Genetics by genetic algorithm: Defining an ideal platelet donor population to support patients with HLA‐mediated alloimmune refractoriness

Background Immune factors underlie approximately 20% of patients exhibiting platelet transfusion refractoriness (PTR). PTR can be mitigated by supplying HLA‐A and B compatible platelets to these patients. Since 2019, Canadian Blood Services has managed a program to provide compatible platelets to alloimmunized patients. This study evaluates donor pool size and ethnic diversity options to serve Canada's population. Study Design and Methods We adapted simulation‐based stem cell matching methods by generating simulated patients and matching them to existing and simulated donors using a Python algorithm. Recruitment scenarios included census‐aligned, single‐group, and meta‐heuristic–optimized distributions to enhance match rates and equity. Results More typed donors increase match rates, but rates vary significantly by ethnicity. Non‐Black patients achieved 95% coverage with 13,000–18,000 new donors, whereas Black patients required ~55,000 new donors. Single‐ethnicity recruitment improved the targeted group's rate but reduced overall match rates and disadvantaged other populations. A Pareto‐optimal donor mix—augmenting Black, Hispanic, Asian Pacific Islander, and Native American/First Nations donors while modestly reducing White typing—preserved or improved rates but yielded only modest gains for Black patients. A balanced strategy further prioritizing Black and Hispanic donors with slight reductions in White, Asian, and Native American/First Nations typing achieved improvements for the Black population with minimal losses for others. Discussion While Pareto‐optimal allocation enhances overall efficiency, targeted trade‐offs, focusing on underrepresented groups, are essential to correct persistent disparities and achieve equitable HLA‐matched platelet availability.