Anemia and Hematopoietic GF Flashcards
the mcc of anemia is what?
insufficient supply of iron, vit b12 or folic acid - all 3 are necessary for production of RBC
what is the mc type of anemia?
microcytic hypochromic anemia caused by iron deficiency
what is the most common type of vitamin b12 anemia? what is the cause?
pernicious anemia; defect in synthesis of intrinsic factor - protein required for absorption of b12
what are the transport and storage proteins of iron respectively?
transferrin and ferritin
true or false: there is no mechanism for efficient excretion of iron, regulation of body iron.
true - this is why regulation of body iron occurs through modulation of intestinal absorption
remember, iron is taken up into the intestines as ferrous iron. what then happens to intestinal iron?
intestinal cell iron is either stored as ferritin or the ferrous iron is transported across the basolateral membrane by ferroportin and oxided to ferric iron by ferroxidase
true or false: minimal amounts of iron are lost from the body with sweat and saliva.
true
what is the only clinical administration for iron?
prevention or tx of iron deficiency anemia
what is the dietary supplement given to iron deficiency pts?
ferrous sulfate, ferrous gluconate or ferrous fumarate
what is special about iron dextran, sodium ferric gluconate complex and iron sucrose? (in terms of their preparation)
they are parenteral iron preparations
should you give iron in hemolytic anemia?
NEVER - b/c iron stores are ELEVATED and not depressed in this type of anemia
acute iron intoxication is most common in which demographic?
children; typically they ingest iron supplementation tablets by accident
what are some of the signs and sx of iron toxicity?
depending on the dose it can range from narcotizing gastroenteritis, shock, metabolic ACIDOSIS, coma and even death.
chronic iron overload is known as what?
hemochromatosis - remember that this state damages the organs that store excess iron (heart, liver and pancreas)
what are the two ways you can get hemochromatosis?
either via inherited abnormality of iron absorption or from frequent transfusions
what is the DOC that chelates iron that is used in treatment of acute iron intoxication?
deferoxamine
what is the treatment option for genetic form of hemochromatosis?
phlebotomy
what is the treatment for chronic iron toxicity that is NOT genetic?
deferoxamine OR the newer deferasirox which does the name thing.
true or false: impairment of synthesis of DNA is felt more with RBCs b/c they must be produced continuously?
TrUE - remember that vit b12 and folic acid are necessary in the transfer of 1-carbon units which is a necessary step in DNA synthesis
how is vit b12 produced?
by bacteria and CANNOT be synthesized by multicellular organisms; remember it is absorbed in the GI tract in the presence of intrinsic factor
true or false: vit b12 is stored in the liver in large amounts
true - two forms: cyanocobalamin and hydroxycobalamin (this last one has a longer half life)
vitamin b12 is essential in what two reactions?
conversion of methylmalonylcoenzyme A (CoA) to succinyl-CoA and also the conversion of homocysteine to methionine. the second reaction is linked to folic acid metabolism and synthesis of deoxythmidylate (dTMP).
