Five days after a red cell transfusion, a patient has an unexplained fall in hemoglobin, an increased bilirubin, and a newly positive direct antiglobulin test with anti-IgG. What is the most likely diagnosis?
1Acute hemolytic transfusion reaction
2Febrile nonhemolytic transfusion reaction
3Transfusion-associated circulatory overload
4Delayed hemolytic transfusion reaction✓ 정답
해설
Timing is decisive. Hemolysis appearing several days after transfusion, rather than during or immediately after it, reflects a secondary immune response with an anamnestic rise in antibody. This is a delayed hemolytic transfusion reaction; an acute hemolytic reaction presents during or right after the transfusion.