What is the evidence for the presence of a therapeutic window of opportunity in rheumatoid arthritis? A systematic literature review

Prevention of Rheumatoid Arthritis in At-Risk Individuals: Current Status and Future Prospects

Early intervention has been the cornerstone of improving outcomes in patients with rheumatoid arthritis. Over the past decade, the boundaries have been pushed in an attempt to achieve effective prevention strategies in those who are at high risk of developing rheumatoid arthritis. Core risk factors including the presence of serum anti-citrullinated protein antibodies, arthralgia and subclinical inflammation on imaging are highly predictive of arthritis development. The influence of air pollution, diet and the role of microbiome on disease progression are less clear. In turn, therapeutic focus has shifted to an earlier pre-arthritis phase of the disease continuum where the clinically apparent arthritis may potentially be intercepted. Seven proof-of-concept interventional trials in at-risk individuals have been conducted so far. Whether true prevention of rheumatoid arthritis is possible remains elusive. Promising signals towards permanent disease modulation and improvement in symptom burden were seen with some immunomodulatory therapies, whilst others were unsuccessful. Long-term follow-up is required to ascertain a true effect. Looking forward, a better understanding of the natural history and underlying biological mechanisms of arthritis development and more accurate, validated risk stratification is needed.

Feasibility of Physiotherapist-Led Rheumatology Triage: A Randomized Study

OBJECTIVE

Given global shortages in the rheumatology workforce, the demand for rheumatology assessment often exceeds the capacity to provide timely access to care. Accurate triage of patient referrals is important to ensure appropriate utilization of finite resources. We assessed the feasibility of physiotherapist (PT)-led triage using a standardized protocol in identifying cases of inflammatory arthritis (IA), as compared to usual rheumatologist triage of referrals for joint pain, in a tertiary care rheumatology clinic.

METHODS

We performed a single-center, prospective, nonblinded, randomized, parallel-group feasibility study with referrals randomized in a 1:1 ratio to either PT-led vs usual rheumatologist triage. Standardized information was collected at referral receipt, triage, and clinic visit. Rheumatologist diagnosis was considered the gold standard for diagnosis of IA.

RESULTS

One hundred two referrals were randomized to the PT-led triage arm and 101 to the rheumatologist arm. In the PT-led arm, 65% of referrals triaged as urgent were confirmed to have IA vs 60% in the rheumatologist arm (P = 0.57), suggesting similar accuracy in identifying IA. More referrals were declined in the PT-led triage arm (24 vs 8, P = 0.002), resulting in fewer referrals triaged as semiurgent (6 vs 23, P = 0.003). One case of IA (rheumatologist arm) was incorrectly triaged, resulting in significant delay in time to first assessment.

CONCLUSION

PT-led triage was feasible, appeared as reliable as rheumatologist triage of referrals for joint pain, and led to significantly fewer patients requiring in-clinic visits. This has implications for waitlist management and optimal rheumatology resource utilization.

Biosimilars and access to biologic therapy in immune-mediated diseases

BACKGROUND

The rise of biologic agents has been a major breakthrough in treating immune-mediated inflammatory diseases (IMIDs). However, their high cost underscores the need for strategies to optimize treatment efficiency. Biosimilars offer cost-effective alternatives to biologics. This study aimed to assess biosimilar drug availability's impact on biologic therapy access for IMIDs.

RESEARCH DESIGN AND METHODS

A retrospective observational study in 15 Spanish hospitals analyzed IMID patients (arthropathies, inflammatory bowel disease and psoriasis) initiating biologic therapy with originator or biosimilar drugs (infliximab, etanercept, adalimumab). Time to availability and initiation of biologic therapy were assessed.

RESULTS

267 patients were included, with 58.4% starting on biosimilars. The mean time to availability of the biologic drugs in the hospitals was 15.9 ± 6.7 months, (20.0 ± 12.4 for originator and 11.8 ± 5.2 for biosimilars). Mean time to biologic treatment was 7.7 ± 9.0 years (8.6 ± 8.9 for originators and 7.0 ± 9.0 for biosimilars). Showing statistically significant differences among conditions.

CONCLUSION

The emergence of biosimilar drugs has enhanced market competition and accelerated their adoption into hospitals' therapeutic regimens over original reference drugs. This has significantly improved access to biologic therapy for patients with IMIDs, evidenced by a notable 1.6-year reduction in access time for biosimilar drugs.

Joint-specific memory, resident memory T cells and the rolling window of opportunity in arthritis

In rheumatoid arthritis, juvenile idiopathic arthritis and other forms of inflammatory arthritis, the immune system targets certain joints but not others. The pattern of joints affected varies by disease and by individual, with flares most commonly involving joints that were previously inflamed. This phenomenon, termed joint-specific memory, is difficult to explain by systemic immunity alone. Mechanisms of joint-specific memory include the involvement of synovial resident memory T cells that remain in the joint during remission and initiate localized disease recurrence. In addition, arthritis-induced durable changes in synovial fibroblasts and macrophages can amplify inflammation in a site-specific manner. Together with ongoing systemic processes that promote extension of arthritis to new joints, these local factors set the stage for a stepwise progression in disease severity, a paradigm for arthritis chronicity that we term the joint accumulation model. Although durable drug-free remission through early treatment remains elusive for most forms of arthritis, the joint accumulation paradigm defines new therapeutic targets, emphasizes the importance of sustained treatment to prevent disease extension to new joints, and identifies a rolling window of opportunity for altering the natural history of arthritis that extends well beyond the initiation phase of disease.

Predictors of quality of life, functional status, depression and fatigue in early arthritis: comparison between clinically suspect arthralgia, unclassified arthritis and rheumatoid arthritis

BACKGROUND

Rheumatoid arthritis (RA) is often preceded by symptomatic phases during which classification criteria are not fulfilled. The health burden of these "at-risk" stages is not well described. This study assessed health-related quality of life (HRQoL), function, fatigue and depression in newly presenting patients with clinically suspect arthralgia (CSA), unclassified arthritis (UA) or RA.

METHODS

Cross-sectional analysis of baseline Patient-Reported Outcome Measures (PROMs) was conducted in patients from the Birmingham Early Arthritis Cohort. HRQoL, function, depression and fatigue at presentation were assessed using EQ-5D, HAQ-DI, PHQ-9 and FACIT-F. PROMs were compared across CSA, UA and RA and with population averages from the HSE with descriptive statistics. Multivariate linear regression assessed associations between PROMs and clinical and sociodemographic variables.

RESULTS

Of 838 patients included in the analysis, 484 had RA, 200 had CSA and 154 had UA. Patients with RA reported worse outcomes for all PROMs than those with CSA or UA. However, "mean EQ-5D utilities were 0.65 (95%CI: 0.61 to 0.69) in CSA, 0.61 (0.56 to 0.66) in UA and 0.47 (0.44 to 0.50) in RA, which was lower than in general and older (≥ 65 years) background populations." In patients with CSA or UA, HRQoL was comparable to chronic conditions such as heart failure, severe COPD or mild angina. Higher BMI and older age (≥ 60 years) predicted worse depression (PHQ-9: -2.47 (-3.85 to -1.09), P < 0.001) and fatigue (FACIT-F: 5.05 (2.37 to 7.73), P < 0.001). Women were more likely to report worse function (HAQ-DI: 0.13 (0.03 to 0.21), P = 0.01) and fatigue (FACIT-F: -3.64 (-5.59 to -1.70), P < 0.001), and residents of more deprived areas experienced decreased function (HAQ-DI: 0.23 (0.10 to 0.36), P = 0.001), greater depression (PHQ-9: 1.89 (0.59 to 3.18), P = 0.004) and fatigue (FACIT-F: -2.60 (-5.11 to 0.09), P = 0.04). After adjustments for confounding factors, diagnostic category was not associated with PROMs, but disease activity and polypharmacy were associated with poorer performance across all PROMs.

CONCLUSIONS

Patient-reported outcomes were associated with disease activity and sociodemographic characteristics. Patients presenting with RA reported a higher health burden than those with CSA or UA, however HRQoL in the pre-RA groups was significantly lower than population averages.

The Association of Rheumatologist Supply and Multidisciplinary Care With Timely Patient Access to Rheumatologists: Evidence From British Columbia, Canada

OBJECTIVE

The objective was to understand how the expansion of rheumatology supply and the introduction of multidisciplinary care was associated with access to rheumatology services.

METHODS

We accessed Population Data BC, a longitudinal database with de-identified individual-level health data on all residents of British Columbia, Canada, to analyze physician visits and prescribing from 2010-2011 to 2019-2020. We calculated access as the time from referral to first rheumatologist visit and, for people with rheumatoid arthritis (RA), time to first disease-modifying antirheumatic drug (DMARD). Associations between lag time, patient characteristics, and system variables were explored using quantile regression.

RESULTS

Over the study period, there were 149,902 new rheumatologist visits, with 31% more visits in 2019-2020 than in 2010-2011. The proportion of first visits for patients with inflammatory arthritis increased from 28% to 51%. The median time from referral to first visit decreased by 22 days (35%) from 63 days (interquartile range 21-120 days) in 2010-2011. For people with RA, time from referral to DMARD decreased by 4 days (6%) to 62 days. Male sex, living in metropolitan areas, and having a rheumatologist who used a multidisciplinary care assessment code were associated with shorter times from referral to first DMARD.

CONCLUSION

Access to rheumatology care improved, and the increased proportion of patients with IA in the first visits case-mix indicates that rheumatologist supply and incentives for multidisciplinary care may have improved referral patterns. However, time to DMARDs for people with RA remained long, and we found signals of unequal access for female patients and people living outside of metropolitan areas.

Remission definitions guiding immunosuppressive therapy in rheumatoid arthritis: which is best fitted for the purpose?

OBJECTIVE

To assess which definition of remission best predicts good radiographic outcome (GRO) and good functional outcome (GFO) in rheumatoid arthritis, focusing the updated American College of Rheumatology/European Alliance of Associations for Rheumatology criteria.

MATERIAL AND METHODS

Meta-analyses of individual patient data (IPD) from randomised controlled trials (RCTs). Six definitions of remission were considered: (1) Boolean with Patient Global Assessment (PGA)≤1 (Boolean); (2) Simplified Disease Activity Index (SDAI)≤3.3; (3) Clinical Disease Activity Index (CDAI)≤2.8; (4) Boolean with PGA≤2 (Updated-Boolean); (5) Boolean with Physician Global Assessment (PhGA≤1) replacing PGA (Boolean-PhGA) and (6) Boolean excluding PGA (3VBoolean). GRO was defined as a worsening ≤0.5 units in radiographic score and GFO as a no worsening in Health Assessment Questionnaire (HAQ), that is, ∆HAQ-DI≤0.0 units. Relationships between each remission definition at 6 and/or 12 months and GRO and GFO during the second year were analysed. Pooled probabilities for each outcome for each definition and their predictive accuracy were estimated.

RESULTS

IPD from eight RCTs (n=4423) were analysed. Boolean, SDAI, CDAI, Updated-Boolean, Boolean-PhGA and 3VBoolean were achieved by 24%, 27%, 28%, 32%, 33% and 43% of all patients, respectively. GRO among patients achieving remission ranged from 82.4% (3VBoolean) to 83.9% (SDAI). 3VBoolean showed the highest predictive accuracy for GRO: 51.1% versus 38.8% (Boolean) and 44.1% (Updated-Boolean). The relative risk of GFO ranged from 1.16 (Boolean) to 1.05 (3VBoolean). However, the proportion of GFO correctly predicted was highest for the 3VBoolean (50.3%) and lowest for the Boolean (43.8%).

CONCLUSION

3VBoolean definition provided the most accurate prediction of GRO and GFO, avoiding the risk of overtreatment in a substantial proportion of patients without increment in radiographic damage progression, supporting the proposal that 3VBoolean remission is preferable to guide immunosuppressive treatment. The patient's perspective, which must remain central, is best served by an additional patient-oriented target: a dual-target approach.

Patterns and determinants of response to novel therapies in juvenile and adult-onset polyarthritis

Biologic and targeted synthetic DMARDs (b/tsDMARDs) have revolutionized the management of multiple rheumatic inflammatory conditions. Among these, polyarticular JIA (pJIA) and RA display similarities in terms of disease pathophysiology and response pattern to b/tsDMARDs. Indeed, the therapeutic efficacy of novel targeted drugs is variable among individual patients, in both RA and pJIA. The mechanisms and determinants of this heterogeneous response are diverse and complex, such that the development of true 'precision'-medicine strategies has proven highly challenging. In this review, we will discuss pathophysiological, patient-specific, drug-specific and environmental factors contributing to individual therapeutic response in pJIA in comparison with what is known in RA. Although some biomarkers have been identified that stratify with respect to the likelihood of either therapeutic response or non-response, few have proved useful in clinical practice so far, likely due to the complexity of treatment-response mechanisms. Consequently, we propose a pragmatic, patient-centred and clinically based approach, i.e. personalized instead of biomarker-based precision medicine in JIA.

Association of large joint involvement at the start of biological disease-modifying antirheumatic drugs and Janus kinase inhibitors with disease activity and drug retention in patients with rheumatoid arthritis: The ANSWER cohort study

AIM

To investigate the association of large joint involvement (LJI) with disease activity and drug retention in patients with rheumatoid arthritis (RA) who started receiving a biological disease-modifying antirheumatic drug or Janus kinase inhibitor.

METHODS

Patients with RA from a Japanese multicenter observational registry were enrolled. Our definition of large joints included the shoulder, elbow, hip, knee, and ankle joints. Linear mixed-effects models were used to examine changes in the clinical disease activity index (CDAI) score at Week 24 as the primary outcome, and drug retention rates were compared between patients with and without LJI using Cox proportional hazards models. We examined the potential effect modifications of changes in the CDAI by baseline characteristics.

RESULTS

Overall, 2507 treatment courses from 1721 patients were included (LJI, 1744; no LJI, 763). Although LJI was associated with significantly higher changes in CDAI from baseline at Week 24 (difference in change in CDAI: -5.84 [-6.65 to -5.03], p < .001), CDAI was significantly higher in patients with LJI over time. Retention rates were similar in both groups. The association of LJI with changes in disease activity was more prominent in patients with a short disease duration, negative anti-citrullinated peptide antibodies, and interleukin-6 receptor inhibitor (IL-6Ri) use.

CONCLUSION

Although LJI was associated with a greater reduction in disease activity from baseline, higher disease activity at baseline was not offset over time in patients with LJI, demonstrating that LJI is an unfavorable predictor. An early treat-to-target strategy using an IL-6Ri may be beneficial for patients with LJI.

Diagnostic Value of Short Course Low-dose Prednisolone in Patients with Clinically Suspected Seronegative Inflammatory Arthritis - A Retrospective Study

OBJECTIVE

We aim to establish the utility of a trial of low-dose systemic glucocorticoid therapy in the assessment of new clinically suspected inflammatory arthritis patients.

METHODS

We retrospectively identified patients from a private rheumatology practice in Melbourne, Australia between January 1st, 2019, and December 31st, 2021, who presented with clinically suspected inflammatory arthritis and subsequently underwent a trial of low-dose prednisolone (15 mg daily weaned over three weeks in 5 mg increments). We excluded patients with known autoimmune/ inflammatory disorders or concurrent immunosuppression at presentation. We collected basic participant demographic details and clinical details of their presentation, glucocorticoid response, investigations, and treatment.

RESULTS

We recruited 177 participants with a median age of 52, and 69.5% were female gender. The median symptom time to presentation was 12 months. Hands were the most affected joint in 63.3% and 85% had bilateral disease. Among the participants, 29.4% had synovitis on clinical review and 75.7% had imaging performed as part of the initial assessment. At presentation, the median CRP was 11 and the median ESR was 16. 79.7% of the cohort experienced significant improvement in their arthritis symptoms from low-dose glucocorticoids and 83.6% of the cohort required long-term immunosuppression for an underlying inflammatory condition. Of those who responded to glucocorticoids, 92.1% were diagnosed with an inflammatory condition. Rheumatoid arthritis was the most common overall diagnosis in 28%.

CONCLUSION

An initial trial of low-dose glucocorticoids in undifferentiated arthritis patients is useful in predicting the diagnosis of inflammatory arthritis. It is also a predictor of further long-term steroid-sparing therapy.

Patient Acceptability of Symptom Screening and Patient Education Using a Chatbot for Autoimmune Inflammatory Diseases: Survey Study

BACKGROUND

Chatbots have the potential to enhance health care interaction, satisfaction, and service delivery. However, data regarding their acceptance across diverse patient populations are limited. In-depth studies on the reception of chatbots by patients with chronic autoimmune inflammatory diseases are lacking, although such studies are vital for facilitating the effective integration of chatbots in rheumatology care.

OBJECTIVE

We aim to assess patient perceptions and acceptance of a chatbot designed for autoimmune inflammatory rheumatic diseases (AIIRDs).

METHODS

We administered a comprehensive survey in an outpatient setting at a top-tier rheumatology referral center. The target cohort included patients who interacted with a chatbot explicitly tailored to facilitate diagnosis and obtain information on AIIRDs. Following the RE-AIM (Reach, Effectiveness, Adoption, Implementation and Maintenance) framework, the survey was designed to gauge the effectiveness, user acceptability, and implementation of the chatbot.

RESULTS

Between June and October 2022, we received survey responses from 200 patients, with an equal number of 100 initial consultations and 100 follow-up (FU) visits. The mean scores on a 5-point acceptability scale ranged from 4.01 (SD 0.63) to 4.41 (SD 0.54), indicating consistently high ratings across the different aspects of chatbot performance. Multivariate regression analysis indicated that having a FU visit was significantly associated with a greater willingness to reuse the chatbot for symptom determination (P=.01). Further, patients' comfort with chatbot diagnosis increased significantly after meeting physicians (P<.001). We observed no significant differences in chatbot acceptance according to sex, education level, or diagnosis category.

CONCLUSIONS

This study underscores that chatbots tailored to AIIRDs have a favorable reception. The inclination of FU patients to engage with the chatbot signifies the possible influence of past clinical encounters and physician affirmation on its use. Although further exploration is required to refine their integration, the prevalent positive perceptions suggest that chatbots have the potential to strengthen the bridge between patients and health care providers, thus enhancing the delivery of rheumatology care to various cohorts.

The Role of Marine n-3 Polyunsaturated Fatty Acids in Inflammatory-Based Disease: The Case of Rheumatoid Arthritis

Inflammation is a conserved process that involves the activation of immune and non-immune cells aimed at protecting the host from bacteria, viruses, toxins and injury. However, unresolved inflammation and the permanent release of pro-inflammatory mediators are responsible for the promotion of a condition called "low-grade systemic chronic inflammation", which is characterized by tissue and organ damage, metabolic changes and an increased susceptibility to non-communicable diseases. Several studies have demonstrated that different dietary components may influence modifiable risk factors for diverse chronic human pathologies. Marine n-3 polyunsaturated fatty acids (n-3 PUFAs), mainly eicosapentaenoic (EPA) and docosahexaenoic acid (DHA), are well-recognized anti-inflammatory and immunomodulatory agents that are able to influence many aspects of the inflammatory process. The aim of this article is to review the recent literature that relates to the modulation of human disease, such as rheumatoid arthritis, by n-3 PUFAs.

Early axial spondyloarthritis according to the ASAS consensus definition: characterisation of patients and effectiveness of a first TNF inhibitor in a large observational registry

OBJECTIVE

To characterise the population fulfilling the Assessment of SpondyloArthritis international Society (ASAS) consensus definition of early axial spondyloarthritis (axSpA) and to determine the effectiveness of a first tumour necrosis factor inhibitor (TNFi) in early versus established axSpA in a large observational registry.

METHODS

A total of 3064 patients with axSpA in the Swiss Clinical Quality Management registry with data on duration of axial symptoms were included (≤2 years=early axSpA, N=658; >2 years=established axSpA, N=2406). Drug retention was analysed in patients starting a first TNFi in early axSpA (N=250) versus established axSpA (N=874) with multiple-adjusted Cox proportional hazards models. Adjusted logistic regression analyses were used to determine the achievement of the ASAS criteria for 40% improvement (ASAS40) at 1 year.

RESULTS

Sex distribution, disease activity, impairments of function and health-related quality of life were comparable between patients with early and established axSpA. Patients with established disease were older, had more prevalent axial radiographical damage and had a higher impairment of mobility. A comparable TNFi retention was found in early versus established disease after adjustment for age, sex, human leucocyte antigen-B27 status, education, body mass index, smoking, elevated C reactive protein and sacroiliac inflammation on MRI (HR 1.05, 95% CI 0.78 to 1.42). The adjusted ASAS40 response was similar in the two groups (OR 1.09, 95% CI 0.67 to 1.78). Results were confirmed in the population fulfilling the ASAS classification criteria.

CONCLUSION

Considering the recent ASAS definition of early axSpA, TNFi effectiveness seems comparable in early versus established disease.

Rheumatoid arthritis prevention in arthralgia: fantasy or reality?

The concept of a 'window of opportunity' in treating a disease assumes the existence of a time frame during which the trajectory of the disease can be effectively and permanently modified. In rheumatoid arthritis (RA), optimal timing of this period is presumed to be during the phase before arthritis is clinically apparent and disease is diagnosed. Several proof-of-concept trials of treatment during the 'arthralgia' phase of RA have been completed in the past 4 years, with the underlying notion that temporary treatment at this stage could prevent the development of RA or induce a sustained reduction in the burden of disease. This Review summarizes the results of these trials and reflects on the outcomes in relation to the patients' perspectives. Overall, the majority of symptomatic at-risk individuals could benefit from a fixed period treatment, even if RA does not develop. Various factors must be taken into consideration when translating these findings into clinical practice. More evidence is needed to target the individuals at highest risk, and additional tools are needed to monitor treatment and guide decisions about whether treatment can be discontinued. Without these tools, there is a paradoxical risk of seemingly increasing the incidence of the disease and prolonging disease duration, which is the opposite of what the concept of intervening in the window of opportunity entails.

Outcomes of undifferentiated peripheral inflammatory arthritis in real-world practice. A longitudinal cohort study

OBJECTIVES

Undifferentiated peripheral inflammatory arthritis (UPIA) may have 3 different courses, including evolution to differentiated arthritis, remaining undifferentiated, and self-limited course. The purpose of this study was to provide a real-world evidence for predictors of outcomes in UPIA in a longitudinal cohort of patients.

METHODS

Patients enrolled in the CTDRC-UA cohort were screened for eligibility. Inclusion criteria were: (i) having synovitis in ≥ 1 joint, (ii) not meeting the criteria of any other rheumatic disease, (iii) having at least 2 visits per year, iv) included in the cohort during the period of 2004 to 2021, and (v) having active disease at cohort entry. Two hundred and three patients who met the inclusion criteria were followed up until January 2023.

RESULTS

Medication-free remissions occurred in 42 (20.7%) cases. In 24 (11.8%) cases, the disease met the criteria of other rheumatic diseases, of which rheumatoid arthritis (RA) was the most common. In addition, joint damage occurred in 33 (16.3%) cases. Predictors of medication-free remissions were absence of comorbidity, starting a sustained remission at ≤ 6 months, and having no flare. Factors associated with disease evolution to RA were anti-citrullinated peptide antibody (ACPA) positivity, non-adherence to therapy, not going into sustained remission and having flare. Delay in treatment for > 3 months and being ACPA positive were the predictors of joint damage.

CONCLUSION

Although the majority of UIPA cases treated with step-up combination therapy with DMARDs do not progress to RA, most require continued treatment and a few achieve medication-free remissions. Key Points • Undifferentiated peripheral inflammatory arthritis (UPIA) can progress to rheumatoid arthritis in 11% of cases; and lack of sustained remission, being anti-citrullinated peptide antibody positive, non-adherence to therapy, and having flare are its predictors. • Medication-free remissions occur in 21% of patients with UPIA; and absence of comorbidity, starting a sustained remission at ≤ 6 months, and having no flare are its predictors. • Initiating treatment in the window of opportunity may lead to a better joint outcome.

Innate immune memory in inflammatory arthritis

The concept of immunological memory was demonstrated in antiquity when protection against re-exposure to pathogens was observed during the plague of Athens. Immunological memory has been linked with the adaptive features of T and B cells; however, in the past decade, evidence has demonstrated that innate immune cells can exhibit memory, a phenomenon called 'innate immune memory' or 'trained immunity'. Innate immune memory is currently being defined and is transforming our understanding of chronic inflammation and autoimmunity. In this Review, we provide an up-to-date overview of the memory-like features of innate immune cells in inflammatory arthritis and the crosstalk between chronic inflammatory milieu and cell reprogramming. Aberrant pro-inflammatory signalling, including cytokines, regulates the metabolic and epigenetic reprogramming of haematopoietic progenitors, leading to exacerbated inflammatory responses and osteoclast differentiation, in turn leading to bone destruction. Moreover, imprinted memory on mature cells including terminally differentiated osteoclasts alters responsiveness to therapies and modifies disease outcomes, commonly manifested by persistent inflammatory flares and relapse following medication withdrawal.

Challenges in the Management of Psoriatic Arthritis in Latin America: A Systematic Review

PURPOSE

In 2020, the International League of Associations for Rheumatology published recommendations for managing psoriatic arthritis (PsA), aiming to adapt the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis and the European Alliance of Associations for Rheumatology recommendations to low-income countries. At that time, the paucity of clinical studies examining the management of patients with PsA in Latin America was remarked on by the international working group. Therefore, the primary objective of this systematic literature review was to investigate the main challenges in managing PsA in Latin America as described in recent publications.

METHODS

A systematic literature review of trials reporting at least one challenge/difficulty in the management of PsA in Latin America was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. References published in the PubMed, EMBASE, and LILACS (Latin American and Caribbean Health Sciences Literature) databases between 1980 and February 2023 were included. The selection of references was conducted independently by 2 researchers in the Rayyan Qatar Computing Research Institute program. Two other reviewers independently extracted data. All challenges were noted and categorized into domains. Data analysis was descriptive.

FINDINGS

The search strategy yielded 2085 references, with 21 studies included in the final analysis. Most studies were conducted in Brazil (66.6%; n = 14) and were observational studies (100%; N = 21). Difficulties faced by PsA patients and physicians included the high incidence of opportunistic infections (described in 42.8% of the publications; n = 9), followed by nonadherence to therapy, discordance between patients and physicians regarding remission rates, low drug persistence, limited access to disease-modifying antirheumatic drugs, issues related to the storage of biologic drugs, elevated cost of biologic drugs, limited access to medical care, diagnostic delay, and the individual- and country-level impact of socioeconomic factors on work- and health-related outcomes.

IMPLICATIONS

Challenges in the management of PsA in Latin America extend beyond the care of opportunistic infections, encompassing several other socioeconomic factors. More research is needed to better understand the peculiarities of treating PsA in Latin America to improve patient care. PROSPERO identifier: CRD42021228297.

Matrix metalloproteinases in arthritis: towards precision medicine

Proteolysis of structural molecules of the extracellular matrix (ECM) is an irreversible post-translational modification in all arthropathies. Common joint disorders, including osteoarthritis and rheumatoid arthritis, have been associated with increased levels of matrix remodelling enzymes, including matrix metalloproteinases (MMPs). MMPs, in concert with other host proteinases and glycanases, destroy proteoglycans, collagens and other ECM molecules. MMPs may also control joint remodelling indirectly by signalling through cell-surface receptors or by proteolysis of cytokines and receptor molecules. After synthesis as pro-forms, MMPs can be activated by various types of post-translational modifications, including proteolysis. Once activated, MMPs are controlled by general and specific tissue inhibitors of metalloproteinases (TIMPs). In rheumatoid arthritis, proteolysis of the ECM results in so-called remnant epitopes that enhance and perpetuate autoimmune processes in susceptible hosts. In osteoarthritis, the considerable production of MMP-13 by chondrocytes, often concurrent with mechanical overload, is a key event. Hence, information about the regulation, timing, localization and activities of MMPs in specific disease phases and arthritic entities will help to develop better diagnostics. Insights into beneficial and detrimental effects of MMPs on joint tissue inflammation are also necessary to plan and execute (pre)clinical studies for better therapy and precision medicine with MMP inhibitors. With the advances in proteomics and single-cell transcriptomics, two critical points need attention: neglected neutrophil MMP biology, and the analysis of net proteolytic activities as the result of balances between MMPs and their inhibitors.

Do it fast! Early access to specialized care improved long-term outcomes in rheumatoid arthritis: data from the REAL multicenter observational study

BACKGROUND

Early rheumatoid arthritis (RA) offers an opportunity for better treatment outcomes. In real-life settings, grasping this opportunity might depend on access to specialized care. We evaluated the effects of early versus late assessment by the rheumatologist on the diagnosis, treatment initiation and long-term outcomes of RA under real-life conditions.

METHODS

Adults meeting the ACR/EULAR (2010) or ARA (1987) criteria for RA were included. Structured interviews were conducted. The specialized assessment was deemed "early" when the rheumatologist was the first or second physician consulted after symptoms onset, and "late" when performed afterwards. Delays in RA diagnosis and treatment were inquired. Disease activity (DAS28-CRP) and physical function (HAQ-DI) were evaluated. Student's t, Mann-Whitney U, chi-squared and correlation tests, and multiple linear regression were performed. For sensitivity analysis, a propensity score-matched subsample of early- vs. late-assessed participants was derived based on logistic regression. The study received ethical approval; all participants signed informed consent.

RESULTS

We included 1057 participants (89.4% female, 56.5% white); mean (SD) age: 56.9 (11.5) years; disease duration: 173.1 (114.5) months. Median (IQR) delays from symptoms onset to both RA diagnosis and initial treatment coincided: 12 (6-36) months, with no significant delay between diagnosis and treatment. Most participants (64.6%) first sought a general practitioner. Notwithstanding, 80.7% had the diagnosis established only by the rheumatologist. Only a minority (28.7%) attained early RA treatment (≤ 6 months of symptoms). Diagnostic and treatment delays were strongly correlated (rho 0.816; p < 0.001). The chances of missing early treatment more than doubled when the assessment by the rheumatologist was belated (OR 2.77; 95% CI: 1.93, 3.97). After long disease duration, late-assessed participants still presented lower chances of remission/low disease activity (OR 0.74; 95% CI: 0.55, 0.99), while the early-assessed ones showed better DAS28-CRP and HAQ-DI scores (difference in means [95% CI]: -0.25 [-0.46, -0.04] and - 0.196 [-0.306, -0.087] respectively). The results in the propensity-score matched subsample confirmed those observed in the original (whole) sample.

CONCLUSIONS

Early diagnosis and treatment initiation in patients with RA was critically dependent on early access to the rheumatologist; late specialized assessment was associated with worse long-term clinical outcomes.

Stratified distribution of Th17 and Treg cells in patients with multi-stage rheumatoid arthritis

OBJECTIVE

Rheumatoid arthritis (RA) is a typical, progressive autoimmune disease. Its occurrence and development are associated with dysregulation of T and B cell numbers. However, the specific immune characteristics of different RA courses remain incompletely defined. Here, we describe the peripheral blood lymphocyte subsets, particularly CD4 + T subsets, of different RA courses with a focus on early RA (Ea-RA).

METHODS

In all, 131 patients with Ea-RA, 117 with advanced RA (Ad-RA), and 109 with treated RA (Tr-RA) were enrolled. We collected general clinical data. Whole blood samples obtained from the patients and 97 healthy controls (HCs) were analysed via flow cytometry.

RESULTS

Decreased absolute NK cell numbers and increased CD4/CD8 T cell ratios were observed in different RA groups, including Ea-RA, compared to healthy controls. In Ea-RA patients, the Th17 and Treg cell numbers were similar to those in HCs. We performed k-means clustering based on the profiles of Th17 and Treg cells for patients with multi-stage of RA. We identified three patient types: type A characterised by relatively low Treg and Th17 cell numbers, type B with moderate levels of Treg cells and levels of Th17 cells similar to that of type C patients, and type C with high levels of Treg cells and levels of Th17 cells similar to that of type B patients.

CONCLUSION

The immune characteristics of Ea-RA patients differ from those of HCs; an immune system disorder is apparent although no differences in Th17 and Treg levels were evident between Ea-RA patients and HCs. We found distributional heterogeneities of Th17 and Treg cells in patients with multi-stage of RA. Stratified management based on such heterogeneity may serve as a useful novel immunotherapy allowing of early intervention.

Difficult-to-treat rheumatoid arthritis (D2T RA): clinical issues at early stages of disease

OBJECTIVES

Most studies on difficult-to-treat rheumatoid arthritis (D2T RA) have focused on established RA. Here, we analyse whether disease activity in the early stages of RA could influence progression to a D2T RA under real-life conditions. Other clinical and treatment-related factors were also analysed.

METHODS

A longitudinal multicentre study of patients with RA was conducted from 2009 to 2018. Patients were followed up until January 2021. D2T RA was defined based on EULAR criteria (treatment failure, signs suggestive of currently active/progressive disease and management being perceived as problematic by the rheumatologist and/or patient). The main variable was disease activity in the early stages. The covariates were sociodemographic, clinical and treatment-related factors. We ran a multivariable logistic regression analysis to investigate risk factors associated with progression to D2T RA.

RESULTS

The study population comprised 631 patients and 35 (5.87%) developed D2T RA. At the time of diagnosis, the D2T RA group were younger, with a higher disability, 28-joint Disease Activity Score (DAS28) score, tender joint count and pain scores. In our final model, DAS28 was not statistically significantly associated with D2T RA. No differences were found between groups for therapy. Disability was independently associated with D2T RA (OR: 1.89; p=0.01).

CONCLUSIONS

In this cohort of patients newly diagnosed with RA, our results do not allow us to prove the influence of active disease according to DAS28. However, we did find that younger patients and those with elevated initial disability scores are more likely to develop D2T RA regardless of other factors.

Therapeutic window of opportunity in the acute uveitic phase of Vogt-Koyanagi-Harada disease: Prevention of late autoimmune complications by early intervention

PURPOSE

To determine relationship between timing of treatment initiation and disease outcomes and whether a therapeutic window of opportunity exists in initial-onset acute uveitis associated with Vogt-Koyanagi-Harada disease.

METHODS

Retrospective analysis of 112 patients (224 eyes). Main outcome measures were final visual acuity, progression to chronic recurrent evolution, development of complications, particularly 'sunset glow fundus', and drug-free remission cure of uveitis.

RESULTS

Forty-six patients (92 eyes) presented in the phase preceding anterior segment (AS) inflammation (early presentation) and 66 patients (132 eyes) had AS inflammation at presentation (late presentation). In significantly more eyes in the early presentation group (85.9%), final visual acuity of 20/20 was achieved compared with those in the late presentation group (66.7%) (p = 0.001). None of the eyes in the early presentation group progressed to chronic recurrent evolution and none developed 'sunset glow fundus', whereas in the late presentation group, 28.8% of the eyes progressed to chronic recurrent evolution (p < 0.001) and 56.1% developed 'sunset glow fundus' (p < 0.001). Patients in the early presentation group were able to discontinue treatment without relapse of inflammation at significantly shorter time intervals compared to patients in the delayed presentation group (p < 0.001). In the late presentation group, logistic regression analysis demonstrated that presenting clinical features predicting unfavourable outcomes were posterior synechiae (odds ratio = 4.03; 95% confidence interval [CI] = 1.29-12.23), bullous exudative retinal detachment extending to the periphery (odds ratio = 3.35; 95% CI = 1.53-7.32) and female gender (odds ratio = 2.05; CI = 1.08-3.90).

CONCLUSIONS

Our findings suggest that the window of opportunity lies in the phase preceding AS inflammation and initiation of effective treatment during this phase results in cure of uveitis and prevents blinding complications.

Decreasing delays in the diagnosis and treatment of rheumatoid arthritis in Brazil: a nationwide multicenter observational study

BACKGROUND

Management delays imply worse outcomes in rheumatoid arthritis (RA) and, therefore, should be minimized. We evaluated changes in diagnostic and treatment delays regarding RA in the last decades in Brazil.

METHODS

Adults fulfilling the ACR/EULAR (2010) criteria for RA were assessed. Delays in diagnosis and treatment, and the frequencies of early management initiation within thresholds (windows of opportunity) of 3, 6, and 12 months from symptoms onset were evaluated. The Mann-Kendall trend test, chi-squared tests with Cramer's V effect sizes and analysis of variance were conducted.

RESULTS

We included 1116 patients: 89.4% female, 56.8% white, mean (SD) age 57.1 (11.5) years. A downward trend was found in diagnostic (tau = - 0.677, p < 0.001) and treatment (tau = - 0.695, p < 0.001) delays from 1990 to 2015. The frequency of early management increased throughout the period, with ascending effect sizes across the 3-, 6-, and 12-month windows (V = 0.120, 0.200 and 0.261, respectively). Despite all improvements, even in recent years (2011-2015) the diagnostic and treatment delays still remained unacceptably high [median (IQR): 8 (4-12) and 11 (5-17) months, respectively], with only 17.2% of the patients treated within the shortest, 3-month window.

CONCLUSION

The delays in diagnosis and treatment of RA decreased during the last decades in Brazil. Improvements (effect sizes) were greater at eliminating extreme delays (≥ 12 months) than in attaining really short management windows (≤ 3 months). Very early treatment was still an unrealistic goal for most patients with RA.

Inducibility or predestination? Queries and concepts around drug-free remission in rheumatoid arthritis

INTRODUCTION

Drug-free remission (DFR) and its maintenance have been defined as the most desirable outcome for rheumatoid arthritis (RA) patients. DFR is linked to resolution of arthritis-related symptoms and restoration of normal functioning. However, there is currently no consensus if an optimal strategy, upon the initiation of treatment to the proper drugs withdrawal, is enough to induce it, or whether it is a predetermined condition related to patients' intrinsic characteristics.

AREAS COVERED

This review focuses on two key concepts around DFR. First, we analyze patients' intrinsic factors that may increase the chance of DFR, regardless of therapeutic choices. Second, we discuss on the evidence that it can be induced thanks to adequate, extrinsic disease management. Finally, we provide a glimpse into consequences of drugs discontinuation.

EXPERT OPINION

The early initiation of DMARD and the subsequent strict monitoring and drug adjustments are of primary importance to allow patients to achieve DFR, irrespective of initial treatment strategy. Once remission is obtained and maintained, it is possible to gradually taper and discontinue drugs with no dramatic consequences on the disease course. Among those who stop medication, ACPA-negative patients more often maintain the remission. Thus, DFR might depend on a combination of intrinsic and extrinsic factors.

Is symptom duration before DMARD therapy a determinant of direct and indirect costs in DMARD-naïve RA patients? A systematic review

Objective

Early treatment of RA improves clinical outcomes; however, the impact on health economic outcomes is unclear. This review sought to investigate the relationship between symptom/disease duration and resource utilization/costs and the responsiveness of costs following RA diagnosis.

Methods

A systematic search was performed on Pubmed, EMBASE, CINAHL and Medline. Studies were eligible if patients were DMARD-naïve and fulfilled 1987 ACR or 2010 ACR/EULAR RA classification criteria. Studies had to report symptom/disease duration and resource utilization or direct/indirect costs as health economic outcomes. The relationships between symptom/disease duration and costs were explored.

Results

Three hundred and fifty-seven records were identified in a systematic search; nine were eligible for analysis. The mean/median of symptom/disease duration in studies ranged between 25 days and 6 years. Annual direct costs of RA following diagnosis showed a U-shaped distribution in two studies. Longer symptom duration before starting a DMARD (>180 days) was associated with lower health-care utilization in the first year of RA diagnosis in one study. Annual direct and indirect costs 6 months before RA diagnosis were higher in patients with shorter symptom duration (<6 months) in one study. Given the clinical and methodological heterogeneities, the association between symptom/disease duration and costs after diagnosis was not computed.

Conclusion

The association between symptom/disease duration at the time of DMARD initiation and resource utilization/cost in patients with RA remains unclear. Health economic modelling with clearly defined symptom duration, resource utilization and long-term productivity is vital to address this evidence gap.

Diagnostic Performance and Clinical Utility of Referral Rules to Identify Primary Care Patients at Risk of an Inflammatory Rheumatic Disease

OBJECTIVE

To determine the diagnostic performance and clinical utility of the Rotterdam Early Arthritis Cohort (REACH) and the Clinical Arthritis Rule (CARE) referral rules in an independent population of unselected patients from primary care.

METHODS

This study consisted of adults who were suspected of the need for referral to a rheumatologist by their general practitioner. Diagnostic accuracy measures and a net benefit approach were used to compare both rules to usual care for recognizing inflammatory arthritis and inflammatory rheumatic diseases (IRDs). Using the least absolute shrinkage and selection operator method and cross-validation we created an optimal prediction rule for IRD.

RESULTS

This study consisted of 250 patients, of whom 42 (17%) were diagnosed with inflammatory arthritis and 55 (22%) with an IRD 3 months after referral. Considering inflammatory arthritis, the area under the receiver operating characteristic curve (AUC) was 0.72 (95% confidence interval [95% CI] 0.64-0.80) for REACH and 0.82 (95% CI 0.75-0.88) for CARE. Considering IRD, the AUC was 0.66 (95% CI 0.58-0.74) for REACH and 0.76 (95% CI 0.69-0.83) for CARE. CARE was of highest clinical value when compared to usual care. The composite referral rule for IRD of 10 parameters included sex, age, joint features, acute onset of symptoms, physical limitations, and duration of symptoms (AUC 0.82 [95% CI 0.75-0.88]).

CONCLUSION

Both validated rules have a net benefit in recognizing inflammatory arthritis as well as IRD compared to usual care, but CARE shows superiority over REACH. Although the composite referral rule indicates a greater diagnostic performance, external validation is needed.

Glucocorticoids in rheumatoid arthritis: Balancing benefits and harm by leveraging the therapeutic window of opportunity

Glucocorticoids have been available since the early 1950s and have since become an integral part of the management of rheumatoid arthritis (RA). Due to their rapid effect, glucocorticoids have an appealing profile for treating flares or as "bridging" agents in early RA. The efficacy of glucocorticoids to treat RA has been well established, both to control disease activity and to delay the progression of joint damage. However, despite their benefits, glucocorticoids have equally well-known adverse effects. It is generally accepted that long-term use of glucocorticoids, particularly at higher doses, is not advisable, and recent guidelines for the management of RA therefore either recommend against the use of glucocorticoids or suggest using them only as bridging therapy. Perceptions on the harmful effects of glucocorticoids remain, although mainly based on observational studies. Prolonged glucocorticoid therapy at low doses is still highly prevalent in clinical practice, but recent data suggest a rather favourable risk-benefit balance for this strategy, even in senior patients. Balancing the benefits and risks of treating RA with glucocorticoids thus remains a somewhat controversial topic. This narrative review outlines the historical and current position of glucocorticoids in the management of RA, while summarising recent evidence on their beneficial and detrimental effects. Furthermore, practical strategies for the current use and tapering of glucocorticoids in RA are formulated.

Joint-Specific Memory and Sustained Risk for New Joint Accumulation in Autoimmune Arthritis

OBJECTIVE

Inflammatory arthritides exhibit hallmark patterns of affected and spared joints, but in each individual, arthritis affects only a subset of all possible sites. The purpose of this study was to identify patient-specific patterns of joint flare to distinguish local from systemic drivers of disease chronicity.

METHODS

Patients with juvenile idiopathic arthritis followed without interruption from disease onset into adulthood were identified across 2 large academic centers. Joints inflamed at each visit were established by medical record review. Flare was defined as physician-confirmed joint inflammation following documented inactive disease.

RESULTS

Among 222 adults with JIA, 95 had complete serial joint examinations dating from disease onset in childhood. Mean follow-up was 12.5 years (interquartile range 7.9-16.7 years). Ninety (95%) of 95 patients achieved inactive disease, after which 81% (73 patients) experienced at least 1 flare. Among 940 joints affected in 253 flares, 74% had been involved previously. In flares affecting easily observed large joint pairs where only 1 side had been involved before (n = 53), the original joint was affected in 83% and the contralateral joint in 17% (P < 0.0001 versus random laterality). However, disease extended to at least 1 new joint in ~40% of flares, a risk that remained stable even decades after disease onset, and was greatest in flares that occurred while patients were not receiving medication (54% versus 36% of flares occurring with therapy; odds ratio 2.09, P = 0.015).

CONCLUSION

Arthritis flares preferentially affect previously inflamed joints but carry an ongoing risk of disease extension. These findings confirm joint-specific memory and suggest that prevention of new joint accumulation should be an important target for arthritis therapy.

Impact of triage by a rheumatologist on appropriateness of referrals from primary to secondary care: a cluster randomized trial

OBJECTIVE

The quality of referrals is often criticized, and the effectiveness of improvement efforts remains uncertain. We assessed the impact of a rheumatologist triaging patients in primary care on the appropriateness of referrals to secondary care, healthcare utilization, and patient experience and outcomes.

METHOD

A cluster randomized controlled trial was conducted with patients experiencing musculoskeletal complaints. Intervention practices deployed an experienced rheumatologist triaging patients through in-person review. Usual care was performed in control practices, where practitioners referred patients based on their own judgement. The primary outcome was the proportion of inflammatory rheumatic diseases (IRDs) diagnosed by rheumatologists in referred patients. Healthcare utilization (iMTA Medical Consumption Questionnaire), quality of life (EuroQol 5 Dimensions), and experience of care (Consumer Quality Index) were determined after 3 months of follow-up. Data were analysed according to the intention-to-treat principle.

RESULTS

In total, 544 participants were included [mean age 51.4 (range 18-87) years; 24% were men]. Of all referred patients, 51% had an IRD in the intervention group versus 21% in the control group (p = 0.035). After 3 months of follow-up, patients from the triage intervention showed lower healthcare utilization (p = 0.006) and higher quality of life (p = 0.011), without a decline in experienced quality of care (p = 0.712), compared to controls.

CONCLUSION

Triage by a rheumatologist in primary care provides appropriate care and adequate experience of care, leading to a higher quality of life. Long-term evidence is needed to assess the value on cost-effectiveness before implementing this strategy nationwide.

Treating spondyloarthritis early: does it matter? Results from a systematic literature review

OBJECTIVE

To summarize evidence on the relationship between early treatment (definition based on symptom/disease duration or radiographic damage) and treatment clinical response in patients with SpA.

METHODS

A systematic literature review was conducted in studies on SpA patients treated with NSAIDs or b/tsDMARDs addressing the impact of symptom/disease duration or presence of radiographic damage on treatment response assessed by any disease activity outcome. For categorical outcomes, relative risk, relative risk ratio (RRR) and number needed to treat were calculated, and for continuous outcomes, differences in differences, to compare groups stratified based on symptom/disease duration or the presence of radiographic damage.

RESULTS

From the 8769 articles retrieved, 25 were included and 1 added by hand-search, all in axSpA, most of them with low risk of bias. Twenty-one studies compared groups based on symptom duration (n = 6) or disease duration (n = 15) and 7 studies based on absence/presence of radiographic damage (2 studies used two comparisons). When early axSpA was defined by symptom duration (<5 years) in RCTs, early treatment was associated with better outcomes in patients with nr-axSpA (n = 2, ASAS40 RRR 5.24 (95%CI 1.12-24.41) and 1.52 (0.60-3.87)) but not in r-axSpA (n = 1) [ASAS20 0.96 (0.53-1.73)]. When early axSpA was defined based on disease duration or radiographic damage, no differences were found between groups.

CONCLUSION

Evidence towards better outcomes in early axSpA is very limited and restricted to nr-axSpA and <5 years symptom duration. When early axSpA is defined based on disease duration or radiographic damage, no differences in response to treatment are found.

A systematic review on time trend incidence of rheumatoid arthritis in outpatient rheumatology clinics

Objectives

To classify patients with rheumatoid arthritis (RA) in an earlier stage of the disease, the ACR/EULAR classification criteria were updated in 2010. These criteria might have led to an increased incidence of RA in the rheumatology clinic. Since a higher incidence increases the socio-economic burden of RA, it is worthwhile to evaluate whether there is a time effect.

Materials and methods

A systematic review was conducted using Embase, Medline Ovid, Cochrane Central, and Web of Science from database inception to February 2021. Included were only articles that addressed incidence rates of rheumatoid arthritis from rheumatology outpatient clinics.

Results

Of the 6,289 publications only 243 publications on RA were found eligible for full-text review. Nine studies were included reporting incidence. The pooled incidence for RA was 11% (95% CI 6-16%) per year. Over time the incidence increased after the introduction of the 2010 ACR/EULAR classification criteria. Overall there was a high intragroup heterogeneity (I 2 = 97.93%, p < 0.001), caused by geographical area, study design and differences in case definitions.

Conclusion

Although the incidence seems to increase after the introduction of the 2010 ACR/EULAR criteria, no conclusions can be drawn on this time effect due to heterogeneity.

Predictors of flare in rheumatoid arthritis patients with persistent clinical remission/low disease activity: Data from the TARAC cohort

To identify predictors of rheumatoid arthritis (RA) disease activity flare in RA patients who achieved low disease activity (LDA) or persistent remission from the observational Thai Army Rheumatoid Arthritis Cohort study. RA patients with persistent clinical remission, defined by disease activity score 28 (DAS28) < 2.6 and LDA defined by DAS28 ≤ 3.2 for 3 consecutive months, were recruited and followed-up for at least 2 years. The flare was defined by an escalation of DAS28 ≥ 1.2 plus their physicians' decision to enhance RA treatment. Differences between sustained remission/LDA and flare groups were analyzed, by Chi-square test and unpaired Student t test. Multivariate Cox proportional hazard regression analysis was conducted to determine flare predictors. From 199 RA patients, female were 82.9%. Anticitrullinated peptide antibodies (ACPA) or Rheumatoid factor (RF) were found in 69.8% of patients. Flares occurred in 69 patients (34.9%). Multivariate analysis found that the timescale from symptoms emergence to DMARD commencement, the timescale from DMARD commencement to when RA patients showed remission/LDA, the occurrence of RF or ACPA, LDA (in contrast to remission) and the increased DAS28 score when remission/LDA was achieved and tapering DMARDs promptly when persistent remission/LDA was achieved were predictors of RA flares with hazard ratios of (95% confidence interval [CI]) of 1.017 (1.003-1.030), 1.037 (1.015-1.059), 1.949 (1.035-3.676), 1.926 (0.811-4.566), 2.589 (1.355-4.947), and 2.497 (1.458-4.276), respectively. These data demonstrated that early and aggressive DMARDs treatment approach could maintain remission espcially in seropositive patients. Tapering should be applied minimally 6 months after reaching remission.

Anti-Citrullinated Protein Antibody Titers Are Independently Modulated by Both Disease Activity and Conventional or Biologic Anti-Rheumatic Drugs

This study aimed to analyze the factors that influence anti-citrullinated protein antibody (ACPA) titers in a seropositive early arthritis (EA) population under non-protocolized treatment with disease-modifying anti-rheumatic drugs (DMARDs). A total of 130 ACPA-positive patients from the PEARL (Princesa Early Arthritis Longitudinal) study were studied along a 5-year follow-up. Sociodemographic, clinical, and therapeutic variables, along with serum samples, were collected at five visits by protocol. Anti-cyclic citrullinated peptide 2 (CCP2) ACPA titers were measured by ELISA. The effect of different variables on anti-CCP2 titers was estimated using longitudinal multivariate analysis models, nested by visit and patient. Data from 471 visits in 130 patients were analyzed. A significant decrease in anti-CCP2 titers was observed at all time-points, compared to baseline, following the decline of disease activity. In the multivariate analysis, active or ever smoking was significantly associated with the highest anti-CCP2 titers while reduction in disease activity was associated with titer decline. After adjusting for these variables, both conventional synthetic (cs) and biologic (b) DMARDs accounted for the decline in anti-CCP2 titers as independent factors. Conclusion: In patients with EA, an early and sustained reduction in ACPA titers can be detected associated with the decline in disease activity, irrespective of the treatment used.

IgA rheumatoid factor in rheumatoid arthritis

OBJECTIVES

Rheumatoid factor (RF) is a well-established marker for the diagnosis and classification of rheumatoid arthritis (RA). Most studies evaluated IgM RF or isotype-nonspecific total RF assays. We evaluated the added value of IgA RF in this context.

METHODS

An international sample cohort consisting of samples from 398 RA patients and 1073 controls was tested for IgA RF with 3 commercial assays. For all RA patients and 100 controls essential clinical and serological data for ACR/EULAR classification were available.

RESULTS

The sensitivity of IgA RF for diagnosing RA was lower than the sensitivity of IgM RF. Differences in numerical values between IgA RF assays were observed. With all assays, the highest IgA RF values were found in patients with primary Sjögren's syndrome. Double positivity for IgM RF and IgA RF had a higher specificity for RA than either IgM RF or IgA RF. The sensitivity of double positivity was lower than the sensitivity of either IgA RF or IgM RF. Single positivity for IgA RF was at least as prevalent in controls than in RA patients. Adding IgA RF to IgM RF and anti-citrullinated protein antibodies (ACPA) did not affect RA classification. However, combined positivity for IgA RF, IgM RF and IgG ACPA had a higher specificity and lower sensitivity for RA classification than positivity for either of the antibodies.

CONCLUSIONS

IgA RF showed a lower sensitivity than IgM RF. Combining IgA RF with IgM RF and ACPA did not improve sensitivity of RA classification. Combined positivity (IgA-RF/IgM-RF/ACPA) increased specificity.

Proteome Profiling Identifies Serum Biomarkers in Rheumatoid Arthritis

Rheumatoid arthritis (RA) causes serious disability and productivity loss, and there is an urgent need for appropriate biomarkers for diagnosis, treatment assessment, and prognosis evaluation. To identify serum markers of RA, we performed mass spectrometry (MS)-based proteomics, and we obtained 24 important markers in normal and RA patient samples using a random forest machine learning model and 11 protein–protein interaction (PPI) network topological analysis methods. Markers were reanalyzed using additional proteomics datasets, immune infiltration status, tissue specificity, subcellular localization, correlation analysis with disease activity-based diagnostic indications, and diagnostic receiver-operating characteristic analysis. We discovered that ORM1 in serum is significantly differentially expressed in normal and RA patient samples, which is positively correlated with disease activity, and is closely related to CD56dim natural killer cell, effector memory CD8⁺T cell, and natural killer cell in the pathological mechanism, which can be better utilized for future research on RA. This study supplies a comprehensive strategy for discovering potential serum biomarkers of RA and provides a different perspective for comprehending the pathological mechanism of RA, identifying potential therapeutic targets, and disease management.

Multicentre study to improve clinical interpretation of rheumatoid factor and anti-citrullinated protein/peptide antibodies test results

BACKGROUND

Rheumatoid factor (RF) and anti-citrullinated protein/peptide antibodies (ACPA) are important biomarkers for diagnosis of rheumatoid arthritis (RA). However, there is poor harmonisation of RF and ACPA assays. The aim of this study was to refine RF and ACPA interpretation across commercial assays.

MATERIALS AND METHODS

Six total RF isotype-non-specific assays, 3 RF IgM isotype-specific assays and 9 ACPA immunoglobulin G assays of 13 different companies were evaluated using 398 diagnostic samples from patients with RA and 1073 disease controls.

RESULTS

Using cut-offs proposed by the manufacturer, there was a large variability in diagnostic sensitivity and specificity between assays. Thresholds of antibody levels were determined based on predefined specificities and used to define test result intervals. Test result interval-specific likelihood ratios (LRs) were concordant across the different RF and ACPA assays. For all assays, the LR for RA increased with increasing antibody level. Higher LRs were found for ACPA than for RF. ACPA levels associated with LRs >80 were found in a substantial fraction (>22%) of patients with RA.

CONCLUSION

Defining thresholds for antibody levels and assigning test result interval-specific LRs allows alignment of clinical interpretation for all RF and ACPA assays.

Pre-RA: Can early diagnosis lead to prevention?

Rheumatoid arthritis (RA) is currently diagnosed and treated once an individual displays the clinical findings of inflammatory arthritis (IA). However, growing evidence supports that there is a 'pre-RA' stage that can be identified through factors such as autoantibodies in absence of clinically apparent IA. In particular, biomarkers, including antibodies to citrullinated protein antigens (ACPA), demonstrate a high risk for future IA/RA, and multiple clinical trials have been developed to intervene in individuals in pre-RA to prevent or delay clinically apparent disease. Herein, we will discuss in more depth what is currently known about the natural history of RA, and the emerging possibility that early 'diagnosis' of RA-related autoimmunity followed by an intervention can lead to the delay or prevention of the first onset of clinically apparent RA.

Impact of autoimmune serology test results on RA classification and diagnosis

Rheumatoid arthritis (RA) is the most common systemic autoimmune disease and also the most severe arthritic disorder. The measurement of rheumatoid factor (RF) and anti-citrullinated protein antibodies (ACPA) in serum supports the diagnosis of RA, which gained increasing significance over the last 65 years. However, a high variability between RF and ACPA methods has been described, impacting the diagnostic performance of the current ACR/EULAR RA classification criteria.

The great number of commercially available assays, often lacking traceability to an international standard, is a major factor attributing to this in-between assay variability. The adoption of an international standard for ACPA, as is since long available for rheumatoid factor, is therefore highly desirable.

Further harmonization in clinical interpretation of RF/ACPA assays could be obtained by harmonization of the cut-offs, for both the low and high antibody levels, based on predefined specificity in disease controls. Reporting test result specific likelihood ratios (LR) adds value in the interpretation of autoantibody tests. However, a good understanding of the control population used to define antibody test result interval-associated LRs is crucial in defining the diagnostic performance characteristics of antibody serology.

Finally, specificity in RA classification can be improved by refining serological weight scoring taking into account the nature of the antibody, the antibody level and double RF + ACPA positivity.

Outcomes in patients with systemic sclerosis undergoing early versus delayed intervention with potential disease-modifying therapies

OBJECTIVE

To examine whether early therapeutic intervention, compared with delayed intervention, is beneficial for patients with early systemic sclerosis (SSc).

METHODS

This is a single-center, retrospective cohort study of SSc patients who received cyclophosphamide, mycophenolate mofetil, methotrexate, or tocilizumab for diffuse cutaneous SSc (dcSSc) or interstitial lung disease (ILD) within 6 years after disease onset. The patients were divided into early and delayed intervention groups based on the disease duration of ≤ 18 and >18 months at treatment introduction, respectively. Clinical worsening was defined as the development of any original or revised ACR Composite Response Index in Systemic Sclerosis (CRISS) step 1 event or progressive fibrosing ILD (PF-ILD).

RESULTS

There was no difference in baseline characteristics between the early (n = 25) and delayed (n = 21) intervention groups except forced vital capacity (FVC), which was better in the early vs delayed intervention groups. The early intervention group less frequently had stable pulmonary function over one year than did the late intervention group (odds ratio 0.087, 95% confidence interval 0.0079-0.51, p = 0.003). The active disease was significantly decreased from 79% to 42% in the early intervention group (p = 0.007), but the change in the delayed intervention group was not statistically significant (68% to 42%, p = 0.11). Cumulative rates free from clinical worsening events defined by revised ACR-CRISS and PF-ILD were significantly higher in the early vs delayed intervention groups (p = 0.03 and 0.003, respectively).

CONCLUSION

A therapeutic "window of opportunity" might exist in SSc patients.

Inhibition of Structural Joint Damage Progression with Upadacitinib in Rheumatoid Arthritis: 1-Year Outcomes from the SELECT Phase 3 Program

OBJECTIVES

To evaluate the inhibition of progression of structural joint damage through week 48 in patients with moderately to severely active rheumatoid arthritis (RA) receiving upadacitinib as monotherapy or in combination with methotrexate.

METHODS

Radiographic progression was assessed in two phase 3 randomized-controlled trials. Methotrexate-naïve patients were randomized to upadacitinib 15 or 30 mg once daily (QD) or methotrexate monotherapy (SELECT-EARLY, n = 945), while methotrexate inadequate responders (IR) were randomized to upadacitinib 15 mg QD or adalimumab 40 mg every other week or placebo added to background methotrexate (SELECT-COMPARE, n = 1629). Mean changes from baseline in modified Total Sharp Score (mTSS), joint space narrowing (JSN), and erosion scores (ES) were determined. Data were analysed both by linear extrapolation for missing data imputation and treatment switching and as-observed.

RESULTS

In patients naïve or with limited exposure to methotrexate (SELECT-EARLY), mean changes from baseline to week 48 in mTSS were 0.03 for upadacitinib 15 mg, 0.14 for upadacitinib 30 mg, and 1.00 for methotrexate based on linear extrapolation (p < 0.001 for both upadacitinib doses vs methotrexate). Among patients with an inadequate response to methotrexate (SELECT-COMPARE), the mean change from baseline in mTSS was significantly reduced in the upadacitinib 15 mg plus methotrexate group vs placebo plus methotrexate (0.28 vs 1.73; p < 0.001); mean change from baseline in the adalimumab plus methotrexate group was 0.39.

CONCLUSION

Upadacitinib monotherapy or in combination with background methotrexate was effective in inhibiting the progression of structural joint damage through week 48 in methotrexate-naïve and methotrexate-IR patients with RA.

TRIAL REGISTRATION

ClinicalTrials.gov, https://clinicaltrials.gov, NCT02706873 and NCT02629159.

New Perspectives on the Immunopathogenesis and Treatment of Uveitis Associated With Vogt-Koyanagi-Harada Disease

Uveitis associated with Vogt-Koyanagi-Harada (VKH) disease is a bilateral, chronic, granulomatous autoimmune disease associated with vitiligo, poliosis, alopecia, and meningeal and auditory manifestations. The disease affects pigmented races with a predisposing genetic background. Evidence has been provided that the clinical manifestations are caused by a T-lymphocyte-mediated autoimmune response directed against antigens associated with melanocytes in the target organs. Alongside of T lymphocytes, autoreactive B cells play a central role in the development and propagation of several autoimmune diseases. The potential role of B lymphocytes in the pathogenesis of granulomatous uveitis associated with VKH disease is exemplified within several studies. The early initial-onset acute uveitic phase typically exhibits granulomatous choroiditis with secondary exudative retinal detachment and optic disc hyperemia and swelling, subsequently involving the anterior segment if not adequately treated. The disease eventually progresses to chronic recurrent granulomatous anterior uveitis with progressive posterior segment depigmentation resulting in "sunset glow fundus" appearance and chorioretinal atrophy if not properly controlled. Chronically evolving disease is more refractory to treatment and, consequently, vision-threatening complications have been recognized to occur in the chronic recurrent phase of the disease. Conventional treatment with early high-dose systemic corticosteroids is not sufficient to prevent chronic evolution. Addition of immunomodulatory therapy with mycophenolate mofetil as first-line therapy combined with systemic corticosteroids in patients with acute initial-onset disease prevents progression to chronic evolution, late complications, vitiligo, and poliosis. Furthermore, patients under such combined therapy were able to discontinue treatment without relapse of inflammation. These findings suggest that there is a therapeutic window of opportunity for highly successful treatment during the early initial-onset acute uveitic phases, likely because the underlying disease process is not fully matured. It is hypothesized that early and aggressive immunosuppressive therapy will prevent remnant epitope generation in the initiation of the autoimmune process, the so-called primary response. B cell depleting therapy with the anti-CD20 monoclonal antibody rituximab is effective in patients with refractory chronic recurrent granulomatous uveitis. The good response after rituximab therapy reinforces the idea of an important role of B cells in the pathogenesis or progression of chronic recurrent uveitis associated with VKH disease.

The Macrophage Reprogramming Ability of Antifolates Reveals Soluble CD14 as a Potential Biomarker for Methotrexate Response in Rheumatoid Arthritis

The identification of “trained immunity/tolerance” in myeloid cells has changed our perception of the performance of monocytes and macrophages during inflammatory and immune responses. Pemetrexed (PMX) and methotrexate (MTX) are blockers of the one-carbon metabolism (OCM) and commonly used therapeutic agents in cancer and rheumatoid arthritis (RA). We have previously showed that MTX promotes trained immunity in human macrophages. In the present manuscript, we have assessed the anti-inflammatory effects of PMX and MTX and found that OCM blockers alter the functional and gene expression profile of human macrophages and that OCM blockade reprograms macrophages towards a state of lipopolysaccharide (LPS) tolerance at the signaling and functional levels. Moreover, OCM blockade reduced macrophage LPS responsiveness by impairing the expression of membrane-bound and soluble CD14 (sCD14). The therapeutic relevance of these results was later confirmed in early RA patients, as MTX-responder RA patients exhibit lower sCD14 serum levels, with baseline sCD14 levels predicting MTX response. As a whole, our results demonstrate that OCM is a metabolic circuit that critically mediates the acquisition of innate immune tolerance and positions sCD14 as a valuable tool to predict MTX response in RA patients.

Digitalisierung in der Rehabilitation von rheumatischen Erkrankungen: Was ist sinnvoll, was ist bewiesen, welche Perspektiven gibt es?

In Deutschland besteht ein deutlicher Mangel an internistischen Rheumatologen. Um diese Versorgungslücke zu reduzieren, können verschiedene technische Anwendungen genutzt werden. Dies reicht von der Hilfe bei der Früherkennung und Diagnostik für Hausärzte, über Konsilsysteme mit Telemedizin, bis hin zur Videosprechstunde mit den Patienten nach Koordination in einem entsprechenden Netzwerk, das stufenförmig aufgebaut ist, um die vorhandenen Spezialisten möglichst effektiv einzusetzen. Auch Apps für die Nutzung am Smartphone oder Tablet können sowohl Ärzte in Diagnostik und Therapie unterstützen, aber auch vielfältig Patienten bei den jeweiligen Krankheitsbewältigungen helfen. Eine Sonderform sind dabei „Digitale Gesundheitsanwendungen“ (DiGAs), die geprüft wurden und als Medizinprodukte zugelassen und verordnungsfähig sind. Für die Unterstützung von Bewegungsübungen, wie sie bei rheumatischen Erkrankungen so wichtig sind, kommen auch Telemedizinische Assistenzsysteme in Betracht, bei denen über 3D-Kamera und Computeranalyse zu Hause ein individuelles Übungsprogramm angeleitet und kontrolliert wird. Studien zu Anwendungen und Bewertungsoptionen für Apps liegen bereits einige vor, hier besteht aber noch hoher Nachholbedarf.

Perceptions and experiences of individuals at-risk of rheumatoid arthritis (RA) knowing about their risk of developing RA and being offered preventive treatment: systematic review and thematic synthesis of qualitative studies

Objectives

There is increasing interest in identifying individuals at-risk of rheumatoid arthritis (RA) and initiating early treatment to prevent or delay the onset of arthritis. We aimed to describe the perceptions and experiences of at-risk individuals and to inform the conduct of clinical trials and studies, and clinical practice.

Methods

A systematic review and thematic synthesis of qualitative studies was conducted. Two review authors independently screened studies for inclusion, appraised their methodological quality using the Critical Appraisal Skills Programme checklist and assessed confidence in the findings using the Grading of Recommendations Assessment, Development and Evaluation–Confidence in Evidence from Reviews of Qualitative Research approach.

Results

Seven studies involving 115 individuals at-risk of developing RA were included. Three major themes (seven subthemes) were identified: understanding the risk of developing RA (knowledge of RA and identification of potential risk factors); preventive interventions to reduce the risk of developing RA (understanding the value and role of preventive interventions, and engagement with preventive interventions); and perceptions of predictive testing for RA (benefits of predictive testing, decision to undertake predictive testing and concerns about predictive testing). Moderate confidence in most review findings was evident.

Conclusion

While there are clear benefits in informing individuals at-risk of RA about their risk following predictive testing and offering preventive treatment, there are potential barriers to engagement, intensified by the burden of uncertainty. Identification of the optimum approaches for presenting risk information, including the risks and benefits of engaging with preventive interventions, is urgently needed to support individuals at-risk of RA in their decision making.

PROSPERO registration number

CRD42021236034.

Identification of circular RNAs hsa_circ_0140271 in peripheral blood mononuclear cells as a novel diagnostic biomarker for female rheumatoid arthritis

Background

Rheumatoid arthritis (RA) is a chronic autoimmune disease, which commonly affects women. Accumulating evidence shows that differentially expressed circular RNAs (circRNAs) play crucial roles in the progress of RA. However, the roles of circRNAs in female RA remains unclear. This study explores potential role and diagnostic value of hsa_circ_0140271 from peripheral blood mononuclear cells (PBMC) in female RA.

Methods

Differential expression of circRNAs was determined by RNA-sequencing in PBMC from 4 healthy controls (HC) and 4 RA patients, and we further measured the level of hsa_circ_0140271 in a validation cohort consisting of 47 RA and 47 HC via RT-qPCR. Besides, correlation studies with clinical variables were also examined. What’s more, we performed bioinformatics analysis to predict the potential role of hsa_circ_0140271.

Results

PBMC expression of hsa_circ_0140271 of female RA was significantly higher than that of female HC, and it was positively correlated with antistreptolysin (ASO). Furthermore, the receiver operating characteristic (ROC) curve indicated that hsa_circ_0140271 could distinguish female RA from female HC and female patients with ankylosing spondylitis (AS) or osteoarthritis (OA). Besides, the combined diagnosis anti-cyclic citrullinated peptide (Anti-CCP) + hsa_circ_0140271 could improve diagnostic accuracy with an area under the curve (AUC) of 0.818 to compared with Anti-CCP. Furthermore, KEGG pathway enrichment analysis indicated hsa_circ_0140271 may act as microRNA sponge and participate in fatty acid metabolism pathways.

Conclusion

Hsa_circ_0140271 was likely to be used as a promising diagnostic biomarker for female RA; it may act as microRNA sponge to regulate fatty acid metabolism pathways in RA.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13018-021-02794-8.

Treatment response and several patient-reported outcomes are early determinants of future self-efficacy in rheumatoid arthritis

Background

Self-efficacy, or patients’ confidence in their ability to control disease and its consequences, was recently prioritised in EULAR recommendations for inflammatory arthritis self-management strategies. However, it remains unclear which factors influence self-efficacy in early rheumatoid arthritis (RA).

Methods

Data were analysed from the 2-year RCT Care in early RA (CareRA), which studied remission-induction treatment regimens for early RA. Participants completed the Arthritis Self-Efficacy Scale (ASES), Short-Form 36 (SF-36), Revised Illness Perception Questionnaire (IPQ-R), Utrecht Coping List (UCL), RAQoL and Health Assessment Questionnaire (HAQ). Depending on time to first remission (DAS28-CRP < 2.6) and persistence of remission, treatment response was defined as persistent response, secondary failure, delayed response, late response or non-response. The association between ASES scores and clinical/psychosocial factors was explored with Spearman correlation and multivariate linear mixed models. Baseline predictors of week 104 ASES were identified with exploratory linear regression followed by multiple regression of significant predictors adjusted for DAS28-CRP, HAQ, treatment arm, treatment response, cumulative CRP/SJC28 and demographic/serologic confounders.

Results

All 379 patients had a recent diagnosis of RA and were DMARD-naïve at study initiation. Most patients were women (69%) and RF/ACPA-positive (66%), and the mean (SD) age was 52 (13) years. For all tested outcome measures, better perceived health correlated with higher self-efficacy. While patient-reported factors (HAQ, SF-36, RAQoL, IPQ-R, pain, fatigue and patient’s global assessment) showed moderate/strong correlations with ASES scores, correlations with physician-reported factors (physician’s global assessment, SJC28), TJC28 and DAS28-CRP were weak.

Only more favourable outcomes on patient-reported factors and DAS28-CRP were associated with higher ASES scores at each time point.

An earlier, persistent treatment response predicted higher ASES scores at both weeks 52 and 104. Significant baseline predictors of week 104 ASES included HAQ; SF-36 mental component score, vitality, mental health and role emotional; IPQ-R illness coherence, treatment control, emotional representations and consequences; UCL Passive reacting; and the RAQoL.

Conclusions

Patient-reported outcomes and treatment response were early determinants of long-term self-efficacy in an early RA trial. These results provide further relevance for the window of opportunity in an early treat-to-target strategy and could help to timely identify patients who might benefit from self-management interventions.

Trial registration

EudraCT 2008-007225-39

Supplementary Information

The online version contains supplementary material available at 10.1186/s13075-021-02651-3.

Anti-Carbamylated Fibrinogen Antibodies Might Be Associated With a Specific Rheumatoid Phenotype and Include a Subset Recognizing In Vivo Epitopes of Its γ Chain One of Which Is Not Cross Reactive With Anti-Citrullinated Protein Antibodies

To identify the targets recognized by anti-carbamylated protein antibodies (anti-CarP) in patients with early Rheumatoid Arthritis (RA), to study the cross-reactivity between anti-CarP and anti-citrullinated protein antibodies (ACPA) and to evaluate their prognostic value. 331 patients (184 RA and 147 other rheumatisms) from the Very Early Arthritis (VErA) French cohort were analyzed. We performed mass spectrometry analysis of RA sera displaying anti-CarP activity and epitope mapping of the carbamylated fibrinogen γ chain to identify immunodominant peptides. The specificity of these targets was studied using competition assays with the major antigens recognized by ACPA. The prognostic value of anti-carbamylated fibrinogen IgG antibodies (ACa-Fib IgG) was compared to that of anti-cyclic citrullinated peptide antibodies (anti-CCP) and anti-CarP using an in-house ELISA. Besides the α chain, the γ chain of fibrinogen, particularly one immunodominant epitope that has a specific reactivity, was identified as a circulating carbamylated target in sera. The prevalence of ACa-Fib was 37% at baseline and 10.9% for anti-CCP-negative RA. In anti-CCP-negative patients, ACa-Fib positivity was associated with a more inflammatory and erosive disease at baseline but not with rapid radiological progression, which remains strongly related to anti-CCP antibodies. Fibrinogen seems to be one of the antigens recognized in vivo by the anti-CarP response, particularly 2 epitopes of the γ chain, one of which is not cross reactive with ACPA. This specificity might be associated with a distinct clinical phenotype since ACa-Fib IgG were shown to be linked to systemic inflammation in very early RA but not to rapid radiological progression.

Assessing improved risk prediction of rheumatoid arthritis by environmental, genetic, and metabolomic factors

OBJECTIVE

We sought to improve seropositive rheumatoid arthritis (RA) risk prediction using a novel weighted genetic risk score (wGRS) and preclinical plasma metabolites associated with RA risk. Predictive performance was compared to previously validated models including RA-associated environmental factors.

METHODS

This nested case-control study matched incident seropositive RA cases (meeting ACR 1987 or EULAR/ACR 2010 criteria) in the Nurses' Health Studies (NHS) to two controls on age, blood collection features, and post-menopausal hormone use at pre-RA blood draw. Environmental variables were measured at the questionnaire cycle preceding blood draw. Four models were generated and internally validated using a bootstrapped optimism estimate: (a) base with environmental factors (E), (b) environmental, genetic and gene-environment interaction factors (E + G + GEI), c) environmental and metabolic factors (E + M), and d) all factors (E + G + GEI + M). A fifth model including all factors and interaction terms was fit using ridge regression and cross-validation. Models were compared using area under the receiver operating characteristic curve (AUC).

RESULTS

150 pre-RA cases and 455 matched controls were included. The E model yielded an optimism-corrected AUC of 0.622. The E + M model did not show improvement over the E model (corrected AUC 0.620). Including genetic factors increased prediction, producing corrected AUCs of 0.677 in the E + G + GEI model and 0.674 in the E + G + GEI + M model. Similarly, the performance of the cross-validated ridge regression model yielded an AUC of 0.657.

CONCLUSION

Addition of wGRS and gene-environment interaction improved seropositive RA risk prediction models. Preclinical metabolite levels did not significantly contribute to prediction.