Modeling unrelated blood stem cell donor recruitment using simulated registrant cohorts: Assessment of human leukocyte antigen matching across ethnicity groups.

Continued large recruitment cohorts are needed to add new 8/8 HLA matches to registry inventories. Likelihoods of novel HLA matches varied across ethnic groups, reflecting varied HLA haplotype frequencies across groups. Simulated cohort modeling can inform recruitment strategies that will generate new donor options for patients.