High-resolution HLA-DRB1 Genotyping Research Articles

HLA-DRB1 Amino Acid Positions and Residues Associated with Antibody-positive Rheumatoid Arthritis in Black South Africans.

To investigate the association of specific amino acid positions, residues, and haplotypes of HLA-DRB1 in black South Africans with autoantibody-positive rheumatoid arthritis (RA). High-resolution HLA-DRB1 genotyping was performed in 266 black South Africans with autoantibody-positive RA and 362 ethnically and geographically matched controls. The alleles were converted to specific amino acid residues at polymorphic sites for downstream analyses. Logistic regression models were used to test whether variability at site, specific amino acid residues, and haplotypes (constructed from positions 11, 71, and 74) were associated with RA. Of the 29 amino acid positions examined, positions 11, 13, and 33 (permutation p = 3.4e-26, 1.2e-27, and 2.1e-28, respectively) showed the strongest association with RA. Univariate analyses of individual amino acid residues showed valine at position 11 (OR 5.1, 95% CI 3.7-7.0) and histidine at position 13 (OR 6.1, 95% CI 4.2-8.6) conferred the highest risk. The valine containing haplotypes of position 11, 71, 74, V_K_A conferred the most risk (OR 4.52, 95% CI 2.68-7.61) and conversely the haplotype with serine at this position, S_K_R, conferred the most protection (OR 0.83, 95% CI 0.61-1.15). Autoantibody-positive RA in black South Africans is associated with histidine at position 13 and valine at position 11 of HLA-DRB1, and haplotypes with valine at position 11 conferred the highest risk; conversely, serine at position 11 conveyed protection.

A123: HLA Associations in a Matched Cohort of Juvenile Idiopathic Arthritis Children With and Without Uveitis

Background/Purpose:Studies have shown that HLA‐DRB1*8, 11 and 13 are strong risk alleles for various juvenile idiopathic arthritis (JIA) subtypes. There are few studies investigating the role of HLADRB1 alleles in children with uveitis. Our objective is to determine the association of these alleles with uveitis in a matched cohort of children with JIA and JIAassociated uveitis (JIA‐U). We will also explore associations with uveitis complications and the need for antitumor necrosis factor (TNF) agents.Methods:We matched children with JIA and JIA‐U on race, ethnicity, sex, age at arthritis diagnosis, and JIA subtype. We included Non‐Hispanic White (NHW) controls. We performed high‐resolution HLADRB1 genotyping. Odds ratios and 95% confidence intervals are presented. In some instances, exact confidence intervals and p‐value are provided due to small sample sizes.Results:There were 373 controls, 43 children with JIA‐U and 48 with JIA of whom 37 were matched. Each matched group had 29 (78.4%) females and 28 children with oligoarticular (6 extended, 22 persistent) and 9 polyarticular rheumatoid factor (RF) negative JIA.In our matched analysis comparing children with JIA‐U and JIA, there was a difference in the frequency of carriage of DRB1*11 (35.1% vs. 18.9%) and both DRB1*11 and DRB1*13 alleles (16.2% vs. 2.7%) which approached significance, reflecting our modest sample size (OR 2.32, p = 0.116 and OR 6.97, p = 0.107, respectively).In comparison with controls, children with JIA and JIA‐U had increased odds of having DRB1*8 (OR 5.54, p < 0.001 and OR 9.00, p < 0.001, respectively) and DRB1*13 (OR 2.38, p = 0.005 and OR 2.40, p = 0.007). Additionally, compared to controls, children with JIA and JIA‐U had greater odds of having at least one of the following: DRB1*8, 11 or 13 (OR 4.27, p < 0.001 and OR 5.37, p < 0.001) and DRB1*11 or 13 (OR 2.30, p = 0.006 and OR 2.29, p = 0.010). Only children with JIA‐U had increased odds of having DRB1*11 (OR = 2.22, p = 0.024), and carriage of both DRB1*11 and 13 (OR 9.92, p < 0.001).No increase in allele frequency was noted with regards to ocular complications or the use of anti‐TNF agents in children with JIA‐U. Comparison of HLA‐DRB1 in children with JIA and JIA‐U HLA Configuration % OR p value Matched JIA (N = 37) vs JIA‐U (N = 37) JIA (N = 48) vs controls JIA‐U (N = 43) vs controls DRB1*8 21.6% vs. 27.0% 22.9% vs. 5.1% 32.6% vs. 5.1% OR 1.34 OR 5.54 OR 9.00 P=NS P<0.001 P <0.001 DRB1*11 18.9% vs. 35.1% 18.9% vs. 16.4% 30.2% vs. 16.4% OR 2.32 OR 1.18 OR 2.22 P=0.116 P=NS P=0.024 DRB1*13 54.1% vs. 54.1% 41.7% vs. 23.1% 41.9% vs. 23.1% OR 1.000 OR 2.38 OR 2.40 P=NS P=0.005 P=0.007 DRB1*8, 11 or 13 78.4% vs. 81.1% 75.0% vs. 41.3% 79.1% vs. 41.3% OR 1.18 OR 4.27 OR 5.37 P=NS P <0.001 P <0.001 DRB1*11 or 13 64.9% vs. 62.2% 58.3% vs. 37.8% 58.1% vs. 37.8% OR 1.12 OR 2.30 OR 2.29 P=NS P=0.006 P=0.010 DRB1*11/8 2.7% vs. 5.4% 4.2% vs. 1.1% 4.7% vs. 1.1% OR 2.06 OR 3.95 OR 4.50 P=NS P=NS P=NS DRB1*11/13 2.7% vs. 16.2% 2.1% vs. 1.6% 14.0% vs. 1.6% OR 6.97 OR 1.30 OR 9.92 P=0.107 P=NS p<0.001 DRB1*13/8 2.7% vs. 5.4% 2.1% vs. 0.5% 7.0% vs. 0.5% OR 2.06 OR 3.95 OR 13.91 P=NS P=NS P=0.009 NS = not significantConclusion:This is the first matched analysis of children with JIA and JIA‐U. Carriage of both DRB1*11 and 13 appear to increase the risk for developing uveitis. Further studies should be conducted in a larger matched cohort of children with JIA, and the role of HLA in the risk for ocular complications and severe disease should be considered.

Иммуногенетические аспекты раннего ревматоидного артрита

The study is aimed to investigate the distribution of alleles of HLA-DRB1 gene in patients with early rheumatoid arthritis and healthy individuals in Russian population, and evaluate their significance as molecular genetic markers of rheumatoid arthritis predisposition and protection. The association between alleles of HLA-DRB1 genes, antibodies to cyclic citrullinated peptides and IgM rheumatoid factor was also studied. Low and high resolution HLA-DRB1 genotyping were compared. In the cohort of patients with early rheumatoid arthritis, the alleles of HLA-DRB1 gene were found to be markers of rheumatoid arthritis protection/risk, especially in the homozygous state. They determined production of antibodies to cyclic citrullinated peptides but were not associated with rheumatoid factor IgM levels. These findings support different autoimmune mechanisms of rheumatoid arthritis pathogenesis.

G.P.63 High-resolution analysis of HLA-DRB1 alleles and diplotypes in an Australian inclusion body myositis cohort

In Caucasians, susceptibility to sporadic inclusion body myositis (s-IBM) is associated with the HLA-DR3 serotype and the HLA-DRB1∗0301 allele which encodes it, and with the extended 8.1 MHC ancestral haplotype. Most previous HLA studies in s-IBM have used serological typing or low-resolution (2-digit) genotyping to identify disease-associated alleles, and the contribution of alleles other than HLA-DRB1∗0301 and of the complementary in trans allele at the HLA-DRB1 locus has received little attention. In the present study we performed high-resolution (4-digit) HLA-DRB1 genotyping in an Australian cohort of 105 s-IBM patients and 189 controls from the Busselton Population Study and analysed risk-associated alleles and effects on age-at-onset (AAO) of the disease. Case–control logistic regression analysis showed that, apart from the strongly associated HLA-DRB1∗0301 allele (OR 13.6), HLA-DRB1∗0101 (OR 3.65) and HLA-DRB1∗1301 (OR 3.31) are independent risk alleles. A number of other alleles, HLA-DRB1∗0401, ∗0404, ∗0701, ∗0901, ∗1101 and ∗1501 were reduced in frequency in s-IBM cases and may be protective. We evaluated the influence of allele combinations on disease risk and found that the strongest estimated risk is with the HLA-DRB1∗0301/∗0101 diplotype, while other allele combinations have diminishing risk effects. HLA-DRB1∗0301 was associated with an AAO 4.3 years earlier than other alleles and DRB1∗1301 with an AAO 4.5 years later, despite it being a risk factor. The findings indicate that the influence of HLA-DRB1 in s-IBM is complex, influencing both disease risk and AAO, and that allelic interactions at the HLA-DRB1 locus contribute to disease susceptibility.

G.P.61 Influence of HLA-DRB3 on susceptibility to sporadic inclusion body myositis

In Caucasians, sIBM susceptibility is associated with the HLA-DRB1*0301 allele and the extended 8.1 MHC ancestral haplotype (HLA-A1, B8, DRB3*0101, DRB1*0301, DQB1*0201). Previous studies suggested that HLA-DRB1*0301 itself may not be the risk-conferring allele, but is in linkage disequilibrium with the susceptibility allele. In a recent recombinant mapping study Scott et al. (Neuromuscular Disorders 2011;235:77–83) refined the susceptibility region to a 172kb segment including HLA-DRB3, HLA-DRA and BTNL2. In this study we analysed the carrier frequency of HLA-DRB3 and its alleles, DRB3*0101, DRB3*0202 and DRB3*0301, in 75 biopsy-confirmed sIBM patients of largely Anglo-Celtic origin who had previously undergone high-resolution HLA-DRB1 genotyping. HLA-DRB3 genotyping was performed using PCR–RFLP analysis. As the second expressed HLA-DRB locus, when present, can be either HLA-DRB3 or HLA-DRB4 or HLA-DRB5, carriage of HLA-DRB4 and HLA-DRB5 was also determined, by the presence or absence of amplified DRB4 or DRB5 specific amplicons. The percentage of sIBM individuals who carried a second DRB locus was higher than published figures from a normal Welsh population study (95.2% vs 74.2%, p<0.001; Dorak et al., Genes & Immunity 2002; 3:263–9), as was the frequency of HLA-DRB3 homozygosity (65% vs 14%; p<0.001). Fifty-one of the 75 sIBM patients carried the HLA-DRB3*0101 allele, compared with 54/75 who were HLA-DRB1*0301 carriers; 50/75 carried both DRB1*0301 and DRB3*0101. Thirty of the 51 DRB3*0101 carriers were homozygous, and the allelic frequency of DRB3*0101 was significantly higher than that of DRB1*0301 (52.7% vs 39%, p=0.02). Our findings suggest that preferential carriage of HLA-DRB3 as the second expressed HLA-DRB locus, and homozygosity for HLA-DRB3*0101, which is in linkage dysequilibrium with HLA-DRB1*0301, are associated with increased susceptibility to sIBM.

High-resolution HLA-DRB1 genotyping in an Australian inclusion body myositis (s-IBM) cohort: An analysis of disease-associated alleles and diplotypes

We performed high-resolution (4-digit) HLA-DRB1 genotyping in an Australian cohort of 105s-IBM patients and 189 controls. Our findings showed that whilst the strongest association was with the HLA-DRB1*03:01 allele and the HLA-DRB1*03:01/*01:01 diplotype, HLA-DRB1*01:01 and HLA-DRB1*13:01 are also risk alleles. A number of other alleles, HLA-DRB1*04:01, *04:04, *07:01, *09:01, *11:01 and *15:01, as well as the HLA-DRB1*03:01/*04:01 and HLA-DRB1*03:01/*07:01 diplotypes were reduced in s-IBM cases and may be protective. The HLA-DRB1*03:01 and HLA-DRB1*13:01 alleles also appear to have an influence on the age at onset of the disease and severity of muscle weakness. Our findings indicate that the influence of HLA-DRB1 in s-IBM is complex and that epistatic interactions at the HLA-DRB1 locus contribute both to disease susceptibility and to the clinical phenotype.

Smoking interacts with HLA-DRB1 shared epitope in the development of ACPA-positive rheumatoid arthritis: a case-control study from Malaysian epidemiological investigation of rheumatoid arthritis (MyEIRA)

Backgroundand objectivesTo investigate whether smoking and HLA-DRB1 shared epitope (SE) alleles may interact differently in the development of the two major subgroups of rheumatoid arthritis (RA), anti-citrullinated proteins antibody (ACPA)-positive...

Smoking interacts with HLA-DRB1 shared epitope in the development of anti-citrullinated protein antibody-positive rheumatoid arthritis: results from the Malaysian Epidemiological Investigation of Rheumatoid Arthritis (MyEIRA)

IntroductionRheumatoid arthritis (RA) is a multifactorial autoimmune disease in which genetic and environmental factors interact in the etiology. In this study, we investigated whether smoking and HLA-DRB1 shared-epitope (SE) alleles interact differently in the development of the two major subgroups of rheumatoid arthritis (RA), anti-citrullinated proteins antibody (ACPA)-positive and ACPA-negative disease, in a multiethnic population of Asian descent.MethodsA case-control study comprising early diagnosed RA cases was carried out in Malaysia between 2005 and 2009. In total, 1,076 cases and 1,612 matched controls participated in the study. High-resolution HLA-DRB1 genotyping was performed for shared-epitope (SE) alleles. All participants answered a questionnaire on a broad range of issues, including smoking habits. The odds ratio (OR) of developing ACPA-positive and ACPA-negative disease was calculated for smoking and the presence of any SE alleles separately. Potential interaction between smoking history (defined as "ever" and "never" smoking) and HLA-DRB1 SE alleles also was calculated.ResultsIn our multiethnic study, both the SE alleles and smoking were associated with an increased risk of developing ACPA-positive RA (OR SE alleles, 4.7; 95% confidence interval (CI), 3.6 to 6.2; OR smoking, 4.1; 95% CI, 1.9 to 9.2). SE-positive smokers had an odds ratio of ACPA-positive RA of 25.6 (95% CI, 10.4 to 63.4), compared with SE-negative never-smokers. The interaction between smoking and SE alleles was significant (attributable proportion due to interaction (AP) was 0.7 (95% CI, 0.5 to 1.0)). The HLA-DRB1*04:05 SE allele, which is common in Asian populations, but not among Caucasians, was associated with an increased risk of ACPA-positive RA, and this allele also showed signs of interaction with smoking (AP, 0.4; 95% CI, -0.1 to 0.9). Neither smoking nor SE alleles nor their combination was associated with an increased risk of ACPA-negative RA.ConclusionsThe risk of developing ACPA-positive RA is associated with a strong gene-environment interaction between smoking and HLA-DRB1 SE alleles in a Malaysian multiethnic population of Asian descent. This interaction seems to apply also between smoking and the specific HLA-DRB1*04:05 SE allele, which is common in Asian populations but not in Caucasians.

Spinal cord involvement in multiple sclerosis: A correlative MRI and high-resolution HLA-DRB1 genotyping study

Background There have been few magnetic resonance imaging (MRI) studies of the spinal cord in large multiple sclerosis (MS) patient cohorts and little is known about correlations between cord lesions and human leukocyte antigen (HLA) alleles. Objective To investigate the spectrum of MRI changes in the spinal cord in MS and associations with the HLA-DRB1 genotype. Methods Two hundred and fifty two consecutive MS patients from the Perth Demyelinating Diseases Database had MRI of the spinal cord and brain and high-resolution HLA-DRB1 genotyping. The numbers, locations, shape and segmental extent of cord lesions were analysed and were correlated with carriage of individual HLA-DRB1 alleles and diplotypes. Results Focal cord lesions were present in 82.9% of cases, with numbers being maximal in the cervical cord and increasing with disease duration. Focal lesions were usually round or oval in shape but in 35% of cases subpial wedge-shaped lesions were present. Diffuse cord involvement was present in 10% of cases and correlated with carriage of HLA-DRB1*1501 and with higher disability. Carriage of the minor allele HLA-DRB1*0701 was significantly associated with numbers of wedge-shaped lesions and lesions in the cervical cord, while HLA-DRB1*1104 and DRB1*0103 were significantly associated respectively with higher and lower numbers of thoracic cord lesions. HLA-DRB1*1501 and the HLA-DRB1*11 sub-alleles DRB1*1101 and DRB1*1104 were significantly associated with the segmental length of cord lesions. Conclusions Our study is the first to investigate the frequency of subpial wedge-shaped lesions in the cord in vivo and has provided preliminary evidence that HLA-DRB1 alleles may play a role in determining the severity and extent of spinal cord involvement in MS.

HLA-DRB1 allele heterogeneity influences multiple sclerosis severity as well as risk in Western Australia

Susceptibility to multiple sclerosis (MS) has been consistently associated with the Human Leukocyte Antigen (HLA)-DRB1⁎1501 genotype, however effects on disease severity and clinical outcome have varied in different populations. We present the results of a high-resolution HLA-DRB1 genotyping and genotype–phenotype correlation study in a large West Australian MS cohort. Our findings indicate that in this population, which is of largely Anglo-Celtic and Northern European origin, HLA-DRB1⁎1501 is not only a strong determinant of disease risk but may also be associated with disease severity as measured by the Multiple Sclerosis Severity Score (MSSS), with the MSSS increasing by an estimated 0.51 per DRB1⁎1501 allele. We also found evidence that the HLA-DRB1⁎1201 allele is associated with less severe disease.

Presence of CSF oligoclonal bands (OCB) is associated with the HLA-DRB1 genotype in a West Australian multiple sclerosis cohort

High-resolution HLA-DRB1 genotyping was performed in 97 OCB-positive and 68 OCB-negative cases with demyelinating disease to determine the influence of HLA-DRB1 alleles on the presence of OCB in a West Australian multiple sclerosis (MS) cohort. Carriage of the HLA-DRB1*1501 allele was associated with both OCB-positive and OCB-negative MS compared with controls, but more strongly with the OCB-positive group, and increased the likelihood of having OCB 2.1-fold with evidence of a dominant dose–effect. The HLA-DRB1*0301 allele was negatively correlated with OCB, with all homozygotes OCB-negative, suggesting a possible recessive protective effect of HLA-DRB1*0301. There was no significant correlation between OCB and the DRB1*04 alleles which have been associated with OCB-negative MS in previous Swedish and Japanese studies. Evidence of allelic interactions was found with HLA-DRB1*1501/*1301 heterozygotes having a reduced frequency of OCB and HLA-DRB1*0301/*0401 heterozygotes all being OCB-negative. These findings confirm the strong association between HLA-DRB1*1501 and OCB which has been found in other populations but indicate that the influence of other HLA-DRB1 alleles varies in different populations. Our study is the first to show that HLA-DRB1 allele interactions and dose–effects influence the frequency of OCB.

Gene–environment interaction between HLA-DRB1 shared epitope and heavy cigarette smoking in predicting incident rheumatoid arthritis

Background:Previous studies have reported an interaction between ever cigarette smoking and the presence of the human leukocyte antigen (HLA)-DRB1 shared epitope (SE) genotype and rheumatoid arthritis (RA) risk. To address...

Characteristics of Vogt-Koyanagi-Harada Disease in a French Cohort: Ethnicity, Systemic Manifestations, and HLA Genotype Data

Purpose: To assess in patients followed in a French referral center the clinical spectrum of Vogt-Koyanagi-Harada (VKH) disease and the HLA-DRB1*04 genotype. Methods: Patients previously diagnosed as having VKH disease were re-evaluated in a cross-sectional study using the VKH Committee's revised criteria. High-resolution HLA-DRB1 genotyping was performed. Results: Eleven white patients satisfied ophthalmologic diagnostic criteria. All originated from Mediterranean countries. Nine and 3 patients had neurologic and/or cutaneous abnormalities, respectively. Among DRB1*04-positive patients, the HLA-DRB1*0405 subtype was 71%. Conclusion: These VKH patients predominantly had an incomplete form. The HLA-DRB1*0405 subtype allele was enriched in a group of Mediterranean stock.

High-resolution HLA-DRB1 and DQB1 genotyping in Japanese patients with testicular germ cell carcinoma.

We report for the first time the frequency distributions of HLA-DRB1 and -DQB1 genes in 55 patients with testicular germ cell carcinoma (TGC) using the modified PCR-RFLP method and compare the results with those for 1216 healthy Japanese control subjects. The modified PCR-RFLP method produced accurate, reproducible cleavage patterns that are easily discriminated. HLA-DRB1*0410 was the susceptibility allele (RR = 3.26, P = 0.006) and DQB1*0602 appears to be a candidate protective allele (RR = 0.26, P = 0.02) for TGC in the Japanese. None of the HLA-DRB1 and -DQB1 alleles showed a specific tendency for histological type or clinical stage of the tumours. Previous studies based on serotyping methods failed to show these allelic associations. High-resolution genotyping is essential because the peptide-binding domain of MHC class II molecules is determined more precisely by their genotypes than by their serotypes. In addition, inherent technical difficulties and typing errors of up to 25% make serotyping inefficient. Our results suggest that high-resolution genotyping is a useful genetic marker to determine risk for TGC.

40 - High resolution HLA-DRB1 genotyping in patients with RCC

40 - High resolution HLA-DRB1 genotyping in patients with RCC