Hematology - 05 Leukocytes

HEMATOLOGY LEUKOCYTES OUTLINE • Leukocytes o Function o Classification o Properties of Leukocytes • Granulocytes o Neutrophil o Eosinophil o Basophils o Mast Cells • Agranulocytes o Monocyte o Lymphocyte • WBC Anomalies o Morphologic Abnormalities o Functional Abnormalities LEUKOCYTES • Aka white blood cells o They are relatively colorless FUNCTION • Immunity o Innate Immunity ▪ Naturally occurring, Non-specific ▪ Existent since birth ▪ Attack any foreign bodies regardless of specificity o Adaptive Immunity ▪ Acquired, Specific ▪ Acquired through vaccination, prior infection CLASSIFICATION • According to Progenitor • According to Function • According to Physical Attributes ACCORDING TO PROGENITOR • Progenitor - cell of origin • Myeloid Cells o Neutrophils o Eosinophils o Basophils o Monocytes • Lymphoid Cells o Lymphocytes (T cell, B cell, NK cell) ACCORDING TO FUNCTION • Phagocytes – participates in innate immunity (phagocytosis); non-specific o Neutrophil o Eosinophil o Basophil o Monocytes and Macrophages (mononuclear phagocyte system) • Immunocytes – participates in adaptive immunity; specific o Lymphocytes ACCORDING TO PHYSICAL ATTRIBUTES • Segmented Cells (Granulocytes) o Neutrophil o Eosinophil o Basophil • Mononuclear Cells ( Agranulocytes) o No visible granules o Monocytes o Lymphocytes PROPERTIES OF LEUKOCYTES • Diapedesis • Chemotaxis • Opsonization • Pinocytosis • Phagocytosis DIAPEDESIS • Outward passage of blood cells through intact vessel walls. • WBC are transient cells; they move out from the circulation into the tissues Average life span of WBC (Blood) Average life span of WBC (Tissues) Neutrophils 7 hours Variables Eosinophils 18 hours At least 6 days Basophils 60 hours *not normally found in tissues Monocytes 3 days Variable Lymphocytes Days (B cells) Months to years (T cells) • Neutrophil is variable because it depends if it’s active • Basophil is not normally found because of its low count CHEMOTAXIS • Cellular movement towards or away from the source of chemical stimulus (chemokines) o Bacteria can produce chemokines • Positive Chemotaxis – movement towards the chemical stimulus • Negative Chemotaxis – movement away the chemical stimulus

OPSONIZATION • Binding of opsonins to a foreign material which can trigger or enhance phagocytosis by leukocytes • Opsonins - antibodies, complement proteins/components o Derived from Greek “to prepare for eating” o Prepare foreign material for phagocytosis o Links to phagocytes to initiate phagocytosis PINOCYTOSIS • “cell drinking” • Cellular uptake of fluids with dissolved small particles PHAGOCYTOSIS • Ingestion of live particles or live microorganisms into a cell • 4 Stages of Phagocytosis o Recognition and Attachment Phase ▪ Phagocyte receptors binds to foreign particle and opsonins o Ingestion Phase ▪ Cytoplasmic pseudopodia surrounds the foreign particle (phagosome) • Phagosome - bacteria inside a vacuole inside the phagocyte o Killing and Digestion ▪ Oxygen Dependent • Synthesize super-oxides (hypochlorite) • NADH oxidase complexes with phagosome to generate H 2 O 2 which is converted to Hypochlorite by myeloperoxidase (primary granule) • Hypochlorite - powerful oxidizing agent that contribute to killing of foreign bodies within the phagocyte • NADH - can depolarize the WBC membrane o Depolarized WBC membrane - semi permeability is altered o pH increases leading to O2-independent ▪ Oxygen Independent • The pH within the phagosome becomes alkaline and then neutral (digestive enzymes optimal pH) • Primary and secondary granules fuse to phagosomes and release their contents within (Phagolysosome) o Formation of Neutrophil Extracellular Traps (Exocytosis) ▪ Extracellular threadlike structure generated after neutrophils die (chains of nucleosome/DNA) ▪ Chains have neutrophilic granules ▪ Can trap bacteria & fungi and eventually kill them GRANULOCYTES • Segmented cells NEUTROPHIL SEGMENTED NEUTROPHIL • aka polymorphonuclear neutrophils (PMN) • Most common WBC in normal peripheral blood • First phagocytes to reach the infected areas followed by monocytes • Spends 7 hours in the peripheral before it migrates to marginal pool • Major function is phagocytosis and destruction of microorganisms • Size : 9-15 um • Cytoplasm : Lilac-pink to purple granules • Nucleus : Multilobed (2-5) connected by threadlike filaments NEUTROPHIL BAND • aka Non-segmented neutrophil, neutrophil stab or staff • Youngest granulocytic precursor to appear normally in the peripheral blood • Start of secretory granules synthesis • Size and cytoplasm similar with PMN • Nucleus : indented (>1/2 of diameter) o C, S or Z shaped, Sausage-shaped

NEUTROPHIL GRANULES • Primary (Azurophilic) Granules o Formed during the promyelocyte stage o Last to be released (exocytosis) o Contain: ▪ Myeloperoxidase ▪ Acid β-glycerophosphatase ▪ Cathepsins ▪ Defensins ▪ Elastase ▪ Proteinase-3 ▪ Others • Secondary (Specific) Granules o Formed during myelocyte and metamyelocyte stages o Third to be released o Contain: ▪ β 2 -Microglobulin ▪ collagenase ▪ gelatinase ▪ Lactoferrin ▪ Neutrophil gelatinase-associated lipocalin ▪ Others • Tertiary Granules o Formed during metamyelocyte and band stages o Second to be released o Contain ▪ Gelatinase ▪ Collagenase ▪ Lysozyme ▪ Acetyltransferase ▪ β 2 -Microglobulin • Secretory Granules (Secretory Vesicles) o Formed during band and segmented stages o First to be released (fuse to plasma membrane) o Contain (attached to the membrane): ▪ CD11b/CD18 ▪ Alkaline phosphatase ▪ Vesicle-associated membrane-2 ▪ CD10, CD13, CD14, CD16 ▪ Cytochrome b 558 ▪ Complement 1q receptor ▪ Complement receptor-1 NEUTROPHIL KINETICS • Movement of cell from in and out of circulation • In the bone marrow o Mitotic Pool (2.11 x 10 9 cells/kg) ▪ Includes HSC, Common myeloid progenitor, granulocyte-monocyte progenitor, myeloblast, promyeloblast, myelocytes. ▪ Cells capable of mitosis o Storage Pool (5.6 x 10 9 cells/kg) ▪ Cells after the myelocyte stage (metamyelocytes, band cells, mature neutrophils) • In the peripheral blood o Cells released are divided randomly (50:50 ratio) between CNP & MNP o Circulating Neutrophil Pool (CNP) ▪ Neutrophils that are freely circulating ▪ Measured during WBC Count/Differential Count o Marginated Neutrophil Pool (MNP) ▪ Attached to endothelial cells of blood vessel lumen ▪ Neutrophils are not measurable ▪ Adhesion to endothelial walls are promoted by integrins and selectins (important for margination of neutrophils) • Tissue Pool o Diapedesis move WBCs from circulation to tissues REFERENCE RANGES Relative Count (%) Absolute Count (/mm 3 ) Neutrophil 47 - 77% 1,600 - 7,260 Bands/Staff /Stab 2 - 6% 350 - 700 CLINICAL SIGNIFICANCE • Neutrophilia (>8.7 x 109/L) o Increase in WBC count o Bacterial infections o Appendicitis o Myelogenous leukemia o Venoms (spiders, bees, wasps) o Actinomyces fungi o Chemicals (lead, mercury) o Drugs (digitalis, phenancetin) o Corticosteroids o Lithium o Response to therapy o Physiologic Neutrophilia (Pseudoneutrophilia) ▪ Causes: exercise, excessive temperature changes, nausea and vomiting, pregnancy and labor, rage, panic and stress. • Neutropenia (<2.0 x 109/L) o Chemical toxicity (benzene) o Marrow replacement o Nutritional deficiencies o Cytotoxic drugs o Overwhelming viral infections o Agranulocytosis ▪ aka Extreme Neutropenia ▪ <0.5 x 10 9 /L ▪ Associated with amidopyrine and cephalosporins. • Shift to the left o Increase in the number of young forms of WBC (usually neutrophils) o Two types : o Degenerative Shift to the Left ▪ Increase number of young forms of WBC (neutrophils) ▪ Often accompanied by normal/decreased WBC count ▪ Example : Tuberculosis o Regenerative Shift to the Left ▪ Increase number of young forms of WBC (neutrophils) accompanied by increased WBC count ▪ Example : Appendicitis • Shift to the right o Increase in the number of old forms of WBC (usually neutrophils) o Example: Pernicious anemia

LEUKEMOID REACTION • Leukocyte count above 50 x10 9 /L • Accompanied by o Neutrophilia o Marked left shift • Confused with Chronic Myelogenous Leukemia DISTINGUISHING BETWEEN CHRONIC MYELOGENOUS LEUKEMIA AND LEUKEMOID REACTION • Chronic Myelogenous Leukemia o Increases in all granulocytes including eosinophils and basophils and their immature forms o Dyspoietic morphology such as mixed granulation or pseudo Pelger-Huët o Involvement of platelets including giant, hypogranular forms o Leukocyte alkaline phosphatase score is markedly decreased • Leukemoid Reaction o Increases in neutrophils and their immature forms; possible increased monocytes but eosinophils and basophils are frequently absent o No dyspoietic morphology; however, reactive morphology is usually present o No abnormal platelet morphology o Leukocyte alkaline phosphatase score is markedly increased LEUKOERYTHROBLASTIC REACTION • Synonyms : Leukoerythroblastic anemia/ Leukoerythroblastosis • Blood smear : nRBC and immature neutrophils • Provides evidence of underlying disease or stress to the hematopoietic compartment (bone marrow) • Striking and Sustained Leukoerythroblastic Reaction o Involves presence of space-occupying lesions in the marrow (myelophthisis) ▪ Seen in metastatic tumor, fibrosis, lymphoma, leukemia • Mild and Transitory Leukoerythroblastic Reaction o Hemolytic anemia, severe infections, cardiac failure, uremia, megaloblastic anemia EOSINOPHIL • Increased in helminthic infections and allergic disorders • Functions for immune regulation • Size : 9-15 um • Cytoplasm : Coarse reddish-orange granules o Granuels doe sn’t obscure the nucleus • Nucleus : Bilobed • Reference Range : o Relative count : 0-6% o Absolute count : 45-440/mm3 EOSINOPHIL GRANULES • Primary Granules o Similar with neutrophil granule with addition of Charcot-Leyden crystal protein o Formed during promyelocyte stage o Contain: Charcot-Leyden crystal protein • Secondary Granules o Formed throughout remaining maturation o Contain: ▪ Major basic protein (core) ▪ Eosinophil cationic protein (matrix) ▪ Eosinophil-derived neurotoxin (matrix) ▪ Eosinophil peroxidase (matrix) ▪ Lysozyme (matrix) ▪ Catalase (core and matrix) ▪ β - Glucoronidase (core and matrix) ▪ Cathepsin D (core and matrix) ▪ Interleukins 2,4, and 5 (core) ▪ Interleukin-6 (matrix) ▪ Granulocyte-macrophage colony-stimulating factor (core) ▪ Others • Small Lysosomal Granules o Acid phosphatase o Arylsulfatase B o Catalase o Cytochrome b 558 o Elastase o Eosinophil cationic protein • Lipid Bodies o Cyclooxygenase o 5-Lipoxygenase o 15-Lipoxygenase o Leukotriene C 4 synthase o Eosinophil peroxidase o Esterase • Storage Vesicles o Carry proteins from secondary granules to be released into the extracellular medium EOSINOPHIL FUNCTIONS • Parasitic helminths – destroying and preventing reinfection (secretion of major basic protein and eosinophil cationic protein) • Immune regulation - acting as antigen-presenting cells and promoting the proliferation of effector T cells • Hallmark of allergic disorders – asthma, food allergy, Crohn’s disease CHARCOT-LEYDEN CRYSTALS • Hexagonal bipyramidal crystals • Product of eosinophil disintegration • Composed of lysophospholipase • Generally colorless, but stained with: o Hematoxylin – Black o Eosin – Red o Trichrome – purplish red EOSINOPHIL KINETICS • Eosinophilic myelocyte to mature eosinophil – 3.5 days • Storage pool (bone marrow) – 9-14 x 10 8 cells/kg • Peripheral blood – about 18 hours • Tissues – 6 days

CLINICAL SIGNIFICANCE • Eosinophilia (>0.4 x 10 9 /L) o Increase in eosinophils o Asthma o Hay fever o Psoriasis o Eczema o Scarlet fever (caused by Streptococcus pyogenes ) o Parasitic infections (Helminthic) ▪ Trichinosis ( Trichinella spiralis ) - produces the highest eosinophil count o Eosinophilic leukemia • Eosinopenia (<0.09 x 10 9 /L) o ACTH administration (Adrenocorticotropic Hormone) ▪ ACTH - can promote diapedesis o Infection and inflammation accompanied with neutrophilia BASOPHIL • initiators of immune response and allergic and hypersensitivity reactions • The least numerous WBC • Have IgE receptors on surface membrane • Size : 10-16 um • Cytoplasm : coarse bluish-black granules o Granules obstruct the nucleus • Nucleus : Multilobed (3-4) • Reference range : o Relative Count : 0-1% o Absolute Count : 45-110/mm3 BASOPHIL GRANULES • Secondary Granules o Histamine o Platelet activating factors o Leukotriene C 4 o Interleukin-4 o Interleukin-13 o Vascular endothelial growth factor A o Vascular endothelial growth factor B o Chondroitin sulfates (eg. Heparin) BASOPHIL FUNCTION • Granules are released when IgE receptors in the surface membrane crosslinks with antigen • Innate and adaptive immunity - capable of releasing large quantities of subtype 2 helper T cell cytokines such as IL-4 and IL-13 that regulate the TH2 immune response • Induce B cells to synthesize IgE o B-cell - antibody-producing lymphocytes • Control of helminth infections alongside with eosinophil (promote eosinophilia and contribute to efficient worm expulsion) BASOPHIL KINETICS • Development and Storage (Bone Marrow): 4.3 d ± 11 hrs • Bone marrow to Peripheral blood : 3.7 days ± 11 hours • Average Life Span : 60 hours o Activated by IL-3 (prolongs life span) o IL-3 - initiate anti-apoptotic pathway preventing apoptosis (programmed cell death) CLINICAL SIGNIFICANCE • Basophilia (>0.15 x 10 9 /L) o Malignant Myeloproliferative Neoplasm (e.g. CML) ▪ Most common cause of basophilia ▪ CML - Chronic Myelogenous Leukemia o Immediate Hypersensitivity Reaction o Hypothyroidism o Ulcerative colitis o Estrogen therapy o Bee stings o Variola and Varicella infections • Basopenia o Difficult to observe due to low amount of basophil o Acute infections o Stress o Hyperthyroidism o Increased levels of glucocorticoids o Chronic urticaria MAST CELLS • A tissue cell found in connective tissues • Have several phenotypic and functional similarities with both basophils and eosinophils • Granules : Heparin, serotonin, bradykinin, histamine • Two types : o MC TC – with chymase and tryptase granules o MC T – tryptase granules only • Functions : o Effector cells in allergic reactions o Anti-inflammatory and immunosuppressive functions o Antigen-presenting cells AGRANULOCYTES MONOCYTE • The largest cell in the circulation • Strongly positive with nonspecific esterase (NSE) stain o NSE Stain - histochemical stain • Size : 15-20 um • Nucleus : Kidney-bean shaped with brain-like convolutions o Horse-shoe shaped or lobulated • Cytoplasm : Abundant, blue-gray, containing fine, indistinct granules called “azure dust” (ground-glass appearance) o With or without vacuoles • Reference Ranges : o Relative Count: 2-10% o Absolute Count: 180-880/mm3

MACROPHAGES • Tissue monocytes • Most abundant cell in the body • Size : 15-85 um (40-50 um) • Nucleus : oval with net-like (reticulated) chromatin pattern • Cytoplasm : pale, frequently vacuolated, and often filled with debris of phagocytized cells or organisms MONOCYTE DESTINATION • Specific name of a monocyte/macrophage depends on its location Location Specific Name Liver Kupffer cells Lungs Alveolar macrophage/Dust cell Kidneys Mesangial cells Brain Microglial cells Skin Langerhans cells Spleen Splenic macrophage/Littoral cells Bone Osteoclasts Placenta Hoffbauer cells MONOCYTE/MACROPHAGE FUNCTION • Innate immunity o pattern recognition receptors stimulate inflammatory cytokine production and phagocytosis. o Fc receptors and complement receptors ▪ Receptors for opsonins (promote phagocytosis) • Adaptive immunity o antigen-presenting cells (macrophages and dendritic cells) • Housekeeping functions o Removal of dead cells, destruction of old RBC, storage pool of iron, and protein synthesis MONOCYTE KINETICS • Normally: • Increased demand for monocytes • Circulation (3 days): o Unequal division o Marginal Pool – 3.5x more than CP o Circulating Pool • Macrophage lifespan is variable o Kupffer cells (21 days) o Inflammatory macrophage (hours) CLINICAL SIGNIFICANCE • Monocytosis (>1.1 x 10 9 /L) o Tuberculosis o Subacute Bacterial Endocarditis o Syphilis o Protozoal and Rickettsial infections ▪ Malaria, typhus o Brucellosis o Typhoid o Gaucher disease o Hodgkin’s Disease o Collagen Vascular Disease (SLE) o Gastrointestinal Disease o Surgical Trauma • Monocytopenia (<0.4 x 10 9 /L) o Aplastic anemia o Overwhelming infections with immunocompromised patients o Hemodialysis o Epstein-Barr Virus Infection (kissing disease) o Steroid therapy (prednisone) o Hairy cell leukemia LYMPHOCYTE • 3 groups: o T cells, B cells, Natural Killer cells • Unique feature : o Lymphocytes are not end cells (memory cells and effector cells) ▪ Resting blast forms in the circulation ▪ Blastogenesis - cell division of resting blast forms of lymphocytes when they are stimulated o Lymphocytes recirculate o Production of antibodies and surface receptors o T cells and NK cells develop outside the Bone Marrow ▪ T-cell develop in thymus ▪ NK cells may develop in bone marrow or in thymus • Reference Ranges : o Relative Count : 20-40% o Absolute Count : 960-4,400/mm3 • Sizes : o Small Lymphocytes : 7-10 um (resting lymphocytes) o Medium Lymphocytes : 10-12 um ▪ Variant lymphocytes (reactive) o Large Lymphocytes : 11-25 um ▪ Variant lymphocytes (reactive) • Cytoplasm : Sky blue/Robin egg blue o Medium & large are indented by RBC • Nucleus : Round and compact o Crushed velvet appearance o Oval shape - mature

LYMPHOCYTE DEVELOPMENT Antigen-Independent Antigen-Dependent Bone marrow and Thymus Spleen, Lymph nodes, Tonsils, and Mucosa-associated lymphoid tissue (Peyer’s patches in intestinal wall) Central or Primary lymphatic organs Peripheral or Secondary lymphatic organs B-LYMPHOCYTES • aka “B-cells” • Develop in bone marrow • Antibody-producing lymphocytes • 10-15% of circulating lymphocytes • When it comes in contact with antigen, it cell divides: o Memory cells, Effector B-cells (Plasma cells and Plasmacytoid lymphocytes) • Resting blast form • Functions : o Antibody production (matured into plasma cell) o Antigen presenting cells (T cells) o CD4 activation o Produce cytokines that regulates T cells and antigen presenting cell functions PLASMA CELLS • Final maturation stage of B-cells • Size : 10-28 um • Nucleus : small/oval shaped; eccentric • Cytoplasm : Dark blue; ovoid shaped; non-granular o “Tortoise shell” or “Cartwheel” in appearance o Contains Russel Bodies ▪ Immunoglobulin in plasma cell ▪ Vacuoles represent production of antibodies T-LYMPHOCYTES • aka “T-cells” • Participated in cellular immunity • 85% of circulating lymphocytes • When it comes in contact with antigen, it cell divides: o Reactive/Variant lymphocytes ( medium/large lymphocyt ) • Develop in thymus and produce receptors o Receptors may act with different antigens o Some receptors may act with self-antigens; these are allowed to die because they may be fatal due attacking cell antigen • Types : o T-helper Cells (CD4+) o T-cytotoxic cells (CD8+) REACTIVE LYMPHOCYTES • aka Reactive lymphocytes, atypical lymphocytes, virocytes, stress lymphocytes, Downey cells, transformed lymphocytes, transitional lymphocytes, glandular fever cells • Lymphocytes that are in contact with antigen (T cells) • Size : 12-15 um • Nucleus : immature looking • Cytoplasm : abundant, deeply basophilic o Indented by the RBCs NATURAL KILLER (NK) CELLS • Part of the innate immunity • Capable of killing certain tumor cells and virus-infected cells • It develops either in bone marrow or thymus • 2% of circulating lymphocytes • Heterogenous group of cell: CD56+, CD16+, CD3-, CD8- • Mature NK cells – larger than other resting lymphocytes (increased cytoplasm with azurophilic granules that are peroxidase negative) – large granular lymphocytes CLINICAL SIGNIFICANCE • Lymphocytosis o Children : >10.0 x 10 9 /L o Adult : >4.8 x 10 9 /L o Infectious Mononucleosis o Acute Infectious Lymphocytosis (from coxsackievirus (A, B6), echovirus, adenovirus type 12) o Cytomegalovirus infection o Acute Viral Hepatitis o Bordetella pertussis infection (Whooping cough) o Brucellosis o Toxoplasmosis • Lymphocytopenia (Lymphopenia) o Children : <2.0 x 10 9 /L o Adult : <1.0 x 10 9 /L o Steroid treatment (most common cause) o HIV infection (T-lymphocytopenia) ▪ Targets CD4+ cells (T-helper cells)

WBC ANOMALIES (NON-MALIGNANT) MORPHOLOGIC ABNORMALITIES PELGER-HUËT ANOMALY (PHA) • Most common genetic disorder of WBC (neutrophils) • Failure of neutrophil nucleus to segment • Caused by mutation of lamin B receptor o Lamin B Receptor - intergral protein for nuclear membrane structure • Homozygous PHA o Granulocytes with round or oval nuclei (no segmentation) • Heterozygous PHA o Granulocytes whose nucleus is segmented only once o “pince nez” or “spectacle” form of nucleus Homozygous PHA Heterozygous PHA • Pseudo-Pelger-Huet Anomaly o Acquired condition o Seen in variety of malignant myeloproliferative neoplasms (chronic myelogenous leukemia) o Differentiated from inherited-PHA: ▪ Inherited PHA > Pseudo-PHA • Pseudo PHA has more normal ** ▪ Pseudo-PHA is accompanied by presence of blast forms of WBC. HEREDITARY NEUTROPHIL HYPERSEGMENTATION • Aka hypersegmentation • Neutrophil nucleus with 5-10 lobes • Seen in: o Benign autosomal dominant condition o Megaloblastic anemia o Myelokathexis o Folic acid deficiency o Undritz anomaly LUPUS ERYTHEMATOSUS (LE) CELLS • A neutrophil with ingested antibody-coated nucleus of another neutrophil or has engulfed the homogenous, globular nuclear mass of a destroyed cell • Usually seen in vitro (in peripheral blood) • Found in: o Systemic lupus erythematosus (SLE) o Other connective tissue disorders ALDER-REILLY ANOMALY • Granulocytes with Alder-Reilly Bodies/Reilly bodies o Large, darkly staining metachromatic granules that resemble toxic granulation. o Composed of mucopolysaccharides ▪ Due to inability of body to metabolize mucopolysaccharide (mucopolysaccharidoses) • Seen in mucopolysaccharidoses: o Hunter Syndrome o Hurler Syndrome o San Filippo Syndrome • CHEDIAK-HIGASHI SYNDROME (CHS) • Rare and fatal autosomal recessive disease • Characterized by cells with enlarged lysosomal vesicles. • Hematologic findings: o Giant lysosomal granules in granulocytes, monocytes, and lymphocytes • Patient usually observed to have partial albinism o Abnormal packaging of melanosomes o Silvery hair, pale skin, photophobia Monocyte (giant lysosomal granule) Neutrophil TART CELLS • A monocyte with ingested lymphocyte or a nucleus • Seen in drug sensitivity • Name after the first patient with the cell •

TOXIC GRANULATIONS • Increase in mucosubstance within primary granules of neutrophils • Cytoplasm : dark-blue to black granules • Seen in severe infections and chemical poisoning • JORDAN’S ANOMALY • Characterized by presence of fat-containing vacuoles in granulocytes and monocytes • Seen in muscular dystrophy and ichthyosis • DOHLE BODIES • Neutrophils with round or oval blue-staining cytoplasmic inclusions (composed of ribosomal RNA) • Found in severe burns, infections, and in pregnancy • MAY-HEGGLIN ANOMALY (MHA) • One of the four overlapping autosomal dominant platelet disorders (inherited disorders) • Characterized by presence of gray-blue spindle-shaped inclusions in the cytoplasm of granulocytes and monocytes o Inclusions are messenger RNA (Dohle-like bodies) • Also characterized by: o Leukopenia o Variable thrombocytopenia o Giant platelets • FUNCTIONAL ABNORMALITIES LEUKOCYTE ADHESION DEFICIENCY (LAD) • Inability of neutrophils and monocytes to adhere to endothelial cells and to transmigrate from blood to tissues o Incapable of diapedesis • No abnormal cell morphology • Seen in recurrent infections and high mortality CHRONIC GRANULOMATOUS DISEASE (CGD) • An inherited disorder characterized by defects in the respiratory burst oxidase system (oxygen-dependent digestion of ingested foreign bodies) o Affect conversion of H 2 O 2 into hypochlorite • Normal neutrophil morphology • May form granulomas o Can obstruct hollow organs • Seen in frequent infections especially in children • Tests : o Chemiluminescence o Flow cytometry o Nitro-Blue Tetrazolium Reduction Test ▪ Normal Neutrophil : Dark blue insoluble formazan ▪ Nitro-blue - yellow soluble** MYELOPEROXIDASE DEFICIENCY • The most common neutrophil abnormality • Low or absent myeloperoxidase enzyme • Normal cell morphology • ** analyzer • Discovered through automated hematology analyzer that detects myeloperoxidase SPECIFIC GRANULE DEFICIENCY • Patient presents with recurrent bacterial infections, atypical bilobed nuclei. • Neutrophils also have defective chemotaxis NIEMANN-PICK DISEASE • Sphingomyelinase deficiency o Sphingomyelinase - required to breakdown lipids** • Rare autosomal recessive disease (Ashkenazi Jews) • Patient exhibits splenomegaly and hepatomegaly • Characteristic Cells : o Foam Cells/Pick Cells : ▪ Abnormal macrophage whole cytoplasm is completely filled with many small lipid droplets (sphingomyelin)

• GAUCHER DISEASE • The most common lysosomal lipid storage disease • Defects in ß-glucocerebrosidase (catabolic enzyme) • Accumulation of glucocerebroside in macrophages throughout the body. • Gaucher Cell o Found in the bone marrow o Large macrophage with small, eccentric nucleus o Cytoplasm: distended with glucocerebrosides (crumpled tissue paper appearance; onion skin-like) • LAZY LEUKOCYTE SYNDROME • Poor response of neutrophil to chemotactic agents • Characterized by neutropenia JOB SYNDROME • aka Hyperimmunoglobulinemia E • Neutrophils: poor directional mobility o Neutrophils are unable to reach infections • Characterized by: o Elevated IgE o Skeletal abnormalities o Recurrent severe bacterial infections