Analysis on polymorphism of high-resolution HLA-A, -B, -C, -DRB1 and -DQB1 in hematopoietic stem cells donors of Chinese Han population from Southern China

Objective To explore the human leukocyte antigen (HLA)-A, -B, -C, -DRB1 and -DQB1 high-resolution alleles polymorphism in hematopoietic stem cells donors of Chinese Han population from Southern China. Methods A total of 4 262 cases hematopoietic stem cell donors of chinese Han population in Shenzhen China Marrow Donor Program (CMDP) from January 2016 to December 2017 were selected as subjects. HLA-A, -B, -C, -DRB1 and -DQB1 loci for high resolution typing of these 4 262 cases hematopoietic stem cell donors were detected by PCR-sequence-specific oligonucleotide probes (SSO) and next-generation sequencing (NGS) analysis. The frequencies of common, well-documented and rare alleles were studied by direct counting method. The χ2 test was used to determine whether the distribution of HLA-A, -B, -C, -DRB1 and -DQB1 alleles of these 4 262 cases hematopoietic stem cell donors accorded with the Hardy-Weinberg equilibrium. Results ① Compared observed values of HLA-A, -B, -C, -DRB1 and -DQB1 alleles in these 4 262 cases hematopoietic stem cell donors of Chinese Han population from Southern China with the expected values, there were not statistically significance (χ2=295.068, 572.482, 355.205, 362.584, 312.150; P>0.05), which indicated that the distribution of HLA-A, -B, -C, -DRB1 and -DQB1 alleles of all hematopoietic stem cell donors in this study conformed with Hardy-Weinberg equilibrium. ② The alleles of HLA-A, -B, -C, -DRB1 and -DQB1 loci in 4 262 cases hematopoietic stem cells donors of Chinese Han population from Southern China were 49, 97, 37, 48 and 22, respectively. Among them, the common alleles with frequencies higher than 0.05 included HLA-A*11∶01, 24∶02, 02∶07, 02∶01, 33∶03 and 02∶03; HLA-B*40∶01, 46∶01, 58∶01, 13∶01 and 51∶01; HLA-C*01∶02, 07∶02, 03∶04, 08∶01, 03∶02, 06∶02 and 03∶03; HLA-DRB1*09∶01, 15∶01, 12∶02, 07∶01, 08∶03, 03∶01, 11∶01 and 04∶05; and HLA-DQB1*03∶01, 03∶03, 06∶01, 05∶02, 03∶02, 02∶01, 05∶03, 06∶02 and 02∶02. For each of the locus, the cumulative allele frequencies of common alleles were 0.767 1, 0.471 6, 0.782 5, 0.656 4 and 0.877 6, respectively. ③ The well-documented and rare alleles of HLA-A, -B, -C, -DRB1 and -DQB1 loci were detected as 22, 42, 14, 11 and 7. Among them, the rare alleles of HLA-A*29∶03; HLA-B*18∶04, 15∶296 and 54∶03; HLA-C*12∶12; HLA-DRB1*04∶101 and HLA-DQB1*02∶10 were not included in the Common Alleles and Well-Documented Alleles (CWD) v2.3 of CMDP. Conclusions Relatively complete high-resolution allelic distribution data of HLA-A, -B, -C -DRB1 and -DQB1 loci in hematopoietic stem cells donors of Chinese Han population from Southern China were obtained in this study. And HLA well-documented and rare alleles were recorded. The results of this study contribute to the accumulation on population distribution and polymorphism data of HLA gene in hematopoietic stem cell donors, and provide reference for improving CWD of CMDP. Key words: HLA antigens; Alleles; Gene frequency; Polymerase chain reaction; High resolution genotyping; Common alleles; Well-documented alleles; Rare alleles; Polymerase chain reaction-sequence-specific oligonudeotide; Next-generation sequencing