Hematopoiesis and its impairments Flashcards
What can excess dietary Zinc cause?
Microcytic anemia…. Serum oxidase to convert Fe2+ –> Fe3+ is copper dependent and excess zinc cause inhibit copper uptake
What cofactor is necessary for Iron absorption
Vitamin C (Ascorbate)
What is the Iron serum transport protein?
Transferrin
What is the glycoprotein hormone that causes erythrocyte differentiation?
Erythropoieten (Epo)
What stimulates Epo production?
Hypoxia
Where is Epo produced?
Renal peritubular cells
What 2 cytokines stimulate Jak-2 activity upon binding to their respective receptors?
Epo and Tpo
Constitutive activation of the Jak-2 kinases can cause what?
Hematologic malignancy, blood clots
What happens after ligand binds the Jak-2 kinases?
They move closer in proximity, phosphorylate/activate each other, and initiate downstream kinase cascades
What precursor cell does a platelet come from?
Megakaryocyte
What glycoprotein hormone stimulates thrombopoiesis?
Thrombopoietin (Tpo)
What happens when Tpo binds to a megakaryocyte?
It stimulates production of megakaryocytes from immature precursors and megakaryocyte differentiation into platelets
What is stored Iron bound to and where is it stored?
Ferritin in macrophages in the spleen, liver, and bone marrow
What chromosome is the beta globin locus on?
Chromosome 11
What causes megaloblastic anemia?
Folate and B12 deficiency
How does B12 deficiency contribute to neurologic defects?
It is needed to convert homocysteine to Methionine. Methionine is needed to make myelin (This is what is thought to occur, Pathomas says something different, so there is disagreement)
What can be elevated in the serum with B12 deficiency?
Methyl malonate
What are the main 2 functions of Hepcidin?
Impairs release of Iron from storage and impairs Iron uptake
Why is it important to not have unbound serum Iron?
Because it would aid bacterial proliferation and catalyze the formation of reactive oxygen species
What would you measure if you were concerned someone had an abnormal amount of storage Iron?
Serum Ferritin level
What happens in anemia of chronic inflammation?
Transferrin is pulled out of circulation. Ferritin will go up. This is all mediated by Hepcidin secretion
What cytokine stimulates Hepcidin production in anemia of chronic inflammation?
IL-6
What is Anisocytosis?
variation in size of erythrocytes; due to severe Iron deficiency
What is Poikilocytosis?
variation in shape of erythrocytes; due to severe Iron deficiency
What do both anisocytosis and poikilocytosis indicate?
severe Iron deficiency
4 lab findings indicating Iron Deficiency Anemia?
- decreased ferritin
- increased TIBC
- decreased serum iron (Fe)
- decreased % saturation (of transferrin)
