Anemia Flashcards
Angina is a symptom of anemia particularly in whom?
CAD pts
What are the three lab values used in determining RBC mass?
- Hb
- HCT
- RBC count
Why aren’t Hb, HCT and RBC count perfect measures of anemia?
Can be diluted out (they’re concentration dependent)
What is the normal range of MCV?
80-100 fL
What is the direct cause of microcytosis? Why does this occur?
Extra division of progenitor RBCs in an attempt to maintain the same [Hb]
What is heme?
Fe and protoporphoryin
What are the four causes of microcytic anemia?
- Fe deficiency
- Anemia of chronic disease
- Sideroblastic anemia
- Thalassemia
What is the pathophysiology of sideroblastic anemia?
Decrease in the production of the porphoryn ring
What are the two forms of dietary Fe? Which is more readily absorbed?
heme and nonheme
Heme form is more readily absorbed
Where does Fe absorption take place in the GI tract?
Enterocytes of the duodenum
What is the protein that brings in Fe from the gut lumen?
DMT1
What is the protein channel on enterocytes that transports Fe into the blood, from the enterocyte?
Ferroportin
True or false: the body has no real way to excrete Fe
True
What is the regulated step in Fe absorption What is the molecule that regulates this?
Ferroportin
Hepcidin
What is the protein that transports Fe and delivers it to the liver and bone marrow macrophages?
Transferrin
What is the protein within cells that stores Fe? Why is this important?
Ferritin
Prevent ROS productino
What is serum Fe measuring?
Actual Fe ions in the blood, even if bound to transferritn
What is TIBC measuring?
Measures number of transferrin molecules (regardless of if they are bound or not)
What is % saturation measuring?
% of transferrin molecules bound by Fe
What does serum ferritin?
How much Fe is present in cells
What are the two common causes of adult Fe deficiency anemia? Infants?
- Peptic ulcer disease
- Menorrhagia
-Breast feeding in neonates / infants
What are the two hookworms that cause anemia?
- Ancylostoma duodenale
- Necator americanus
What form of Fe is absorbed? (Fe 2+ or Fe 3+)
Fe2+ goes into the body
What is the role of acid and Fe absorption? How does a gastrectomy affect this?
Maintains the Fe2 + state, which is more readily absorbed
Gastrectomy will cause a decrease in acid production
What are the four stages of Fe deficiency?
- Storage Fe depleted
- Serum Fe is depleted
- Normocytic anemia
- Microcytic, hypochromic anemia
What happens to serum ferritin as the storage Fe is depleted? TIBC?
Serum ferritin goes down
TIBC goes up
What happens to serum iron levels as serum fe is depleted? % saturation?
Both go down
What is koilonychia seen in Fe deficiency anemia?
Spoon-shaped nails
What happes to the color of RBCs in Fe deficiency anemia?
Hypochromic
What happens to RDW with Fe deficiency anemia? Why?
Increases
Because bone marrow still trying to produce normal RBCs, but is getting to the point where it no longer can d/t demand for oxygen
What does RDW measure?
The variance of RBC size. Thus a high RDW means there is a large variability between each RBC size
What happens to free erythrocyte protoporphyrin in the progression of Fe deficiency anemia? Why?
Increases since no Fe to bind to it.
What is the treatment for Fe deficiency anemia?
Treat underlying cause
Supplemental ferrous sulfate
What is Plummer-Vinson syndrome?
Fe deficiency anemia that causes esophageal webs, atrophic glossitis
What is anemia of chronic disease? What is the MOA of this?
Anemia associated with chronic inflammation or CA, causing increase in hepcidin
What is the role of hepcidin? (3)
- Locks Fe in storage sites
- Prevents uptake of Fe by ferroportin
- Suppresses EPO production
What happens to ferritin in anemia of chronic disease? Why?
Increases, since hepcidin prevent the release of Fe from storage
What happens to TIBC in anemia of chronic disease? Why?
Decreases since transferrin molecules goes down
What happens to serum Fe in anemia of chronic disease? Why?
Decreases since bone marrow takes up to produce RBCs
What happens to % saturation in anemia of chronic disease? Why?
Decreases since there is lower Fe to bind to ferritin
What happens to FEP in anemia of chronic disease? Why?
Increases since there is no Fe to bind to the porphyrins produced
What is the treatment for anemia of chronic disease? (2)
- Treat underlying cause
- Exogenous EPO
What is the enzyme that is involved in the rate limiting step of protoporphyrin production? What is the cofactor for this enzyme?
ALA synthase
Vit B6
What is the enzyme that converts ALA to PBG? What is the metal that inhibits this enzyme?
ALA dehydrogenase
Pb
What is the enzyme that adds Fe to the protoporphyrin ring? Where does this occur?
Ferrochelatase
In the mitochondria
What causes the ringed-sideroblasts seen in sideroblastic anemia?
Fe stored in mitochondria surrounding the nucleus
Ringed sideroblasts = what disease?
Sideroblastic anemia
What is the blue stain that is used to identify Fe in cells?
Prussian blue
Where does the Fe accumulate in sideroblastic anemia?
In mitochondria surrounding nucleus of cells
What is the most common cause of sideroblastic anemia?
Defect in the ALA-synthase enzyme
What are the three acquired causes of sideroblastic anemia?
- Alcoholism
- Pb poisoning
- Vit B6 deficiency
What are the two enzymes that Pb inhibits?
ALA dehydrogenase
Ferrochelatase
What is the drug that causes B6 deficiency, and thus inhibits ALA synthase, causing sideroblastic anemia?
Isoniazid
What happens to ferritin in sideroblastic anemia?
Increased
What happens to TIBC levels in sideroblastic anemia?
Decrease
What happens to Serum Fe in sideroblastic anemia?
increase
What happens to % saturation in sideroblastic anemia?
Increases
Sideroblastic anemia labs look identical to what disease?
Hemochromatosis
What is the pathophysiology of thalassemia? Is this a macro or microcytic anemia?
Decreased production of Hb chains
Microcytic