 1 46 Stimate, 406 Stimulated erythropoiesis, 8-9 Stippling, 1 79, 1 80f Stomatocytosis, 1 50, 1 50f Streptococcus pneumoniae, 8 1 Streptokinase, 46 1 , 462 Streptomycin, 146 Stroke, 452 Stromal cells, 19 5 Subacute degeneration of cord, 97 Subclavian vein thrombosis, 430 Subcutaneous panniculitis-like T-cell lymphoma (SCPTCL), 292 Sudden severe aplastic anemia, 33 Sugar water test, 1 1 7 Sulfa drugs, 45 1 Sulfonamide antibiotics, AlP and, 1 79 Suppression, 249

500

I N DEX

Supravital stain film, 74 Surface markers, lymphomas and, 284 Surgery anticoagulation after, 453 aspirin and, 450--45 1 blood screening, 468 gastric, tablet iron and, 62 hemophilia A and, 404 intraoperative blood loss, 1 33-1 34 LMWH, 459 peri-surgical blood loss, 1 27 recombinant VIla, 408 Surgical prophylaxis, vWF, 394, 394t Survival. See also International Prognostic Scoring System B-cell lymphoma, 288, 288t Burkitt lymphoma, 296 cerebral thrombosis, 44 1 clinical stage and, HL, 308-309, 309f CML and, 236 dysplastic anemias, 1 20, 1 20f HCL and, 277 International Staging System, 326, 326t platelet transfusion therapy, 4 72 primary thrombocythemia, 238 sickle cell anemia, 85, 86f in thalassemia, 7 7-78 Survival curves, CML, 234f Sweet syndrome, 197 Systemic acidosis, 5 Systemic chemotherapy, T-cell lymphomas, 296 Systemic lupus erythematosus (SLE), 3 74, 443 children, 44 1 , 44 1 t T

T cell{s), 33, 20 1 , 20 1f, 248-249, 250-252, 256, 259 altered self, 250 CD8 T cells, 3 2 1 classification, b y cytokine production, 25 1 compartment, 3 2 1 cytokine secretion, 250 defects, 266 development, 246, 247f function, 259 immunodeficiency state, 269 inflammation and cytotoxicity, 250-25 1 malignancies, 284 malignant, 25 1 , 275, 296 phenotypic classification, 247f, 25 1 receptor genes, 275, 282, 290 T-cell leukemias, 277 T-cell lymphomas, 25 1 , 290 characteristic phenotypes, 286f classification, 290-293 leukapheresis, 296 treatment regimens, 296 T-cell non-Hodgkin lymphoma, 33 T lymphocytes, 335 Tacrolimus, drug-induced TTP, 370 TAF!. See Thrombin-activated fibrinolysis inhibitor Tamoxifen vascular purpura and, 3 6 1 warfarin and, 45 1

TAR syndrome, 367 Targeted radiation, 3 1 0 Tartrate-resistant acid phosphatase stain, HCL and, 276, 276f Taste loss, 97 TB!. See Total body irradiation T-cell prolymphocytic leukemia (T-PLL) , 274 y/'6 T-cell lymphoma, 292-293 TCI!. See Transcobalamin II TCR-� gene, 275 TdT. See Terminal deoxynucleotide transferase TE. See Thromboembolism Teardrop red cells, 232f Technetium sulfa colloid scan, 30 Telangiectases, on lips, 356 Telomere, 1 55-156 Template bleeding time, and platelet function analysis, 348-349 Terminal deoxynucleotide transferase (TdT), 249 Testosterone, anemia and, 48--49 TF. See Tissue factor TFP!. See Tissue factor pathway inhibitor TfR. See Transferrin receptors TFR2. See Transferrin receptors-2 TFR2 gene. See Transferrin receptors-2 gene TFR2 gene mutation, 187 TfR/ferritin ratio, 26 Thalassemia, 64, 65-78, 68f, 1 48t, 191, 1 92. See also Severe thalassemia; Tha­ lassemia intermedia; Thalassemia major; Thalassemia minor bone marrow transplantation, 7 7 case history, 6 5 , 7 1 , 75 classification of, 66--67, 67t clinical features of, 66--7 1 diagnosis of, initial detection, 72-73, 72f differential diagnosis, 73-75 ethnic background, 65 gene therapy for, 7 7 geographic distribution of, 66, 66f laboratory studies, 68-7 1 lethal defect, 74 molecular diagnosis, 72 points to remember, 78 prenatal diagnosis, 73 silent carrier states, 73 therapy for iron chelation, 76-77 transfusion, 75-76 Thalassemia intermedia, 67, 67t diagnosis, 72-73, 72f hematologic picture, 67t, 7 7 laboratory studies, 68 therapy for, 7 5 Thalassemia major (Cooley anemia), 67, 67t clinical course, 7 7-78 diagnosis, 72-73, 72f laboratory studies, 68 therapy for, 7 5 Thalassemia minor, 67, 67t diagnosis, 69, 72-73, 72f genotypes for, 73 iron deficiency versus, diagnosis of, 72 a/� Thalassemia, 74

a-

Thalassemia, 1 3 , 67, 69, 70t differential diagnosis, 73 hemoglobin patterns in, 70-7 1 , 70t sickle cell anemia and, 86f a- Thalassemia minor, 7 1 �-Thalassemia, 6 7 , 69, 70t global distribution, 66f molecular diagnosis, 72 �E-Thalassemia, 7 4 �-Thalassemia intermedia, 70, 78 �-Thalassemia major, 70, 78 �-Thalassemia minor, 69-70, 78 Thalidomide, MM, 326, 327 2-CDA therapy, myelofibrosis, 241 Thrombate Ill, 443 Thrombin, 345, 346, 4 1 1 . See also Anti-thrombin; Direct thrombin inhibitor; Thrombin time; Thrombin-activated fibrinolysis inhibitor activation, 345 of platelets, 342 formation, 427 generation, 445 Thrombin time (TT), 355 assays, 347 dysfibrinogenemias, 4 1 3 DIC, 422 Thrombin-activated fibrinolysis inhibitor {TAFI ) , 345, 345f, 42 1 , 429 Thrombocythemia, peripheral smear, 440f Thrombocytopenia, 220, 352, 3 54, 362, 364-383, 426, 463, 474 case history, 364, 381 chemotherapy and, 34 7 clinical features, 365-366 differential diagnosis, 366-367, 367t HL, 3 1 0 laboratory studies, 366 points to remember, 381-382 therapy and clinical course, 3 75-380 TTP and, 369 Thrombocytopenic hepatitis C, interferon therapy, 3 7 6 Thromboembolic disease cardiac, 442--443 complications, 408 recombinant factor VIla, 405 family history, primary hypercoagulable states and, 436 during pregnancy, 435 treatment, 457 Thromboembolism (TE), 346, 428. See also Arterial thromboembolism; Venous thromboembolism in elderly, 44 1--442, 442f visceral malignancies, 424 Thrombolysis, 347, 420--42 1 , 421f, 443, 445, 463 contraindications, 463 VTE in, 44 1 , 44 1t Thrombolytic drugs adverse effects, 462 clinical applications, 462 pharmacokinetics, 461--462 Thrombolytic therapy, 433 Thrombomodulin, 345, 345f, 357

I NDEX

Thrombophilia, 444 Thromboplastin, commercial, INR determination, 454f Thrombopoietin (TPO), 28f, 365 drugs with homology to, 376 RNA, 365 Thrombosis, 420-42 1 , 42 1f. See also specific thrombosis

disease-related, 440f of microvasculature, 421 retrograde, 440f Thrombotic disease conditions associated, 433, 433t diagnosis, 430 location and extent, 439 Thrombotic disorders, 428-446 case history, 428, 434, 444, 46 1 clinical features, 429-435 differential diagnosis, 435-439 management, 439-444 points to remember, 445, 463 Thrombotic tendency, pathophysiology of, 429f, 434t, 435 Thrombotic thrombocytopenic purpura (TIP), 354, 368, 369-3 70, 369f, 380, 385, 423 , 438. See also Heparin-induced thrombocytope­ nia; Thrombocytopenia in adults, 372-3 74 management of, 377 ticlopidine and, 448 Thrombus formation, 341 abnormal, 428 normal control of, 428-429 pathologic, prevention of, 429f Thymic enlargement, pure red blood cell aplasia and, 34 Thyroid hormone, anemia and, 48-49 TIBC. See Total iron-binding capacity Ticarcillin, platelet function and, 389, 389t Ticlopidine, 2 1 1 , 448-449 drug-induced TIP, 370 Tinzaparin, pregnancy and, 440 Tirofiban, 447, 448, 463 clinical applications, 449 therapeutic guidelines, 450 Tissue factor (TF), 343, 4 I 1, 424 Tissue factor pathway inhibitor (TFPI ), 343, 357, 4 1 1 , 420-42 1 , 42 l f Tissue factor-VIla-Xa complex, 4 1 1 Tissue histiocytosis, 336 Tissue inflammation, 2 1 3 Tissue injury, extrinsic pathway and, 4 1 8 Tissue iron overload, 1 7 8 painful sickle crises and, 90 Tissue iron stores, repeated transfusion and, 37 Tissue oxygen supply, 1 1 Tissue oxygen viscosity, 6 Tissue plasminogen activator (t-PA), 34 1 , 357, 42 1 , 429 Tissue-factor-bearing cells, 407-408 TN F-a. See Tumor necrosis factor-a TNF-related apoptosis-inducing ligand (TRAIL), 328

Toll-like receptors, 335 Tongue laceration, hemophilia and, 404 mucosa atrophy, 97 Total blood volume, blood loss and, 1 24, 1 25t Total body iron stores, 56-57, 57t Total body irradiation (TBI ), 38, 47, 47f Total fibrinogen protein, measurement of, 413 Total iron-binding capacity (TIBC), 2 2 , 26, 29, 44-45, 56, 58, 60, 67, 69, 73, 99, l OOt, 167, 1 9 1 iron overload and, 1 85 , 1 85t porphyria, 1 77 Tourniquet test, 358 Toxic chemicals, 284, 367 Toxic granulation, 207 t-PA. See Tissue plasminogen activator T-PLL. See T-cell prolymphocytic leukemia TPO. See Thrombopoietin TRAIL. See TNF-related apoptosis-inducing ligand TRALI. See Transfusion-related acute lung injury Tranexamic acid hemophilia A, 406 liver disease, 4 1 7 Transcobalamin I I (TCII), 95, 98-99 Transcobalamin proteins, 167 Transcranial Doppler imaging, sickle cell anemia, 85 Transcription factors, 3 1 2-3 1 3 Transferrin, 2 2 , 54f, 1 6 1 , 1 88, 192 Transferrin receptors (TfR), 54-55, 54f Transferrin receptors-2 (TFR2), 1 83, 1 83f, 1 84 Transferrin receptors-2 gene ( TFR2 gene), 1 89 Transferrin-iron response, 43-44, 43f Transfusion(s), 40, 427. See also Hypertransfusion; Platelet transfusions ABO-compatible blood, 152 blood, 186 compatibility testing, 468 blood cell, 469-470, 469t blood components, 1 3 4 dependence, 1 8 8 elderly and, 1 20 fully crossmatched RBCs, 468 homologous blood, 1 2 7 indications for, 89t iron overload, 2 1 long-term, painful sickle crises and, 90 low platelet count, 376-3 7 7 multiple, 50 painful sickle crises, 89 RBC, 24, 1 20- 1 2 1 , 130-13 1 , 466-470 alternatives to, 4 70-4 7 1 requirements, 7 5 risk reduction, 7 5 sickle cell anemia, 91 support, anemias, 36-37 thalassemia and, 74-75 whole blood, 465 Transfusion-induced hemolysis, 89 Transfusion-related acute lung injury (TRALI), 469t, 470, 474, 475

50 1

Transient IgM-related hemolysis, 1 54 Translocation, 233 Transmissible diseases, 4 74 Transplantation, marrow, stem cell, 3 1 7 Treatment-sensitive relapse, 295 Triamterene, 1 05 Trichome stain, 29 Tricyclic antidepressants occasional idiosyncratic neutropenia, 2 1 1 toxicity, 32 Triggering cells, 202 Trousseau syndrome, 424 T-suppressor cell malignancies, 2 1 1 TI. See Thrombin time TIP. See Thrombotic thrombocytopenic purpura Tumor(s), 2 1 3 . See also MALT tumors; Neo­ plasms; Non-lymphoid tumors; Solid tumors; Tumor markers; Tumor vaccines; sjJecific tumors B cell, 285 ferritin studies, 1 86, 1 86f growth studies, ALL, 3 1 5 Lukes-Butler classification, 302, 303t metastasis, 30 plasma cells, 322f Tumor lysis syndrome, 3 1 6, 3 1 6t Tumor markers CLL, 270f large granular lymphocytic leukemia, 275 malignancy staging and, 255 Tumor necrosis factor receptor-associated periodic syndrome, 262 Tumor necrosis factor-a (TNF-a), 7, 44, 47, 1 1 0, 205-206 Tumor suppressor gene p53 mutations, 288 Tumor vaccines, 227 2,3-DPG. See Diphosphoglycerate Tyrosine kinase activity, 1 95 inhibitors, 227 Tyrosine kinase receptor FLT3, AML and, 2 1 9, 2 1 9t u

Umbilical cord stem cell transplants, 39 Uncommon enzyme defects test, 142 Unconjugated serum bilirubin, 19 Uncrossmatched type 0, 475 Uncrossmatched type Rh negative, 475 Undifferentiated myelodysplastic syndrome (MDS-U), 1 1 3 Unfractionated heparin, 463 cerebral thrombosis, 44 1 clinical applications, 456 dose adjustment, 457 HIT, 378 pediatric thromboembolism, 44 1 , 44 1 t pharmacokinetics of, 455-456 pregnancy and, 440, 44 1 therapeutic guidelines, 456-457 thrombocytopenia and, 373 Unirradiated transfusion products, 263 Unrelated HLA-matched donor transplants, 240 Unstable hemoglobin molecule, 8 1 genetic defects, 82-83

502

I N DEX

Unstable hemoglobins, 87, 92 Upshaw-Schulman syndrome, 369 Uremia, 475 platelet function in, 388 Uric acid levels, B-cell chronic lymphocytic leukemia, 2 7 1 Urinary porphyrins, 1 8 1 lead poisoning and, 1 79 Urine hemoglobin, 140 hemosiderin, 140, 140f iron loss, 1 1 7 URO-D. See Hepatic uroporphyrinogen decarboxylase enzyme v

Vaccine therapy, 295 H. infl.uen zae, 76, 380 lymphoma, 295 pneumococcal, 76 tumor, 277 Valium. See Diazepam Variegate porphyria (VP), 1 77, 1 79 Vascular access, 223 Vascular consumption, 423 Vascular disorders, 427 Vascular endothelial growth factor (VEGF), 1 1 0, 32 1 Vascular injury, 426 Vascular purpura, 356-363 case history, 356, 359, 36 1 , 362 clinical features, 358 differential diagnosis, 358-359 laboratory studies, 358 points to remember, 362 structural abnormalities, 359-3 6 1 , 359t therapy and clinical course, 36 1-362 Vasculitis, 360 Vasoocclusive events, 85, 92 Vasoocclusive infarction, 88 VCAM- 1 , sickle cell anemia, 91 Vegans, 108 Vegetables, iron absorption and, 55 YEGF. See Vascular endothelial growth factor Vena caval filters, 440f Venofer. See Iron sucrose Venous thromboembolism (VTE), 430, 443 , 445, 453 anticoagulation therapy, duration of, 453-454 diagnostic tests, 430 management, 439-444 Venous thrombosis, 1 1 7, 1 65 Venous ultrasonography, 43 1 Vessel. See Blood vessel Vessel wall defect, bleeding and, 356 Vibrio vulnificus, 1 85 Vincristine ALL, 3 1 6, 3 1 6t Burkitt lymphoma, 296 chronic eosinophilic leukemia, 242 severe autoimmune thrombocytopenia, 379, 3 79f Vincristine, doxorubicin, and dexamethasone (VAD), 326 Viral antibody, 468

Viral diseases, 46 Viral hepatitis, 367. See also Hepatitis A virus; Hepatitis B virus; Hepatitis C virus hemophilia and, 401 marrow-damage anemia and, 32 Viral infections, 1 45-146, 40 1 . See also Antiviral therapy; sjJecific viral infections

Viral transmission, 407, 407t Visceral malignancies, 424 Viscosity, sickle cell anemia and, 85 Vitamin B6, 48, 1 76, 443-444 Vitamin B1 2 , 437 , 443-444 absorption and transport, 95-96, 95f, 1 04 binding proteins AML and, 221 myeloproliferative disorders and, 233 deficiency, 1 1 , 95, 1 07-108, 376 blood cobalamin level and, 159 causes, 1 04, 1 04t clinical features, 96-101 diagnosis of, 101-103 elderly and, 1 59-1 60 laboratory studies, 97-101 methylmalonic acid screening, 1 60 therapy for, 1 05-1 06 malabsorption, 1 08 Schilling test, 1 00-- 1 0 1 metabolism, normal, 95-96, 95f neuropathy, 1 06 nutrition, 96 preparations, 1 06-107 store depletion, 101 studies, 48 therapeutic response to, 1 03f Vitamin B 1 2 deficiency anemia, 101-103 Vitamin C children, 425 deficiency, 107, 359, 3 6 1 Vitamin K, 4 1 9, 455 deficiency, 4 1 4, 4 1 4t, 4 1 8 treatment, 4 1 6-4 1 7, 4 1 6t metabolism, 4 1 4, 4 1 4t, 45 1 £ pharmacokinetics, 45 1 , 45 1 £ Vitamin K-dependent coagulation factors, 353, 4 1 4, 4 1 4t, 4 1 8 Vitamin-deficiency anemia, 1 6 1 Vitamin-dependent factors, 350 Vitamins deficiency, 52, 73, 1 06 differential diagnosis, 1 03-105 prophylaxis, 1 06 replacement therapy, 24 therapy dysplastic anemias and, 1 2 1- 1 22 evaluations of, 107 Vivax, 1 45 Volume expander, 1 29, 1 29t, 1 30, 1 3 1 , 389, 389t von Clauss kinetic assay, 3 5 1 von Willebrand disease (vWD), 347, 349, 384-397 diagnosis, 391 platelet function and, 385, 386t platelet type, 392-393 points to remember, 395, 396

von Willebrand disease (Cont . ) : screening tests, 3 9 1 treatment, 4 7 4 type 1 disease, 391-392 type 2 disease, 392 type 3 disease, 392-393 variants, 3 9 1 , 3 9 1 t vascular purpura, 3 5 8 von Willebrand factor (vWF), 346, 349, 357, 369, 384, 423 , 449 assays, 386 replacement, 394-395 vascular purpura, 358 von Willebrand factor-cleaving protease activity, 3 70 Voriconazole, 223 VP. See Variegate porphyria VTE. See Venous thromboembolism vWD. See von Willebrand disease vWF. See von Willebrand factor w

Waldenstri:im macroglobulinemia (WM), 3 1 9, 330-33 1 , 332, 3 6 1 , 362 Warfarin, 347, 349, 4 1 4, 443, 460 anticoagulation, reversal of, 454-455 cerebral thrombosis, 441 HIT, 378 kinetics, drug interactions and, 45 1 long-term management, 455 maintenance therapy, 452 metabolism, 45 l f genotyping, 452 pediatric thromboembolism, 44 1 , 44 1 t pharmacokinetics, 45 1 , 45 1 £ pregnancy and, 454 resistance to, by drug interaction, 452 target ranges for, 453t therapeutic guidelines, 452 Warfarin sodium (Coumadin), 45 1 Warfarin with aspirin therapy, 452 Warfarin-induced skin necrosis, 443 Warm-antibody AIHA, 1 54 Warming, blood cells, 469 Warm-reacting AIHA, 147. 1 47t, 152, 153, 154 Washed red blood cells, 466 Watershed strokes, 86 Wegener granulomatosis, 293 Weibel-Palade (WP), 357 White blood cell count, 3 1 3-3 14, 3 1 4f White blood cell differential, 203 White thrombus, 344 WHO (World Health Organization) anemia, 156 leukemia classification, 2 1 6-220, 2 1 6t polycythemia vera criteria, 1 69, 1 69t WHO classification system cutaneous T-cell lymphomas, 291-292, 29 1 t lymphoma, 280, 280t, 281 WHO/FAB classification, 1 1 3, 1 1 3t, 1 22 Whole blood, 465

I NDEX

Whole blood platelet function analysis (PFA), 347 Whole body irradiation, 32 Widened arterial-venous difference, 5 WinRho, 379 Wiskott-Aldrich syndrome, 260, 368, 368f, 390 WM. See Waldenstrom macroglobulinemia Working Formulation lymphoma classifica­ tion system, 280, 280t for clinical usage, 293-294, 293t

World Health Organization. See WHO Wound healing, dysfibrinogenemias, 4 1 3 WP. See Weibel-Palade Wright-Giemsa stain, 1 1 0 X

Ximelagatran, 460 X-linked A-variant G6PD deficiency, 146, 146t X-linked disorders, 409 X-linked hyper lgM syndrome, 260

503

y

Yeast, 20 ! Yeast infections, 223 Yersinia enterocolitica, 1 85 z

ZAP-70 expression, 277 Zidovudine (AZT), 210 AIDS, 5 1 AIDS-associated thrombocytopenia, 379 thrombocytopenia and, 373