HLA-A,B,DRB1 Alleles Polymorphism In Hans From Shandong Province Of China

HLA(Human Leukocyte Antigen) is encoded by the major histocompatibility complex(MHC) of human. HLA gene is the most complicated polymorphic human genetic system which locates on the short arm of chromosome 6(6p21.3). HLA differs in ethnic distribution, which may be the results of genetic and geographic origin. HLA compatibility between donor and recipient is the most critical immunological factor of unrelated bone marrow transplantation(BMT). HLA matching before transplantation is very complicated. It involves at least three high polymorphic loci , HLA-A, -B and -DRB1,which encodes more than 500 alleles. Previously, HLA typing was based on a serological technique named microlymphocytotoxicity test and there was about 25% error rate in the method. The sample size of previous studies on HLA polymorphism in China was small. In this study, PCR-SSP(polymerase chain reaction-sequence specific primers) was used to determine HLA-A,B,DRB1 alleles of 7418 unrelated healthy Han volunteer donors from Shandong Hematopoietic Stem Cell Data Bank of China. The polymorphism and the geographic characters of the three loci were studied. 18 HLA-A, 44HLA-B and 13 HLA-DRB1 low resolution alleles including some rare HLA alleles that had not been reported in China were discovered in this study . We also achieved a clear distribution result of some alleles whose distribution in China was unclear previously. In Hans population of Shandong Province , the most prevalent HLA type was A*02, B*13 and DRB1*15, with gene frequency of 0.2883, 0.1431 and 0.1762 respectively. The most common two-locus HLA-A-B haplotype was found to be A*30-B*13, with a strong statistical significance ( x ~2=3347), a haplotype frequency of 0.0896 and a delta value of 0.0743. The most common three-locus HLA-A-B-DRB1haplotype was A*3O-B*13-DRB1*O7. In comparison with other previously published data of other race and Chinese, significant differences were found in different ethnic population and area groups.This study was supported by the Youth foundation of Shandong Health Department. The HLA data were transmitted into Chinese hematopoietic Stem Cell Data Bank. The gene frequency of HLA-A,B,DRB1 m Shandong Province had its own genetic characters. Our study provides a more comprehensive and more accurate data on HLA gene polymorphism for potential hematopoietic stem cell recipients to find more optimal donors so as to decrease graft-versus-host disease(GVHD). The result may be of great significance in studies on population genetics, vaccine design and disease association. It is also helpful in estimating the number of samples in studies of disease association.