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31 Cards in this Set
- Front
- Back
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What is the definition of macrocytosis?
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<100 fl
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What are reticulocytes?
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Occurs after extrusion of nucleus from orthochromic normoblast
Remains in marrow for approx 3 days Released into circulation – remodeled with loss of water and membrane Normal retics are macrocytic |
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How does alcohol cause macrocytosis?
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can induce membrane changes
Interferes with cellular division |
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How does liver disease cause macrocytosis?
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May be caused by increased lipid deposition on red cell membranes
Target Cells are present in liver disease macrocytosis |
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How does thyrois disease cause macrocytosis?
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Mechanism of macrocytosis unknown
Autoimmune thyroiditis associated with antiparietal cell antibodies |
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What is Spurious Macrocytosis?
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Artifacts that can occur to normal sized RBCs
Clumps of RBCs counted as single cells by automated cell counters |
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What is myelodysplastic syndrome?
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National Cancer Institute definition: A group of diseases in which the bone marrow does not make enough healthy blood cells. Also called preleukemia and smoldering leukemia.
Hypolobulated or hypogranular neutrophils Large and/or abnormally granulated platelets Monocytosis Occasional blast forms |
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What is megaloblastic anemia?
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Megaloblastic anemia – anemia, often pancytopenia, with macrocytic red blood cells and hypersegmented neutrophils due to an impairment in DNA synthesis
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What doe megaloblastic anemia occur?
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Inadequate conversion of deoxyuridylate to thymidylate
Slows DNA synthesis Delayed nuclear maturation Nuclear/cytoplasmic dyssynchrony (ie, immature nucleus/mature cytoplasm |
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What are common causes of megaloblatic anemia?
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Folate deficiency
Cobalamin deficiency Drugs Inhibit absorption of B12 or folate Inhibit enzymes required for DNA synthesis |
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What are sources of b12?
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animal products- fish eggs poultry
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What are sources of folate?
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our diet i fortified with folic acid
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How long do we store b12 in our bodies?
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3-5 years
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What are some common causes of defect in b12 absorption?
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achlorhydria
antibodies to intrisic factor and/or parietal cells defct in pancreatic enzymes cubulin defect transcobalamin receptor defect |
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What does a cubulin defect and transcobalamin reception defect cause?
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juevenille megaloblastic anemina
This is rare---typically a disease in older adults |
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What is the normal range for cobalamin?
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200-900pg/ml
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What happens to methylmalonic acid in b12 deficiency?
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It is high
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What happens to methylmalonic acid in folate deficiency?
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Nothing it stays normal
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What is the normal range for MMA?
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70-270 nM
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What is the normal range of homocysteine?
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5-16mM
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What happens to homocysteine in b12 deficiency?
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It is HIGH
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What happens to homocysteine?
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It is HIGH
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Which defiency causes hypesegmentation of neutrophils?
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folate deficiency
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What are the clinical manifestations of colabalamin and folate deficiency
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glossitis
"beefy" red tongue atrophy os gastric mucosa weight loss thrombosis--from homocystienemia hyperpigmentation immune defiency |
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What are the hematologic changes found in the peripheral blood in megaloblastic anemia?
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Hypersegmented neutrophils
Basophilic stipplingis Oval macrocytosis with or without anemia MCV higher than normal Thrombocytopenia leukoerythroblastic changes |
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What are the hematologic changes found in the bone marrow in megaloblastic anemia?
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hypercellular
giant bands or metamyeloctytes nuclear cytoplasmic dyssunchron open and immature chromatin pattern Karryhohexis |
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What is karryohexis?
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A stage of cellular necrosis in which the fragments of the nucleus fragments and its chromatin are distributed irregularly throughout the cytoplasm.
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What happens to the blood chemistry in megaloblastic anemia?
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increased indirect bilirubin
increases lactate dehydrogenase |
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What is pernicious anemia?
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B12 deficiency causes neuropsychiatric manifestations
Peripheral neuropathies Dorsal column involvement (loss of position and vibratory sense, ataxia) Subacute combined degeneration of spinal cord Psychiatric symptoms (dementia, psychosis) |
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How do you treat pernicious anemia?
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1000 ug B12 weekly by IM injection x 8 weeks then monthly for life
Consider oral therapy with close monitoring Folate 1 mg po per day Warning: Folate repletion without B12 repletion may normalize MCV and Hgb but allow neurologic manifestions to persist |
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Causes of folate deficiency?
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diet lacking fruits and vegetables
alcoholism Crohn's disease hemodialysis Increased cellular proliferation |
