[Rapid onset of hemolytic anemia after allogeneic bone marrow transplantation from an unrelated ABO major mismatched donor].

A 46-year-old woman with chronic myelogenous leukemia received allogeneic bone marrow transplantation from an unrelated human leukocyte antigen (HLA) matched (but mixed lymphocyte culture (MLC) positive to graft-versus host disease (GvHD) donor. The blood type of the recipient was A type Rh (+) while the donor blood type was B type Rh (+). The patient received busulfan 8 mg/kg, cyclophosphamide 120 mg/kg, and total-body irradiation 10 Gy before bone marrow transplantation. Short-term administration of methotrexate and cyclosporin was given for prophylaxis of GvHD. The mononuclear cells harvested from the donor were concentrated by COBE Spectra before bone marrow transplantation. Although engraftment of transplanted bone marrow in the recipient was confirmed on day 11, the patient suffered from severe anemia on day 10. Since the direct Coombs' test to A type red blood cells was positive, and anti-A antibody titer increased 16-fold, we diagnosed her anemia as hemolytic anemia caused by ABO mismatched transplantation. In addition to hemolytic anemia, she had skin symptoms of acute GvHD grade II, microangiopathic hemolytic anemia, and died of multiple organ failure on day 44. This experience indicated that some allogeneic transplant recipients are at risk of severe hemolytic anemia in the early stage after unrelated ABO mismatched donor and that it is necessary to establish proper treatment and prophylaxis.