LBP02: AGE DEPENDENT HLA PROFILES IN A WORLD OF POPULATION MIGRATION: IMPACT ON HEMATOPOIETIC CELL DONOR RECRUITMENT AND AVAILABILITY

Aim International migration is a growing global trend. It is estimated that more than 232 million international migrants are living in the world today. The admixture of distant populations and the procreation of progeny of heterogeneous ethnic background may introduce significant challenges in establishing national donor registries that properly represent the patient population. Approximately 3 million people have immigrated to the state of Israel since it was founded, hence the Israeli population serves as an invaluable opportunity to investigate such processes. We hypothesized that the immunogenetic profile of the younger Israeli generation may consist of a genetic mixture of formerly distinct population groups. We aimed to investigate whether HLA profiles in the Israeli population are age dependent, and how this influences representation of various age groups in local donor registries. Methods We determined HLA A ∗ , B ∗ , DRB1 ∗ low resolution phenotypes of three age groups ( n  = 4169 in each): (1) Cord blood units collected between 2009 and 2013 (BABIES). Adult registry donors: (2) Aged 18–28 (YOUNG) and (3) aged 49–60 (OLD). We compared the results with virtual groups that simulate the offspring of the actual study groups. Results None of the three actual age groups was in Hardy–Weinberg Equilibrium. The YOUNG presented 4 HLA-B alleles that were absent in the OLD and BABIES. A significantly higher percentage among the OLD and BABIES had a ‘matched’ individual within their group in comparison to the YOUNG. In the YOUNG the 10 most common haplotypes account for 16.7% of the population, in comparison to 18.2% in the OLD or 19.8% in the BABIES group. The BABIES group was genetically remote from all other groups. Further disparities were found between the actual and the corresponding virtual groups. Conclusions We conclude that discrete age groups in Israel present distinct immunogenetic profiles, where the younger generation is more heterogeneous. The population dynamics of the age-dependent HLA profile is multifactorial: gradual inter-subgroup admixture, non-random mating and entry of new alleles. Age dependent immunogenetic considerations should be taken into account in long-term donor recruitment planning.