Pathoma Anemia section Flashcards
What is the MCV for microcytic anemia
MCV less than 80
What is the MCV for normocytic anemia
MCV 80 - 100
What is the MCV for macrocytic anemia
greater than 100
What does MCV give you?
the size of the red blood cell
What causes microcytic anemia
low Hb
What is heme made of
iron and protoporphorin
Anemia of chronic disease
iron locked away in the macrophages due to an inflammatory state
- low iron
- low heme
Which anemia has a decrease in protophorin
sideroblastic anemia
- microcytic anemia
What is thalasemia
decreased production of globin chain = decreased Hb
- microcytic anemia
What are the 4 microcytic anemias
iron def., ACD, sideroblastic anemia, thalassemia
Where does absorption of iron occur
duodenum, enterocytes transport iron into blood via ferroportin
What is the role of ferroportin
key transporter that takes iron from the enterocyte and places it in the blood
What does transferrin do
binds iron and transports it to liver and bone marrow macrophages and then stored in the cell bound to ferritin
What is iron bound to when it is being stored?
ferritin
What do you measure if you want to measure how many transferrin is in the blood
TIBC
What would you use to calculate how much iron is present in the storage sites
serum ferritin
How does a gastrectomy lead to iron def. anemia
Fe2+ is more easily absorbed
- acid maintains the Fe2+ state and more readily absorbed
- losing part of the stomach = decreased acid = decreased iron in the 2+ state
What is the measure of storage iron?
ferritin
What happens when ferritin go down
TIBC goes up, which shows a decrease in transferrin
What are three features of iron deficiency
anemia, koilonychia (spoon shaped nails), pica (chew on abnormal things)
What is the RDW in iron deficiency anemia
increased RDW = increased spectrum of size of RBC size
What will the ferritin levels be in a patient with iron def. anemia
decreased ferritin
What is the treatment for iron def anemia
ferrous sulfate to replace the iron
Plummer-Vinson syndrome
iron def. anemia
- beefy red tongue
- anemia
- dysphagia
hepcidin
sequesters iron in storage sites, locks iron in
- heme is low, so it results in microcytic anemia
what will be the levels of ferritin in ACD
high ferritin, so you will have low TIBC (low number of transferrin in the blood)
What type of anemia is ACD
microcytic anemia but can also sometimes be normocytic
What is the treatment of ACD
exogenous EPO
What causes sideroblastic anemia
decreased protoporphyrin = microcytic anemia
What does ALA synthase catalyze
Succinyl Coa to ALA
What is the rate limiting step in the production of ALA
ALA synthase
What is a cofactor for ALA synthase
vitamin B6
What does ALA dehydrogenase catalyze
ALA to prophobilinigen
What is the role of ferrochelatase
catalyzes the reaction of protoporhyrin and iron to heme in the mitochondria
Where is the iron present in sideroblastic anemia
iron is trapped in the mitochondria
What is the most common cause of congenital sideroblastic anemia
defect in ALAS (rate limiting that catalyzes succinyl Coa to ALA enzyme)
What is the most common cause of acquired sideroblastic anemia
- alcoholism (mitochondrial poison, don’t make protoporhyrin)
- lead poisoning - denatures ALAD and ferochelatase
- Vitamin B6 (ALAS won’t function properly,)
What denatures and what happens if you have a defect in ALAD or ferrochetalase
ALAD - decrease protoporphyrin and it will get trapped in the mito
ferrochetelease - won’t make heme
What will the ferritin levels be in sideroblastic levels
high stores of iron in bone marrow macrophages and high levels of serum iron
- store all the iron from all the dead erythroid precursors
