title: Reduction of Relapse after Unrelated Donor Stem Cell Transplantation by KIR-Based Graft Selection.
abstract: Besides donor T cells, natural killer (NK) cells are considered to have a major role in preventing relapse after allogeneic hematopoietic stem cell transplantation (HSCT). After T-cell-depleted haploidentical HSCT, a strong NK alloreactivity has been described. These effects have been attributed to killer-cell immunoglobulin-like receptors (KIR). Abundant reports suggest a major role of KIR not only on outcome after haploidentical HSCT but also in the unrelated donor setting. In this review, we give a brief overview of the mechanism of NK cell activation, nomenclature of KIR haplotypes, human leukocyte antigen (HLA) groups, and distinct models for prediction of NK cell alloreactivity. It can be concluded that KIR-ligand mismatch seems to provoke adverse effects in unrelated donor HSCT with reduced overall survival and increased risk for high-grade acute graft-versus-host disease. The presence of activating KIR, as seen in KIR haplotype B, as well as the patient's HLA C1/x haplotype might reduce relapse in myeloid malignancies.
authors.affiliation: Department of Stem Cell Transplantation, University Medical Center Hamburg-Eppendorf , Hamburg , Germany.
authors.forename: Silke
authors.initials: S
authors.lastname: Heidenreich
authors.affiliation: Department of Stem Cell Transplantation, University Medical Center Hamburg-Eppendorf , Hamburg , Germany.
authors.forename: Nicolaus
authors.initials: N
authors.lastname: Kröger
keywords: HSCT; NK-cell; haplotype; killer-cell immunoglobulin-like receptor; stem cell; transplantation; unrelated