A study on allele frequencies and mismatching proportion of HLA-A, B, Cw, DRB1 and DQB1 on high-resolution donor-recipient typing in Chinese Han population

Abstract

To analyze the allele frequencies and polymorphism of human leukocyte antigens (HLA) -A, B, Cw, DRB1 and DQB1 between donors-recipients on high-resolution typing; and to analyze the matching and mismatching proportion between donors and recipients. HLA high-resolution types were determined by sequence based typing (SBT), sequence specific oligonucleotide probe (SSOP) and sequence specific primer (SSP) on 2540 unrelated Chinese Han individuals including 1168 recipients and 1372 donors, then statistical analyses were carried out. Forty-four HLA-A alleles were detected, and among them the frequencies of A*1101, A*2402, A*0201, A*0207, A*3303, A*0206 and A*3001 exceeded 0.05, and accounted for 80.4%. Eighty-one HLA-B alleles were detected, and the frequencies of B*4001, B*4601, B*5801, B*1302 and B*5101 exceeded 0.05, and accounted for 43.0% of total. There were 44 HLA-Cw alleles, among them the frequencies of Cw*0702, Cw*0102, Cw*0304, Cw*0801, Cw*0602, Cw*0303, Cw*0302 and Cw*0401 exceeded 0.05, and were 80.3% of total. There were 61 HLA-DRB1 alleles, the frequencies of DRB1*0901, DRB1*1501, DRB1*1202, DRB1*0803, DRB1*0701, DRB1*0405, DRB1*0301 and DRB1*1101 exceeded 0.05, and were 70.1% of total. Finally, 22 HLA-DQB1 alleles were detected, the frequencies of DQB1*0301, DQB1*0303, DQB1*0601, DQB1*0602, DQB1*0202, DQB1*0302, DQB1*0401, DQB1*0502 and DQB1*0201 exceeded 0.05, and they were 87.4% of total. All the five loci were of heterozygote deficiency. The HLA-A, B and DRB1 loci conformed to Hardy-Weinberg equilibrium (HWE) (P > 0.05); but HLA-Cw and HLA-DQB1 loci did not (P < 0.05). Except several particular genotypes, all the five loci conformed to HWE. After comparing data between donors and recipients, only 22.4% of recipients found HLA matched donors (10/10); 24.6% of recipients found single HLA allele mismatched donors (9/10); 26.3% of recipients had two HLA alleles mismatched donors (8/10). The characteristics of allele frequencies and polymorphism of HLA-A, B, Cw, DRB1 and DQB1 on high-resolution typing in Chinese Han population is valuable for donor searching in unrelated hematopoietic stem cell transplantation, and it provides genetic basis for donor registry and usage of donor resource for Chinese Marrow Donor Program.