Transient thrombocytopenia after incompatible red blood transfusion in an infant girl with autoimmune hemolytic anemia.

We report on 5-month-old girl with severe autoimmune hemolytic anemia (hemoglobin 2.9 g/dl, positive direct Coombs test) in whom thrombocytopenia developed after red blood cell transfusion. The platelet count was 62.1 x 10(4)/mm3 on admission and rapidly fell to 6.0 x 10(4)/mm3 rapidly after transfusion of incompatible red blood cells with intravenous predonisolone administration. No increased hemolysis or alloimmunization was observed after transfusion. The platelet count and hemoglobin levels gradually improved over 8 weeks with corticosteroid therapy. We suspect that the thrombocytopenia in our patient was transfusion-induced.