Practice questions answers Anemia IV
Practice questions answers
Anemia IV
© Jun Wang, MD, PhD
Abbreviations:
Hb: hemoglobin |
HCT: hematocrit |
MCV: Mean Corpuscular Volume |
MCH: Mean Corpuscular Hemoglobin |
RDW: Red Cell Distribution Width |
TIBC: total iron binding capacity |
1. E. This is a case of anemia with history of bleeding. Her lab results
show microcytic anemia with elevated RDW. Peripheral blood smear reveals
enlarged central pallor area, consistent with hypochromic anemia. One of the most
cause in such a setting is iron
deficiency anemia. Bone marrow biopsy
is useful in specific diagnosis of many anemia, especially hematopoietic stem
cell abnormalities, such as aplastic
anemia and myeloid
neoplasms. Direct antiglobulin test can identify antibodies/complement
bound directly to RBCs, usually positive for immune
hemolytic anemia. Hemoglobin analysis by electrophoresis of HPLC is very helpful
in diagnosing hemoglobin abnormalities, including thalassemia,
sickle
cell anemia, HbC
and HbE. Eosin-5-maleimide binding assay and osmotic fragility test is used to
diagnose hereditary
spherocytosis.
2. D. Her iron tests reveal low ferritin, an indicator of iron storage,
and low serum iron levels. These are consistent with iron
deficiency anemia, that will have elevated TIBC. Reduce haptoglobin and
elevated bilirubin are indicating for hemolysis,
when the patients have jaundice, schistocytes or spherocytes. Hepcidin usually
suppress iron metabolism and are elevated in cases of iron overloading, or
chronic inflammation. Its level is reduced in iron
deficiency anemia, when transferrin saturation is reduced.
3. E. The clinical presence and lab iron studies are consistent
with the diagnosis of iron
deficiency anemia, that bone marrow iron storage is commonly reduced or
depleted. Erythroid precursor with iron particles
surrounding nuclei, or ring sideroblasts, are seen in sideroblastic
anemia. Hypocellular bone marrow with focal fibrosis
is commonly associated with aplastic
anemia. Isolated erythroid hyperplasia with
nuclear atypia is a sign of myeloid
neoplasms. Myeloid precursors with hypersegmented nuclei are seen in megaloblastic
anemia, commonly associated with folate and/or
VB12 deficiency.
4. E.
Reduced heme synthesis is seen in iron
deficiency anemia, since iron is a part of heme. Acute
hemorrhage usually cause normocytic normochromic anemia. Delayed division
of hematopoietic precursors is seen in megaloblastic
anemia, commonly associated with folate and/or
VB12 deficiency. Erythroid stem cell defects is seen in various types of aplastic
anemia. Red cell membrane instability is seen
in hereditary
spherocytosis.
5. C. Chronic bleeding is a common cause of
iron
deficiency anemia. This patient does have history of heavy bleeding. Other
options do not have supportive clinical history.
6. B.
See discussion of question 2. Alpha
thalassemia carrier usually has normal Hb levels. Lead
associated anemia usually neurological presentations, RBCs with basophilic
stippling, and normal to elevated ferritin. Megaloblastic
anemia has higher MCV. Sickle
cell anemia has sickle cells.
7. D. Iron supplementation is needed for
patients with iron
deficiency anemia. Bone marrow molecular
test for clonal proliferation is used for myeloid
neoplasms. Colonoscopy exam and endometrial biopsy are useful to rule out
underlying causes of iron
deficiency anemia in older patients. Vitamin
B12 supplementation is used for megaloblastic
anemia associated with VB12 deficiency.
8. B. See discussion of questions 1, 6 and
7. Renal function panel is used to diagnose renal
failure, that may be associated with anemia
of chronic disease, a normocytic anemia. Serum lead test is used to confirm
lead
poisoning, a cause of microcytic anemia.
9. A. This is a case of microcytic anemia
with high serum ferritin, commonly seen in sideroblastic
anemia. Bone marrow biopsy with iron studies may estimate the presence of
ring sideroblasts, and evaluate the possibility of myeloid
neoplasms. Also see discussion of questions 1, 7 and 8.
10. A. The image reveals a few ring sideroblasts,
consistent with sideroblastic
anemia. The cause of sideroblastic
anemia include excessive alcohol use, lead
poisoning, myeloid
neoplasms, etc. This patient has history of heavy alcohol use, and is most
likely to be the cause of his anemia. Hemoglobin abnormalities, including thalassemia,
sickle
cell anemia, HbC
and HbE, have red cell changes, such as sickle cell, rhomboidal crystals,
or target cells. Iron
deficiency anemia has low serum ferritin and transferrin saturation. Vitamin
B12 deficiency is associated with megaloblastic
anemia.
11. D. The cause of abnormal intracellular
iron deposit in sideroblastic
anemia is defects in iron utilization during heme synthesis. Other conditions
will neither cause iron overload in erythroid, nor seen in sideroblastic
anemia.
12. E. See discussion of questions 9 and 10.
13. E. This case is characterized by
macrocytic anemia with hypersegmented neutrophils, consistent with megaloblastic
anemia, commonly associated with folate and/or
VB12 deficiency. Also see discussion of questions 1 and 8.
14. Megaloblastic
anemia is commonly associated with folate and/or
VB12 deficiency and usually has elevated homocysteine. Hepcidin level is
associated with iron
metabolism, but not VB12 or folate deficiencies. Indirect bilirubin is increased
when there is hemolysis.
Iron level is high in sideroblastic
anemia. Lead level is elevated in lead
poisoning, usually has microcytic anemia. TIBC is elevated in iron
deficiency anemia but not megaloblastic
anemia.
15. A. Folate and VB12 are needed for DNA
synthesis. Deficiency of both or either will cause DNA synthesis defect and
delayed cell division in megaloblastic
anemia, characterized by macrocytic anemia with hypersegmented granulocytes.
Hemoglobin abnormalities, including thalassemia,
sickle
cell anemia, HbC
and HbE, have red cell changes, such as sickle cell, rhomboidal crystals,
or target cells, but not hypersegmented granulocytes. Inhibition
of δ-aminolevulinate dehydratase is seen in lead
poisoning, usually has microcytic anemia. Iron
deficiency causes iron
deficiency anemia, a microcytic anemia. Red
cell membrane instability cause spherocytic appearance, characterized by loss
of central pallor area, as seen in hereditary
spherocytosis.
16. A. Absorption of VB12 needs intrinsic
factor produced by parietal cells. This patient has a history of autoimmune
gastritis, when the parietal cells are destroyed by autoantibodies. The
patient does not have history for other options.
17. D. See discussion of questions 13 and
15. Pernicious anemia is a type of megaloblastic
anemia due to VB12 deficiency, associated with autoimmune
gastritis. Hereditary
spherocytosis has RBCs with spherocytic
appearance, characterized by loss of central pallor area.
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