Coagulation Disorders USMLE Step 1 Practice Question
A 43-year-old man with chemotherapy-induced thrombocytopenia receives a platelet transfusion. Thirty minutes later, he develops fever (38.9°C), chills, and malaise. Vital signs show HR 108/min, BP 128/82 mmHg, RR 18/min, SpO2 98% on room air. Physical examination reveals no rash, no dyspnea, and urinalysis shows no hemoglobinuria. WBC differential demonstrates left shift. He takes no prophylactic antibiotics. Which of the following is the most likely explanation for this transfusion reaction?
Answer choices
- AIgE-mediated reaction to donor IgA
- BRecipient antibodies reacting against donor leukocytes or cytokines in the blood productCorrect answer
- CRecipient anti-ABO antibodies causing complement activation
- DDelayed anti-Rh antibody formation
- EPulmonary capillary leak due to donor anti-HLA antibodies
- FBacterial contamination of the transfused platelet product causing septic transfusion reaction
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