Major histocompatibility complex genetic variants in potential hematopoietic stem cells donors in Republic of Kazakhstan

Aim. To compare the prevalence of HLA-system antigens genetic variants in potential hematopoietic stem cells donors in Kazakhstan and worldwide.

Methods. Prevalence of HLA-antigens genetic variants in blood samples of potential hematopoietic stem cells donors included in hematopoietic stem cells donors register of Kazakhstan was analyzed and compared to a «Allele frequencies in Worldwide populations» database developed by the Royal Liverpool University Hospital.

Results. The biggest overlap of Kazakhstan and World registers was seen in the distribution of 31-01 allele: 68 (4.5%) in Kazakhstan register, 1678 (4.63%) worldwide; odds ratio (OR) = 0.97 (0.76 to 1.24), F=0.851441, χ2=0.06. The biggest difference between the two registers was found in the distribution of locus A antigens: A 02-01 (χ2=24.59), A 02-07 (χ2=24.42), A 32-01 (χ2=27.1), A 02-37 (χ2=23.96), A 11-38 (χ2=3.96). In locus B alleles, the biggest overlap between the two comparison groups was in В 14:02 allele: Kazakhstan register - 31 (2.05%), worldwide register - 757 (2.01%) [OR=1.02 (0.71 to 1.47), F=0.851990, χ2=0.01], followed by 38:02 (χ2=0.02), 44:05 (χ2=0.03), in 27:07 (χ2=0.04), 54:01 (χ2=0.07). The biggest difference between the two registers was in 13:02 (χ2=256.9), 08:01 (χ2=26.92) locus B alleles. Distribution of locus C alleles was discovered to have the biggest statistical similarity of two registers provided by C 07:01 (χ2=0.07), 08:02 (χ2=0.15), 15:02 (χ2=0.23) 12:03 (χ2=0.76). The biggest difference in the distribution of locus C alleles between the two registers was in 06:02 (χ2=125.78) and C 03:02 (χ2=103.64).

Conclusion. The overlap of HLA-antigens genetic variants distribution in Kazakhstan and global registers varies from 41 to 52% by loci (locus A - 50%, B - 52%, C - 48%, DRB1 - 51%, DQB1 - 41%, mean 48.4%, median 50%). Kazakhstan register contains information on unique HLA-antigens genetic variants not included in the general database, manifesting the need for national register development and its integration into the «Allele frequencies in Worldwide populations» register.