MCQ Hematology 21

You are asked to see a 25-year-old white man who experienced marked weakness and dyspnea 4 days after being admitted for a compound arm fracture after falling from a tree. Estimated blood loss from the initial fracture episode was 600 mL, and the patient was transfused with one unit of packed erythrocytes. The initial crossmatch was reported as compatible by the transfusion service. The patient has never been transfused before this incident and has no other serious medical illnesses.

The patient's arm fracture was treated with surgical pinning and prophylactic antibiotics consisting of cefotetan 2 g IV every 12 hours. On examination, the patient is febrile and mildly tachycardic, with no evidence of wound infection or compartment syndrome. Laboratory data show a hematocrit of 15%, absolute reticulocyte count of 600,000 μL, and total bilirubin of 70 umol/L with direct bilirubin of 9 umol/L. The peripheral smear shows many spherocytes. No hemoglobinemia or hemoglobinuria is seen on visual inspection of the plasma and urine.

The transfusion service reports that the direct Coombs' test is now strongly positive using anti-IgG and only weakly positive with anti-C3d antisera. They further report that routine compatibility tests show no new erythrocyte antibodies in the patient's serum and that, when they attempted to elute antibody from the patient's RBCs and test against normal RBCs, the results were negative. What is the most likely diagnosis?

A. Hemolytic transfusion reaction caused by an ABO incompatibility
B. Delayed hemolytic transfusion reaction
C. Autoimmune hemolytic anemia of warm antibody type
D. Autoimmune hemolytic anemia of cold antibody type
E. Drug-induced immune hemolytic anemia

Answer

Tags: MCQ, Hematology, Hemolytic Anemia,

Category: Hematology MCQs