Improved survival of acute lymphoblastic leukemia patients of HLA-A3/11 absent for donor KIR3DL2 after non-T-cell depleted HLA-identical sibling hematopoietic stem cells transplantation

A potential factor influencing hematopoietic stem cells transplantation (HSCT) outcome is the presence of donor-derived alloreactive natural killer (NK) cells. This retrospective analysis studied the impact of NK alloreactivity based on the missing KIR ligand, for acute myeloid leukemia (AML) or acute lymphoblastic leukemia (ALL) patients undergoing non-T-cell depleted HLA-identical sibling HSCT. A total of 78 patients were studied, including 40 patients with AML and 38 patients with ALL. Nearly, all patients were received a uniform myeloablative conditioning regimen and prophylaxis for GVHD. All were genotyped for KIR genes and HLA ligands by means of polymerase chain reaction-sequence specific primers (PCR-SSP). Missing KIR ligand without HLA-A3/11 had no effect on disease-free survival (DFS), overall survival (OS), or relapse in patients receiving transplants for AML or ALL. In patients with ALL, however, there was a significant missing KIR ligand with HLA-A3/11 effect on DFS (P=0.04) and OS (P=0.02). These data indicate that the absence of HLA class I ligand in the recipient for donor-inhibitory KIR can be a prognostic factor for transplantation outcomes in non-T-cell depleted HLA-identical sibling hematopoietic stem-cell transplantation and that the lack of HLA-A3/11 for donor KIR3DL2 can contribute to improved survival for patients with ALL.