Association of HPA Genotypes w ith Platelet Apheresis Donation Frequency and Yield Among Chinese Donors: A Cross-Sectional Study.

BACKGROUND

Human platelet antigens (HPA) are clinically significant in transfusion refractoriness, but whether HPA genotypes are associated with cumulative donation frequency or apheresis yield remains unknown.

METHODS

We genotyped 1,242 platelet apheresis donors from Harbin, China for eight HPA systems (HPA-1, -2, -3, -4, -5, -6, -15, and -21). Outcomes were cumulative donation count and index yield (0.5/1/2 units). Univariate analyses used Kruskal-Wallis and Mann-Whitney tests. Multivariable negative binomial and binary logistic regressions adjusted for age, sex, ABO, and ethnicity. Sensitivity analyses excluded first-time donors, stratified by age, and removed the top 5% of donors.

RESULTS

HPA-3 and HPA-15 were the most polymorphic (b-allele frequencies: 42.0% and 44.5%). However, neither HPA-3 nor HPA-15 was significantly associated with cumulative donation count in multivariable negative binomial regression (HPA-15 ab vs aa+bb: IRR=1.02, 95% CI: 0.90-1.15, P=0.79; HPA-3 b carrier vs aa: IRR=0.97, 95% CI: 0.85-1.10, P=0.66). Similarly, no significant association was found between HPA-15 b carrier status and apheresis yield (OR=0.97, 95% CI: 0.76-1.25, P=0.83). These null findings remained consistent across all sensitivity analyses.

CONCLUSION

In this cohort of northern Chinese Han platelet apheresis donors, HPA genotypes-including the polymorphic HPA-3 and HPA-15 systems-were not significantly associated with donation frequency or apheresis yield.