The use of partially matched, unrelated donors in clinical bone marrow transplantation.

It is estimated that 60-70% of patients who might benefit from a bone marrow transplant will not have a suitably matched, related donor. We have, therefore, designed a clinical experiment to test the safety and feasibility of using marrow from partially matched, unrelated donors. This paper details our transplant experience in the first eight patients with leukemia. The first four patients had advanced leukemia at the time of transplantation. Each showed hematopoietic recovery, but all died from septic complications largely related to extended neutropenia encompassing both the pre-marrow-grafting and the post-marrow-grafting period. The next four patients were in remission at the time of transplantation. Each showed prompt and sustained hematopoiesis with variable graft-versus-host disease (GVHD). No acute or chronic GVHD was seen in two patients, grade II (skin only) was seen in one patient, and grade IV (skin, liver, and gut) was seen in one patient. One patient has died from sepsis five-and-one-half months following transplantation, and three are alive and well six-and-one-half to nine-and-one-half months postengraftment. This preliminary experience, together with several case reports in the literature, leads us to conclude that bone marrow transplantation with partially matched, unrelated marrow is a safe and feasible approach. If these results are confirmed by longer follow-up in a larger group of patients, the development of marrow donor pools would appear to be justified.