KIR-Genotype Mismatch, Donor KIR Locus 3DS1 Positive or 2DS3 Negative Facilitates a Positive Outcome of Allogeneic Hematopoietic Stem Cell Transplantation: A Single-Center Retrospective Study of 74 Patients

Objection: To investigate the potential influence of donor-recipient KIR genotype matching and KIR alleles on the prognosis of allogeneic hematopoietic stem cell transplantation (allo-HSCT).

Method:74 cases of AML patients who admitted and treated in the transplantation ward of our hospital from May 2015 to May 2019 were analyzed retrospectively. Binary Logistic regression and k-m survival curve were used to demonstrate the influence of donor age, blood group ABO compatibility, donor-recipient HLA matching, donor-recipient KIR mismatch model and donor KIR gene locus on the transplant outcome.

Result:Among the 74 patients with AML, 44 were male (59.5%) and 30 female (40.5%), with the median age of 24 years (1-59 years). 49 cases (66.2%) were in remission at the time of transplantation, and 25 (33.8%) not in remission. aGVHD occurred in 16 patients (21.6%) and recurrence occurred in 11 patients (14.9%). Multivariate analysis revealed that KIR-genotype matching was closely related to the increased risk of aGVHD. The incidence of aGVHD in the KIR mismatching group was significantly lower than that in the matching group (12% vs 31%, P=0.019), but no significant effects on survival and recurrence. Donor KIR 3DS1 negative had an increased risk of aGVHD compared with those with 3DS1 positive (28.2% vs 11.7%, P=0.033). The recurrence rate (RR) of donor KIR 2DS3 negative, even when the recipients with hematologic malignancies were not in remission at the time of HSCT, were much lower than those with 2DS3 positive (10% vs 66.7%, P=0.045). However, donor age, blood group ABO compatibility, donor-recipient HLA matching, and other donor KIR locus had no significant effect on OS, aGVHD and RR.

Conclusion: Thus, it is recommended to select the donor with KIR mismatching, KIR locus 3DS1 positive or 2DS3 negative to improve the outcome of allo-HSCT by reducing the risk of aGVHD or recurrence risk, which offer a clinically applicable donor selection strategy.