NK-KIR Gene Repertoire and Outcome of Patients with Acute MyeloidLeukemia after Allogeneic Hematopoietic Cell Transplantation from UnrelatedDonors

In this retrospective study, the influence of donor and recipient KIR-gene content and their respective ligands including clinical parameters as potential confounding variables on the outcome of 150 acute myeloid leukemia (AML) patients undergoing allogenic hematopoietic cell transplantation (HCT) from unrelated donors was systematically investi- gated. There was no significant influence of KIR ligand mismatching and of donor/recipient KIR haplotype combinations on overall survival (OS), disease free survival (DSF), non-relapse mortality (NRM) and relapse. Isolated effects of KIR haplotypes, were detected for acute, chronic Graft versus Host Disease (aGvHD and cGvHD) as well as for the cumula- tive incidence of non-relapse mortality and relapse. The incidence of non-relapse mortality was evaluated in donor and re- cipient pairs harbouring KIR AA homozygosity (AA/Bx: p=0.038, HR=0.73, 95% CI=0.35-1.46 and AA/AA: p=0.043, HR=0.64, 95% CI 0.53-1-17). Our data suggest that KIR genotyping may be useful in patients in whom several HLA- identical unrelated donors can be identified but is probably not necessary for the primary donor selection algorithm.