Bone marrow transplantation from donors other than HLA matched siblings for hematological malignancies. Nagoya Bone Marrow Transplantation Group and Tokai Marrow Donor Bank

One hundred and fourteen patients with hematological malignancies received bone marrow transplantation from donors other than HLA-identical siblings. Sixty-three patients received transplantations from related donors; 20 were phenotypically identical for HLA-A, B, D/DR (RM0). 32 differed at one locus (RM1) and 11 differed at more than one loci (RM2). Fifty-one transplantations were from unrelated donors; 37 were phenotypically identical and mixed lymphocyte culture (MLC) negative (UR0) and 14 were MLC positive (UR1). One hundred and four patients had durable engraftment. Four (RM1(1), RM2(2), UR0(1)) failed to achieve engraftment. In terms of the probability of > or = Grade II acute graft-versus-host disease (GVHD), there was no significant difference among the groups according to HLA disparity (RM0:25%, UR0:33%, UR1:39%, RM1:47%, and RM2:50%). The probability of chronic GVHD was significantly higher in UR0 and UR1 than RM0 (71%, 75% vs 28%, p < 0.05). The disease-free survival at 3 years was 45% (RM0), 50% (RM1) and 42% (UR0). More than 50% of patients other than RM0 died of fatal complications including GVHD within 60 days after grafting. In conclusion, unrelated donor and related donor mismatched at one locus could be selected for marrow graft in the case of the absence of an HLA-matched related donor. However, more advances in post-transplant management and in histocompatibility testing should be required.