Positive association of DRB1*04 and DRB1*15 alleles with Fya immunization in a Southern European population

BACKGROUND: Anti-Fy^a has been implicated in hemolytic transfusion reactions. However, not all Fy(a−) patients develop anti-Fy^a after transfusion with 1 unit of blood [Fy(a+)]. This study was designed to identify HLA-DRB1 alleles associated with a predisposition to Fy^a immunization after blood transfusion.
STUDY DESIGN AND METHODS: To identify HLA-DRB1 alleles prone to immunization after blood transfusion or pregnancy, HLA-DRB1 genotyping using polymerase chain reaction with sequence-specific oligonucleotide nonradioactive probe/sequence-specific priming methods was performed on blood samples from 67 immunized patients and 200 unrelated controls from the same southern European population in a case-control retrospective study.
RESULTS: Ninety-six percent of patients with anti-Fy^a had at least one HLA-DRB1 * 04 or HLA-DRB1 * 15 allele compared to 34% of controls (p_c < 0.001). Furthermore HLA-DRB1 * 04 and HLA-DRB1 * 1501 frequencies were significantly increased in Fy^a-immunized patients (35% vs. 12%, p_c < 0.001; and 30% vs. 19%, p_c < 0.001, respectively). Among HLA-DRB1 * 04 allelic subtypes, DRB1 * 0401 and DRB1 * 0403 alleles were more strongly correlated with Fy^a immunization (51% vs. 24% and 19% vs. 9%; p_c < 0.001, respectively).
CONCLUSIONS: This study indicated that HLA-DRB1 * 04 and DRB1 * 1501 are overrepresented in Fy^a-immunized patients. The correlation between these alleles and Fy^a immunization could be due to a particular presentation of the Fy^a peptide in HLA-DRB1 molecules.     

Antibiotic-refractory Lyme arthritis is associated with HLA-DR molecules that bind a Borrelia burgdorferi peptide

An association has previously been shown between antibiotic-refractory Lyme arthritis, the human histocompatibility leukocyte antigen (HLA)-DR4 molecule, and T cell recognition of an epitope of Borrelia burgdorferi outer-surface protein A (OspA163-175). We studied the frequencies of HLA-DRB1-DQA1-DQB1 haplotypes in 121 patients with antibiotic-refractory or antibiotic-responsive Lyme arthritis and correlated these frequencies with in vitro binding of the OspA163-175 peptide to 14 DRB molecules. Among the 121 patients, the frequencies of HLA-DRB1-DQA1-DQB1 haplotypes were similar to those in control subjects. However, when stratified by antibiotic response, the frequencies of DRB1 alleles in the 71 patients with antibiotic-refractory arthritis differed significantly from those in the 50 antibiotic-responsive patients (log likelihood test, P = 0.006; exact test, P = 0.008; effect size, Wn = 0.38). 7 of the 14 DRB molecules (DRB1*0401, 0101, 0404, 0405, DRB5*0101, DRB1*0402, and 0102) showed strong to weak binding of OspA163-175, whereas the other seven showed negligible or no binding of the peptide. Altogether, 79% of the antibiotic-refractory patients had at least one of the seven known OspA peptide-binding DR molecules compared with 46% of the antibiotic-responsive patients (odds ratio = 4.4; P < 0.001). We conclude that binding of a single spirochetal peptide to certain DRB molecules is a marker for antibiotic-refractory Lyme arthritis and might play a role in the pathogenesis of the disease.     

The alloimmune response to the human platelet antigen-1a is not related to maternal-fetal killer immunoglobulinlike receptor/HLA-Cw combinations

BACKGROUND: Human platelet antigen (HPA)-1a fetomaternal alloimmune thrombocytopenia, responsible in the most severe cases for fetal or neonatal intracranial hemorrhages leading to death or survival with neurologic sequelae, was shown to be restricted to the human leukocyte antigen (HLA) Class II DRB3*0101-encoded molecule. Whereas more than 90 percent of alloimmunized mothers display the DRB3*0101 allele, the positive predictive value of the presence of DRB3*0101 is only 35 percent. Additional genetic risk factors may exist of which elucidation could improve the undertaking of incompatible pregnancies in at-risk families, encouraging an antenatal screening. Interactions of killer immunoglobulinlike receptors (KIRs) on maternal decidual NK cells with HLA-Cw molecules on fetal trophoblasts were reported as one of the mechanisms involved in the fetomaternal tolerance during pregnancy. STUDY DESIGN AND METHODS: Genotyping was performed of 16 KIR genes in HPA-1a-negative/DRB3*0101-positive alloimmunized mothers and in HPA-1a-negative/DRB3*0101-positive nonimmunized mothers as well as HLA-Cw genotyping in thrombocytopenic children and their nonaffected siblings. RESULTS: No particular KIR genes or KIR genotypes were observed in the alloimmunized or nonimmunized mothers. Distribution of HLA-Cw genes in affected infants and nonaffected siblings did not reveal any HLA-Cw specificity associated with triggering or modulation of the HPA-1a alloimmunization. No maternal KIR/fetal HLA-Cw combinations were demonstrated in association with a detrimental or a protective effect on the HPA-1a alloimmunization. CONCLUSION: Maternal KIR/fetal HLA-Cw gene combinations that are involved in the fetomaternal tolerance do not appear to play a role in the HPA-1a alloimmunization.     

On investigation of markers that may influence alloantibody responses to HPA-1a

In > 99% of cases, HPA-1a antibody production during pregnancy is associated with maternal DRB3*0101 positivity. However, only 35% of HPA-1a neg/DRB3*0101 women produce antibodies (Ab). This study attempted to identify additional genetic marker(s) that may better predict anti-HPA-1a production in these women.
Seventy-eight DRB3*0101 pos HPA-1a neg, women (40 HPA-1a Ab pos, 38 Ab neg) with HPA-1a pos infants, were typed for HLA-DRB1*, -B3*, -B4*, -B5*. Results were compared with those from 83 DRB3*0101 pos normal donors. SNaPshot™ was used to test for a polymorphism of the TNF-α locus.
The frequency of DRB1*15 was significantly lower in Ab pos mothers (1/40) compared to controls (16/83; P  = 0·03), but not compared to Ab neg mothers (6/38; P  = 0·07). DRB1*12 was found only in Ab neg mothers (5/38) (controls 0/83; P  = 0·02). A study of TNF-α genotype ( n  = 30, Ab pos; Ab neg; controls) found no difference between the mothers' groups, or mothers and controls.
Presence of DRB1*15 or DRB1*12 may lower the likelihood of HPA-1a Ab production. Raised frequency of DRB4* was seen in mothers with affected neonates (13/22) (unaffected, Ab pos 3/11; P  = 0·02). DRB4* may increase the odds of HPA-1a alloimmunization. Three NAITP cases due to anti-HPA-1a have been reported (2 local, 1 published), involving mothers DRB3*0101 neg, but DRB4* pos. TNF-α genotype may not predict anti-HPA-1a production in these women. Studies with larger groups would establish the value of these markers in defining women at high risk of HPA-1a alloimmunization.     

The Jk(a−b−) phenotype in New Zealand Polynesians

The Kidd locus phenotype Jk(a-b-) was detected in 0.9 percent of Polynesians living in New Zealand. Over a period of 13 years, nine examples of anti-Jk3 were detected, one of which caused a delayed hemolytic transfusion reaction. Other examples resulted in mild hemolytic disease of the newborn. The anti-Jk3 reacted as an inseparable antibody, confirmed that inheritance of the Jk(a-b-) phenotype was best explained by the presence of a silent Jk allele.     

The HLA-DRB1*11 group-specific allele is a predictor for alloantibody production in the transfusion-dependent thalassemia patients

Background and ObjectivesRecently, researchers have shown an increased interest in thalassemia for detecting susceptible factors in alloimmunization development. Alloimmunization, especially against Rh and Kell blood, occurs in 30% of thalassemia dependent transfusion (TDT) patients. The aim of this study is to determine the role of HLA-DRB1*11 and HLA-DRB1*13 group-specific alleles in the production of Rh and Kell alloantibodies.Materials and Methods106 TDT patients were recruited for this study (54 responders and 52 non-responders). Responder patients developed Rh, Kell and/or specificities alloantibodies. HLA genotyping was done with Sequence-Specific Primers (SSP-PCR) and the results were compared between two groups.ResultsA significant association was found between anti-K (P=0.021, OR=2.546, 95%CI) and anti-E (P=0.049, OR=2.304, 95%CI) alloantibodies production with DRB1*11, respectively. Development of Anti-K and Anti-E alloantibodies were associated with DRB1*11 (P = 0.021, OR = 2.546, 95%CI) (P = 0.049, OR = 2.304, 95%CI), respectively. Further analysis showed that DRB1*11 is more frequent in multi responders (responder with both Rh and Kell alloantibodies) than mono-responders, 71% Versus 29%. There was not found any association between the DRB1*13 group-specific allele and the production of alloantibodies (P = 0.584, OR = 0.308, 95%CI).ConclusionsThe evidence from this study suggests that detecting the DRB1*11 group-specific allele before starting transfusion can be useful to identify susceptible patients, increase HSCT transplantation compatibility and blood transfusion management.     

HLA-DRB1等位基因与儿童特发性血小板减少性紫癜

目的：研究人类白细胞抗原（LA）DRB1等位基因与儿童特发性血小板减少性紫癜（ITP）的关系。方法：用PCR－SSO法对42例ITP患儿进行HLA－DRB1等位基因分型，同时用改良的血小板抗原单抗特异性固相化法（MAIPA）检测其中36例ITP患儿血清中的抗GPⅡb/Ⅲa和GPⅠb/Ⅸ自身抗体。结果：（1）与健康对照相比，ITP患儿HLA－DRB1＊17基因型显著升高（P＜0．05，RR＝2．76，EF＝0．1064），而HLA－DRB1＊1202基因型显著降低（P＜0．025，RR＝0．20，PF＝0．7616）。（2）慢性难治性ITP患儿与非难治性患儿相比，HLA－DRB1＊11基因型显著升高（P＜0．025），且具有DRB1＊11的患儿主要（5／6）为女性年长患儿；（3）抗GPⅡb/Ⅲa及抗GPⅠb/Ⅸ自身抗体的阳性率都与HLA－DRB1＊02（15／16）基因型显著相关（P分别为0．02和0．01），但难治性和非难治性ITP患儿间抗体阳性差异无显著性（P＞0．1）。结论：（1）DRB1＊17可能与儿童ITP的易感性有关，而DRB1＊1202则可能对儿童ITP的发病具有保护作用；（2）具有DRB1＊11基因型的患儿易发展为慢性难治性ITP；（3）血小板自身抗体与抗原表位的反应可能受DRB1＊02限制，但自身抗体阳性与否并不能预示ITP患儿的预后。     

Donor anti-Jk(a) causing hemolysis in a liver transplant recipient

BACKGROUND: Hemolytic transfusion reactions have been observed in recipients of ABO- and/or D-mismatched marrow, peripheral blood, and solid organs. Passenger lymphocyte syndrome occurs when immunocompetent donor lymphocytes transferred during transplantation produce alloantibodies against host antigens. CASE REPORT: The first case of a delayed, anti-Jk(a)-mediated hemolytic reaction in a liver transplant recipient, caused by passenger donor lymphocytes, is reported here. A 43-year-old man underwent liver transplantation. Six weeks later, the patient underwent a second liver transplant. On Day 10 of the second transplant, clinical hemolysis ensued; anti-Jk(a) was detected. The patient's DAT became positive, and anti-Jk(a) was eluted from his RBCs. On Day 35 of the patient's second transplant, 3 weeks after the last blood transfusion, the patients' DAT was still weakly positive with anti-Jk(a) in the eluate. Six months later, serum antibody screening was negative, but the DAT was still weakly positive. The patient's RBCs tested Jk(a+), whereas the second donor's RBCs were Jk(a-). CONCLUSION: This is the first documentation of clinically significant hemolysis caused by anti-Jk(a), produced by passenger lymphocytes transferred from the donor's liver to the transplant recipient.     

DNA typing of HLA-class II genes in idiopathic nephropathy]

The association between idiopathic nephropathy and HLA-class II antigen has been reported in many ethnic groups. We attempted to ascertain the HLA regions more specifically, associated with Japanese idiopathic membranous nephropathy (IMN), IgA nephropathy (IgAN) and minimal change nephrotic syndrome (MCNS), by examining HLA-class II genes. DNA typing of HLA-class II genes showed that IMN was associated with HLA-DRB1*1501-DRB5*0101-DQA1*0102-DQB1*0602, IgA with HLA-DQA1*0301, and MCNS with DQB1*0302. We also found a common epitope of HLA-class II (at 38th amino acid position of HLA-DR beta in IMN, at 55th of HLA-DQ beta in MCNS) in Japanese and Caucasian patients. These particular epitopes seem to be important for the susceptibility to IMN or MCNS.     

HLA-DRB alleles and systemic lupus erythematosus in Jamaicans

BACKGROUND: The human leukocyte antigens (HLA) are associated with susceptibility to systemic lupus erythematosus (SLE) and manifestations of SLE in different ethnic groups. METHODS: A DNA-based HLA-typing method was used to determine alleles of HLA-DRB1, DRB3, DRB4 and DRB5 in Jamaican patients. A total of 70 patients and 100 control subjects were studied. RESULTS: HLA-DRB3*01/03 was significantly associated with susceptibility to SLE, while DRB1*15/16 was associated with the presence of oral ulcers in patients with SLE. The haplotype DRB1*13/14.DRB3*01/03 was also more frequent in SLE patients. No other significant associations were found. CONCLUSION: The SLE HLA associations in Jamaicans differ from those in other black populations.     

广西沿海地区Graves病与HLA-DQA1、DQBIDRB1*09等位基因的相关性研究

目的研究广西沿海地区Graves病（gravesdisease,GD）患者中HLADQA1、DQB1及DRB1＊09等位基因的分布情况及其关系。方法采用序列特异性引物PCR（PCR—SSP）方法检测162例广西沿海地区GD患者及90例健康者的HLA—DQA1、DQB1及DRB1＊09的基因型,计算和比较各组间等位基因频率。结果与健康对照组比较,HLADQA1＊0501、DQB1＊0303和HLA—DRB1＊0901在GD患者组的分布频率明显增高（P〈0．05）;GD女性患者组中的HLADQA1＊0301频率比健康对照组女性明显升高,差异有统计学意义（P〈0．05）。结论HLADQA1＊0501、HLA-DQB1＊0303及HLADRB1＊0901是广西沿海地区GD遗传易感基因;DQA1＊0301是广西沿海地区女性GD患者中的遗传易感基因。     

甘肃汉族HLA-DRB1基因多态性与白血病的相关性研究

为了研究甘肃地区汉族白血病病人易感性与HLA-DRB1基因多态性的相关性研究并寻找白血病的易感基因,采用PCR和特异性寡合苷酸探针杂交（PCR/SSO）法,对74名西北汉族白血病工人和82名健康对照者的HLA-DRB1基因分型进行了研究.结果表明：甘肃地区汉族急性髓性白血病病人HLA-DRB1＊03（x^2=8.125,P=0.004）,HLA-DRB1＊07（x^2=13.526,P=0.000）,HLA-DRB1＊08（x^2=18.855,P=0.000）和HLA-DRB1＊13（x^2=7.039,P=0.008）明显增多;慢性髓性白血病病人HLA-DRB1＊07（x^2=5.689,P=0.017）,HLA-DRB1＊11（x^2=7.73,P=0.005）,HLA-DRB1＊12（x^2=4.234,P=0.040）,HLA-DRB1＊13（x^2=38.333,P=0.000）明显增多.急性淋巴细胞白血病病人HLA-DRB1＊01（x^2=5.294,P=0.021）明显增多.这些数据与对照组比较有差异性.结论：HLA-DRB1＊03,HLA-DRB1＊07,HLA-DRB1＊08,HLA-DRB1＊13与急性髓性白血病正相关.HLA-DRB1＊07,HLA-DRB1＊11,HLA-DRB1＊12,HLA-DRB1＊13与慢性髓性白血病的发病正相关.HLA-DRB1＊01急性淋巴细胞白血病病人的发病有一定联系.可以推测,HLA构象的多态性与白血病发生有相关性.     

斑秃患者HLA-A、B、DRB1基因多态性调查分析

目的 调查河南汉族斑秃患者HLA-A、B、DRB1中低分辨多态性分布,探讨该病与HLA的关联性.方法 收集2007年10月至2008年2月被河南省某医院皮肤科诊断为斑秃的121例河南籍汉族无血缘关系者血液标本,提取基冈组DNA,采用PCR-SSO流式荧光微珠法进行HLA-A、B、DRB1中低分辨检测,统计分析A、B、DRB1等位基因频率,并与本地区24 930份造血干细胞捐献者(对照组)进行对比,u检验分析两组样本间率的差异的显著性.结果 共检测斑秃患者血样121例,其中A位点等位基因频率较高的有A*02(0.2603)、A*11(0.1653)、A*24(0.1240),B位点等位基因频率较高的有B*15(0.2107)、B*13(0.1198)、B*40(0.1074),DRB1位点等位基因频率较高的有DRB1*15(0.2273)、DRB1*07(0.1364)、DRB1*09(0.1198)、DRB1*04(0.1074);在对照组中A位点等位基因频率较高的有A*02(0.2909)、A*11(0.1666)、A*24(0.1570),B位点基因频率较高的有B*15(0.1370)、B*13(0.1316)、B*40(0.1315)、B*51(0.0765),DRB1位点基因频率较高的有DRB1*15(0.1786)、DRB1*07(0.1322)、DRB1*09(0.1302)、DRB1*04(0.1082),两组样本A位点等位基因分布差异无统计学意义;斑秃患者DRB1*12频率低于正常对照组(P<0.05),B*15(62)和DRB1*15基因频率显著高于正常对照组(P<0.05).结论 斑秃患者与正常人群中HLA-A位点等位基因分布差异无统计学意义.DRB1*12可能对于斑秃的发病有抵御作用,B*15(62)和DRB1*15可能为斑秃的易感基因.     

四川骨髓库汉族人群HLAD-RB1~*14等位基因分布

目的研究四川骨髓库中四川籍汉族人群HLAD-RB1*14等位基因分布。方法在四川骨髓库8934名四川汉族造血干细胞捐献志愿者中随机筛选107例中低分辨为DRB1*14的样本,以PCR-SBT分型技术检测DRB1位点的第2外显子以鉴定HLAD-RB1*14等位基因。结果共检出6种DRB1*14等位基因,包括DRB1*140101/1454(56.0%),DRB1*1403(1.8%),DRB1*1404(11.0%),DRB1*140501(27.5%),DRB1*140701(1.8%)和DRB1*1425(1.8%);其中最主要的DRB1*140101/1454频率与美国亚裔/太平洋岛民接近,而与高加索人、非洲裔美国人、西班牙裔及韩国人和中国北方汉族中的分布有显著性差异;DRB1*140501和DRB1*1404则与中国北方汉族分布类似;本研究未检到的等位基因在四川汉族DRB1*14阳性个体中的频率低于3%。结论四川汉族人群HLA-DRB1*14等位基因呈现多样性并存在自身特点。     

Association of amino acid sequences in the HLA-DQB1 first domain with antitopoisomerase I autoantibody response in scleroderma (progressive systemic sclerosis).

Previous studies in Caucasians with progressive systemic sclerosis (PSS) have suggested associations of antitopoisomerase I (antitopo I) autoantibodies with either serologically defined HLA-DR2 or DR5. To better define class II HLA associations with the antitopo I response, 161 PSS patients (132 Caucasians and 29 American blacks) were studied for antitopo I autoantibodies by immunodiffusion and immunoblotting, and their HLA-DRB1, DRB3, DQA1, and DQB1 alleles were determined by restriction fragment length polymorphic analysis and DNA oligotyping. Among Caucasians with antitopo I, HLA-DR5(DRB1*1101-*1104), DRB3*0202 and DQw3 (DQw7,8,9) were significantly increased in frequency. In American blacks, however, only HLA-DQB1*0301(DQw7) was significantly increased. The presence of HLA-DQB1*0301(DQw7) and other HLA-DQB1 alleles bearing the uncharged polar amino acid residue tyrosine at position 30 of the outermost domain was found in all antitopo I-positive Caucasian PSS patients compared with 66% of antitopo I-negative PSS patients (pc = 0.007) and 70% of normal controls (pc = 0.008), as well as all antitopo I-positive black patients. The association with HLA-DQB1 was independent of HLA-DR5(DRB1*1101-*1104) or any other HLA-DRB1, DRB3, or DQA1 alleles. Alternative or additional candidate epitopes for this autoimmune response include alanine at position 38 and threonine at position 77 of these same DQB1 alleles. These data suggest that genetic predisposition to the antitopo I response in PSS is associated most closely with the HLA-DQB1 locus.     

HLA-A、-B、-DRB1等位基因多态性与儿童获得性再生障碍性贫血的易感相关性研究

本研究探讨儿童再生障碍性贫血(AA)易感与HLA-A、-B、-DRB1等位基因多态性之间的相关性。获得性AA患儿80例,其中男48例、女32例,平均年龄8.1岁。在80例AA患者中非重型AA(nsAA)6例,重型AA(sAA)74例。同地区随机选择健康献血者109例作为对照。采用PCR-SSP方法进行HLA-A、-B、-DRB1高分辨等位基因分型。基因频率差异分析采用Pearsonχ2检验或连续性校正χ2检验或Fisher精确概率法。结果表明,与健康对照组比较,80例AA儿童患者中,HLA-B*48:01、DRB1*09:01表达频率升高(均P<0.05,OR分别为12.000和3.403);HLA-B*51:01、DRB1*03:01、DRB1*11:01表达频率降低(均P<0.05,OR分别为0.207、0.266和0.139)。研究还发现,在74例SAA患儿中HLA-B*48:01、DRB1*09:01的表达频率与健康对照组相比亦呈显著升高,而HLA-B*51:01、DRB1*03:01、DRB1*11:01的表达频率与健康对照组相比均显著降低。结论:HLA-B*48:01、DRB1*09:01与儿童期AA相关联,可能是罹患儿童期SAA的易感风险基因。HLA-B*51:01、DRB1*03:01、DRB1*11:01在儿童AA中低表达,是否为相对的保护基因有待进一步研究。     

Prognostic Value Evaluation of HLA-DRB1*07:01, *10, *12, *13:01 Alleles for Alloimmunization in Transfusion-Dependent Thalassemia

BackgroundTransfusion is a lifesaving treatment for lots of patients. However, in chronic blood recipients such as thalassemia patients, there are high concerns about alloantibody production that affects the quality of their life. Therefore, research on risk factors of alloimmunization has been started and followed. This study aimed at the determination of correlation probability between some HLADRB1 alleles and alloimmunization in Iranian thalassemia patients.Materials and methodsThe present study was conducted on 60 alloimmunized and 60 non-alloimmunized transfusion-dependent thalassemia patients. Antibody screening and identification tests were carried out using the tube method, and HLA-DRB1 genotyping was done using a single specific primer-polymerase chain reaction (PCRSSP).ResultsThe results of antibody screening showed that the most prevalent alloantibodies were Anti-K (46.7 %), and followed by Anti-E (32.5 %), Anti-C (15.8 %), Anti-D (13.3 %), Anti-e (8 %), and Anti-c (5.8 %), respectively. DRB1*07:01 was detected more in non-responder patients (28.3 %). However, data analysis showed that there is no significant relationship between DRB1*07:01, *10, *13:01 frequency among responder and non-responder groups (p = 0·195, 0.648, 0.402, respectively). There was not any significant correlation between HLA-DRB1*10 and *13:01 allele and alloimmunization. There was a significant association between HLA-DRB1*12 and alloimmunization (p < 0·05, OR = 2.071, CI: 1.716–2.501).ConclusionThe findings of this study represented that there is a significant relationship between HLADRB1*12 and Kell and E alloantibodies. Although more developed studies on other HLA alleles are demanded, these findings can be valuable in determining important alloimmunization risk factors to better management of transfusion complications.     

The linkage of the major histocompatibility complex to autoimmune thyroid diseases]

To investigate the association between human leukocyte antigen (HLA) and development of autoimmune thyroid diseases such as Graves' disease (GD), Hashimoto's thyroiditis (HT), and Graves' disease patients with undetectable TSH-binding inhibitor immunoglobulin (TBII-negative GD), HLA typing was done. 1. We previously reported increased frequencies of HLA-A2 and DPB1*0501 in TBII-positive GD patients, 2. significantly increased frequencies of HLA-A2 and DPB4*0101 in patients with HT, 3. more TBII-negative GD patients having both HLA-B46 and DPB1*0202 than those having each allele alone, suggesting that these 2 alleles may play a synergistic role in controlling the susceptibility to TBII-negative GD, and 4. contrarily that the frequencies of DQA1*0102 in HT patients and of DQB1*0501 in GD patients were significantly decreased, suggesting that DQA1*0102 and DQB1*0501 might confer resistance to the development of HT and GD.     

HLA-DRB1基因与湘西土家、汉族人群不明原因反复流产的相关性研究

目的 探讨HLA-DRB1基因多态性与湘西土家族、汉族人群不明原因反复流产(URSA)的遗传关联性.方法 采用聚合酶链反应-序列特异性引物(PCR-SSP)技术,对76例湘西土家族、68例汉族人群URSA患者和82例湘西土家族、75例汉族人群健康对照者的HLA-DRB1等位基因进行分析.结果 ①土家族、汉族URSA组的DRB1*04基因频率显著高于土家族及汉族对照组(RR>1,PC<0.01);DRB1*12的基因频率显著低于对照组(RR<1,PC<0.01).②土家族URSA组的DRB1*07基因频率明显高于汉族URSA组(18.08%比5.28%,PC<0.01).结论 HLA-DRB1*04可能是湘西土家族、汉族人群不明原因反复流产的易感基因,HLA-DRB1*12可能为保护基因.     

Peptide binding specificity of HLA-DR4 molecules: correlation with rheumatoid arthritis association

We have investigated whether sequence 67 to 74 shared by beta chains of rheumatoid arthritis (RA)-associated HLA-DR molecules imparts a specific pattern of peptide binding. The peptide binding specificity of the RA-associated molecules, DRB1*0401, DRB1*0404, and the closely related, RA nonassociated DRB1*0402 was, therefore, determined using designer peptide libraries. The effect of single key residues was tested with site-directed mutants of DRB1*0401. The results have demonstrated striking differences between RA-linked and unlinked DR allotypes in selecting the portion of peptides that interacts with the 67-74 area. Most differences were associated with a single amino acid exchange at position 71 of the DR beta chain, and affected the charge of residues potentially contacting position 71. The observed binding patterns permitted an accurate prediction of natural protein derived peptide sequences that bind selectively to RA-associated DR molecules. Thus, the 67-74 region, in particular position 71, induces changes of binding specificity that correlate with the genetic linkage of RA susceptibility. These findings should facilitate the identification of autoantigenic peptides involved in the pathogenesis of RA.