anemias

Question 1

How does 2,3-DPG change the hemobglobin-oxygen saturation curve?

Answer 1

increased 2,3-DPG shifts the hemoglobin-oxygen saturation curve to the right (decreased affinity btw hemoglobin and O2 at a given concentration)

Question 2

What are the main types of hemolytic anemias?

Answer 2

drug induced, G6PD deficiency, mechanical hemolysis, immune mediated, hereditary spherocytosis

Question 3

What is drug-induced hemolytic anemia? Which drugs are most frequently implicated? results of coombs test?

Answer 3

multiple mechanisms: bind to RBC membranes and cause oxidative destruction, induce production of antidrug antibodies, form immune complexes that can fix complement, or induce anti Rh antibodies

• may have schistocytes, burr cells
• direct coombs test + unless due to oxidative destruction
• penicillin, methyldopa, qunidine

Question 4

What are immune mediated hemolytic anemias? Treatment? results of coombs test?

Answer 4

cold agglutinin (IgM) that cause RBC agglutination or warm agglutinin (IgG). Both are direct coombs positive. Tx is steroids, avoid cold, possible splenectomy if refractory

Question 5

hereditary spherocytosis: pathology, test results, tx

Answer 5

genetic defect of RBC membranes leading to spherical RBCs. negative coombs test, hepatosplenomegaly common. tx: splenectomy

Question 6

G6PD deficiency: offending drugs/triggers, blood smear findings, coombs test

Answer 6

can’t repair oxidative damage to RBCs. oxidants trigger this condition: fava beans, high dose ASA, sulfa drugs, dapsone, qunine, quinidine, primaquine, nitrofurantoin
RBCs have bites taken out of them, Heinze bodies are visible
coombs negative

Question 7

What are physical signs and sx of iron deficiency anemia?

Answer 7

pica, spooning of nails in severe cases, angular cheilitis

Question 8

What toxins/ingestions can cause a microcytic anemia?

Answer 8

lead, alcoholism, isoniazid

Question 9

What are the lab findings of lead poisoning anemia?

Answer 9

normal or high iron, normal ferritin, normal TIBC, with basophilic stippled, microcytic RBCs on blood smear

Question 10

What is the treatment for lead poisoning anemia?

Answer 10

remove lead source, add EDTA or dimpercaptosuccinic acid (DMSA). dimercaprol in kids with severe intoxication often added

Question 11

What drugs can reduce folate levels and cause anemia?

Answer 11

methotrexate, trimethoprim, phenytoin

Question 12

What groups of people are most likely to have folate deficiency anemia?

Answer 12

elderly, alcoholics because of poor nutritional intake. folate deficiency develops much faster than B12 deficiency

Question 13

What infection can cause B12 deficiency?

Answer 13

diphyllobothrium latum (fish tapeworm)

Question 14

What is the schilling test?

Answer 14

performed for suspected vitamin B12 deficiency

1. administer oral radioactively labeled vit B12
2. normal labeled excretion suggests an etiology that is NOT pernicious anemia
3. If there is decreased labeled B12 excretion, repeat the test with the addition of intrinsic factor
4. if B12 excretion is normal when administered with intrinsic factor, the pt has pernicious anemia
5. If B12 excretion is still low when administered with intrinsic factor, B12 deficiency is due to intestinal malabsorption

Question 15

What are causes of aplastic anemia?

Answer 15

drugs like chloramphenicol, sulfonamides, phenytoin, chemo, toxins, radiation, viral infection, or congenital causes

Question 16

What is sideroblastic anemia and what are the causes of sideroblastic anemia?

Answer 16

• anemia due to defective heme synthesis that cuases decreased Hgb levels
• may be genetic or caused by EtOH, lead, or isoniazid

Question 17

How do you tell the difference between sideroblastic anemia and anemia of chronic disease?

Answer 17

sideroblastic anemia has high serum iron, whereas chronic disease and iron deficiency have low serum iron
sideroblastic due to genetics has high ferritin and low TIBC, just like chronic disease, where as lead poisoning may be normal TIBC and ferritin.

Question 18

What are the findings on peripheral smear of sideroblastic anemia?

Answer 18

multiple sizes of RBCS with normocytic, microcytic, and macrocytic RBCs possible. ringed sideroblasts in the bone marrow.

Question 19

How is sideroblastic anemia treated?

Answer 19

if hereditary, give B6 supplementation. If acquired, try EPO supplementation. for both, do phlebotomy and/or chelation with deferoxamine for iron overload.

Question 20

What is an important complication of sideroblastic anemia?

Answer 20

10% of pts progress to acute leukemia