Interrogating the impact of KIR ligand mismatch in engraftment following HLA-disparate stem cell transplantation.

The effects of donor-derived natural killer (NK) cell alloreactivity on disease relapse and transplant-related mortality following allogeneic stem cell transplantation have been described while the impact of recipient-derived NK cell alloreactivity on donor engraftment is not well known. Epitopes of HLA Class I molecules act as ligands for NK cell killer immunoglobulin-like receptors (KIR) regulating their cytotoxicity. As such, NK cell alloreactivity is predictable from KIR ligand mismatches between donors and recipients.