Disentangling heterogeneity in contemporary undifferentiated arthritis – A large cohort study using latent class analysis

Objectives: Undifferentiated arthritis(UA) is clinically heterogeneous and differs in outcomes ranging from spontaneous resolution to RA-development. Therefore, we hypothesized that subgroups exist within UA and we aimed to identify homogeneous groups based on clinical features, and thereafter to relate these groups to the outcomes spontaneous resolution and RA-development. These outcomes can only be studied in UA-patients in which DMARD-treatment does not influence the natural disease course; these cohorts are scarce. Methods: We studied autoantibody-negative UA-patients (not fulfilling 1987/2010 RA-criteria, no alternate diagnosis), included in the Leiden Early Arthritis Clinic between 1993 and 2006, when early DMARD-treatment in UA was infrequent. Latent class analysis was used to identify subgroups based on combinations of clinical features. Within these subgroups, test-characteristics were assessed for spontaneous resolution of arthritis and RA-development within 1 year. Results: 310 consecutive UA-patients were studied. Five classes were identified: location and number of swollen joints were most distinguishing. Classes were characterized by: 1) polyarthritis, often symmetric; 2) oligoarthritis, frequently with subacute onset; 3) wrist-monoarthritis, often with subacute onset, increased BMI and without morning stiffness; 4) small-joint monoarthritis, often without increased acute phase reactants, and 5) large-joint monoarthritis, often with subacute onset. Studying the classes in relation to the outcomes revealed that patients without spontaneous resolution (thus having persistent disease) were nearly absent in the classes characterized by monoarthritis (specificity &gt;90%). Additionally, patients who developed RA were infrequent in monoarthritis classes (sensitivity &lt;7%). Conclusion: Using a data-driven unsupervised approach, five subgroups within contemporary UA were identified. These have differences in the natural course of disease.</p

The relationship between the presence of anti-cyclic citrullinated peptide antibodies and clinical phenotype in very early rheumatoid arthritis

<p>Abstract</p> <p>Background</p> <p>Anti-cyclic citrullinated peptide (anti-CCP) antibodies are highly specific for RA, but are not detectable in all RA patients. The aim of this study was to establish whether the clinical phenotypes of anti-CCP positive and negative disease are distinct at the earliest clinically apparent phase of disease.</p> <p>Methods</p> <p>Patients were recruited from the Birmingham early inflammatory arthritis clinic. Participants were included in the current study if they presented within 3 months of symptom onset and fulfilled 1987 ACR criteria for RA at some point during an 18 month follow-up. Data were collected on demographic variables, joint symptoms and tender (n = 68) and swollen (n = 66) joint counts. CRP, ESR, rheumatoid factor and anti-CCP2 status were measured.</p> <p>Results</p> <p>92 patients were included (48 anti-CCP positive). The anti-CCP positive and negative groups were comparable in terms of demographic variables, inflammatory markers, joint counts and 1987 ACR classification criteria, except that more anti-CCP positive patients were rheumatoid factor positive (83.3% vs. 11.4%, p < 0.01). There was no significant difference in the pattern of joint involvement, except for an increased prevalence of knee joint swelling in anti-CCP positive patients (42.9% vs. 22.2%, p = 0.03).</p> <p>Conclusions</p> <p>Patients with and without anti-CCP antibodies present in a similar way, even within three months of clinically apparent disease that eventually develops into RA.</p

Association of the 6q23 region with the rate of joint destruction in rheumatoid arthritis

BACKGROUND: /st> Two novel genetic polymorphisms on chromosome 6q23 are associated with susceptibility to rheumatoid arthritis (RA). Both polymorphisms (rs6920220 and rs10499194) reside in a region close to the gene encoding tumour necrosis factor alpha-induced protein 3 (TNFAIP3). TNFAIP3 is a negative regulator of NF-kappaB and is involved in inhibiting TNF-receptor-mediated signalling effects. Interestingly, the initial associations were detected in patients with longstanding RA. However, no association was found for rs10499194 in a Swedish cohort with early arthritis. This might be caused by over-representation of patients with severe disease in cohorts with longstanding RA. OBJECTIVE: /st> To analyse the effect of the 6q23 region on the rate of joint destruction. METHODS: /st> Five single nucleotide polymorphisms in 6q23 were genotyped in 324 Dutch patients with early RA. Genotypes were correlated with progression of radiographic joint damage for a follow-up time of 5 years. RESULTS: /st> Two polymorphisms (rs675520 and rs9376293) were associated with severity of radiographic joint damage in patients positive for anti-citrullinated protein/peptide antibodies (ACPA). Importantly, the effects were present after correction for confounding factors such as secular trends in treatment. CONCLUSIONS: /st> These data associate the 6q23 region with the rate of joint destruction in ACPA+ RA.Pathophysiology and treatment of rheumatic disease

The Features of the Synovium in Early Rheumatoid Arthritis According to the 2010 ACR/EULAR Classification Criteria

OBJECTIVES: It has been shown in early arthritis cohorts that the 2010 ACR/EULAR criteria for rheumatoid arthritis (RA) enable an earlier diagnosis, perhaps at the cost of a somewhat more heterogeneous patient population. We describe the features of synovial inflammation in RA patients classified according to these new criteria. METHODS: At baseline, synovial tissue biopsy samples were obtained from disease-modifying antirheumatic drug (DMARD)-naïve early RA patients (clinical signs and symptoms <1 year). Synovial tissue was analyzed for cell infiltration, vascularity, and expression of adhesion molecules. Stained sections were evaluated by digital image analysis. Patients were classified according to the two different sets of classification criteria, autoantibody status, and outcome. FINDINGS: Synovial tissue of 69 RA patients according to 2010 ACR/EULAR criteria was analyzed: 56 patients who fulfilled the criteria for RA at baseline and 13 who were initially diagnosed as undifferentiated arthritis but fulfilled criteria for RA upon follow up. The synovium at baseline was infiltrated by plasma cells, macrophages, and T cells as well as other cells, and findings were comparable to those when patients were selected based on the 1987 ACR criteria for RA. There was no clear cut difference in the characteristics of the synovium between RA patients initially diagnosed as undifferentiated arthritis and those who already fulfilled classification criteria at baseline. CONCLUSION: The features of synovial inflammation are similar when the 2010 ACR/EULAR classification criteria are used compared to the 1987 ACR criteria

Рідке мило на основі соапстоків після нейтралізації олій та жирів в нейтралізуючому розчині, що містить етанол

Development and application of statistical models for medical scientific researc

Smoking is associated with the concurrent presence of multiple autoantibodies in rheumatoid arthritis rather than with anti-citrullinated protein antibodies per se:a multicenter cohort study

BACKGROUND: The contribution of smoking to rheumatoid arthritis (RA) is hypothesized to be mediated through formation of anti-citrullinated protein antibodies (ACPA). In RA, however, autoantibodies such as ACPA, rheumatoid factor (RF), and anti-carbamylated protein antibodies (anti-CarP) often occur together, and it is thus unclear whether smoking is specifically associated with some autoantibodies rather than others. We therefore investigated whether smoking is only associated with ACPA or with the presence of multiple RA-related autoantibodies. METHODS: A population-based Japanese cohort (n = 9575) was used to investigate the association of smoking with RF and anti-cyclic citrullinated peptide antibodies (anti-CCP2) in individuals without RA. Furthermore, RA patients fulfilling the 1987 criteria from three early arthritis cohorts from the Netherlands (n = 678), the United Kingdom (n = 761), and Sweden (n = 795) were used. Data on smoking, RF, anti-CCP2, and anti-CarP were available. A total score of autoantibodies was calculated, and odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated by logistic regression. RESULTS: In the population-based non-RA cohort, no association was found between smoking and one autoantibody (RF or anti-CCP2), but smoking was associated with double-autoantibody positivity (OR 2.95, 95% CI 1.32-6.58). In RA patients, there was no association between smoking and the presence of one autoantibody (OR 0.99, 95% CI 0.78-1.26), but smoking was associated with double-autoantibody positivity (OR 1.32, 95% CI 1.04-1.68) and triple-autoantibody positivity (OR 2.05, 95% CI 1.53-2.73). CONCLUSIONS: Smoking is associated with the concurrent presence of multiple RA-associated autoantibodies rather than just ACPA. This indicates that smoking is a risk factor for breaking tolerance to multiple autoantigens in RA

<i>RPA3-UMAD1</i> rs12702634 and rheumatoid arthritis-associated interstitial lung disease in European ancestry

Objective Recently, a genome-wide association study identified an association between RA-associated interstitial lung disease (ILD) and RPA3-UMAD1 rs12702634 in the Japanese population, especially for patients with a usual interstitial pneumonia (UIP) pattern. We aimed to replicate this association in a European population and test for interaction with MUC5B rs35705950.Methods In this genetic case-control association study, patients with RA and ILD and controls with RA and no ILD were included from France, the USA and the Netherlands. Only cases and controls from European genetic ancestries determined by principal components analysis were included in the analyses. RA was defined by the 1987 ACR or 2010 ACR/EULAR criteria and ILD by chest high-resolution CT scan, except in the control dataset from the Netherlands, where the absence of ILD was determined by chart review. Patients were genotyped for RPA3-UMAD1 rs12702634 and MUC5B rs35705950. Associations were tested using logistic regression adjusted for sex, age at RA onset, age at ILD onset or at certified absence of ILD, tobacco smoking status and country of origin.Results Among the 883 patients included, 322 were RA-ILD cases (36.5%). MUC5B rs35705950 was strongly associated with RA-ILD in all datasets {combined adjusted odds ratio [OR] 2.9 [95% CI 2.1, 3.9], P = 1.1 x 10-11. No association between RPA3-UMAD1 rs12702634 and RA-ILD was observed [combined OR 1.2 (95% CI 0.8, 1.6), P = 0.31. No interaction was found between RPA3-UMAD1 rs12702634 and MUC5B rs35705950 (P = 0.70).Conclusion Our findings did not support a contribution of RPA3-UMAD1 rs12702634 to the overall RA-ILD susceptibility in the European population.What does this mean for patients?Interstitial lung disease (ILD) can develop in 10-60% of patients with rheumatoid arthritis (RA) and is associated with an increased risk of death. We do not yet fully understand why RA-ILD occurs, but risk factors include genetics and environmental factors such as tobacco smoking. Identifying new genetic risk factors for RA-ILD may improve our understanding of how this disease occurs, help us categorize patients in terms of their risk level and help us to potentially identify new drug targets. A previous Japanese genetic study identified the RPA3-UMAD1 rs12702634 common genetic variant as a risk factor for RA-ILD. However, a second Japanese study failed to replicate these findings. In this international study including patients with European ancestry, we did not find that RPA3-UMAD1 rs12702634 contributed to the overall risk of RA-ILD. Our findings highlight the importance of conducting analyses that try to replicate the results of a study. We also emphasize that genetic associations-even those already reported-require rigorous testing in different groups of people before we can conclude that they contribute to disease risk. Ongoing collaboration and multi-ancestry genetic studies are essential in order to advance our understanding of the complex genetics underlying RA-ILD

Genetic associations with radiological damage in rheumatoid arthritis: Meta-analysis of seven genome-wide association studies of 2,775 cases

Background Previous studies of radiological damage in rheumatoid arthritis (RA) have used candidate-gene approaches, or evaluated single genome-wide association studies (GWAS). We undertook the first meta-analysis of GWAS of RA radiological damage to: (1) identify novel genetic loci for this trait; and (2) test previously validated variants. Methods Seven GWAS (2,775 RA cases, of a range of ancestries) were combined in a meta-analysis. Radiological damage was assessed using modified Larsen scores, Sharp van Der Heijde scores, and erosive status. Single nucleotide polymophsim (SNP) associations with radiological damage were tested at a single time-point using regression models. Primary analyses included age and disease duration as covariates. Secondary analyses also included rheumatoid factor (RF). Meta-analyses were undertaken in trans-ethnic and European-only cases. Results In the trans-ethnic primary meta-analysis, one SNP (rs112112734) in close proximity to HLA-DRB1, and strong linkage disequilibrium with the shared-epitope, attained genome-wide significance (P = 4.2x10-8). In the secondary analysis (adjusting for RF) the association was less significant (P = 1.7x10-6). In both trans-ethnic primary and secondary meta-analyses 14 regions contained SNPs with associations reaching P<5x10-6; in the European primary and secondary analyses 13 and 10 regions contained SNPs reaching P<5x10-6, respectively. Of the previously validated SNPs for radiological progression, only rs660895 (tagging HLA-DRB1*04:01) attained significance (P = 1.6x10-5) and had a consistent direction of effect across GWAS. Conclusions Our meta-analysis confirms the known association between the HLA-DRB1 shared epitope and RA radiological damage. The lack of replication of previously validated non-HLA markers highlights a requirement for further research to deliver clinically-useful prognostic genetic markers