HLA—B27亚型及其与强直性脊柱炎关系的研究进展

强直性脊柱炎（AS）是与HLA关联最强的疾病。HLA－B27由22个以上同种异型基因型（亚型：B*2701-B*22)组成，不同亚型核苷酸序列之间只存在个别位点的差异，其亚型具有分布不同的种族和人种流行情况，以B＊2705分布最广。近年来建立了大量的AS动物模型，人类B27转基因鼠实验证实B27分布是AS的原发关联成分，这种带有B27等位基因的实验动物可发生类似人类AS疾病。目前倾向于关节源性肽假说来解释HLA－B27在AS发病中的作用。     

HLA-B27等位基因和亚型与强直性脊柱炎关系研究进展

大量的研究证明,强直性脊柱炎(AS)是与人类白细胞抗原(HLA)相关性最强的疾病。AS的发病与HLA-B27阳性密切相关,并与B7、B13、B40等几个等位基因有一定关系。HLA-B位点有42个等位基因,其中HLA-B27具有高度多态性,含有22个以上的亚型,不同亚型的碱基序列间只有个别差异。B27亚型在AS患者中的分布因地区和种族上的差别而不同,在中国主要以B2704和B2705为主,但以B2705分布最广。这几年大量的人B27转基因鼠实验证明AS与B27的关联性。     

HLA-B27亚型及其与强直性脊柱炎关系的研究进展

强直性脊柱炎(AS)是与mA关联最强的疾病.HLA-B27由22个以上同种异型基因型(亚型B*2701～B*22)组成,不同亚型核苷酸序列之间只存在个别位点的差异,其亚型具有分布不同的种族和人种流行情况,以B*2705分布最广.近年来建立了大量的AS动物模型,人类B27转基因鼠实验证实B27分子是AS的原发关联成分,这种带有B27等位基因的实验动物可发生类似人类AS疾病.目前倾向于以关节源性肽假说来解释HLA-B27在AS发病中的作用.     

西藏珞巴族HLA-A,-B基因多态性研究

目的调查西藏地区珞巴族群体HLA—A，—B基因的多态性。方法用聚合酶链反应-序列特异性寡核苷酸探针反向斑点杂交技术，对西藏林芝地区3代内无血缘关系的92个珞巴族健康个体进行了HLA—A，—B位点的基因分型。结果在HLA—A位点共检出10种等位基因，在HLA—B位点检出19种等位基因；在HLA—A位点高频等位基因是HLA—A*11、-A*02、-A*24，它们的频率分别为36．40％、25．50％、23．90％，这3种等位基因共占珞巴族可检出等位基因的85．80％。在HLA—B位点高频基因为HLA—B*40(频率为27．20％)、-B*15(11．40％)和-B*38(10．90％)，它们占等位基因的49．5％。结论珞巴族与其他各华人群体间都存在较大的差异，显示其HLA等位基因频率分布的民族独特性；但其HLA—A、—B等位基因多态性与藏族的很接近，这与民族学、历史学和社会学研究结果相一致。     

格林—巴利综合征HLA—A、—B基因关联的研究

目的：研究急性运动性轴索型神经病（AMAN）的易感性与HLA－A、－B等位基因分型的关系,探讨AMAN患者免疫遗传的特点。方法：用改良快速盐析法自研究对象静脉血中抽提基因组DNA,采用聚合酶链反应－顺序特异性引物法（PCR－SSP）对33例AMAN患者和132例健康人进行HLA－A、－B位点等位基因分型。结果：发现AMAN组HLA－B15、－B35频率升高,RR（relative risk）值分别为4．09和7．08。Pc分别为0．015和0．0008。结论：HLA－B15、－B35与AMAN的易感性可能有关联。     

HLA-B40组等位基因多态性和血清学分型不明确标本分析

目的：利用DNA分型技术调查上海汉族人群HLA－B40组等位基因多态性并比较配型标本中HLA－B40抗原血清学和DNA分型的结果：方法：采用反向PCR－SSOP技术进行DNA分型，可检出HLA－B＊4001－4011等11个等位基因，结果：所有标本DNA分型均获成功，无假阳性和假阴性结果出现，质控DNA分型结果与UCLA结果相符，上海地区汉族人群共检出B＊4001－4003，4005－4007，4011等等位基因，未检出B＊4004，4008－4010等等位基因，296名无关个体中HLA－B40＊组等位基因频率为0．1402，血清学方法检测HLA－B40组抗原错误率为12．82％（10／78），结论：该技术用于HLA－B40分型分辨率高，分型结果较血清学方法更加精确，可确保HLA分型的准确。     

关于不同HLA-B27基因亚型强直性脊柱炎患者合并心血管疾病风险的探讨

目的 比较不同HLA-B27基因亚型强直性脊柱炎(ankylosing spondylitis, AS)患者合并心血管疾病风险，进而为临床的个体化精准预防和治疗提供依据。方法 选取204例HLA-B27基因阳性AS患者(其中HLA-B2704型99例，HLA-B2705型90例，HLA-B2702型4例，杂合子型11例),以及97例健康体检者，利用Kruskal-Wallis H差异性分析不同基因亚型和健康组间超敏C反应蛋白(hs-CRP)、总胆固醇(TC)、三酰甘油(TG)、脂蛋白a(Lp(a))、载脂蛋白A1(ApoA1)、载脂蛋白B(ApoB)、高密度脂蛋白(HDL-C)、低密度脂蛋白(LDL-C)、同型半胱氨酸(Hcy)差异有无统计学意义。同时将所有HLA-B27基因阳性患者作为总体阳性组与健康对照组进行统计学分析，比较以上血清学指标差异有无统计学意义。结果 与健康对照组相比，总体阳性组hs-CRP、Hcy、ApoB水平明显较高，ApoA1h和HDL-C水平明显较低，差异有统计学意义(P<0.05);与健康对照组相比，HLA-B2704阳性组hs-CRP、ApoB、Hcy...     

HLA和强直性脊柱炎

强直性脊柱炎(ankylosing spondylitis)以下简称AS)是一种病因不明,主要侵犯骶髂关节和脊柱的炎症性疾病。临床上曾长期把AS划为类风湿关节炎的一个亚型,60年代以来,才认为AS是一种不同于类风湿关节炎的独立疾病。 1973年,Brewerton等和Schlosstein等发现AS患者中HLA-B27抗原(以下简称B27,其它HLA抗原也均略去HLA)频率显著高于正常人群。Schlosstein等同时发现类风湿关节炎患者中B27频率与正常人群无显著差别。这一发现进一步从遗传     

HLA-DQA1*0301及*0103与腔隙性脑梗死和原发性高血压的遗传易感性研究

目的：针对腔隙性脑梗死（lacunar stroke,LS）和原发性高血压（essential hypertension,EH)及多基因致病特点,进行HLA－DQA1位点的基因分型,分析其遗传易感性。方法：采用PCR－SSP方法对62例LS、52例EH和64例正常对照进行HLA－DQA1位点的基因分型。结果：①HLA－DQA1*0301等位基因与LS及EH呈显著正相关。②HLA－DQA1＊0103等位基因与LS及EH呈显著负相关。结论：HLA－DQA1*0301等位基因与LS及EH的发病有一定的关联,而HLA－DQA1＊0103等位基因可能是LS及EH的保护性基因。     

云南汉族人群HLA-B基因多态性与类风湿性关节炎的相关性研究

目的 探讨HLA-B基因多态性与类风湿性关节炎(rheumatoid arthritis,RA)的关联性.方法 采用DNA测序和序列特异性引物聚合酶链式反应(polymerase chain reaction-sequencespecific primer,PCR-SSP)方法检测云南汉族中271例类风湿性关节炎患者和264例正常人群的HLA-B基因多态性并进行关联性分析.结果 女性类风湿性关节炎患者的HLA-B*40基因频率(8.84％)明显低于女性对照组(18.33％)(P=0.000),HLA-B*51基因频率(9.53％)明显高于对照组(2.83％)(P=0.000),HLA-B*48基因频率(0.23％)明显低于对照组(2.33％)(P=0.007),差异均有统计学意义.HLA-B*40、HLA-B*51、HLA-B* 48的基因频率在男性类风湿性关节炎患者和男性对照中的分布无统计学差异(P值分别为0.535、0.691、0.289).结论 云南汉族人群中HLA-B基因分布存在多态性.HLA-B基因多态性与云南汉族人群女性类风湿性关节炎的发病相关,HLA-B*51可能是易感基因,HLA-B*40、HLA-B* 48可能是保护性等位基因.     

HLA-B27 polymorphism in patients with juvenile and adult-onset ankylosing spondylitis in Southern China

Abstract
Distribution of B27 subtypes in juvenile and adult-onset ankylosing spondylitis (JAS and AAS) in Southern China was studied. A total of 505 patients belonged to Han population were included (145 JAS and 360 AAS patients), and 1368 healthy individuals were included as controls. Human leukocyte antigen (HLA)-B27 typing was performed by Luminex liquid array combining polymerase chain reaction-sequence specific oligonucleotide probe (PCR-SSOP) and/or serological method. HLA-B27 subtyping was performed by polymerase chain reaction-sequence specific primer (PCR-SSP). The sequence-based typing was performed for the B*2715 samples to verify the PCR-SSP results. HLA-B27 was presented in 453 of 505 patients (89.7%), compared with 74 of 1368 controls (5.41%). B*2704 subtype in AS group was significantly higher than controls and B*2705 subtype significantly lower. B*2715 and B*2702 were found in 1.32% and 0.66% of the B27-positive patients but none in controls, and there was no significant difference between either of them and controls. B27-positive patients were 134 (92.4%) in JAS group and 319 (88.6%) in AAS group. There was no significant difference for B27 subtypes distribution between JAS (B*2704, 05, 15) and AAS (B*2704, 05, 15, 02) groups. The frequency of B*2715 in two groups was 3 (2.24%) and 3 (0.94%), respectively. The onset age of three JAS patients carrying B*2715 was 5, 9 and 13 years old, respectively. Our results suggested that B*2704 was the predominant subtype in AS patients in Southern China. B*2715 was observed in AS group only and slightly more in JAS than in AAS, and the patients carrying this allele tended to have early onset, B*2715 may be disease-association subtype.     

HLA-B27 in the Greek Cypriot population: distribution of subtypes in patients with ankylosing spondylitis and other HLA-B27-related diseases. The possible protective role of B*2707

The major purpose of the present study was to investigate the frequency of human leukocyte antigen (HLA)-B27 alleles in healthy controls and in patients with ankylosing spondylitis (AS) and other HLA-B27–related diseases in the Greek Cypriot population. We selected 102 HLA-B27–positive individuals (60 controls and 42 patients). Typing of the HLA-B27 alleles was performed by polymerase chain reaction amplification with sequence-specific primers. Only two alleles were detected in the patient group: B*2702 (n = 31, 73.8%) and B*2705 (n = 11, 26.2%). The HLA-B*2707 allele was detected (n = 10, 16.7%) only in the healthy controls in addition to the B*2702 (n = 31, 51.7%) and B*2705 (n = 19, 31.7%) alleles. Our results show a restricted number of HLA-B27 subtypes associated with AS and other B27-related diseases and an elevated frequency of the B*2702 allele in the AS patients. The allele B*2707 seems to have a protective role in the population studied because it was found only in the healthy controls.     

HLA-B27 polymorphism in Mumbai, Western India

Human leucocyte antigen (HLA)-B27 encompasses an increasing number of subtypes that show diverse racial/ethnic prevalence in the world. One thousand-one-hundred and seventy unrelated individuals from Mumbai, Maharashtra, Western India were typed for HLA-B27 antigen by serological methods. HLA-B27 positivity was confirmed by polymerase chain reaction using sequence specific primers. High-resolution typing using sequence specific primers for HLA-B27 alleles (B*2701 - B*2721) was carried out in 70 HLA-B27-positive individuals. The frequency of B27 ranged between 1.48 and 9.6% among the caste groups studied. HLA-B27 subtyping identified B*2702 (1.43%), B*2704 (14.29%), B*2705 (70%), B*2707 (12.86%) and B*2718 (1.43%), respectively. The findings illustrate substantial genetic variation and heterogeneity within population groups from India. Extensive subtyping in other Indian caste groups will be necessary to resolve the evolutionary implications of HLA-B27 subtypes and their relationship to disease association in the Indian context.     

HLA-B*27 subtypes in Northern and Northeastern Thais, Karens, and Bamars determined by a high-resolution PCR-SSP technique

Human leukocyte antigens (HLA), class I, are a group of antigens expressed on most nucleated cell surfaces. They transport endogenous peptides to the cell surface for recognition by T-cell receptors. Their functions are involved in immune responses. Many diseases are associated with HLA alleles, especially HLA-B*27 that is strongly associated with ankylosing spondylitis (AS). HLA-B*27 consists of 42 subtypes. Different subtypes of HLA-B*27 were reported in different ethnic groups of AS patients. In this study, a high-resolution polymerase chain reaction–sequence-specific primer technique has been developed to define all the HLA-B*27 subtypes with a total of 29 primer mixtures. Two of the primer mixes were used to detect the HLA-B*27 -specific group, and 27 primer mixes were used to identify 42 subtypes ( B*2701–B*2721 and B*2723–B*27 43). The HLA-B*27 -group-specific primers have been tested in unrelated healthy subjects; 846 Northeastern Thais (NET), 334 Northern Thais (NT), 264 Karens, and 310 Bamars. Sixty-three NET (phenotype frequency, PF = 7.4%), 24 NT (PF = 7.1%), 5 Karens (PF = 1.8%), and 12 Bamars (PF = 3.9%) were positive for HLA-B*27 . Only B*2704 was found in Karens, whereas B*2704 , B*2705/37/39 , B*2706 , and B*2707 were found in NET and NT. In Bamars, B*2704 , B*2705/37/39 , B*2706 , and B*2725 were found. The distribution of HLA-B*27 subtypes was compared with other studies in Asian and Caucasian populations. Significant differences of the distribution of HLA-B*27 subtypes were found in most of the populations. This study established a simple technology for HLA-B*27 subtyping and provided basic information for anthropology and further studies in disease associations.     

Lack of carboxyl–terminal tyrosine distinguishes the B2706–bound peptide repertoire from those of B2704 and other HLA–B27 subtypes associated with ankylosing spondylitis

B*2704 and B*2706 are two closely related HLA-B27 subtypes, which differ from the common B*2705 by the Asp>Ser77, Val>Glu152, and Ala>Gly211 amino acid changes. In addition, B*2706 differs from B*2704 by the His>Asp114 and Asp>Tyrl 16 changes. In spite of their similarity B*2704, but not B*2706, was associated to ankylosing spondylitis in a same population. We have carried out pool sequence analyses of the peptides naturally bound to each of these subtypes, and of several individual peptide ligands. B*2704 and B*2706 shared with B*2705, among other features, their selectivity for Arg² and their allowance for some aliphatic and aromatic C-terminal residues in their bound peptides. The main features that distinguished both subtypes from B*2705 were: 1) their failure to present peptides with C-terminal basic residues, and 2) their allowance for both polar and nonpolar residues at peptide position 3. A major difference between B*2704 and B*2706 was that C-terminal Tyr was prominent among the peptides bound to B*2704, but was not detected among those from B*2706. The use of Tyr as a C-terminal anchor motif is the only functional feature shared by the disease-associated B*2705, B*2702, and B*2704 subtypes that is absent in B*2706. This suggests that the ability of HLA-B27 to present peptides with C-terminal Tyr might be critical for its association to spondyloarthropathy,     

HLA-B27 and ankylosing spondylitis: tales from China

Abstract
The two most frequent HLA-B27 subtypes worldwide are B*2704 and B*2705. In the Han population of China B*2704 and, to a lower extent, B*2705 are found with significant frequency, and both are associated to ankylosing spondylitis (AS). Two articles in this issue report that the association to AS in this ethnic group is stronger for B*2704 than for B*2705. Thus, at least among the Han, B*2704 would be the strongest known susceptibility factor for AS.     

Diversity of human leukocyte antigen-B27 alleles in Han population of Hunan province, southern China

This study was to investigate the frequency of HLA-B27 and its subtypes in the Han population of Hunan province, southern China. One hundred and sixty-nine healthy unrelated donors were tested for HLA-B27 by polymerase chain reaction-sequence-specific primer (PCR-SSP). One hundred and twenty-eight B27-positive spondyloarthropathy patients and 18 B27-positive healthy controls were subtyped using the high-resolution PCR-SSP. The phenotype frequency of human leukocyte antigen (HLA)-B27 was found to be 2.36% in healthy population. Five B27 alleles were identified: B*2704, B*2705, B*2706, B*2707, and B*2724. No significant difference was found in the distribution of HLA-B27 subtypes between the patients and controls studied. Notably, B*2724 was observed in a juvenile patient with ankylosing spondylitis. This subtype has not been previously reported in Chinese ankylosing spondylitis (AS) patients and other ethnic groups.     

B*2707 differs in peptide specificity from B*2705 and B*2704 as much as from HLA-B27 subtypes not associated to spondyloarthritis

HLA-B*2707 is associated with ankylosing spondylitis in most populations. Like the non-associated allotypes B*2706 and B*2709, it lacks Asp116 and shows preference for peptides with nonpolar C-terminal residues. The relationships between the peptide specificity of B*2707 and those of the disease-associated B*2705 and the non-associated subtypes were analyzed by determining the overlap between the corresponding peptide repertoires, the sequence of shared and differential ligands, and by comparing allospecific T cell epitopes with peptide sharing. The B*2707-bound repertoire was as different from that of B*2705 as from those of B*2706, B*2709, or the two latter subtypes from each other. Differences between B*2707 and B*2705 were based on their C-terminal residue specificity and a subtle modulation at other positions. Differential usage of secondary anchor residues explained the disparity between the B*2707-, B*2706-, and B*2709-bound repertoires. Similar differences in residue usage were found between B*2707 and both B*2704 and B*2706, as expected from the high peptide overlap between the two latter subtypes. T cell cross-reaction paralleled peptide sharing, suggesting that many shared ligands conserve their alloantigenic features on distinct subtypes. Our results indicate that association of HLA-B27 subtypes with ankylosing spondylitis does not correlate with higher peptide sharing among disease-associated subtypes or with obvious peptide motifs.     

HLA-B27 polymorphism in the Malays

The frequency of HLA-B27 and its subtypes was determined in 878 Malay subjects. Thirty-five of the subjects typed for HLA-A, -B and -DR were found to be positive for HLA-B27. The frequency of this allele in the Malay population was found to be 3.99%. The subtypes observed and their frequencies are: HLA-B*2704 (19.4%), HLA-B*2705 (5.6%), HLA-B*2706 (72.2%) and HLA-B*2707 (2.8%).     

Discrimination of HLA-B27 alleles by group-specific amplification followed by solid-phase sequencing

HLA-B27 is known to be highly associated with ankylosing spondylitis. Until now, nine B27 subtypes have been sequenced and may contribute in different fashions to ankylosing spondylitis. Additionally, the divergent subtypes may be of clinical importance in bone marrow transplantation with alternative donors. The purpose of this study was to determine the different subtypes of HLA-B27 by a direct sequencing approach. The typing strategy is based on a group-specific amplification of the second and third exon followed by automated fluorescence sequencing of the polymorphic regions. The extensive sharing of sequence motifs between the different B alleles made it impossible to specifically amplify the B27 group under the precondition of including all sequence variations necessary for a postamplification specificity step. Therefore, for setting up a direct sequencing approach of B27, co-amplified B alleles had to be taken into account. In order to get unambiguous sequencing chromatograms without any heterozygous positions, nested sequencing primers were used which selectively matched sequence motifs only present in the second and third exon of the amplified B27 alleles. This strategy allowed in all cases investigated a clear separation of the haplotypes, revealing unequivocal sequencing results. Using this method, we have investigated 93 B27-positive individuals. Sequencing identified the alleles B*2702, 2703, 2704, 2705, and 2707. B*2701, 2706, 2708, and 2709 were not represented in the population studied.