MEGALOBLASTIC ANEMIA Flashcards
DNA synthesis is ineffective in what vitamin deficiencies?
B12 and/or folate (B9) deficiency
ineffective DNA synthesis results in? what is the effect on RNA synthesis and cytoplasmic maturation
abnormal enlargement of cells due to delayed mitosis
normal
hematopoietic cells in bone marrow have large carrying nuclei relative to their true stage in maturation
nuclear-cytoplasmic asynchronicity
these appear large in blood smear, MCV>100, macrocytic cells
RBC precursors
these appear in bone marrow may be enlarged
hypersegmentation
granulocyte precursors
this vitamin is found in nearly all raw food
heat labile, green leafy sources, absorbed in duodenum and jejunum
folate (vit B9)
this vitamin is produced by bacterial and present in all animal foods
resistant to cooking, 2-5 years reserved stored in liver, malabsorption is the most common cause of deficiency, pernicious anemia results from inadequate production, function or binding of intrinsic factor (IF)
cobalamin (vit B12)
causes of B12 deficiency?
clinical picture?
autoimmune
mechanical
other like gastric atrophy
anemia with jaundice
atrophy of mucosal surfaces
neurological effects caused by demyelination; subacute combined degeneration
what is the main diagnosis of megaloblastic anemia?
macrocytic
excluding other causes like alcoholism, liver disease
folate and B12 levels
test used to measure B12 deficiency?
steps
schilling test, oral administration of radioactive B12
administer B12
add IF
add antibiotics
add pancreatic enzymes
what is the result of decreased stem cell production?
renal failure
- decreased production of erythropoietin
- normochromic, normocytic anemia
- treat with recombinant EPO
aplastic anemia
this is the result of decreased stem cell production, suppression of pluripotent hematopoietic stem cells
what results?
aplastic anemia, can be idiopathic too
pancytopenic
pure red cell aplasia
