Identifying NK Alloreactive Donors for Haploidentical Hematopoietic Stem Cell Transplantation.

NK cell alloreactivity mediated by donor NK cells is a fundamental therapeutic tool in HLA haplotype mismatched hematopoietic transplantation in adult acute myeloid leukemia and pediatric acute lymphoblastic leukemias. NK cell is mediated by donor NK cells recovering very early after transplant. The self donor KIR ligands educates the donor NK repertoire and arms functional NK cells which express inhibitory killer cell immunoglobulin-like receptor(s) (KIRs) for self-class I ligand(s), They sense missing expression of donor KIR ligand(s) in the recipient and mediate alloreactivity. Donor-versus-recipient NK cell alloreactivity is evaluated by KIR genotyping and phenotyping and functional assay.