- Compare the incidence of graft-versus-host disease (GVHD) grades III and IV in patients with hematologic malignancies treated with bone marrow transplantation (BMT) using donors with 1 HLA-A or B non-cross-reactive group mismatch vs control patients previously treated with BMT using donors with 1 HLA-A or B cross-reactive group (CREG) mismatch.