A variant of HLA-DR4 determines susceptibility to rheumatoid arthritis in a subset of Israeli Jews

High-resolution HLA genotyping identifies risk alleles in both class I and II for primary autoimmune neutropenia in early childhood in a Danish cohort

HLA studies in patients with autoimmune neutropenia (AIN) have shown very consistent results for the association with HLA class II alleles at low resolution. This study aimed to examine the association of both HLA class I and class II at high resolution to clarify the contribution of risk alleles to the disease. A total of 107 AIN patients were genotyped for six loci of HLA class I (HLA-A, -B and -C) and class II (HLA-DRB1, -DQB1, and -DPB1) genes by a high-resolution (3-field, 6-digit) analysis and compared with HLA typing of 1000 healthy controls. Compared with the controls, the allele frequencies were significantly higher in AIN patients for A*02:17:01G, C*01:02:01G, DRB1*10:01:01G, DRB1*14:01:01G, DRB1*16:01:01G, DQB1*05:02:01G, and DQB1*05:03:01G but lower significant for C*03:04:01G, DRB1*04:01:01G, DRB1*13:02:01G, DQB1*03:02:01G, and DQB1*06:04:01G. Frequently associated two-locus haplotypes were found to be DRB1*10:01:01G-DQB1*05:01:01G and DRB1*16:01:01G-DQB1*05:02:01G, while the S2 (Q- or D-KRAA) shared epitope (SE) was associated with lower risk. A unique association with HLA alleles was observed between patients with specific anti-HNA-1a antibodies and broad-reacting anti-FcγRIIIb. Anti-HNA-1a antibody-positive patients were associated with C*01:02:01G, DRB1*01:01:01G, DRB1*16:01:01G, DQB1*05:01:01G, DQB1*05:02:01G, DQB1*06:04:01G, and DPB1*10:01:01G; the two-locus haplotypes DRB1*01:01:01G-DQB1*05:01:01G and DRB1*16:01:01G-DQB1*05:02:01G; and the S3P (Q- or R-RRAA) SE. Anti-FcγRIIIb antibody-positive patients were associated with the alleles A*02:17:01G, DRB1*10:01:01G, and DQB1*05:02:01G; the haplotypes DRB1*10:01:01G-DQB1*05:01:01G and DRB1*11:01:02G-DQB1*05:02:01G; and the S3D (DRRAA) SE. The different associations regarding FcγRIIIb antibody specificities could indicate disease heterogeneity.

HLA associations in inflammatory arthritis: emerging mechanisms and clinical implications

Our understanding of the mechanisms underlying HLA associations with inflammatory arthritis continues to evolve. Disease associations have been refined, and interactions of HLA genotype with other genes and environmental risk factors in determining disease risk have been identified. This Review provides basic information on the genetics and molecular function of HLA molecules, as well as general features of HLA associations with disease. Evidence is discussed regarding the various peptide-dependent and peptide-independent mechanisms by which HLA alleles might contribute to the pathogenesis of three types of inflammatory arthritis: rheumatoid arthritis, spondyloarthritis and systemic juvenile idiopathic arthritis. Also discussed are HLA allelic associations that shed light on the genetic heterogeneity of inflammatory arthritides and on the relationships between adult and paediatric forms of arthritis. Clinical implications range from improved diagnosis and outcome prediction to the possibility of using HLA associations in developing personalized strategies for the treatment and prevention of these diseases.

HLA-DRB1 shared epitope genotyping using the revised classification and its association with circulating autoantibodies, acute phase reactants, cytokines and clinical indices of disease activity in a cohort of South African rheumatoid arthritis patients

Introduction

The revised shared epitope (SE) concept in rheumatoid arthritis (RA) is based on the presence (S) or absence (X) of the SE RAA amino acid motif at positions 72 to 74 of the third hypervariable region of the various human leucocyte antigen (HLA)-DRB1 alleles. The purpose of this study was to investigate SE subtypes on the basis of the American College of Rheumatology 1987 revised criteria for the classification of RA in a cohort of South African RA patients (n = 143) and their association with clinical and circulating biomarkers of disease activity (autoantibodies, acute phase reactants and cytokines).

Methods

Genomic DNA was analysed using high-resolution recombinant sequence-specific oligonucleotide PCR typing of the HLA-DRB1 allele. Subtypes of the SE were classified according to the amino acids at positions 72 to 74 for the RAA sequence, and further sub-divided according to the amino acids at positions 70 and 71, which either contribute to (S2, S3P), or negate (S1, S3D) RA susceptibility. Disease activity was assessed on the basis of (1) Disease Activity Score in 28 joints using C-reactive protein (CRP), (2) rheumatoid factor (RF), (3) CRP and (4) serum amyloid A by nephelometry, anticyclic citrullinated peptide antibodies (aCCP) by an immunofluorometric procedure, and cytokines by multiplex bead array technology.

Results

Of the 143 RA patients, 81 (57%) were homozygous (SS) and 50 (35%) were heterozygous (SX) for the SE alleles with significant overexpression of S2 and S3P (respective odds ratios (ORs) 5.3 and 5.8; P < 0.0001), and 12 (8%) were classified as no SE allele (XX). Both the SS and SX groups showed a strong association with aCCP positivity (OR = 10.2 and P = 0.0010, OR = 9.2 and P = 0.0028, respectively) relative to the XX group. Clinical scores and concentrations of the other biomarkers of disease activity (RF, CRP and T helper cell type 1 (Th1), Th2, macrophage and fibroblast cytokines) were also generally higher in the SS group than in the SX and XX groups.

Conclusions

RA susceptibility alleles investigated according to revised criteria for the classification of RA were significantly increased in South African RA patients and strongly associated with aCCP in particular as well as with circulating cytokines and disease severity.

HLA-DRB1 genotyping in patients with juvenile idiopathic arthritis in Taiwan

The object of this study was to investigate whether there is an association between HLA-DRB1 alleles and the development of juvenile idiopathic arthritis (JIA) in Taiwan. HLA-DRB1 alleles were studied in 60 patients with JIA and 200 healthy controls using polymerase chain reaction (PCR)/sequence-specific oligonucleotide probes (SSO). The frequency of HLA-DRB1*0405 in patients with JIA was found to be significantly higher than that in healthy controls [odds ratio (OR) 2.64, 95% confidence interval (CI) 1.01-6.91]. The DRB1*0405 allele was significantly associated with the development of both polyarthritis (OR 4.30, 95% CI 1.34-13.80) and oligoarthritis (OR 3.27, 95% CI 1.01-10.58). The frequency of HLA-DRB1*1502 was higher in Taiwanese JIA patients with systemic arthritis than in controls (OR 18.09, 95% CI 2.25-145.73). We conclude that, in Taiwan, HLA-DRB1*0405 is associated with the development of polyarthritis and oligoarthritis in children, and HLA-DRB1*1502 is associated with the development of systemic arthritis.

HLA-DRB1 alleles encoding the “shared epitope” are associated with susceptibility to developing rheumatoid arthritis whereas HLA-DRB1 alleles encoding an aspartic acid at position 70 of the β-chain are protective in Mexican mestizos

The risk to develop rheumatoid arthritis (RA) has been associated with the presence of HLA-DRB1 alleles encoding the "shared epitope" (SE). Additionally, HLA-DRB1 alleles encoding an aspartic acid at position 70 (D70+ ) have been associated with protection against the development of RA. In this study we tested the association between either SE or D70+ and rheumatoid arthritis in Mexican Mestizos. We included 84 unrelated Mexican Mestizos patients with RA and 99 unrelated healthy controls. The HLA-typing was performed by PCR-SSO and PCR-SSP. We used the chi-squared test to detect differences in proportions of individuals carrying at least one SE or D70+ between patients and controls. We found that the proportion of individuals carrying at least one HLA-DRB1 allele encoding the SE was significantly increased in RA cases as compared to controls (p(c) = 0.0004, OR = 4.1, 95% CI = 2.2-7.7). The most frequently occurring allele was HLA-DRB1*0404 (0.161 vs 0.045). Moreover, we observed a significantly increased proportion of HLA-DRB1 SE+ cases with RF titers above the median (p = 0.005). Conversely, the proportion of individuals carrying at least one HLA-DRB1 allele encoding the D70+ was significantly decreased (p(c) = 0.004, OR = 0.4, 95% CI 0.2-0.7) among RA patients compared with controls. In conclusion, the SE is associated with RA in Mexican Mestizos as well as with the highest titers of RF.

Inhibition of T-cell activation with HLA-DR1/DR4 restricted Non-T-cell stimulating peptides

It has been reported that collagen II (CII) derived peptide CII263-272 induced T-cell activation via its amino acids responsible for T-cell receptor (TCR) recognition. The impact of substitution of the TCR contacting amino acids of CII263-272 on T-cell activation was evaluated in this study using a panel of altered CII263-272 peptides. Computer modeling revealed that the side chains of 263F and 266E in CII263-272 were coupled with amino acids on alpha1 and beta1 chains of HLA-DR1 or -DR4, mainly via hydrogen bonds, whereas the side chains of 267Q and 270K protrude out of the cleft and might be recognized by TCR. Intracellular delivery of the altered peptides, and their binding to HLA-DR1 and -DR4 molecules on cell surface, were demonstrated by confocal microscopy and flow cytometry. The results also revealed that the substitution of 267Q, 268G, 269P, and 270K individually or consecutively by alanine (A) or glycine (G) led to weak or non-T-cell responses. Furthermore, the altered peptides with 270K substitution (270A) or with consecutive substitution of 268G, 269P, and 270K (sub268-270) dramatically inhibited T-cell activation. It is suggested that the altered peptides derived from CII263-272 with substitution of amino acids responsible for TCR contact might be of inhibitory effect on T-cell responses.

Reshaping the shared epitope hypothesis: HLA-associated risk for rheumatoid arthritis is encoded by amino acid substitutions at positions 67-74 of the HLA-DRB1 molecule

OBJECTIVE

To further analyze the association of HLA-DRB1 alleles with disease susceptibility in recent-onset rheumatoid arthritis (RA).

METHODS

One hundred sixty-seven Caucasian RA patients and 166 healthy controls were typed for HLA-DRB1.

RESULTS

The association of susceptibility to RA with the group of alleles encoding the shared epitope susceptibility sequences (SESSs) was confirmed in recent-onset RA. Among non-SESS alleles, DRB1*07, *1201, *1301, and *1501 showed significant protective effects. Even after correction for the influence of SESS alleles, significant independent protective effects of DRB1 alleles were observed. Protective alleles shared a third hypervariable region motif. Independent homozygosity effects were observed both for susceptibility and for protective alleles.

CONCLUSION

Nonsusceptibility alleles differ significantly with regard to RA risk. Protective alleles show clear homology at positions 67-74, often encoding isoleucine at position 67 or aspartic acid at position 70. Susceptibility and protective alleles both show homozygosity effects. Based on these results and on data reported in the literature, in order to incorporate the finding of differential risks among nonsusceptibility alleles, we propose to reshape the shared epitope hypothesis as follows: HLA-associated risk for RA is encoded by amino acid substitutions at positions 67-74 of the HLA-DRB1 molecule.

Combination of HLA-A and HLA class II alleles controls the susceptibility to rheumatoid arthritis

Two hundred and four unrelated Japanese patients with rheumatoid arthritis (RA) were typed for HLA by serological typing and DNA typing. The serological typing revealed that frequencies of HLA-A11, DR4, DR53 and DQ4 were increased and those of DR8 and DQ1 were decreased in the patients. The DNA typing has precisely defined the disease-associated HLA class II alleles; DRBl*0405, DQAl*03 and DQBl*0401 showed positive associations, while negative associations were found with DRBl*0803, DQAl*0103 and DQBl*0601. The risk for RA was found to be closely associated with particular amino acid sequences of DR-beta chain, including glycine residue at the 86th position in addition to those between 70 and 74, which are known to confer binding specificity and affinity to antigenic peptides. The observation that the frequency of HLA-A11 was increased in the DRBl*0405-positive patients suggested the interaction of these two alleles in the susceptibility to RA. On the other hand, the frequency of DPB1*0201 was increased in the DRBl*0405-negative patients and the frequency of HLA-A2 was increased in the DPBl*0201-positive patients, especially in the younger onset group. These findings suggested that the combination of HLA-A2 and DPBl*0201 may confer the susceptibility in the DRBl*0405-negative patients. Our results suggested the possibility that the susceptibility to RA is controlled by the interaction of HLA-A and DRBl genes or by that of HLA-A and DPBl genes in different patient subgroups.

An HLA-DRB1-derived peptide associated with protection against rheumatoid arthritis is naturally processed by human APCs

Predisposition to rheumatoid arthritis (RA) is thought to be associated with HLA-DR1, -DR4, and -DR10. However, many epidemiological observations are better explained by a model in which the DQ alleles that are linked to these DR alleles, i.e., DQ5, DQ7, and DQ8, predispose to RA, while certain DR alleles have a dominant protective effect. All protective DRB1 alleles, e.g., *0402, *1301, and *1302, encode a unique motif, (70)DERAA(74). The protection may be explained by the presentation of DRB1-derived peptides by DQ to immunoregulatory T cells, because it was demonstrated in various autoimmune disease models that T cell responses to certain self-Ags can be involved in disease suppression. The aim of this study was to analyze whether peptides carrying the DERAA motif are naturally processed by human APC and presented in the context of the RA-predisposing DQ. Using a synthetic peptide carrying the DRB1*0402-derived sequence (65)KDILEDERAAVDTYC(79), we generated DERAA peptide-specific DQ-restricted T cell clones (TCC) from a DQ8 homozygous individual carrying DERAA-negative DR4 alleles. By analyzing the proliferation of these TCC, we demonstrated natural processing and presentation of the DERAA sequence by the APC of all the individuals (n = 12) carrying a DERAA-positive DRB1 allele and either DQ8 or the DQ8-related DQ7. Using a panel of truncated synthetic peptides, we identified the sequence (67)(I)LEDERAAVD(TY)(78) as the minimal determinant for binding to DQ8 and for recognition by the TCC. These findings support a model in which self-MHC-derived peptide can modulate predisposition to autoimmune disease in humans.

HLA class II association with rheumatoid arthritis: facts and interpretations

We have reviewed the literature on the association of HLA class II with rheumatoid arthritis (RA). Strong linkage disequilibrium among DQB1, DQA1 and DRB1 alleles makes it difficult to evaluate the individual contribution of each locus. Nonetheless, there is a strong case for the role of DQB1*03 and *04 combined with DQA1*03 in susceptibility to severe RA while DQB1*0501 combined with DQA1*0101 and *0104 weakly predisposes to a mild form of RA. However, it is also clear that DRB1*0401 has a particular role in predisposition to the most severe form of the disease while other DRB1 alleles might provide protection. We would like to propose that in RA, as in type I diabetes, both DQ and DR loci contribute to predisposition to the disease.

Racial origin and its effect on disease expression and HLA-DRB1 types in patients with rheumatoid arthritis: a matched cross-sectional study

OBJECTIVE

There are a significant number of patients with rheumatoid arthritis (RA) of North Indian or Pakistani origin (Asian) now living in the UK. RA has been poorly studied in this racial group. The aim of this study was to compare RA in this Asian group with RA in the indigenous northern European (European) population. It was hypothesized that these two racial groups would have different disease expressions and immunogenetics that could be relevant to pathogenesis, prognosis and therapy.

METHODS

One hundred and seven Asian RA patients, who fulfilled the 1987 American College of Rheumatology criteria, were stringently matched for age, sex and disease duration with 107 European RA patients, and were fully assessed.

RESULTS

The Asian RA patients had significantly fewer bony erosions [median Larsen score 58.5 (interquartile range 45.5-77.8) vs 68 (52-93) for European patients; P: = 0.0066, Mann-Whitney U:-test] and rarely had nodules (5.7 vs 20%, P: = 0. 0019, Fisher's exact test). The two groups had the same prevalence of rheumatoid factor positivity, number of swollen joints and level of inflammation (C-reactive protein). The Asian RA patients had a reduced prevalence of the conserved third allelic hypervariable region (3AHVR) (45 vs 82%, P: < 0.0001, Fisher's exact test), particularly DRB1*0401 (4.5 vs 55%). However, the prevalence of the conserved 3AHVR was significantly increased in the Asian RA patients compared with Asian controls. By contrast, the Asian patients had more tender joints [13.5 (7-22) vs 5.5 (2-11.8); P: < 0.0001 Mann-Whitney U:-test]. The Health Assessment Questionnaire score was also significantly worse in the Asians compared with the Europeans [median 2.0 (1.13-2.63) vs 1.25 (0.5-2.13), P: = 0.0001).

CONCLUSIONS

The Asian patients had similar levels of inflammation and less damage but more pain and disability than the matched European RA patients. Of the known prognostic factors for erosions (rheumatoid factor, conserved 3AHVR, swollen joints and C-reactive protein), only the conserved 3AHVR was reduced in the Asian RA patients, and this was consistent with their less erosive disease. These data also indicate the importance of pain as well as erosive damage in determining disability in Asian patients and stress the importance of adequate pain relief, in addition to disease suppression, when treating Asian RA patients.

Modelling the major histocompatibility complex susceptibility to RA using the MASC method

To explain the association between HLA-DRB1 gene and rheumatoid arthritis (RA), two main hypotheses have been proposed. The first, the shared epitope hypothesis, assumes a direct role of DRB1 in RA susceptibility. The second hypothesis assumes a recessive disease susceptibility gene in linkage disequilibrium with DRB1. To investigate these two hypotheses, we analysed data on the HLA-DRB1 and TNF-LT loci in 49 affected sib-pairs. We used the Marker Association Segregation Chi-square (MASC) method in which the genotype distribution of markers among index cases and the haplotype sharing in affected sib-pairs are jointly taken into account. With DRB1 data alone, both hypotheses were shown to fit but with analysis of TNF data, both hypotheses were strongly rejected. Thus the TNF data provided additional information for a better understanding of genetic susceptibility to RA than was previously possible using only HLA-DR data. A theoretical standpoint is addressed here on the advisability of using different linked markers in a candidate region for modelling the contribution of this region in disease susceptibility.

Relevant residues of DRbeta1 third hypervariable region contributing to the expression and to severity of rheumatoid arthritis (RA) in Mexicans

Rheumatoid arthritis (RA) is a chronic autoimmune disease leading to destruction of the joints. Residues at positions 67-74 of the DRB1 third hypervariable region are involved in susceptibility (S) and resistance (P) to RA. DNA from 83 patients and 175 controls, all of them Mexican Mestizos were oligotyped using PCR-SSOP and PCR-SSP. The (S) alleles are DRB*0404 (p = 0.000004), *0401 (p = 0.007) and *1001 (p = 0.008). Those associated with P are DRB1*0701 (p = 0.0001); *1101 (p = 0.01); *1503 (p = 0.02); *0801 (p = 0.04); *1401 (p = 0.04). Susceptibility/protection are recessive traits; SS genotypes are increased in the patients (p = 0.0003) while PP genotypes are decreased in them (p = 0.00004). The motif at 67-74 and the valine or glycine at position 86 are relevant in the development and severity of RA in Mexicans. The associations suggest that residues 67, 70, 71 are central for susceptibility. The P alleles have D-70 or carry V-86 in the absence of D-70. Thus, susceptibility/protection depends on the combination of basic residues at these positions and a non-polar aa at 86 contributes to resistance. Severity is also HLA influenced. DQA1*03011-DQB1*0302 are associated to severe lesions in the presence of any DR4 subtype. Analyzing different ethnic groups is essential to elucidate the etiopathogenesis of RA.

The HLA-DQ7 and -DQ8 associations in DR4-positive rheumatoid arthritis patients. A combined analysis of data available in the literature

Several different lines of evidence have demonstrated that inherited susceptibility to rheumatoid arthritis (RA) is associated with the DRB1 genes encoding the HLA-DR4 and HLA-DR1 molecules. A contrasting hypothesis has recently been proposed, suggesting that, in general, the DRB1 locus is associated with protection to RA and that the RA-associated DRB1 alleles are not responsible for the primary disease association but merely permissive for the susceptibility conferred by the HLA-DQ alleles with which they are in linkage disequilibrium. We have performed a critical review of the literature on the HLA association in RA with special emphasis on studies in which both an HLA-DR and -DQ association has been investigated. Our analyses provide strong evidence against the hypothesis that HLA-DQ molecules play a major role in the general susceptibility to RA. Thus, the strongest association in rheumatoid arthritis is with DRB1 genes rather than DQB1 genes.

The role of HLA-DR-DR and HLA-DR-DP interactions in genetic susceptibility to rheumatoid arthritis

In order to analyze the relationships between the DR and DP loci in the genetic susceptibility to RA, HLA-DRB1 and -DPB1 polymorphism was studied in 155 RA patients compared to 150 controls, using a reverse dot-blot analysis. Our data were consistent with the involvement of the amino acid in position 71 of the third hypervariable region of the DR beta 1 chain in susceptibility to the disease. The higher risk for RA was observed in patients who carried the association of a lysine (K), characterizing the DRB1* 0401 susceptibility allele, with an arginine (R), observed in all the other DRB1* susceptibility alleles (21.9% vs 0.6%, p(c) < 10(-6), OR = 42) In the absence of arginine, the presence of lysine was still associated with the disease (33% vs 19%, p(c) < 0.03, OR = 2). In contrast, in the absence of lysine, the frequency of arginine in position 71 was similar in patients and controls (30% vs 26%, p = NS). On another hand, the analysis of the HLA-DPB1 locus showed that the DPB1 *0401 allele frequency was significantly increased in the RA patient group (n = 47) who expressed only arginine at the position 71 of the beta 1 chain (82% vs 56% in controls, p < 0.008), with role of HLA-DR--DR and -DR-DP interactions in the genetic susceptibility to RA.

Polymorphism of HLA-DRB, -DQA1, and -DQB1 in rheumatoid arthritis in Asian Indians: association with DRB1*0405 and DRB1*1001

We investigated the DRB, DQA1, and DQB 1 polymorphism and haplotypes in sporadic and familial RA subjects of Asian Indian origin by PCR oligotyping using biotinylated SSOPs. Molecular subtyping of DRB 1*04 in RA patients showed strongest association with highest relative risk with DRB 1*0405, followed by DRBI*0401. A significant decreased frequency of DRBI*1502 was observed in patients compared to controls (chi 2 = 4.5). Among other alleles, DRBI*1001 was found to be significantly increased. A total of 73.3% of patients carried the shared sequence of the third HVR (67-74) of DRB1 domain compared to its presence in only 37.6% of controls. A significant number of patients carried DR4 haplotypes on DQBI*0302 (58%) as against DQBI*0301 which was present only on 10.5% of the haplotypes. When compared to controls, the difference was significant for the latter allele only. Few unique DRDQ haplotypes were observed in Asian Indians. Among DR-DQ haplotypes, DRB1*0401-DQB1*0302 gave the highest risk whereas DRB1*0403-DQB1*O301 was negatively associated. Alleles with negative charge at position 70 confer protection or are negatively associated with RA whereas among the associated alleles, glycine at position 86 resulted in higher risk than those with valine at this position. A heterogenous association of DQB1 alleles with DR4 subtypes, influencing susceptibility to RA, suggests the DQB locus is not primarily associated with RA and susceptibility lies in the sequence 67-74 of the DRB1 loci.

Correlation between gold-induced enterocolitis and the presence of the HLA-DRB1*0404 allele

OBJECTIVE

In recent years we have treated 4 rheumatoid arthritis (RA) patients who developed gold-induced enterocolitis, a well-recognized, although rare, complication of chrysotherapy. The aim of the present study was to seek any genetic predisposition for this complication.

METHODS

HLA DNA typing was done on fresh white blood cells from the 4 patients.

RESULTS

Three of the 4 patients (75%) exhibited the DRB1*0404 allele, whereas the prevalence of this allele among the Ashkenazi Jewish population of RA patients without colitis was 9.2% and 10.2% in 2 different studies.

CONCLUSION

The results indicate that the DRB1*0404 may be associated with risk for the development of gold-induced enterocolitis in this population and suggest that HLA DNA typing should be considered in Jews who may be undergoing chrysotherapy.

Sjogren's syndrome in Israel: primary versus secondary disease

Sixty Israeli patients, 30 with primary Sjögren's syndrome (SS) and 30 with rheumatoid arthritis (RA) and secondary SS, were evaluated. The Schirmer-1 test and a positive labial salivary gland biopsy were found to be the most helpful tools in assessing the diagnosis of SS. Extraglandular features such as Raynaud's phenomenon, lymphadenopathy and CNS involvement as well as parotid gland enlargement (p < 0.05) were more common in primary SS. Antinuclear antibodies, especially anti-Ro (SSA) and anti-La (SSB) were also more common in primary SS (p < 0.05). Our results are in accord with those of many European centers, despite the different genetic background.

Lymphocyte responses to DR1/4 restricted peptides in rheumatoid arthritis

OBJECTIVE

To determine whether analog and unrelated DR1/4 binding peptides alter DR1/4 restricted responses of peripheral blood lymphocytes (PBL) from patients with rheumatoid arthritis (RA).

METHODS

PBL from 25 patients with RA and 12 healthy controls were cultured with DR1/4 restricted peptides of the influenza haemagglutinin, amino acids 307-319 (HA) and matrix proteins, amino acids 17-29 (IM). Responses were determined by 3H-thymidine uptake proliferation assays and limiting dilution analysis. Competitor peptides were analogs HA-R312 and HA-K313 differing from HA by one amino acid at the 312 or 313 position respectively or unrelated peptides which bind to DR1/4.

RESULTS

The responses of eight patients with RA to the two stimulatory influenza peptides did not differ significantly from controls and this was confirmed by the frequency estimate of T cells in PBL which responded to HA (mean frequency: 1 in 9.0 x 10(4), n = 5, in DR1/4+ RA patients, 1 in 7.6 x 10(4), n = 5, in DR1/4+ healthy controls). DR1/4 binding analogs of the HA peptide inhibited HA specific peptide responses of PBL from patients with RA and controls. Inhibition was also detected with unrelated peptides which bind to DR1/4 but to which the individual did not respond.

CONCLUSION

Similar responses to two DR1/4 restricted peptides were observed in patients with RA and controls. Both antigen analog- and unrelated peptide-major histocompatibility complexes (MHC) can result in the inhibition of antigen specific responses in multi-clonal human lymphocyte populations. However, an analog peptide may be stimulatory in some individuals. These results provide some initial data for the development of a rational approach to MHC-specific immunomodulation in rheumatoid arthritis.

[HLA-DRB1 and HLA-DQB1 polymorphism in Algerians from Algiers]

The polymorphism of HLA-DRB1 and HLA-DQB1 genes in 100 unrelated Algerians from Alger was investigated using PCR amplification and oligonucleotide typing. Compared to western Europeans, this population shows a higher haplotypic frequency of HLA DRB1*03-DQB1*0201 (21.5%) and a lower haplotypic frequency of DRB1*0101-DQB1*0501 (2%). Two unexpected haplotypes are observed: DRB1*07-DQB1*0301 and DRB1*0406-DQB1*0402. DRB1*0402 is the most common subtype in the DRB1*04 group. Furthermore, we detected a rare DQB1*0305 allele, only found in a Sardinian subject until today.

A shared HLA-DRB1 sequence confers RA susceptibility in Greeks

Previous serological studies of Greek rheumatoid arthritis (RA) patients have failed to demonstrate an association with DR4. Using sequence specific oligonucleotide typing we have identified the DRB1 alleles in panels of Greek RA patients and controls. When patient and control HLA-DRB1 frequencies were compared, significantly higher frequencies of DRB1*0101 (23.3% vs. 7.0%, odds ratio [OR] 4.0, 95% confidence intervals [CI] 1.4-12.0) and DRB1*1001 (20.9% vs. 5.8%, OR 4.3, 95% CI 1.3-13.7) were found in RA patients compared with controls. No association of DRB1*04 with RA was observed (20.9% vs. 14.0% in controls) confirming earlier reports. However DRB1*04 subtyping demonstrated a small but significant increase of DRB1*0405 in patients (14.0% vs. 3.5%, OR 4.5, 95% CI 1.1-18.9). When the frequency of individuals carrying the shared RA susceptibility epitope was compared between patients and controls it was found to be significantly higher in RA patients (60.5% vs. 22.1%, OR 5.4, 95% CI 2.4-12.0). We conclude that the shared epitope is significantly associated with RA in this population, but that it is predominantly accounted for by DRB1*0101 and DRB1*1001. Previous studies of UK RA patients have demonstrated a negative association of DR2 with disease and articular erosions. HLA-DR2 variants, DRB1*1501 and *1502 are not at reduced frequency in Greek RA patients (DRB1*1501, 14.0% in patients vs. 7.0% in controls; DRB1*1502, 7.0% in patients vs. 7.0% in controls). Genes conferring RA resistance may be in linkage disequilibrium with DR2 in UK patients. This does not appear to be the case in Greek RA patients. No association was seen between RA and HLA-DPB1 type.

Analysis of the HLA-DR gene frequencies in Japanese cases of juveniles rheumatoid arthritis and rheumatoid arthritis by oligonucleotide DNA typing

HLA-DR gene frequencies in 59 Japanese children with juvenile rheumatoid arthritis (JRA) and 62 Japanese adults with rheumatoid arthritis (RA) were analyzed by oligonucleotide DNA typing. As in other studies, the frequency of DRB1*0405 in RA patients was significantly higher than in the Japanese controls. In a comparison of non-classified JRA patients with Japanese controls, no significant differences were observed in the frequency of DR types. However, when the JRA patients were classified into four clinical types, i.e., a rheumatoid factor-positive [RF(+)] polyarticular type, a rheumatoid factor-negative [RF(-)] polyarticular type, a pauciarticular type, and a systemic onset type, DRB1*0405 was found to be significantly higher in the RF(+) polyarticular JRA patients than in the controls (P < 0.05). Thus, the RF(+) polyarticular type of JRA had the same HLA association as RA. This result is consistent with the fact that both RF(+) polyarticular JRA and RA cases have a similar clinical course.

Association of HLA-DR4-Dw15 (DRB1*0405) and DR10 with rheumatoid arthritis in a Spanish population

OBJECTIVE

To analyze the associations of HLA class II antigens with rheumatoid arthritis (RA) in a Spanish population.

METHODS

We used DNA oligotyping to determine DR types, DQA1 and DQB1 alleles, and DR4 variants in 70 unrelated seropositive RA patients and 189 healthy controls living in Spain.

RESULTS

A significantly higher frequency of DR4 was seen in RA patients compared with controls (relative risk [RR] = 2.40). The DR10 specificity correlated most strongly with disease susceptibility (RR = 3.84). A significant decrease in the frequency of DR7 was observed in the RA patients (RR = 0.48). DR4-Dw15 (DRB1*0405) was found to be the unique DR4 allele associated with RA (RR = 4.27, P < 0.05), whereas Dw4 (DRB1*0401) and Dw14 (DRB1*0404/0408) showed no association, and both Dw10 (DRB1*0402) and Dw13 (DRB1*0403/0407) were negative risk factors for the disease. Approximately one-third of the cases of RA could not be explained by the "shared epitope" hypothesis. Investigation of the DQ alleles associated with DR4 showed that the haplotype Dw15-DQ8 (DRB1*0405-DQB1*0302) was a susceptibility factor for RA (RR = 6.36, P < 0.05).

CONCLUSION

Our results suggest that HLA class II alleles involved in RA susceptibility can vary among different Caucasian populations.

Sequence-specific oligonucleotide typing in Shona patients with rheumatoid arthritis and healthy controls from Zimbabwe

Seventy-two patients with rheumatoid arthritis (RA) and 82 controls have been typed with the XI Histocompatibility Workshop DRB1 and DQB1 sequence-specific oligonucleotide probes. The increase of DRB1*04 corresponds to an increase of the serologically defined DR4, previously found in a small group of Zimbabwean RA patients and we now show that this increase is due to the subtype DRB1*0405 in association with DQB1*0302. In addition there is a clearcut increase of DRB1*1001 equivalent to the serologically defined DR10. There was no increase amongst RA patients of DRB1*0102 which was the predominant DR1 sub-type amongst controls. In the course of our investigation, we observed a DRB1*04 variant which corresponds to DRB1*0412, newly defined in the XIth Histocompatibility Workshop.

HLA-DRB1 gene sequences in HLA-DR4 positive and negative patients with rheumatoid arthritis

The second exon of the DRB1 gene encoding for the first domain of the HLA-DR beta 1-chain was sequenced in 16 patients (10 DR4/DR1 positive, 6 DR4/DR1 negative) with seropositive rheumatoid arthritis (RA). We could confirm the strong association of susceptibility to RA with functionally equivalent conformations on otherwise distinct MHC molecules. At least one HLA-DR allele in all of the analysed DR4 or DR1 positive patients showed such an epitope with a minimal variability limited to residue 71. However, in HLA-DR4 and -DR1 negative patients such a similar epitope could not be detected.

Molecular analysis of HLA class II genes in primary Sjögren's syndrome. A study of Israeli Jewish and Greek non-Jewish patients

In an attempt to define the role of HLA class II genes in predisposition to primary Sjögren's syndrome, patients of two different ethnic groups (Israeli Jews and Greeks of non-Jewish origin) suffering from this disorder were studied. Oligonucleotide genotyping revealed the majority in both groups to carry either DRB1*1101 or DRB1*1104, alleles that are in linkage disequilibrium with DQB1*0301 and DQA1*0501. The high frequency of the two alleles in these SS patients is in contrast with the accepted association of primary SS with HLA-DR3 in Italian and American individuals. Molecular analysis of DQB1 and DQA1 alleles found in American Caucasian and American black SS (or SLE) patients demonstrated high frequencies of DQB1*0201 and DQA1*0501. The fact that the majority of SS patients, across racial and ethnic boundaries, carry a common allele, DQA1*0501, implies its involvement in the predisposition to primary SS. Based on sequence analysis and the computer imaging of the HLA class II molecule structure, a hypothetical model for the role of the DQ molecule in promoting primary SS is proposed.

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 DR beta determines susceptibility to RA.

HLA-DR1 and rheumatoid arthritis in Israeli Jews: sequencing reveals that DRB1*0102 is the predominant HLA-DR1 subtype

Rheumatoid arthritis (RA) is associated with the HLA-DR4 cellular subtypes Dw4 and Dw14 in Caucasians, with Dw15 in Japanese, and possibly with HLA-DR1 in Israeli Jews. Sequencing studies in Caucasians have shown that these molecules share a common amino acid sequence in the third hypervariable region of the DR molecule (AA 67-74: LLEQRRAA or LLEQKRAA), suggesting that this sequence is primarily associated with RA. An important argument in favor of this shared-epitope hypothesis has been the reported association between DR1 and RA in Israeli Jews. However, a later report did not confirm this association, and cellular typing showed that Israeli DR1 consists of three or more subtypes, suggesting that new subtypes might be present. Since no sequencing data on Israeli HLA-DR1 genes have been reported, we sequenced the first domain (AA 10-91) of the DRB1 gene in 12 DR1-positive Israeli RA patients, 5 healthy controls and a homozygous typing cell (HTC), defining the major Jewish cellular HLA-DR1 subtype. DRB1*0102 (DR1 Dw20) was found in 8 RA patients, 3 controls and the HTC "LVA". DRB1*0101 (DR1 Dw1) was found in 4 RA patients and 2 controls. No other DR1 subtypes were encountered. In all 20 DR1 haplotypes, the DRB1*0101 or 0102 allele was associated with DQA1*0101 and DQB1*0501, being identical to the Caucasian DR1 haplotypes. Thus, at the sequence level, we found no basis for the reported extensive cellular heterogeneity of DR1 in the Israeli population.(ABSTRACT TRUNCATED AT 250 WORDS)

Diversity in HLA-DR4-related DR,DQ haplotypes in Australia, Oceania, and China

The relative distributions of 12 HLA-DR4-related DRB1 alleles in indigenous populations of Australia, Melanesia, Micronesia, Polynesia, and northern and southern China have been determined by analysis of oligonucleotide hybridization patterns of 406 examples of HLA-DR4. DRB1*0405 and DRB1*0410 were common DR4 alleles in Australian aborigines and in Melanesians, while DRB1*0403 was the predominant DR4 allele in coastal Melanesians, Micronesians, and Polynesians; DRB1*0406 was confined to Chinese. A novel DR4 allele, found in 30% of DR4-positive Australian aborigines but exclusive to one aboriginal population, was a combination of DRB1*04 and 0803 nucleotide sequences and was carried on a haplotype with DR4-like DQ linkage arrangements. DQA1 and DQB1 typing generated 12 DR4-related haplotypes; the population distributions of these reflected the ancestral affinities of aborigines and Melanesians, the overlaying of coastal Melanesia with pre-Polynesian DR4 alleles and the colonization of Micronesia by an independent, non-Polynesian group. DR4-related autoimmune disorders such as rheumatoid arthritis (RA) and insulin-dependent diabetes mellitus (IDDM) are virtually unknown in indigenous populations of Australia and Oceania and this study confirmed that high-risk RA determinants, Dw4 and Dw14, occurred rarely. However, the DQw8 allele, thought particularly to predispose to IDDM, was present in the majority of DR4-positive Polynesians and Micronesians.

Heterogeneity in HLA-DR2-related DR,DQ haplotypes in eight populations of Asia-Oceania

The relative distributions of 480 DR2-related DR,DQ haplotypes have been determined in Australian Aborigines, Papua New Guinean Highlanders, coastal Melanesians, Micronesians, Polynesians, Javanese, and Southern and Northern Chinese. Using sequence-specific oligonucleotides (SSOs) for hybridization of polymerase chain reaction (PCR) products from DRB1, DRB5, DQA1, and DQB1 genes, 15 different DR2-related haplotypes were identified. The predominant DR2 haplotype in Oceania involved a novel combination of DRB1*1502, DRB5*0101 alleles; this haplotype occurred sporadically in Java, but not in China. In Southern China, the most frequent DR2 haplotype involved the unusual arrangement DRB1*1602,DRB5*0101; alternatively, DRB1*1602 was associated with a new DRB5 SSO pattern. This study has important implications for molecular HLA-typing protocols that assume particular DRB1, DRB5 or DR,DQ linkage relationships. Further, the novel DRB1, DRB5 haplotype in Oceania suggests that the mixed lymphocyte culture (MLC) determinants Dw2 and Dw12 are discriminated by codon 86 at the DRB1 locus.