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31 Cards in this Set
- Front
- Back
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morphologic classification
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-indices from CBC
-microcytic-hypochromic, normochromic-normocytic, and macrocytic |
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pathophys classification
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resulting from dec RBCs or from increased destruction
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what is ferritin
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major iron storage protein in the body
-composed of a protein shell surrounding an iron core |
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what is hemosiderin
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ferritin that is broken down in secondary lysozomes
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what is transferrin
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major iron transporter in plasma and delivers iron to cells
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all circulating plasma iron normally is bound to transferrin. This chelation serves three purposes:
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it renders iron soluble under physiologic conditions, it prevents iron-mediated free radical toxicity, and it facilitates transport into cells.
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trasnferrin cycle
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apotransferring molecules binds 2 Fe3+
this complex binds to a transferrin-R on target cells complex is internalized into a vacuole that becomes acidified, released iron from apotransferrin which is then recylced to cell surface |
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trasnferrin saturation is measured using
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serum iron and transfrring level or TIBC
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iron transfer to intestine
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DMT1 absorbs Fe2+ from gut
once in enterocyte, iron can be stored by binding to ferratin OR exported across basolateral membrane for use in the body |
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what is ferroportin
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exports iron from intestine
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what is ferroxidase
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aka ceruloplasmin
oxidizes iron to Fe3+ for binding to transferrin |
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development of iron def anemia
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first: decrease of storage pool
second: storage pool is exhausted third: frank anemia |
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what is a sensitive indicator of iron deficiency if decreased
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serum ferritin is proportional to total ferritin
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stage one of iron def anemia
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serum ferritin levels will decrease
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stage two of iron def anemia
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storage pool is exhausted and transport compartment is affected
-dec serum ferratin -dec serum iron -dec % saturation -inc trasnferrin-R -inc free erythocyte protoporphyrin |
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stage 3 of iron def anemia
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-dec Hb
-dec Hct -dec MCV -dec MCH (microcytic hypochromic anemia) -inc RDW |
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what type of anemia is iron def anemia
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microcytic hypochromic
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def of folate or b12 results in
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imparied DNA synthesis
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microscopic findings in b12/folate def anemia
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megaloblastic
large macrocytes in PB |
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symptoms of b12/folate def anemia
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generic and related to anemia
-fatigue, pallor, dyspnea upon exertion, rapid pulse -gastritis, nausea, vomitting, glossitis -neuro symptoms (b12) |
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causes of b12/folate def anemia
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-dietary deficiency
-increased hematopoeitic needs (pregnancy) -impaired absorption (pernicious anemia) |
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altered metabolic pathways in b12/folate def anemia
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5,10-methylene TDF donates a methyl to dUMP to form dTMP which is necessary for DNA synthesis
b12 is required to make THF from 5-me-THF b12 acts as co-enzyme to methionine synthase, where methionine is made from homocysteine |
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lab dx of b12/folate def anemia
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CBC
-dec Hb -dec Hct -inc MCV -inc MCH -inc RDW -hypersegemented neutros -inc unconjugated plasma billirubin -inc plasma LD |
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pernicious anemia
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-type of vit b12 def
-defect: failure of the parietal cells to secrete instrinsic factor which is necessary for absorption of b12 in the ileum -90% >40yo |
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schilling test
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dx pernicious anemia
-oral dose of radioactive B12 -after 2hours: given IV or IM admin of non-radioactive cobalamin -non-radio will saturate the liver and and radio absorbed will be secreted in urine -if urine excretion is low, radioactive cobabalim was not absorbed -if after adding IF with radioactive cobalamin corrects the defect we know its an IF problem |
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anemia of chronic dz/inflammation:
found in what pts |
pts which IBD, malignancy, CT dz
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anemia of chronic dz/inflammation:
RBC charactersitics |
normocytic
(can be microcytic) |
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anemia of chronic dz/inflammation:
hallmarks |
-low serum iron
-low transferin -dec % transferring saturation -nL or high ferritin level |
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anemia of chronic dz/inflammation:
role of hepcidin |
hepcidin: controls most of iron homeostasis
-25 amino acid protein produced primarly by hepatocytes -levels are dec in response to inc serum iron and during iron overload syndromes and inflammation -binds directly to ferroportin and triggers its internalization, thus interrupting iron export from intestinal enterocytes and macs -inflamation: inc IL6 which binds IL6-R, which activates STAT3 which upregulates hepcidin transcription -iron is not efficiently recycles to erythroid precursors - thus anemia |
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hepcidin and HFE
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HFE protein regulates hepcidin gene transcription
-defective in hemochromatosis |
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anemia of chronic dz/inflammation:
levels of transferring and ferritin |
trans: dec
ferr: inc (compared to iron def anemia: trans: inc ferr: dec) |
