HLA–DR4 subtypes in new zealand polynesians. predominance of dw13 in the healthy population and association of dw15 with rheumatoid arthritis

Objective. To analyze HLA–DR4 alleles in New Zealand Polynesians with rheumatoid arthritis (RA). Methods. Thirty Polynesians and 30 Caucasians with RA, as well as 65 Polynesian and 60 Caucasian healthy blood donors, were DR4 subtyped using the polymerase chain reaction and sequence-specific oligonucleotide probes. Results.The frequency of DR4 (DRB1*04) was increased in both Polynesian (P <0.001) and Caucasian (P <0.005) RA patients compared with race-matched controls. Dw4 (DRB1*0401) was detected in 15 of 30 Caucasian patients but only 2 of 30 Polynesian patients (P <0.001). In Polynesians, RA was associated with Dw15 (DRB1*0405), which was present in 11 of 30 patients and 3 of 65 controls (P < 0.001). Dw13 (DRB1*0403) was the most frequent DR4 allele in healthy Polynesians, but was not significantly associated with RA. Conclusion. The predominance of the Dw13 subtype in Polynesians may explain in part the low prevalence of RA in this population. The association of Dw15 with RA in Polynesians supports the hypothesis that the third hypervariable region of DRβ determines susceptibility to RA.     

汉族类风湿关节炎患者HLA—DR和—DQ基因分型研究

为探讨ＨＬＡ－ＤＲ和－ＤＱ等位基因与我国汉族类风湿关节炎（ＲＡ）的相关性，采用聚合酶链反应－限制性内切酶片段长度多态性分析（ＰＣＲ－ＲＦＬＰ）方法对汉族人群中３５例ＲＡ患者和１００名健康人的ＤＲ和ＤＱ位点进行ＤＮＡ定型分析。结果发现，ＤＲ４频率在正常人为２４．０％，在ＲＡ患者为５１．４％（Ｐ＜０．０１，ＲＲ＝３．３０）；ＤＲ４亚型位点分析发现２组均以ＤＲＢ１＊０４０５占多数，但ＤＲＢ１＊０４０５频率在ＲＡ组为３１．４％，高于正常人的１０．０％（Ｐ＜０．０１）。ＤＱ４频率在全部ＲＡ患者为３７．１％，在ＤＲ＋４ＲＡ患者为７２．２％，均高于全部正常人的１０．０％（Ｐ＜０．０１）和ＤＲ＋４正常人的４１．６％（Ｐ＝０．０３７６）；ＤＲ＋４－ＤＱ＋４ＲＡ患者的病情重于ＤＲ－４患者。结果提示，ＤＲ４、主要是ＤＲＢ１＊０４０５与ＲＡ相关，ＤＱ４可增加ＤＲ４对ＲＡ的易感性，ＤＲ＋４－ＤＱ＋４单倍型是ＲＡ病情严重程度的标志。     

Rheumatoid arthritis in Israeli Jews: shared sequences in the third hypervariable region of DRB1 alleles are associated with susceptibility

Rheumatoid arthritis (RA) is known to be associated with class II HLA antigens in most populations, but recent studies in Israeli Jewish patients showed no significant differences in either DR4 or DR1 between patients and controls. In a previous DR4 subset study we found DR4-Dw15 to be associated with susceptibility (RR = 9.2) but this allele occurred in only 12% of the patients. We analyzed all DRB1 genes, using the polymerase chain reaction (PCR) and hybridization with allele specific oligonucleotides, in 49 Jewish patients with RA and 40 normal Jewish controls. Six DRB1 alleles that are similar to the prototype DR4-Dw4 (DRB1*0401) appeared to contribute to the risk for developing RA. In addition to DR4-Dw15 (DRB1*0405) 2 other alleles having substitutions in codons 71 only (DR1-Dw1/DRB1*0101, DR4-Dw14.2/DRB1*0408) or in codons 70 and 71 (DRw10/DRB1*1001) gave highly significant relative risks. Together, this group, with valine in position 85, and glycine in codon 86, gave a relative risk of 11.0 (p = 0.0002). Two other alleles with the same sequence in the third hypervariable region (amino acids 67-74) but with valine in codon 86 (DR4-Dw14.1/DRB1*0404) or alanine in 85 and valine in 86 (DR1-Dw20, DRB1*0102) gave a combined risk of 3.6 (p = 0.049). Altogether these 7 alleles with similar sequences in the third hypervariable region accounted for 55.6% of the patients, with an overall relative risk of 8.6 (p = 0.00002). Our results in this population indicate that shared epitopes in the third hypervariable region of DRB1 alleles also play a role in susceptibility to RA.(ABSTRACT TRUNCATED AT 250 WORDS)     

Linkage Between Rheumatoid Arthritis Susceptibility and the Presence of HLA—DR4 and DRβ Allelic ThIrd Hypervariable Region Sequences in Southern Chinese Persons

Objective. To analyze HLA—DR and DQ associations with rheumatoid arthritis (RA) in patients from southern China. Methods. In 66 patients and 45 controls, restriction fragment length polymorphism studies were performed using DRB, DQA, and DQB probes, and DRB allele—specific typing of polymerase chain reaction—amplified DRB DNA. Results. The frequency of HLA—DR4 was significantly increased among RA patients (42.4% versus 17.8%). Increased frequencies of the DQA3 allele (77.8% versus 48.9%) and the DQB1*0302 allele (71.0% versus 46.3%), which are in linkage disequilibrium with DR4, were also found. Oligonucleotide typing showed that the amino acid sequence LLEQRRAA, spanning amino acid positions 67—74 of the DRβ molecule, was found in 19 of 49 patients and 5 of 32 controls. The main DR4 allelic subtypes found in the population were DRB1*0404 and DRB1*0405, both of which carried the sequence. There was no difference in subtype distribution between patients and controls. Conclusion. Chinese RA patients have an increased frequency of HLA—DR4 alleles which possess the same DRB third allelic hypervariable sequence shown to be associated with susceptibility in Caucasian RA patients.     

Increased susceptibility to rheumatoid arthritis in Koreans heterozygous for HLA–DRB1*0405 and *0901

Objective

To investigate the association of susceptibility and protective HLA–DRB1 alleles with rheumatoid arthritis (RA) and its clinical markers in an Asian population.

Methods

All RA patients (n = 574) and control subjects (n = 392) were Korean. HLA–DRB1 typing and further subtyping of all alleles was performed by polymerase chain reaction, sequence‐specific oligonucleotide probe hybridization, and direct DNA sequencing analysis. We used a relative predispositional effects (RPEs) method and a false discovery rate correction method for multiple comparisons.

Results

The DRB1*0405 and *0901 alleles showed the most significant associations with RA (P = 7.83 × 10⁻²⁴, odds ratio [OR] 4.40 [95% confidence interval (95% CI) 3.24–5.99], and P = 3.76 × 10⁻⁹, OR 2.47 [95% CI 1.82–3.36], respectively). The RPEs test showed that the DRB1*0401 and *0410 alleles conferred susceptibility and that the DRB1*0701, *0802, *1301, *1302, *1403, and *1405 alleles showed significant protective effects. Susceptibility and protective alleles both showed a pattern consistent with additive genetic effects, and each influenced RA independently of the other. The compound heterozygote DRB1*0405/*0901 was associated with the highest risk of RA (corrected P = 1.81 × 10⁻¹¹, OR 58.2 [95% CI 7.95–425.70]). The mean age at disease onset was ∼4 years earlier or was 3 years earlier, respectively, in patients with at least 1 copy of the DRB1*0405 or the DRB1*0901 allele. Radiographic changes (stages II–IV) were more frequent in patients with at least 1 copy of DRB1*0405 (P = 0.032, 92.6% versus 84.3%, OR 2.33 [95% CI 1.24–4.39]).

Conclusion

The DRB1*0405/*0901 heterozygote has the strongest association with RA, suggesting that this heterozygote enhances the susceptibility to RA in Koreans.

     

Genetic analysis of HLA class II alleles and susceptibility to Type 1 (insulin-dependent) diabetes mellitus in Japanese subjects

Summary Although HLA-DQB1 alleles encoding aspartic acid at position 57 (Asp-57) are protective against Type 1(insulin-dependent) diabetes mellitus in Caucasians, most Japanese Type 1 diabetic patients carry at least one Asp-57 DQB1 allele. We analysed the DRB1, DQA1 and DQB1 genes of 99 Japanese patients and 86 control subjects with polymerase chain reaction and sequence-specific oligonucleotide hybridization. We found that (1) the DQA1*0301 allele was significantly increased in Type 1 diabetic patients (RR 7.8,pc < 0.0001); (2) the DRB1*0405 (Dw15) allele, which is a subtype of DR4 haplotype, was significantly increased in DR4-positive patients (RR 12.0,pc < 0.001); and (3) although the DRw8-DQw8 haplotype was positively associated with Type 1 diabetes, the DRBl*0406-DQw8 haplotype was decreased in the diabetic patients. These data indicate that DRB 1 and DQA1 genes also confer susceptibility to Type 1 diabetes in Japanese.     

Analysis of single‐nucleotide polymorphisms in Japanese rheumatoid arthritis patients shows additional susceptibility markers besides the classic shared epitope susceptibility sequences

Objective

To examine the entire HLA region for loci (other than the DRB1 locus) associated with rheumatoid arthritis (RA) susceptibility, by typing HLA–DRB1 alleles and multiple single‐nucleotide polymorphisms (SNPs) in the Japanese population.

Methods

The HLA–DRB1 alleles and 88 SNPs distributed over the HLA gene complex were genotyped, for 828 patients with RA and 1,032 control subjects. The data were evaluated for linkage disequilibrium, and case–control associations were analyzed in 2 ways, in the presence or absence of the disease‐susceptibility DRB1 allele, to detect loci independent of the DRB1 allele.

Results

HLA–DRB1 alleles *0405, *0401, *0901, *0101, *1401, *1602, *0403, and *1405 were significantly associated with RA in the Japanese population. The smallest P value (P = 1.4 × 10⁻²⁷) was observed in association with an intronic SNP of the NOTCH4 gene, which was due to strong linkage disequilibrium with the HLA–DRB1 allele. A strong association that was independent of HLA–DRB1 shared epitope alleles was observed in 2 SNPs: one in the intron of the MICA gene, the other in the intron of the HLA–DQB2 gene. Their association with RA, independent of HLA–DRB1 shared epitope alleles, was suggestive (P = 0.0024 [corrected P (P_corr) = 0.068, and P = 0.00037 [P_corr = 0.012], respectively).

Conclusion

These findings suggest that 1 or more other loci besides the HLA–DRB1 or other DRB1 (non–shared epitope, non‐*0901) alleles are involved in RA susceptibility/protection.

     

大动脉炎易感性与HLA-DRB基因相关性研究

目的 探讨大动脉炎易感性与ＨＬＡ－ＤＲＢ等位基因频率的相关性。方法 以８４例汉族大动脉炎患和１０２例健康汉族人（对照组）为研究对象,采用ＰＣＲ－ＳＳＰ及ＰＣＲ－ＲＦＬＰ方法进行ＨＬＡ－ＤＲＢ等位基因分型,比较其等位基因频率在大动脉炎患与对照组之间的差异。结果 ＨＬＡ－ＤＲ４、ＤＲ７等位基因频率在大动脉炎组显高于对照组（３８．１％比１５．７％,Ｐ〈０．０１,ＲＲ＝２．４３;４７．６％比１０．８     

Novel genetic markers of rheumatoid arthritis in chilean patients,by dr serotyping and restriction fragment length polymorphism analysis

Objective. The analysis of genetic markers of rheumatoid arthritis (RA) in a population in which the DR4 serotype is not strongly associated with the disease. Methods. Chilean RA patients (56 seropositive and 22 seronegative) and 141 controls were studied by serotyping. Southern blot analysis of Bam HI restriction fragment length polymorphism (RFLP) was done in genomic DNA from 46 patients with seropositive RA, 17 patients with seronegative RA, and 45 controls, using a complementary DNA probe specific for DRB1 genes. Results. The prevalence of the HLA—DR9 haplotype was strikingly higher in seropositive RA patients (21%) than in controls (3%) (P_corr < 0.0008, by Fisher's exact test; relative risk [RR] = 9.34). The prevalence of DR4 and DR1 haplotypes, although slightly increased, did not achieve a significant preponderance. The simultaneous presence of two Bam HI fragments (3.6 kb and 4.5 kb) was found with higher prevalence in seropositive patients (83%; RR = 9; P_corr < 0.00002) than in controls (36%), and seemed higher in seronegative RA patients as well (71%; RR = 4). Furthermore, its prevalence remained increased in comparisons of DR4 positive controls (36%) with DR4 positive seropositive patients (100%; RR = 67; P_corr < 0.0002) and DR4 positive seronegative patients (100%; RR = 36; P_corr < 0.006), even after excluding the DR9 positive individuals. A tendency toward higher association with DR1 seropositive RA patients (67%; RR = 12), a group with no DR4 or DR9 positive individuals, than in DR1 positive controls (14%), was also observed. Conclusion. The HLA—DR9 haplotype was definitively consolidated as a very strong genetic marker exclusively for seropositive RA in Chilean patients, as suggested by our previous observations. RFLP analysis showed that the simultaneous presence of 3.6-kb and 4.5-kb Bam HI fragments constituted a better RA marker than did any of the heretofore studied haplotypes. These fragments together would be linked to RA independently of the DR1, DR4, and DR9 haplotypes. The overall evidence indicates that Chilean seropositive RA patients display a genetic background that is different from that underlying RA susceptibility in other populations and suggests the existence of common, as well as distinct, genetic elements predisposing to seronegative and seropositive RA.     

The genotypic distribution of shared-epitope DRB1 alleles suggests a recessive mode of inheritance of the rheumatoid arthritis disease-susceptibility gene

Objective. To test whether the genotypic distribution of rheumatoid arthritis (RA)–associated DRB1 alleles suggests that the DRB1-a ssociated disease-susceptibility gene has a recessive or additive (dominant) mode of inheritance. Methods. Caucasian patients with RA and control subjects were recruited from a faculty outpatient practice. DRB1 typing was done by several DNA-based techniques: polymerase chain reaction (PCR), followed by dot-blot hybridization with sequence-specific oligonucleotides, conventional and PCR-based restriction fragment length polymorphisms (RFLPs), and a multiplex amplification–refractory mutation RFLP system. The genotypic distribution of shared-epitope DRB1 alleles was analyzed by antigen genotype frequency among patients. The analytical method postulates a linkage-disequilibrium model with a disease locus close to a marker locus and a marker allele in linkage disequilibrium with the disease-susceptibility allele. In this instance, the marker allele was defined alternatively by any DR4-g roup allele, by any DR4-g roup or DR1-g roup allele, by any DR4-g roup shared-epitope allele, by any DRC-group shared-epitope allele plus DRB1*0101, or by any shared-epitope DRB1 allele. Observed numbers were compared with those predicted for recessive mode or additive (dominant) mode of inheritance of the DRB1-a ssociated RA disease-susceptibility gene. Results. The genotypic distribution of shared-epitope DRB1 alleles (DRB1*0401, *0404, *0405, *0408, *0101, *0102, or *1001) fit that predicted for a recessive mode of inheritance and was significantly different from that predicted for an additive (dominant) mode. When the analysis was restricted to shared-epitope DR4 alleles alone (DRB1*0401, *0404, *0405, or *0408), the observed genotype numbers fit the recessive mode best. When DR1-g roup alleles were added to DR4-g roup alleles, or alternatively, when the major shared-epitope DR1 allele (*0101) was added to DR4-g roup shared-epitope alleles, there was a less significant deviation from the additive mode of inheritance. The reason for this was derived by comparison of observed genotype frequencies to those expected under Hardy-Weinberg equilibrium; there was a deficit of persons with DRB1*0401,*0101 and an excess of *0101,X. Conclusion. The genotypic distribution of shared-epitope DRB1 marker alleles suggests that the mode of inheritance of the DRB1-a ssociated disease susceptibility gene must be recessive and not additive (dominant).     

HLA Class ii sequence polymorphisms and susceptibility to rheumatoid arthritis in greeks. the hla–drβ shared-epitope hypothesis accounts for the disease in only a minority of greek patients

Objective. In Northern Europeans, rheumatoid arthritis (RA) is strongly associated with a relatively conserved pentapeptide sequence of HLA–DRβ found notably in the HLA–DR4 subtypes Dw4 and Dw14 and in DR1. A previous serologic study of HLA class II polymorphism in a Greek population with RA failed to show significant associations with any antigen. Methods. We characterized HLA–DRB polymorphisms in Greek patients with RA and in control subjects by restriction fragment length polymorphism analysis. Allelic DRB subtypes were examined by polymerase chain reaction amplification and oligonucleotide hybridization. Results. DNA analysis in the RA patients showed that although individual HLA–DR allelic associations were weak, a relatively conserved HLA–DRβ motif was significantly associated with RA in this population of Greek patients. The third hypervariable region amino acid sequences QRRAA, QKRAA, or RRRAA were found in the HLA–DRβ1 of 43.5% of the RA patients versus 15.5% of the controls (unconnected P = 0.00004). Conclusion. Sequences shown to influence susceptibility to RA in patients in the UK also play a role in patients in Greece. However, 57% of Greek patients lack the putative HLA–DRβ motif, which suggests that considerable immunogenetic heterogeneity underlies disease susceptibility in this population.     

Influence of HLA–DR genes on the production of rheumatoid arthritis–specific autoantibodies to citrullinated fibrinogen

Objective

Antibodies directed against citrullinated fibrinogen are highly specific for rheumatoid arthritis (RA). This study was undertaken to test whether RA‐associated HLA–DR alleles are associated with anti–citrullinated fibrinogen in RA patient sera and whether replacement of arginyl by citrullyl residues on fibrinogen peptides modifies their binding to HLA–DR molecules and their recognition by T cells.

Methods

Antikeratin, antifilaggrin, and anti–citrullinated fibrinogen antibodies were assayed in RA patients who had undergone HLA–DR typing. Direct assays were performed to investigate binding of citrullinated or native fibrinogen peptides (encompassing the entire α‐ and β‐chains of fibrinogen) to purified HLA–DR molecules. T cell proliferative responses to citrullinated or native fibrinogen peptides were measured in RA patients and controls.

Results

HLA–DRB1*0404 was associated with anti–citrullinated fibrinogen in RA sera (P = 0.002). For the RA‐associated alleles HLA–DRB1*0401 and HLA–DR1, there was a nonsignificant trend toward association (P = 0.07). Multiple peptides from the α‐ and β‐chains of fibrinogen bound many HLA–DR alleles; DRB1*0404 was the best fibrinogen peptide binder. Citrullination did not influence fibrinogen peptide binding to HLA–DR or fibrinogen peptide recognition by T cells. Peripheral blood T cells that recognized native or citrullinated fibrinogen peptides were common in RA patients but not in healthy controls.

Conclusion

The RA‐associated HLA–DRB1*0404 allele is also associated with production of antibodies to citrullinated fibrinogen. DRB1*0401 and DRB1*01 tend to be associated with anti–citrullinated fibrinogen, but this is not statistically significant. Citrullination of fibrinogen peptide does not influence peptide–DR–T cell interaction. Finally, T cell proliferation in response to citrullinated or uncitrullinated fibrinogen peptides is frequent in RA patients and very infrequent in controls.

     

Antibodies to type II collagen and HLA disease susceptibility markers in rheumatoid arthritis

OBJECTIVE: To seek associations between antibodies to native and denatured type II collagen (NCII and DCII) and HLA in rheumatoid arthritis (RA). METHODS: One hundred fourteen patients with clinically well-defined RA were HLA-DR and DQ typed. Those who were DR4 positive were subtyped for DRB1*0401-*0408 alleles by polymerase chain reaction using allele-specific oligonucleotide probes. Antibodies to human NCII and DCII (heat-denatured) were measured by enzyme-linked immunosorbent assay. The frequency of HLA alleles was compared in patients grouped according to the presence and absence of antibodies to NCII and DCII. RESULTS: Twenty-seven patients (24%) were positive for antibodies to NCII. There was a significant increase in the frequency of HLA-DR7 in anti-NCII-positive patients compared with anti-NCII-negative patients (30% versus 9%; P = 0.019) and a significant decrease in HLA-DR3 (7% versus 28%; P = 0.044). Repeating the analyses after excluding the 16 patients who were DR7 positive revealed a significant increase in the frequency of HLA-DR1 in anti-NCII-positive patients compared with anti-NCII-negative patients (63% versus 27%; P = 0.045). Moreover, antibodies to NCII were associated with the third hypervariability region susceptibility sequence QRRAA that is present in DRB1*0101, *0404, *0405, and *0408 (84% versus 47%; P = 0.0085); 24 of 27 anti-NCII-positive patients were positive for either DR7, DR1, or DRB1*0404 or *0408. Thirty patients (26%) were positive for antibodies to DCII. There was a significant increase in the frequency of HLA-DR3 in anti-DCII-positive patients compared with anti-DCII-negative patients (40% versus 18%; P = 0.028). CONCLUSION: The genetic associations between HLA-DR alleles and antibodies to CII in RA patients is in keeping with the collagen-induced arthritis model and implicates autoimmunity to CII as a major component in the multifactorial pathogenesis of RA.     

The association of DRB1*04 share epitope alleles and tumor necrosis factor-alpha gene polymorphism (−863) with susceptibility to rheumatoid arthritis in Thai

Rheumatoid arthritis (RA) in Thai population is significantly associated with HLA-DR4 shared epitope (SE) alleles, particularly with DRB1*0405 (P = 0.00004, OR = 3.84, 95% CI = 1.93, 7.7). In addition, tumor necrosis factor-alpha (TNF-alpha) gene −863A alleles were found to be significantly increased in 77 RA patients compared to 162 healthy controls (P = 0.03, OR = 1.73, 95% CI = 1.05, 2.87). Interestingly, TNF-863 AC and SE have a synergistic effect on the susceptibility to RA. The OR for the presence of both risk factors (DR4 SE and −863 AC) was cumulative: 15.4 (95% CI = 3.75, 73.6) while the separate OR of DR4 SE and −863 AC were 3.84 and 2.36, respectively. The TNF was not associated with the clinical manifestation and severity of Thai RA patients. However, a highly significant association was found between RF positivity, one marker for severity, and RA patients with DR4 SE (P = 0.0005, OR = 9.42, 95% CI = 2.26, 45.27).     

Transfer of the shared epitope through microchimerism in women with rheumatoid arthritis

Objective

Rheumatoid arthritis (RA) is an autoimmune disease that affects mostly women and is associated with HLA–DRB1 genes having in common a shared epitope sequence. In parallel, cells and/or DNA originating from pregnancy (microchimerism) persist for decades and could contribute to autoimmunity. The aim of this study was to examine whether microchimerism may be a source of the shared epitope among women with RA.

Methods

Women with RA and healthy women who lacked RA‐associated genes such as HLA–DRB1*01 (n = 33 and n = 46, respectively) and/or HLA–DRB1*04 (n = 48 and n = 64, respectively), were tested for DRB1*01 or DRB1*04 microchimerism by HLA‐specific quantitative polymerase chain reaction assays. As controls, alleles not associated with RA (DQB1*02 and DRB1*15/16) were also analyzed.

Results

Compared with healthy women, women (42% with RA had a higher frequency and higher levels of DRB1*04 microchimerism versus 8%; P = 0.00002) as well as DRB1*01 microchimerism (30% versus 4%; P = 0.0015). Moreover, no difference in microchimerism was observed for alleles not associated with RA.

Conclusion

Women with RA had microchimerism with RA‐associated HLA alleles, but not with non–RA‐associated HLA alleles, more often and at higher levels compared with healthy women. These observations are the first to indicate that microchimerism can contribute to the risk of an autoimmune disease by providing HLA susceptibility alleles.

     

Influence of HLA-DRB1 genes and the shared epitope on genetic susceptibility to rheumatoid arthritis in Taiwanese

OBJECTIVE:To investigate the association of predisposing and protective HLA-DRB1 alleles with rheumatoid arthritis (RA) and its clinical markers in a Taiwanese population. METHODS: A total of 273 patients with RA and 480 healthy controls, all of Taiwanese origin, were genotyped for HLA-DRB1 alleles by polymerase chain reaction and sequence-based typing assays. The associations between RA and HLA-DRB1 alleles and genotypes were investigated by chi-squared test. RESULTS: The DRB1*0405 and *1001 phenotypes showed the most significant associations with RA (OR 4.04, 95% CI 2.84-5.77, pc = 3.2 10(-14); OR 5.25, 95% CI 2.10-13.06, pc = 3.0 10(-3), respectively). Individuals carrying single or double doses of the shared epitope (SE/non-SE or SE/SE) had higher risks of RA. The compound heterozygote of DRB1*0405/*1001 showed the largest increase in RA risk (OR 15.8, 95% CI 2.48-100.7, pc = 0.004). Single or double doses of SE alleles were significantly associated with a higher bone erosion rate. Rheumatoid factor positivity and bone erosion were more frequent in patients with at least one copy of DRB1*0405. CONCLUSION: Our results show that SE-encoding HLA-DRB1*0405 and *1001 are associated with RA in a Taiwanese population; this is the first time DRB1*1001 has been described in persons of Asian ethnicity. Heterozygotes of DRB1*0405 and *1001 predicted the strongest susceptibility to RA, suggesting that this genotype enhances susceptibility to RA in Taiwanese.     

Analysis of single-nucleotide polymorphisms in Japanese rheumatoid arthritis patients shows additional susceptibility markers besides the classic shared epitope susceptibility sequences

OBJECTIVE: To examine the entire HLA region for loci (other than the DRB1 locus) associated with rheumatoid arthritis (RA) susceptibility, by typing HLA-DRB1 alleles and multiple single-nucleotide polymorphisms (SNPs) in the Japanese population. METHODS: The HLA-DRB1 alleles and 88 SNPs distributed over the HLA gene complex were genotyped, for 828 patients with RA and 1,032 control subjects. The data were evaluated for linkage disequilibrium, and case-control associations were analyzed in 2 ways, in the presence or absence of the disease-susceptibility DRB1 allele, to detect loci independent of the DRB1 allele. RESULTS: HLA-DRB1 alleles *0405, *0401, *0901, *0101, *1401, *1602, *0403, and *1405 were significantly associated with RA in the Japanese population. The smallest P value (P = 1.4 x 10(-27)) was observed in association with an intronic SNP of the NOTCH4 gene, which was due to strong linkage disequilibrium with the HLA-DRB1 allele. A strong association that was independent of HLA-DRB1 shared epitope alleles was observed in 2 SNPs: one in the intron of the MICA gene, the other in the intron of the HLA-DQB2 gene. Their association with RA, independent of HLA-DRB1 shared epitope alleles, was suggestive (P = 0.0024 [corrected P (P(corr)) = 0.068, and P = 0.00037 [P(corr) = 0.012], respectively). CONCLUSION: These findings suggest that 1 or more other loci besides the HLA-DRB1 or other DRB1 (non-shared epitope, non-*0901) alleles are involved in RA susceptibility/protection.     

Allelic basis for HLA-encoded susceptibility to type 1 autoimmune hepatitis

BACKGROUND & AIMS: In a recent study, we suggested that susceptibility to type 1 autoimmune hepatitis is associated with a six-amino acid motif, LLEQKR, within the DR beta polypeptide, but these data are in conflict with contemporary reports from Japan and Argentina. The purpose of the present study was to reexamine this question in a large independent cohort of patients. METHODS: Eighty-six North American white patients and 102 control subjects were studied. HLA class I antigens were determined serologically, and the DRB1, DQA1, DQB1, and DPB1 genes and the DRB3/4/5 subtypes were determined by high-resolution genotyping. RESULTS: The greatest risk was associated with DRB1*0301 (corrected probability [Pc] = 0.00003; relative risk [RR] = 4.58), and a secondary association with DRB1*0401 was identified (Pc = 0.000132; RR = 5.97). Protection from disease was associated with the DRB5*0101- DRB1*1501 haplotype (Pc = 0.021; RR = 0.3). However, further analysis indicated that a lysine residue at position 71 of the DR beta polypeptide may be the most important determinant of disease susceptibility (P = 0.0000003; RR = 8.6, increasing to RR = 16.38 with four lysine residues). CONCLUSIONS: DRB1*0301 and DRB1*0401 are confirmed as the principal susceptibility alleles for type 1 autoimmune hepatitis, and these data support the hypothesis that a lysine residue at position 71 of the DR beta-polypeptide chain may be the major risk factor. (Gastroenterology 1997 Jun;112(6):2028-35)     

Influence of shared epitope–negative HLA–DRB1 alleles on genetic susceptibility to rheumatoid arthritis

Objective

Most patients with rheumatoid arthritis (RA) express the shared epitope (SE). It is not known whether SE‐negative HLA–DRB1 alleles influence the development of RA. This study examined the influence of SE‐negative HLA–DR alleles (DRB1*X) on the development of RA in 3 different French populations.

Methods

HLA–DRB1 alleles were defined by polymerase chain reaction with sequence‐specific oligonucleotide hybridization or sequence‐specific primers. SE‐negative alleles were classified according to the electric charge of their P4 pocket. HLA–DRB1 alleles *0103, *0402, *07, *08, *11 (except *1107), *12, and *13 have a neutral or negative P4 charge and are called DRB1*XP4n. HLA–DRB1*03, *0403, *0406, *0407, *0901, *1107, *14, *15, and *16 have a positive P4 charge and are called DRB1*XP4p.

Results

Among the SE‐negative subjects, DRB1 genotypes with 1 or 2 DRB1*XP4n alleles were significantly overrepresented in the control subjects compared with the RA patients, whereas DRB1*XP4p/XP4p genotypes were equally represented in the patients and controls. In single‐dose SE–positive subjects, SE/XP4n genotypes were equally represented in the patients and controls. However, SE/XP4p genotypes were significantly overrepresented in the RA patients.

Conclusion

The DRB1*X allele polymorphism influences susceptibility to RA. Alleles that have a neutral or negative electric charge in their P4 pocket (DRB1*XP4n), such as DRB1*0103, *0402, *07, *08, *11 (except *1107), *12, and *13, protect against RA. Alleles that have a positive electric charge in their P4 pocket (DRB1*XP4p), such as DRB1*03, *0403, *0406, *0407, *0901, *1107, *14, *15, and *16, have no influence on the predisposition to RA.

     

Rheumatoid factor,HLA–DR4, and allelic variants of DRB1 in women with recent-onset rheumatoid arthritis

Objective. To examine the relationship of rheumatoid factor (RF) to HLA–DR4 and alleles of DRB1 in women with recent-onset rheumatoid arthritis (RA). Methods. Incident cases of RA were identified as part of a prospective, population-based case–control study. HLA typing was completed for 246 cases meeting criteria for definite or classic RA. Results. One hundred thirty-six patients (55%) were positive for DR4, and 130 (53%) were RF positive. DR4 was found to be strongly associated with seropositivity (odds ratio 4.1, P < 0.0001). Patients with a shorter interval from RA onset to RF testing had a higher frequency of seropositivity than those with a longer interval (≤18 months 60%, >18 months 33%). Further analysis of patients who had RF testing within 18 months of RA onset showed that the frequency of seropositivity was significantly greater among DR4-positive patients who had the shared sequence stretch of DRβ1 associated with RA susceptibility (76% RF positive) than among DR1-positive patients who had this sequence (45% RF positive) (odds ratio 3.8, P = 0.01). Moreover, the frequency of seropositivity among DR1-positive patients with the sequence did not differ from that among all patients without the shared sequence (47%) (odds ratio 0.9, P = 0.8). Conclusion. HLA–DR4 is strongly associated with seropositivity in women with recent-onset RA. The amino acid sequence of DRβ1 that is associated with susceptibility to RA and is shared between DR4 and DR1 appears not to be the primary determinant of seropositivity in these women.