HLA-DMA alleles are possible new markers of rheumatoid arthritis: study of a Corsican group

The HLA-DMA gene, along with the HLA-DMB gene, encodes the not classical class II molecule. This molecule catalyzes the class-II-associated invariant-chain peptide (CLIP)-antigen peptide exchange in classical class II molecule peptide-binding groove. As such, the DM heterodimer is an antigen presentation regulator and may be linked to immune system deficiencies such as those observed in autoimmune diseases. The study of DMA gene polymorphism seems be a reasonable approach to provide an answer to this question. Thanks to PCR-derived methods, the relationship between DMA gene polymorphism and rheumatoid arthritis (RA) was demonstrated in the present study. The DMA*0101 allele was observed to confer a significant predisposition to RA while the DMA*0102 allele significantly protected from this disease. Polymorphism experiments with the HLA-DRB1 gene revealed that this relationship between DMA polymorphism and RA is not a consequence of a linkage disequilibrium with the HLA-DRB1 alleles implicated in this pathology. The study of the DMA gene could therefore prove to be very useful in the early diagnosis of RA. Copyright Copyright 1999 S. Karger AG, Basel     

HLA-DRB1*0403 is associated with dominant protection against IDDM in the general Dutch population and subjects with high-risk DQA1*0301-DQB1*0302/DQA1*0501-DQB1*0201 genotype

Insulin-dependent (Type 1) diabetes mellitus (IDDM) is a genetically controlled T-cell mediated autoimmune disease. Recently, subtyping of HLA-DRB1*04 identified the HLA-DRB1*0403 allele to be associated with protection in Caucasoids with the highest risk heterozygous genotype DQA1*0301-DQB1*0302/DQA1*0501-DQB1*0201. Some studies confirmed this finding, but other reports were not consistent with a dominantly protective trait. We here report the frequency of HLA-DRB1*0403 in a large cohort (n=200) of Dutch patients with IDDM, their first-degree family members (n=370), and random controls (n=420) of the general population in The Netherlands. We found that HLA-DRB1*0403 is strongly associated with dominant protection against development of IDDM in unrelated subject, even in the context of the highest risk HLA-DQ phenotypes and HLA-DR4-DQB1*0302 (P < 0.0001).     

HLA-DRB1 and MHC class 1 chain-related A haplotypes in Basque families with celiac disease

The contribution of HLA genes to the genetic risk for celiac disease (CD) has been known for a long time. Recent publications have pointed to the possibility that a second, independent susceptibility locus could be located in the same genomic region, and a triplet repeat polymorphism in exon 5 of the gene MHC class I chain-related protein A (MICA; located between TNFA and HLA-B) has been associated with several autoimmune disorders, including type 1 diabetes mellitus (DM1) and Addison's disease. On the other hand, a single amino acid change in exon 3 of MICA (M129V) has been shown to strongly reduce MICA binding to NKG2D, an activating natural killer receptor expressed also on T cells, and this could have significant effects on autoimmune reactions. In this study, we have analyzed the contribution of these polymorphisms to CD in 37 Basque families, and have constructed MICA-HLA-DRB1 haplotypes to determine whether MICA has an effect independent from the HLA class II conferred risk. In our population, HLA-DRB1*0301 was associated with an increased risk for CD, while HLA-DRB1*1501 conferred protection from the disease (OR: 7.38 and 0.06, respectively). On the other hand, MICA allele A4 was positively associated with the disease (OR: 4.69) whereas allele A9 showed a trend towards protection (OR: 0.18), although significance did not hold after correction. No association of the exon 3 biallelic polymorphism was observed. A positive allelic association was found for haplotypes A5.1-DRB1*0301 (associated with risk for disease), A4-DRB1*0301 and A6-DRB1*07. In view of our results, both HLA-DRB1 and MICA are associated with CD, but stratification analysis did not show any independent contribution of the MICA polymorphisms analyzed to CD risk. Besides, MICA allele A4 (also A5.1 was associated with risk for CD and other diseases) is in strong linkage disequilibrium with HLA-DRB1*0301. Finally, the major histocompatibility complex region's conferred susceptibility to CD, at least in Basque, is very similar to that observed for DM1, with shared risk and protective haplotypes.     

HLA-DPB1*0401 is associated with dominant protection against type 1 diabetes in the general Saudi population and in subjects with a high-risk DR/DQ haplotype.

The human leukocyte antigen (HLA) class II DQB1*0201/0202-DRB1*04 genotype has been identified as predisposing to type 1 diabetes [insulin-dependent diabetes mellitus (IDDM)] in the Saudi Arabian population (P = 0.0002; odds ratio = 0.67; 95% confidence interval = 0.009-0.381). In this study, we searched for a factor at the DPB1 locus by analysing DPB1 polymorphism using sequence-based typing in 86 Saudi IDDM patients and control subjects, all carrying the HLA-DRB1*04/DQB1*02 haplotype or the known susceptibility allele DQB1*0201/0202. Significant protection was conferred by DPB1*0401, which was observed in 17 of 50 control subjects (55%) and 2 of 36 IDDM patients (5%) with the DQB1*0201/0202 allele (P = 0.0012; odds ratio = 8.75; confidence interval = 1.72-59.70). Our data showing a high frequency of the DPB1*0401 allele even in the presence of the predisposing DQB1*02 allele in healthy subjects may indicate a protective effect of this combination of HLA alleles against type 1 diabetes. This finding supports the hypothesis that protective HLA class II genes can override the risk conferred by HLA-DQ susceptibility alleles. Further studies using larger cohorts of control subjects and patients should be undertaken to confirm this observation.     

Identification of a new HLA-DRB1 allele (DRB1*0318) in three members of a Caucasian Spanish family

This communication reports the identification of a new allele HLA-DRB1*03 in three members of a Caucasian Spanish family. The new allele has been officially named HLA-DRB1*0318 by the World Health Organization Nomenclature Committee. The exon 2 sequence of this new allele is identical to that of DRB1*03011 except for the first nucleotide of codon 45. The nucleotide change (C replacing G) leads to the amino acid substitution of glycine to arginine (GGG-->CGG) at position 45. This position of the beta1 domain shows very little polymorphism among DRB1* alleles (nucleotide changes at this position have only been reported for DRB1*1436 and DRB1*0105) and locates in the vicinity of the highly polymorphic position 47, which is a constituent of the groove's pocket interacting with the amino acid position 7 of the antigen peptide. The familial study showed that the new allele was maternally transmitted into the HLA-A*3002, -B*1801, -Cw*0501, -DRB1*0318, -DRB3*0202, -DQB1*0201 haplotype. Interestingly, the two siblings of the family, which were HLA identical and suffered of insulin-dependent diabetes mellitus (IDDM), were carriers of the two HLA haplotypes (DRB1*03/DQB1*0201 and DRB1*04/DQB1*0302) reported as susceptibility markers to IDDM in Caucasians.     

HLA DMA and DMB show no association with rheumatoid arthritis in US Caucasians

HLA DM is a heterodimeric molecule functioning in normal antigen presentation; it is encoded by adjacent HLA-region loci, HLA DMA and DMB, located between DP and DQ. Some previous studies have suggested that HLA susceptibility to rheumatoid arthritis (RA) is associated with certain DMA and DMB alleles. Our aim was to examine whether this association is also present in US Caucasians. We studied 288 US Caucasian subjects with rheumatoid arthritis and 263 US Caucasian control subjects. DMA and DMB typing was achieved by PCR amplification followed by sequence-specific oligonucleotide hybridization and by PCR–restriction fragment length polymorphism. There was no frequency difference for DMA alleles or DMB alleles between RA and control subjects, indicating no association. Neither was a difference apparent when data were analysed in subgroups based on shared-epitope DRB1, on the rheumatoid factor test, on radiographic changes of RA, or on sex. DRB1-DQB1-DMB analyses for linkage disequilibrium showed that the DRB1*0401-DQB1*0301 haplotype had the DMB*0103 allele more often than DMB*0101 (estimated haplotype frequencies 0.08 and 0.039 in RA, respectively). In contrast, the DRB1*0401-DQB1*0302 haplotype usually had the DMB*0101 allele (haplotype frequency 0.084 compared to 0.01 for DMB*0103). Thus, neither HLA DMA nor DMB was associated with RA in this population, and not all shared-epitope-bearing haplotypes had the same DMB allele distribution.     

HLA-DRB1*04 and susceptibility to type 1 diabetes mellitus in a German/Belgian family and German case-control study. The Belgian Diabetes Registry

HLA-DR4 is a primary disease association marker in type 1 diabetes mellitus (IDDM). We therefore analyzed the transmission of 228 DR4+ haplotypes in 183 families with an IDDM proband (95 from Germany and 88 from Belgium). In a separate case-control data set, we investigated the HLA-DRB1*04 and DQ allele distribution in 245 IDDM patients and 177 controls from Germany, all DR4 positive. HLA-DRB1 *0401 and *0402 linked to DQB1 *0302 were significantly more often transmitted to patients in the studied families (81% and 89%) in contrast to DRB1 *0401-DQB1 *0301 (33%). The case-control study of HLA-DQB1 *0302+ individuals revealed -DRB1 *0405 to be more frequent in patients with IDDM and HLA-DRB1 *0403 and -DRB1 *0404 to be less frequent. HLA-DQA1 *0102-DQB1 *0602 and -DQA1 *0501-DQB1 *0301 in trans complementation with DRB1 *0401-DQB1 *0302 were also significantly less frequent in IDDM patients (P<3x 10(-7) and P<0.02). In conclusion, HLA-DRB1 *0403 and -DQB1*0301 alleles in cis as well as protective DQ haplotypes in trans, confer dominant protection against IDDM in a German / Belgian population.     

Analysis on allelic variation of the HLA-DMB gene in Japanese by PCR-RFLP as well as direct DNA sequencing and identification of a new DMB allele, DMB*0105

In the HLA-D region, one of the class II genes, DMA and DMB have been identified between the DQ and DP genes, and four allelic polymorphisms in each of the DMA (DMA*0101–0104) and DMB (DMB*0101–0104) genes have been so far recognized. Several recent studies suggested that the DM molecule is required for class II antigen presentation pathway especially by promoting the binding of antigenic peptides to the classical HLA class II molecule. In this study, we have analyzed genetic polymorphism and allelic variation of the DMB gene in a Japanese population by the direct DNA sequencing technique and also by the polymerase chain reaction — restriction fragment length polymorphism (PCR-RFLP) method, and could recognize DMB*0101 (49.3%), DMB*0102 (23.2%), DMB*0103 (23.2%), and DMB*0104 (0.4%). Further, a new DMB allele, DMB*0105 characterized by the presence of Val and Iie at two polymorphic sites, codons 144 and 179, respectively was identified. Strong linkage disequilibria were found between DMB*0101 and DRB1*0101, DPB1*0402 and DRB1*1502, and also between DMB*0103 and DRB1*1501 and DQB1*0602. HLA-DMB genotyping using the PCR-RFLP method established here will provide accurate evaluation of the effects of sequence allelism in the DMB gene on the HLA class II disease associations.     

HLA DMA and DMB show no association with rheumatoid arthritis in US Caucasians.

HLA DM is a heterodimeric molecule functioning in normal antigen presentation; it is encoded by adjacent HLA-region loci, HLA DMA and DMB, located between DP and DQ. Some previous studies have suggested that HLA susceptibility to rheumatoid arthritis (RA) is associated with certain DMA and DMB alleles. Our aim was to examine whether this association is also present in US Caucasians. We studied 288 US Caucasian subjects with rheumatoid arthritis and 263 US Caucasian control subjects. DMA and DMB typing was achieved by PCR amplification followed by sequence-specific oligonucleotide hybridization and by PCR-restriction fragment length polymorphism. There was no frequency difference for DMA alleles or DMB alleles between RA and control subjects, indicating no association. Neither was a difference apparent when data were analysed in subgroups based on shared-epitope DRB1, on the rheumatoid factor test, on radiographic changes of RA, or on sex. DRB1-DQB1-DMB analyses for linkage disequilibrium showed that the DRB1*0401-DQB1*0301 haplotype had the DMB*0103 allele more often than DMB*0101 (estimated haplotype frequencies 0.08 and 0.039 in RA, respectively). In contrast, the DRB1 *0401-DQB1 *0302 haplotype usually had the DMB*0101 allele (haplotype frequency 0.084 compared to 0.01 for DMB*0103). Thus, neither HLA DMA nor DMB was associated with RA in this population, and not all shared-epitope-bearing haplotypes had the same DMB allele distribution.     

HLA-DRB4 genotyping by PCR-RFLP: diversity in the associations between HLA–DRB4 and DRB1 alleles

The serologically defined HLA-DR53 antigen is associated with HLA-DR4, -DR7, and -DR9 antigens, and these haplotypes contain two functional genes, DRB1 and DRB4, and two pseudogenes, DRB7 and DRB8. The DRB4 gene encodes the DR53 antigen, and has been officially recognized to contain three allelic variants (DRB4*0101, 0102, and 0103). In this study, we have established the polymerase chain reaction - restriction fragment length polymorphism (PCR-RFLP) method for DRB4 genotyping and analyzed genetic polymorphism of the DRB4 gene in Japanese population. DRB4*0101, DRB4*0102, and DRB4*0103 could be observed at the frequencies of 0.5%, 1.1% and 32.7%, respectively. The same DRB1 allele does not necessarily share an identical DRB4 allele. Further, a tight linkage disequilibrium was found between DRB4*0I02 and DRB1*0401 in Japanese population, whereas DRB1*0401 was associated with DRB4*0101 or *0103 in Caucasian population. These findings reveal extensive diversity of the HLA-DRB1 and -DRB4 haplotypes and may have important implications for HLA-disease associations and donor selection in unrelated transplantation.     

江浙沪汉族人群HLA-DRB1基因座遗传特征及不同人群频率分布比较

目的 调查江浙沪汉族人群HLA—DRBl基因座的遗传多态性，分析不同人群HLA-DRBl基因频率分布特征。方法 利用聚合酶链反应—序列特异寡核苷酸探针反向杂交和聚合酶链反应—序列特异引物技术对江浙沪地区626名健康无关汉族人进行HLA—DRBl基因分型，可检出DRBl*0101-1001，DRB3，DRB4，DRB5等等位基因，计算HLA—DRBl等位基因频率并与不同人群HLA—DRBl基因的多态性进行比较。结果 在江浙沪汉族人群中检出HLA—DRBl*0101、0301、0701、09012、1001、1201、1202、1301／02、1303／04、1401／04／05、1402／03／1305、1501／02、16021以及04xx、08xx等等位基因，其中DRBl*09012(17．97％)、04xx(12．53％)、1202(11．42％)及1501／02(11．02％)基因频率分布较高。江浙沪汉族人群无偏倚期望杂合性为0．9634，多态性信息含量为0．9024。结论 江浙沪汉族人群HLA-DRBl基因具有中国汉族人群共有的遗传特征，但也有其自身的分布特点，频率分布介于南、北汉族之间。在所比较的不同人群中中国汉族人群HLA—DRBl多态性较为丰富。     

人类白细胞抗原-DRB1第3外显子单链测序方法的建立及其多态性分析

目的 建立人类白细胞抗原(human leukocyte antigen,HLA)-DRB1第3外显子单链测序方法,并分析其多态性.方法 采用组特异性引物扩增HLA-DRB1第2和3外显子序列,扩增产物经双酶切后进行双向测序分析,采用Assign 3.5 SBT分析软件指定等位基因型.结果 PCR产物经直接测序后得到清晰的序列冬,并向IMGT/HLA数据库提交了HLA-DRB1*08:09和DRB1*12:02:01第3外显子全部序列.在检测的25个等位基因中,HLA-DRB1第3外显子全长序列中存在27个单核苷酸多态性位点,占第3外显子序列碱基总数的9.56%.建立的方法可有效区分HLA-DRB1*14∶01∶01/14∶54歧义标本,证实中国人群中存在HLA-DRB1*14∶01∶01.结论 本实验建立的HLA-DRB1第3外显子测序方法是可行的,HLA-DRB1第3外显子存在多态性.     

昆明彝族人群HLA-DRB1、DQB1基因多态性

目的　调查昆明彝族 HL A- DRB1、DQB1基因的多态性。方法　应用聚合酶链反应 -序列特异性引物基因分型技术 ,对昆明地区 70名彝族健康儿童进行了 HL A- DRB1、DQB1位点的基因分型。结果在 HL A- DRB1位点共检出了 12种等位基因 ,其中等位基因频率大于 10 %的依次为 HL A- DRB1* 12 (33.5 7% )、DRB1* 0 90 1(11.4 3% )、DRB1* 0 4 (11.4 3% ) ,等位基因频率大于 5 %而小于 10 %的依次为 DRB1* 0 1(8.5 7% )、DRB1* 11(7.86 % )、DRB1* 14 (7.14 % )、DRB1* 15 (7.14 % )、DRB1* 0 8(5 % ) ,等位基因频率小于 5 %依次为 HL A- DRB1* 0 3(2 .86 % )、DRB1* 13(2 .14 % )、DRB1* 0 7(1.4 3% )、DRB1* 16 (1.4 3% )。在 HL A- DQB1位点共检出了 7种等位基因 ,其中等位基因频率大于 10 %的依次为 HL A- DQB1*0 30 1(45 % )、DQB1* 0 5 (2 2 .14 % )、DQB1* 0 30 3(12 .14 % ) ,等位基因频率大于 5 %而小于 10 %的依次为DQB1* 0 4 (6 .4 3% )、DQB1* 0 6 (6 .4 3% ) ,等位基因频率小于 5 %的依次为 DQB1* 0 2 0 1(4.2 9% )、DQB1* 0 30 2 (3.5 7% )。结论　昆明彝族 HL A基因多态性分布不同于北方汉族人群 ,也不同于南方汉族人群 ,有其独特性。     

An investigation of Japanese subjects maps susceptibility to type 1 (insulin-dependent) diabetes mellitus close to the DQA1 gene.

Insulin-dependent diabetic and control subjects of Japanese origin were HLA-DRB1, -DQB1, and -DQA1 typed using restriction fragment length polymorphism analysis and sequence-specific oligonucleotide gene probing. The DQA1 allele DQA1*0301 was positively associated with the disease [48/52 (92%) diabetic patients versus 44/64 (69%) control subjects, Pc less than 0.03, RR = 4.97]. Alleles of the DRB1 and DQB1 genes showed no significant association with the disease. The frequency of DQB1 genotypes encoding the amino acid aspartic acid at position 57 of the DQ beta chain did not differ significantly between subjects with insulin-dependent diabetes mellitus (IDDM) and controls. These findings suggest that a susceptibility allele for IDDM in the Japanese is more closely associated with the DQA1 gene than the DQB1 gene.     

福建汉族人群卸LA-DRB1等位基因多态性研究

目的调查福建汉族人群HLA-DRB1等位基因的多态性。方法应用寡核苷酸基因芯片分型技术对福建地区620名汉族人群进行HLA-DRB1位点的基因分型。结果在HLA-DRB1位点共检出了14种等位基因，基因频率较高的依次为DRB1＊09、12、15、04、08。结论福建汉族HLA-DRB1等位基因多态性与南方汉族人群相近，但也有其独特的特点。     

重庆地区汉族人群HLA-DRB1等位基因多态性研究

目的了解中国重庆地区汉族人群人类白细胞抗原HLA-DRB1基因多态性及其分布特点。方法应用自行建立的聚合酶链式反应-测序为基础的分型方法(PCR-SBT)对190例重庆地区汉族人群进行HLA-DRB1基因分型和多态性分析。结果共检测出13种HLA-DRB1等位基因,20种等位基因型。其中,HLA-DRB1*09:01(29.1%)等位基因频率最高,其次为HLA-DRB1*04:05(12.2%)、HLA-DRB1*08:03(9.3%),基因频率最低的是HLA-DRB1*12:01、HLA-DRB1*12:02、HLA-DRB1*14:05和HLA-DRB1*15:02,各占1.26%。此外,检出的20种HLA-DRB1等位基因型在男女性别间无显著差异。结论成功建立并优化了HLA-DRB1的PCR-SBT基因分型方法;重庆地区汉族人群HLA-DRB1等位基因呈现多态性,为群体遗传和疾病关联的研究提供了可靠的遗传学数据。     

福建汉族人群HLA-DRB1等位基因多态性研究

目的调查福建汉族人群HLA-DRB1等位基因的多态性。方法应用寡核苷酸基因芯片分型技术对福建地区620名汉族人群进行HLA-DRB1位点的基因分型。结果在HLA-DRB1位点共检出了14种等位基因,基因频率较高的依次为DRB1*09、12、15、04、08。结论福建汉族HLA-DRB1等位基因多态性与南方汉族人群相近,但也有其独特的特点。     

HLA-DRB1基因多态性与慢性髓性白血病的相关性研究

目的:探讨HLA-DRB1等位基因多态性与慢性髓性白血病(CML)关联性。方法:采用序列特异性引物聚合酶链反应(PCR-SSP)DNA分型技术对762例慢性髓性白血病患者(男性492例,女性270例)及2 264例正常对照进行了HLA-DRB1基因分型。结果:正常人群的HLA-DRB1*15等位基因频率最高(17.25%),其次为DRB1*09(14.05%)、DRB1*12(11.73%)和DRB1*04(10.98%),DRB1*10等位基因频率最低(1.39%)。CML患者HLA-DRB1*08等位基因频率显著高于正常对照组(7.48%vs 5.39%,χ2=8.963,OR=1.023,P=0.004),男性患者的DRB1*08基因频率也明显高于正常对照(7.72%vs 5.39%,χ2=8.059,OR=1.025,P=0.007)。女性患者的DRB1*08基因频率也高于正常对照(7.04%vs 5.39%,χ2=0.115,OR=0.995,P=0.774),但没有统计学差异。结论:CML男性患者HLA-DRB1*08的表达明显高于正常人群,提示DRB1*08可能是男性CML患者的易感基因。     

CTLA-4 49 A/G dimorphism and type 1 diabetes susceptibility: a French case-control study and segregation analysis. Evidence of a maternal effect.

Several studies have demonstrated an association of cytotoxic T lymphocyte-associated molecule 4 (CTLA-4) (IDDM 12) alanine 17 with type 1 diabetes, but we wished to study the parental effect of CTLA-4 49 A/G dimorphism in diabetic families. The CTLA-4 exon 1 polymorphism (49 A/G), HLA-DRB1 and insulin gene (INS) variable number tandem repeats (VNTR) were analysed in 134 type 1 diabetic patients vs. 273 control subjects. The segregation analysis for transmission was carried out in 70 informative diabetic families using the transmission distortion test (TDT). All genotyping was performed by PCR-RFLP. CTLA-4 49 G allele frequency was not increased in diabetic patients compared to controls (41 vs. 38%, not significant). The distribution of GG, AG and AA CTLA-4 genotypes was similar in the two groups (13, 57 and 30% vs. 11, 54 and 35%, respectively) and was independent of HLA-DRB1 or INS VNTR polymorphism. The CTLA-4 49 G allele showed weak distorted transmission to the diabetic offspring, whereas random transmission was observed in unaffected offspring. This distortion is attributable to a maternal effect (71% compared to the 50% expected ratio; tdt = 4.8; P < 0.03). The combined transmission of maternal CTLA-4 G with HLA-DRB1*03 (90%; tdt = 6.4; P < 0.01) and VNTR class I (80%; tdt = 5.4; P < 0.02) enhanced the susceptibility effect of each marker separately. We noted a slight CTLA-4 49 G and HLA-DRB1*04 distortion of transmission shared in paternal and maternal diabetic meiosis. In non-diabetic offspring, the CTLA-4 49 A allele confers a protective effect in the presence of maternal HLA-DRB1*03 and paternal HLA-DRB1*04 alleles. Despite the absence of a positive association of the CTLA-4 49 G allele with type 1 diabetes, our segregation analysis supports the hypothesis of a modulation by CTLA-4 49 G/A dimorphism of the susceptibility conferred by maternal HLA-DRB1*03 inheritance. This potential parental effect needs to be confirmed in a larger data set.