Acute intravascular hemolysis secondary to out-of-group platelet transfusion

BACKGROUND: Acute intravascular hemolysis is rarely associated with platele t transfusion. Out-of-group single-donor platelets may cause hemolysis if t he donor has high-titer ABO hemagglutinins. CASE REPORT: A 44-year-old woman, blood group A, was recently diagnosed wit h acute myeloid leukemia and was receiving chemotherapy. After the transfus ion of apheresis platelets from a group O donor, back pain, hemoglobinuria, and hemoglobinemia developed, and her Hb dropped by 2.3 g per dL, despite the transfusion of 2 units of RBCs. RESULTS: Investigation revealed acute intravascular hemolysis with a positi ve DAT due to anti-A(1) on her RBCs. The donor's titer of anti-A(1) was gre ater than 16,000. CONCLUSION: Review of published cases raises the possibility that hemolytic reactions to out-of-group platelets may be more frequent since the use of apheresis platelets has increased.