Retransplantation of human bone marrow. Two immunosuppressive drug regimens

A 15-year-old boy with aplastic anemia was successfully retransplanted with matched sibling bone marrow after failure of a first transplant from the same donor. Cyclophosphamide was used as immunosuppression for the first transplant, and cyclophosphamide plus procarbazine plus antithymocyte globulin were used for the second transplant. Laboratory studies of peripheral blood and bone marrow karyotypes and T and B lymphocytes supported the conclusion that immunosuppression was inadequate for the first transplant, but adequate for the second transplant.