Review Question - QID 104738

The labs and peripheral smear are consistent with microangiopathic hemolytic anemia, as would be seen with a prosthetic aortic valve.

Normocytic anemia with increased reticulocyte count, low haptoglobin, elevated LDH, and schistocytes on peripheral blood smear is consistent with microangiopathic hemolytic anemia. Potential etiologies include hemolytic uremic syndrome (HUS), disseminated intravascular coagulation (DIC), thrombotic thrombocytopenic purpura (TTP), malignant hypertension, and mechanical heart valves. In the case of mechanical heart valves, red blood cells are sheared on the valve, resulting in schistocytes (Figure A).

Figure A shows a peripheral blood smear. Note the schistocyte indicated by the arrow.

Incorrect Answers
Answer 1: Hemolysis with ingestion of fava beans is associated with glucose-6-phosphate dehydrogenase deficiency. Although labs would be similar, Heinz bodies, not schistocytes would be diagnostic on peripheral blood smear.
Answer 2: Following splenectomy, a patient would be more susceptible to infection with encapsulated bacteria, but not anemia. Howell-Jolly bodies would be seen on peripheral blood smear.
Answer 4: Clozapine is associated with agranulocytosis. One would expect to see pancytopenia with decreased reticulocyte count.
Answer 5: End-stage renal disease results in anemia when erythropoietin production falls. One would expect to see a decreased reticulocyte count.