11755名中国北方汉族造血干细胞供者HLA-A、B、DRB1基因和单倍型研究

为了研究中国北方汉族造血干细胞供者的人类白细胞抗原（HLA）-A,B,DRB1等位基因、HLA单倍型频率及其连锁不平衡特征,采用PCR-SSP和PCR-SSO流式微磁珠检测方法对中华骨髓库陕西分库内11755名中国北方汉族骨髓供者进行HLA基因低分辨分型,并根据HLA表型群体资料,运用基于最大数学预期值算法（Expectation-Maximization,EM）的计算机软件Arleguin计算HLA单倍型频率。结果表明：11755例样本符合Hardy-Weinberg平衡检验,共检出HLA-A、B、DRB1等位基因（按分解抗原统计）分别为18、42、15种,包括很少在汉族人群中检测到的HLA-A25、B42、B53、B73和DR3,未发现HLA-A36,A43,A80,B78,B82和DR18等6种特异性。HLA-A＊02,A＊11,A＊24,A＊33,A＊30,A＊01,A＊03,A＊13,B62,B＊51,B＊46,B60,B61,B＊35,B＊44,DRB1＊15,DRB1＊09,DRB1＊04,DRB1＊07,DRB1＊12,DRB1＊11,DRB1＊14,DRB1＊08,DRB1＊13的频率〉0.05。EM法计算求得频率〉10-6的HLA-A-B-DR单倍型共计2026种,其中HLA-A30-B13-DR7、A2-B46-DR9、A33-B58-DR17等26种单倍型频率〉0.005,A30-B13-DR7是中国北方汉族最常见单倍型。计算求得的HLA-A-B、A-DR、B-DR单倍型共计538、227、522种,频率〉10-6者分别有409、195、423种,其中A30-B13,A2-B46,A33-B58等28种单倍型频率〉0.01;A2-DR9,A2-DR15,A30-DR7等26种单倍型频率〉0.01;B13-DR7,B46-DR9,B13-DR12等24种单倍型频率〉0.01。具有统计学意义（P〈0.05）的连锁不平衡HLA-A-B、A-DR和B-DR单倍型分别有296种（72%）、130种（67%）和308种（73%）,其中A30-B13、A33-B58、A1-B37、A30-DR7、A33-DR13、A1-DR10、B37-DR10、B8-DR17、B13-DR7、B58-DR17等单倍型表现为显著的正连锁不平衡。结论：本研究使用EM算法获得了目前中国北方汉族样本量最大的HLA-A/B/DRB1等位基因多态性、单倍型频率分布及连锁不平衡的特征,这将有助于临床为患者寻找合适供者,为移植免疫、HLA与疾病相关性及本地区群体遗传学等方面的研究提供了重要依据。

Gene and Haplotype Frequencies for the Loci HLA-A, B and DRB1 in 11755 North Chinese Han Bone Marrow Registry Donors

The study was aimed to investigate the human leukocyte antigen (HLA)-A, B, DRB1 alleles and haplotype frequencies and the characteristics of linkage disequilibrium in north Chinese Han bone marrow donors. HLA phenotype data of 11 755 north Chinese Han bone marrow donors were identified by PCR-SSP and PCR-SSO. HLA-A, B, DRB1 allele and haplotype frequencies were calculated by computer software named Arleguin which was based on Expectation-Maximization (EM) algorithms. The results showed that the population of 11755 unrelated-donors was tested by Hardy-Weinberg equilibrium, and 18,42 and 15 specificities of HLA alleles were identified on the HLA-A, B, DRB1 locus respectively, including HLA-A25, B42, B53, B73 and DR3 which were rarely reported in Han population. HLA-A36, A43, A80, B78, B82 and DR18 were not detected in this study. The most frequent alleles with a frequency of over 0.05 were HLA-A*02, A*11, A*24, A*33, A*30, A*01, A*03, A*13, B62, B*51, B*46, B60, B61, B*35, B*44, DRB1*15, DRB1*09, DRB1*04, DRB1*07, DRB1*12, DRB1*11, DRB1*14, DRB1*08, DRB1*13. There were a total of 2 026 kinds of HLA-A-B-DR haplotypes (with a frequency of over 10(-6)) to be obtained. The each frequency of 26 kinds of three-locus haplotypes including HLA-A30-B13-DR7, A2-B46-DR9, A33-B58-DR17 etc was higher than 0.005. A30-B13-DR7 was the most frequent haplotype in north Chinese Han population. There were a total of 538 kinds of haplotypes for HLA-A-B, 227 kinds for A-DR and 522 kinds for B-DR to be obtained, and there were 409, 195, 423 kinds of haplotypes respectively with a frequency higher than 10 - 6. There were 28 kinds of HLA-A-B haplotypes including A30-B13, A2-B46, A33-B58 etc, 26 kinds of HLA-A-DR haplotypes including A2-DR9, A2-DR15, A30-DR7 etc, and 24 kinds of HLA-B-DR haplotypes including B13-DR7, B46-DR9, B13-DR12 etc with a frequency higher than 0.01. 296 (72%) kinds of HLA-A-B, 130 (67%) kinds of A-DR and 308 (73%) kinds of B-DR haplotypes were statistical linkage disequilibrium. HLA-A30-B13, A33-B58, A1-B37, A30-DR7, A33-DR13, A1-DR10, B37-DR10, B8-DR17, B13-DR7, B58-DR17 were significant positive linkage disequilibrium. It is concluded that this HLA-A, B, DRB1 gene and haplotype frequencies and linkage disequilibrium data with the largest sample size up to now is unique in north Chinese Han population. The study will be helpful to find matched donors for patients and establish the important foundation for further studying of transplantation immunity, HLA-related diseases and population genetics of this area.