Macrocytic Anemia Flashcards
Elevated homocysteine present in
B12 deficiency
B12 converts:
homocysteine –> methionine (methyl donor)
Elevated methylmalonic acid
B12 deficiency
B12 converts
methylmalonic acid –> succinyl-CoA
How does B12 travel through GI system
bound to R-binder until jejunum
pancreatic enzymes cleave it off of R-binder
then binds to IF from parietal cells
absorbed w/ IF
Neurologic Sx seen in this deficiency
B12
severe combined degeneration of spinal cord
Schilling test is used to Dx
B12 deficiency
Autoimmune destruction of parietal cells results in this condition
pernicious anemia
Megaloblastic vs non-megaloblastic macrocytic anemia
macrocytic just means MCV > 100
megaloblastic means all the rapidly dividing cells in the body are large
Infection with what organism can cause B12 deficiency
Diphyllobothrium latum
Megaloblastic anemia
blood smear results
RBC macrocytosis
hypersegmented (>5 lobes) neutrophils
B12 participated in which 2 reactions
homocysteine –> methionine (methyl donor)
methylmalonic acid –> succinyl-CoA
How does pancreatic insufficiency cause megaloblastic anemia
pancreatic enzymes normally free B12 from R-binder in jejunum
if it stays bound then B12 just goes out with the feces
B12 deficiency
PE finding in megaloblastic anemia
glossitis
