Hematology/Oncology Flashcards
Agranulocytosis (drug reaction)
Ganciclovir Clozapine Carbamazepine Colchicine Methimazole Propylthiouracil
Aplastic anemia (drug reaction)
Carbamazepine Methimazole NSAIDs Benzene Chloramphenicol Propylthiouracil
Direct Coombs-positive hemolytic anemia (drug reaction)
Methyldopa
Penicillin
Gray Baby Syndrome (drug reaction)
Chloramphenicol
Hemolysis in G6PD deficiency (drug reaction)
Isoniazid Sulfonamides Dapsone Primaquine Aspirin Ibuprofen Nitrofurantoin
Megaloblastic anemia (drug reaction)
Phenytoin
Methotrexate
Sulfa drugs
Thrombocytopenia (drug reaction)
Heparin
Thrombotic complications (drug reaction)
OCPs
hormone replacement therapy
Erythrocyte
Carries O2 to tissues and CO2 to lungs.
Anucleate and biconcave, with large surface area-to-volume ratio for rapid gas exchange.
Life span = 120 days. Source of energy is glucose (90% used in glycolysis, 10% used in HMP shunt).
Membrane contains Cl-/HCO3 antiporter which allows RBCs to export HCO3 and transport CO2 from the periphery to the lungs for elimination
Polycythemia = portion of blood occupied by RBCs is higher
Erythrocytosis = polycythemia = higher hematocrit
Anisocytosis = varying sizes Poikilocytosis = varying shapes
Reticulocyte = immature RBC; reflects erythroid proliferation
Thrombocyte (platelet)
Involved in primary hemostasis. Small cytoplasmic fragment derived from megakaryocytes.
Life span = 8-10 days. When activated by endothelial injury, aggregates with other platelets and interacts with fibrinogen to form a platelet plug.
Contains dense granules (ADP, Ca) and alpha granules (vWF, fibrinogen).
About 1/3 of platelet pool is stored in spleen.
Thrombocytopenia (low platelet function) results in petechiae
vWF receptor: Gp1b
Fibrinogen receptor: Gp2b/3a
Leukocyte
Divided into granulocytes (N, E, B) and mononuclear cells (M, L). Responsible for defense against infections. Normally 4000 - 10,000 cells/mm3
Differential from highest to lowest
Neutrophils (54-62%) Lymphocytes (25-33%) Monocytes (3-7%) Eosinophils (1-3%) Basophils (0-0.75%)
Neutrophil
Acute inflammatory response cell. Increased in bacterial infections. Phagocytic. Multilobed nucleus.
Specific granules contain ALP, collagenase, lysozyme, and lactoferrin. Azurophilic granules (lysosomes) contain proteinases, acid phosphatase, myeloperoxidase, and B-glucuronidase.
Hypersegmented polys (5 or more lobes) are seen in vitamin B12/folate deficiency
Increased band cells (immature neutrophils) reflect states of higher myeloid proliferation (bacterial infection, CML)
Important neutrophil chemotactic agents: C5a, IL-8, LTB4, kallikrein, platelet-activating factor
Monocyte
Differentiates into macrophage in tissues.
Large, kidney-shaped nucleus. Extensive “frosted glass” cytoplasm
It’s a monocyte in the blood. Macro in tissues.
1 nucleus
Macrophage
Phagocytoses bacteria, cellular debris, and senescent RBCs.
Long life in tissues. Macrophages differentiate from circulating blood monocytes. Activated by gamma interferon. Can function as antigen presenting cell via MHCII
Important component of granuloma formation (TB, sarcoidosis)
Lipid A from bacterial LPS binds CD14 on macrophages to initiate septic shock
Eosinophil
Defends against helminthic infections (major basic protein).
Bilobate nucleus. Packed with large eosinophilic granules of uniform size. Highly phagocytic for antigen-antibody complexes
Produces histaminase and major basic protein (MBP, a helminthotoxin)
Causes of Eosinophilia:
1) Neoplasia
2) Asthma
3) Allergic processes
4) Chronic adrenal insufficiency
5) Parasites (invasive)
Basophil
Mediates allergic reaction. Densely basophilic granules contain heparin (anticoagulant) and histamine (vasodilator). Leukotrienes synthesized and released on demand.
Basophilia is uncommon, but can be a sign of myeloproliferative disease, particularly CML
Mast Cell
Mediates allergic reaction in local tissues. Mast cells contain basophilic granules and originate from the same precursor as basophils but are not the same cell type.
Can bind Fc portion of IgE to membrane. IgE cross-links upon antigen binding, causing degranulation, which releases histamine, heparin, and eosinophil chemotactic factors.
Involved in type 1 hypersensitivity reactions.
Cromolyn sodium prevents mast cell degranulation (used for asthma prophylaxis)
Dendritic cell
Highly phagocytic APC. Functions as link between innate and adaptive immune systems. Expresses MHC II and Fc receptors on surface.
Called Langerhans Cell in the skin
Lymphocyte
Refers to B cells, T cells, NK cells.
B and T mediate adaptive immunity.
NK are part of innate immune response.
Round, densely staining nucleus with small amounts of pale cytoplasm.
B Cell
Part of humoral immune response. Originates from stem cells in bone marrow and matures in marrow. Migrates to peripheral lymphoid tissue (follicles of lymph nodes, white pulp of spleen, unencapsulated lymphoid tissue)
When antigen is encountered, B cells differentiate into plasma cells (which produce antibodies) and memory cells. Can function as an APC via MHCII
CD19, CD20, CD21
T Cell
Mediates cellular immune response. Originates from stem cells in bone marrow, but matures in the thymus. T cells differentiate into cytotoxic T cells (express CD8, recognize MHC1), helper T cells (CD4, recognize MHC2), and regulatory T cells.
CD28 (costimulatory signal) is necessary for T cell activation. The majority of circulating lymphocytes are T cells (80%)
CD4+ helper T cells are primary target of HIV
Th = CD3, CD4 Tc = CD3, CD8
Plasma Cell
Produces large amounts of antibody specific to a particular antigen. “Clock Face” chromatin distribution, abundant RER, and well-developed Golgi apparatus.
Multiple Myeloma is a plasma cell cancer
Universal Donor of RBCs
Type O
Universal recipient of plasma
Universal Recipient of RBCs
Type AB
Universal donor of plasma