Bone marrow transplantation for severe aplastic anemia. Effect of a preparative regimen of cyclophosphamide-low-dose total-lymphoid irradiation and posttransplant cyclosporine-methotrexate therapy.

Twenty-nine patients with severe aplastic anemia were entered into a study of pre- and posttransplant immunosuppressive therapy for bone marrow transplantation. Four of twenty-five previously transfused recipients prepared with cyclophosphamide 200 mg/kg and total-lymphoid irradiation 3 Gy experienced graft failure, indicating that this regimen was inadequate to ensure sustained engraftment. Posttransplant treatment with cyclosporine and methotrexate resulted in an actuarial incidence for grade greater than or equal to 2 graft-versus-host disease of 22 +/- 16%. Actuarial survival was 78 +/- 15%. These data indicate that more effective treatment is necessary to prevent graft failure, but since many patients can be successfully retransplanted, overall survival is comparable to other recent studies.