An association between the natural course of shoulder joint destruction in rheumatoid arthritis and HLA-DRB1*0405 in Japanese patients

Successful treatment of a rheumatoid arthritis patient with severe synovial hypertrophy and impaired shoulder function with microwave ablation technique

Rheumatoid arthritis (RA) is a chronic, inflammatory systemic disorder of synovial joints and results in polyarthritis, chronical degeneration, and finally deformities and ankylosis in severe cases. Synovitis and pannus formation are results of inflammatory changes and lead into restriction in joint movement. Shoulders are among the later affected and larger joints and formation of synovitis in early active stages and pannus in later stages might be concluded with frozen shoulder and severe impairment in functionality. These late-term changes cannot be controlled with systemic or local anti-inflammatory agents and synovectomy is chosen in some cases. However, the results are not satisfactory and recurrence is common. In this case report, we presented a case of RA with severe shoulder pain, restricted movement due to synovial hypertrophy, and pannus formation which are resistant to local and systemic interventions and not suitable for surgical or chemical synovectomy. Microwave ablation (MWA) was performed successfully without any complication and she well responded in terms of DAS-28, functional, and pain scores. Range of motion and funcitonal restriction were recovered. This case report describes the use and promising results of MWA in RA with severe synovial hypertrophy and pannus formation even in the absence of active arthritis and effusion. MWA is a safe and minimally invasive technique that can be easily performed in coordinance of rheumatologists and interventional radiologists in proper cases.

The spectrum of association in HLA region with rheumatoid arthritis in a diverse Asian population: evidence from the MyEIRA case-control study

BACKGROUND

Fine-mapping of human leukocyte antigen (HLA) region for rheumatoid arthritis (RA) risk factors has identified several HLA alleles and its corresponding amino acid residues as independent signals (i.e., HLA-A, HLA-B, HLA-DPB1, and HLA-DQA1 genes), in addition to the well-established genetic factor in HLA-DRB1 gene. However, this was mainly performed in the Caucasian and East Asian populations, and data from different Asian regions is less represented. We aimed to evaluate whether there are independent RA risk variants in both anti-citrullinated protein antibody (ACPA)-positive and ACPA-negative RA patients from the multi-ethnic Malaysian population, using the fine-mapping of HLA region strategy.

METHODS

We imputed the classical HLA alleles, amino acids, and haplotypes using the Immunochip genotyping data of 1260 RA cases (i.e., 530 Malays, 259 Chinese, 412 Indians, and 59 mixed ethnicities) and 1571 controls (i.e., 981 Malays, 205 Chinese, 297 Indians, and 87 mixed ethnicities) from the Malaysian Epidemiological Investigation of Rheumatoid Arthritis (MyEIRA) population-based case-control study. Stepwise logistic regression was performed to identify the independent genetic risk factors for RA within the HLA region.

RESULTS

We confirmed that the HLA-DRB1 amino acid at position 11 with valine residue conferred the strongest risk effect for ACPA-positive RA (OR = 4.26, 95% CI = 3.30-5.49, P_GWAS = 7.22 × 10^-29) in the Malays. Our study also revealed that HLA-DRB1 amino acid at position 96 with histidine residue was negatively associated with the risk of developing ACPA-positive RA in the Indians (OR = 0.48, 95% CI = 0.37-0.62, P_GWAS = 2.58 × 10^-08). Interestingly, we observed that HLA-DQB1*03:02 allele was inversely related to the risk of developing ACPA-positive RA in the Malays (OR = 0.17, 95% CI = 0.09-0.30, P_GWAS = 1.60 × 10^-09). No association was observed between the HLA variants and risk of developing ACPA-negative RA in any of the three major ethnic groups in Malaysia.

CONCLUSIONS

Our results demonstrate that the RA-associated genetic factors in the multi-ethnic Malaysian population are similar to those in the Caucasian population, despite significant differences in the genetic architecture of HLA region across populations. A novel and distinct independent association between the HLA-DQB1*03:02 allele and ACPA-positive RA was observed in the Malays. In common with the Caucasian population, there is little risk from HLA region for ACPA-negative RA.

Polymorphisms in peptidylarginine deiminase associate with rheumatoid arthritis in diverse Asian populations: evidence from MyEIRA study and meta-analysis

Introduction

The majority of our knowledge regarding disease-related mechanisms of uncontrolled citrullination and anti-citrullinated protein antibody development in rheumatoid arthritis (RA) was investigated in Caucasian populations. However, peptidylarginine deiminase (PADI) type 4 gene polymorphisms are associated with RA in East Asian populations and weak or no association was found in Caucasian populations. This study explores the association between the PADI4 polymorphisms and RA risk in a multiethnic population residing in South East Asia with the goal of elucidating generalizability of association in non-Caucasian populations.

Methods

A total of 320 SNPs from the PADI locus (including PADI1, PADI2, PADI3, PADI4 and PADI6 genes) were genotyped in 1,238 RA cases and 1,571 control subjects from the Malaysian Epidemiological Investigation of Rheumatoid Arthritis (MyEIRA) case-control study. Additionally, we conducted meta-analysis of our data together with the previously published studies of RA from East Asian populations.

Results

The overall odds ratio (OR_overall) for the PADI4 (rs2240340) allelic model was 1.11 (95% confidence interval (CI) = 1.00 to 1.23, P = 0.04) and for the genotypic model was 1.20 (95% CI = 1.01 to 1.44, P = 0.04). Haplotype analysis for four selected PADI4 SNPs revealed a significant association of one with susceptibility (P = 0.001) and of another with a protective effect (P = 0.02). The RA susceptibility was further confirmed when combined meta-analysis was performed using these data together with data from five previously published studies from Asia comprising 5,192 RA cases and 4,317 control subjects (OR_overall = 1.23 (95% CI = 1.16 to 1.31, P_{heterogeneity} = 0.08) and 1.31 (95% CI = 1.20 to 1.44, P_{heterogeneity} = 0.32) in allele and genotype-based models, respectively). In addition, we also detected a novel association of PADI2 genetic variant rs1005753 with RA (OR_overall = 0.87 (95% CI = 0.77 to 0.99)).

Conclusion

Our study demonstrates an association between PADI4 and RA in the multiethnic population from South East Asia and suggests additional association with a PADI2 gene. The study thus provides further support for the notion that polymorphisms in genes for enzymes responsible for citrullination contribute to RA development in multiple populations of Asian descent.

Shared epitope alleles remain a risk factor for anti-citrullinated proteins antibody (ACPA)--positive rheumatoid arthritis in three Asian ethnic groups

Background

To investigate the associations between HLA-DRB1 shared epitope (SE) alleles and rheumatoid arthritis in subsets of rheumatoid arthritis defined by autoantibodies in three Asian populations from Malaysia.

Methods

1,079 rheumatoid arthritis patients and 1,470 healthy controls were included in the study. Levels of antibodies to citrullinated proteins (ACPA) and rheumatoid factors were assessed and the PCR-SSO method was used for HLA-DRB1 genotyping.

Results

The proportion of ACPA positivity among Malay, Chinese and Indian rheumatoid arthritis patients were 62.9%, 65.2% and 68.6%, respectively. An increased frequency of SE alleles was observed in ACPA-positive rheumatoid arthritis among the three Asian ethnic groups. HLA-DRB1*10 was highly associated with rheumatoid arthritis susceptibility in these Asian populations. HLA-DRB1*0405 was significantly associated with susceptibility to rheumatoid arthritis in Malays and Chinese, but not in Indians. HLA-DRB1*01 did not show any independent effect as a risk factor for rheumatoid arthritis in this study and HLA-DRB1*1202 was protective in Malays and Chinese. There was no association between SE alleles and ACPA- negative rheumatoid arthritis in any of the three Asian ethnic groups.

Conclusion

The HLA-DRB1 SE alleles increase the risk of ACPA-positive rheumatoid arthritis in all three Asian populations from Malaysia.

Clinical strategies for amyloid A amyloidosis secondary to rheumatoid arthritis

Secondary amyloid A (AA) amyloidosis is an important complication of rheumatoid arthritis (RA) and has remarkable variation in frequency worldwide. It is a serious, potentially life-threatening disorder caused by deposition in organs of AA fibrils, which are derived from the circulatory, acute-phase-reactant, serum amyloid A protein (SAA). The SAA1.3 allele can serve not only as a risk factor for the association of AA amyloidosis but also as a poor prognostic factor in Japanese RA patients. Both the association of AA amyloidosis arising early in RA disease course and symptomatic variety and severity were found in amyloidotic patients carrying the SAA1.3 allele. Etanercept for patients with AA amyloidosis who carry the SAA1.3 allele showed the amelioration of rheumatoid inflammation, including marked reduction of SAA and improvement of renal function. In light of the SAA1.3 allele significance in Japanese RA patients, both a tight control by disease-modifying antirheumatic drugs and an early intervention of biologics for RA inflammation should be applied to suppress acute-phase response, thus preventing the association of AA amyloidosis. It is suggested that SAA plays not only an important role in the development of AA amyloidosis but also interacts with events closely involved in metabolic syndrome as a high- and low-grade inflammatory modulator, respectively.

HLA-DRB1⁎04 gene polymorphisms and expressions profiles of interleukin-18 and interleukin-18 binding protein following in vitro stimulation in human peripheral blood mononuclear cells of healthy individuals and patients with rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic arthritic condition that can lead to deformities and disabilities. Interleukin-18 (IL-18) is a proinflammatory cytokine known to play a role in the acute and chronic inflammatory phases of RA. IL-18 binding protein is the natural antagonist of IL-18 protein. We aim to identify the effect of HLA-DRB1*04 gene polymorphisms on IL-18 and IL-18BP gene expressions profiles as well as the time-course profiles following in vitro stimulation with mitogens. Peripheral blood mononuclear cells from 16 RA patients and 21 healthy controls were cultured for 1, 4, 8, 12, 24, 48 and 72 h following stimulation with either LPS or PHA. mRNA expression of IL-18 and IL 18BP were determined by quantitative real-time PCR using a comparative Ct (threshold cycle) method. IL-18 levels in supernatants were measured by enzyme-linked immunosorbent assay. Basal mRNA (4.5-fold) and protein levels of IL-18 were increased and IL-18BP mRNA expression was decreased (8-fold) in RA patients when compared to controls. Similarly, increased IL-18 levels were observed in active RA patients, whereas IL-18BP expression was increased in inactive patients. There was an increase in mRNA and protein levels of IL-18 in RA patients that peaked at 4 h and 8 h respectively following LPS stimulation. A similar profile was observed for IL-18BP; however, the expression level was higher in controls than RA patients. Persistent high production of IL-18 in RA is associated with disease progression and IL-18 BP seems to inhibit this activity.

HLA-DRB1 genes and disease severity in rheumatoid arthritis in Turkey

OBJECTIVE

Association with human leukocyte antigen (HLA)-DRB alleles, implicated in the aetiopathogenesis of rheumatoid arthritis (RA), is found to be different in various ethnic groups. This study aimed to investigate DRB1 alleles in RA patients in Turkey, and to examine the effect of these alleles on disease severity.

METHODS

We performed PCR-based DRBI genotyping of 104 RA patients recruited from clinical settings and 110 healthy controls. HLA DRB1 alleles frequencies in RA patients and healthy controls were determined. Phenotype frequencies of patients and controls were compared. Disease severity was assessed by radiological erosion, presence of extra-articular involvement, and functional index.

RESULTS

Significant differences were in the frequencies of DRB1*04 (46.2% versus 20.9%, p < 0.001), DRB1*0401 (10.6% versus 0%, p < 0.001), DRB1*0405 (8.7% versus 0%, p = 0.001), DRB1* 0404 (15.4% versus 3.6%, p < 0.01), DRB1*01 (21.2% versus 10.9%, p < 0.05) and DRB1*0101 (16.3% versus 5.5%, p = 0.01) between RA patients and controls. HLA-DRB1 alleles did not show any association with seropositivity, extra-articular involvement, radiological erosion, or functional index.

CONCLUSION

Our results suggest that the HLA-DRB1 alleles, particularly HLA-DRB1*04 and subtypes, were associated with RA.

Single-nucleotide polymorphisms of the interleukin-18 gene promoter region in rheumatoid arthritis patients: protective effect of AA genotype

Rheumatoid arthritis (RA) is a chronic arthritic condition that can lead to deformities and disabilities. Although numerous studies reported the association of human leukocyte antigen (HLA)-DRB1*04 and RA, other genes, e.g. cytokines genes, may contribute towards disease susceptibility. Interleukin-18 (IL-18) is a proinflammatory cytokine postulated to play a role in the acute and chronic inflammatory phases of RA. The IL-18 protein expression seems to be regulated by two single-nucleotide polymorphisms (SNPs) located at positions -607 and -137 in the promoter region of the gene. It is postulated that specific alleles may be associated with susceptibility to the development of RA. In the present study, we described the IL-18 gene promoter region genotypes and combined genotypes (-607/-137) in 106 RA patients and 273 unrelated healthy controls to evaluate the contributions of these alleles to RA predisposition in Chinese, Malays, and Indians. The genotyping were performed using sequence-specific polymerase chain reactions. Rheumatoid factors were assayed by enzyme-linked immunosorbent assay. Biodata were obtained through chart review. The controls had significantly higher frequency of AA genotype at position -607 when compared to RA patients. No significant differences were observed in the distribution of either allelic or genotypic frequencies at position -137. There was no association between the genotypes and the presence of rheumatoid factors. This study did not find evidence of a genetic susceptibility factor but demonstrated the novel finding that the AA genotype at position -607 is associated with a protective effect against development of RA in Chinese individuals. This protection may be mediated through inhibition of cyclic (Adenosine 3', 5'-cyclic monophosphate) AMP-responsive element (CRE)-binding protein by the disruption of the CRE consensus sequence.

The shared epitope and severity of rheumatoid arthritis

After two decades of research involving thousands of RA patients, it is still not possible to precisely define the relation of HLA-DRB1 SE alleles to RA severity. Improvements in our understanding require more careful consideration of several factors such as ethnicity, gender, and the specific SE allele and genotype inherited. Large studies of heterogeneous groups of patients are required and indicate the need for collaborative efforts among researchers. In the interim, meta-analysis of the existing literature may provide some insight, because it allows utilization of the tremendous amount of research already completed. A preliminary meta-analysis highlighted the significant heterogeneity among the existing literature, and a more ambitious meta-analysis that uses individual patient-level data is currently ongoing. Profound implications exist for determination of the precise relationship between the SE and RA severity. This information could be valuable in identifying patients at greater risk of severe complications or as a stratification variable for clinical trials. Moreover, patients genetically predisposed to severe disease may benefit from early initiation of more aggressive therapy. Ultimately, clarification of the role of the SE may be valuable for the development of specific therapies directed toward DRB1 and related targets.

Genetic studies, clinical heterogeneity, and disease outcome studies in rheumatoid arthritis

HLA haplotypes influence various clinical RA features considered to reflect severity in case-control and cohort studies. Of particular note is the fact that HLA generally influences the development of erosive and sometimes seropositive and nodular disease; in prospective studies, it noticeably affects joint surgical intervention. These are valuable clues indicating that HLA influences RA severity and chronicity. Nevertheless, HLA influences are generally weak enough so as to require large study subject numbers for detection. As a result, HLA genotyping has restricted usefulness for prediction of clinical severity in individual patients.