Treatment of leukemia with partially matched related bone marrow transplantation.

The results of partially matched related donor (PMRD) marrow transplantation for 82 patients with leukemia are reported, including 45 who received two antigen disparate grafts. Following intensive radiochemotherapy, patients received grafts which were partially depleted of T cells by the monoclonal antibody T10B9 and complement. Actuarial probability of engraftment was 86% (95% CI = 78-93%). The median day to engraftment was similar among recipients of grafts disparate at one, two or three antigen loci. The incidence of severe (grades III and IV) acute graft-versus-host disease and extensive chronic graft-versus-host disease was 13% and 6%, respectively. The probability of disease-free survival for the entire cohort of patients is 31% at 3 years. Age < or = 30 years, early or intermediate stage disease and a graft disparate at one or two loci predicted longer disease-free survival in multivariant analysis. Moreover, 47% of patients receiving PMRD grafts disparate at two loci who had both these favorable pretransplant characteristics were alive and free of disease 3 years after transplantation. We believe that the utilization of PMRDs, especially those with two antigen disparate grafts, can extend allogeneic transplantation to additional leukemic patients lacking a histocompatible donor, with acceptable results.