HLA-DR-matched parental donors for allogeneic hematopoietic stem cell transplantation in patients with high-risk acute leukemia.

The immunomodulating effect of human leukocyte antigen (HLA)-DR and the central role of CD4 T cells in alloimmunity provide clues suggesting that HLA-DR-matched, partially mismatched related donors could be feasible alternative donors of allogeneic hematopoietic stem cells for transplantations (allo-HSCT). We describe our experience with allo-HSCT in eight patients with high-risk acute leukemia; donors included one of each of the parents. Among the eight patients, seven were identical HLA-DR matches with the donors. The stem cells were not manipulated in vitro. Graft-versus-host disease (GVHD) prophylaxis consisted of antithymocyte globulin, cyclosporine, and methotrexate. All patients had successful trilineage engraftment. Only one patient had grade 2-4 acute GVHD. Two patients died before day +100 due to complications. At the end of follow-up, four patients had survived for 18-48 months and three are alive and without relapse. Our results suggest that HLA-DR fully-matched parents are feasible alternative donors for allo-HSCT in patients with high-risk acute leukemia under an intensive conditioning regimen.