Effects of donor killer-cell immunoglobulin-like receptor genotypes on clinical outcome after allogeneic hematopoietic stem cell transplantation-a systematic review and meta-analysis.

PURPOSED: Natural Killer cell kinetics and Killer-cell immunoglobulin-like receptors (KIRs) are increasingly recognized for their role during allogeneic hematopoietic stem cell transplantation (allo-HSCT), but the prognostic impact of donor KIR haplotype configurations on patient survival remains controversial. To clarify this relationship, we conducted a systematic review and meta-analysis evaluating the impact of donor KIR haplotypes on the survival of patients undergoing allo-HSCT.

METHODS

We systematically searched PubMed, Embase, the Cochrane Library, and CBM. Data were analyzed using RevMan5.4. Pooled hazard ratio (HR) for time-to-event data. Subgroup analyses were performed for sample size, area, donor type, T cell replete or deplete, GVHD prophylaxis, and lymphoid or myeloid.

RESULTS

17 eligible studies were included, and meta-analysis showed that donor KIR B/X genotype is associated with significantly superior overall survival (HR = 0.68, 95%CI, 0.56-0.82; P<0.0001), reduced relapse incidence (HR = 0.61, 95%CI, 0.44-0.85; P = 0.003), and improved relapse-free survival (HR = 0.61, 95%CI, 0.46-0.81; P = 0.0008).

DISCUSSION: The findings suggest that donor KIR B/X haplotype is associated with favorable survival outcomes in allo-HSCT including HLA-matched sibling, unrelated donor, and haploidentical transplantation, supporting its potential utility as a reference biomarker for donor selection.