Intervention with methotrexate in patients with arthralgia at risk of rheumatoid arthritis to reduce the development of persistent arthritis and its disease burden (TREAT EARLIER): a randomised, double-blind, placebo-controlled, proof-of-concept trial

Prevention of rheumatoid arthritis using a familial predictive medicine approach

Most of the chronic-degenerative diseases deserve a very early recognition of symptoms and signs for the earliest secondary prevention, which could be also very useful in many cases for the most precocious clinical approach. The periodic monitoring of a subject at risk of a specific disease, because of genomic predisposition by predictive medicine approach, may help to earlier detection of onset and/or the progression of the pathology itself, through intra-individual monitoring. This is particularly the case of rheumatoid arthritis (RA) for which an early diagnosis is undoubtedly the first step to ensure the most proper therapy for the patient. Thus, the earlier identification of individuals at high risk of RA could lead to ultra-preventive strategies to start for the best lifestyle performances and/or for any other effective therapeutic interventions to contrast the onset, and/or the evolution of the putative RA. This will also optimize both costs and medical resources, according to the health care policies of many countries.

Therapeutic interception in individuals at risk of rheumatoid arthritis to prevent clinically impactful disease

Multiple clinical trials for rheumatoid arthritis (RA) prevention have been completed. Here, we set out to report on the lessons learnt from these studies. Researchers who conducted RA prevention trials shared the background, rationale, approach and outcomes and evaluated the lessons learnt to inform the next generation of RA prevention trials. Individuals at risk of RA can be identified through population screening, referrals to musculoskeletal programmes and by recognition of arthralgia suspicious for RA. Clinical trials in individuals at risk for future clinical RA have demonstrated that limited courses of corticosteroids, atorvastatin and hydroxychloroquine do not alter incidence rates of clinical RA; however, rituximab delays clinical RA onset, and methotrexate has transient effects in individuals who are anticitrullinated protein antibody-positive with subclinical joint inflammation identified by imaging. Abatacept delays clinical RA onset but does not fully prevent onset of RA after treatment cessation. Additionally, subclinical joint inflammation and symptoms appear responsive to interventions such as methotrexate and abatacept. To advance prevention, next steps include building networks of individuals at risk for RA, to improve risk stratification for future RA and to understand the biological mechanisms of RA development, including potential endotypes of disease, which can be targeted for prevention, thus adopting a more precision-based approach. Future trials should focus on interceptions aimed at preventing clinical RA onset and which treat existing symptoms and imaging-defined subclinical inflammation. These trials may include advanced designs (eg, adaptive) and should be combined with mechanistic studies to further define pathophysiological drivers of disease development.

Is a 1-year course of methotrexate in patients with arthralgia at-risk for rheumatoid arthritis cost-effective? A cost-effectiveness analysis of the randomised, placebo-controlled TREAT EARLIER trial

OBJECTIVES

Rheumatoid arthritis (RA) has a considerable disease burden with life-long physical limitations, reduced work productivity and high societal costs. Trials on arthralgia at-risk for RA are therefore conducted, aiming to intercept evolving RA and reduce the disease burden. A 1-year course of methotrexate in patients with clinically suspect arthralgia (CSA) caused sustained improvements in subclinical joint inflammation and physical impairments. Since the cost-effectiveness of treatment in CSA has never been investigated, we investigated whether methotrexate is cost-effective.

METHODS

Cost-effectiveness was assessed using the TREAT EARLIER trial. 236 patients with CSA with subclinical joint inflammation were randomised to 1-year treatment with methotrexate, or placebo, and followed for 2 years. Cost-effectiveness was analysed by computing costs and effects. For costs, both a societal perspective (healthcare-productivity and work-productivity costs) and a healthcare perspective (healthcare costs only) were used. For effects, quality adjusted life years (QALYs) were used.

RESULTS

Treatment increased QALYs by 0.041 (95% CI -0.050 to 0.091), and reduced costs with €-4809 (95% CI -12 382 to 2726) over the course of 2 years using a societal perspective, with a probability of 88.1% that treatment was cost-effective. From a healthcare perspective, the cost-difference between treatment and placebo was estimated at €-418 (95% CI -1198 to 225).

CONCLUSION

A fixed treatment course in individuals with arthralgia at-risk for RA and MRI-detected subclinical joint inflammation resulted in better work productivity, lower healthcare costs and improved quality of life over the course of 2 years; with the largest gain in productivity costs. This is the first evidence that methotrexate treatment aiming at secondary prevention in arthralgia at-risk for RA is cost-effective.

Development of rheumatoid arthritis after methotrexate in anticitrullinated protein antibody-negative people with clinically suspect arthralgia at risk of rheumatoid arthritis: 4-year data from the TREAT EARLIER trial

BACKGROUND

Prevention of rheumatoid arthritis has become a definitive target. However, whether prevention of anti-citrullinated protein antibody (ACPA)-negative rheumatoid arthritis is possible is still unknown. We aimed to assess the efficacy of a 1-year course of methotrexate on the development of rheumatoid arthritis in ACPA-negative people with clinically suspect arthralgia and predicted increased risk of rheumatoid arthritis.

METHODS

For this follow-up analysis, we used 4-year data from the TREAT EARLIER trial, a randomised, double-blind, placebo-controlled, proof-of-concept trial conducted in the southwest region of the Netherlands from which we analysed data collected between April 16, 2015, and Sept 11, 2023. ACPA-positive and ACPA-negative adults aged 18 years or older with arthralgia and subclinical joint inflammation who were at risk of developing rheumatoid arthritis were eligible for enrolment. For TREAT EARLIER, participants were randomly assigned (1:1) to active treatment or placebo. Active treatment consisted of a single intramuscular glucocorticoid injection (120 mg of methylprednisolone) upon inclusion, then a 1-year course of methotrexate. Placebo consisted of a single placebo injection followed by a 1-year course of placebo tablets. Trial visits occurred every 4 months during the first 2 years, at which clinical and questionnaire data were collected. Total follow-up was 4 years. For this analysis, participants were stratified via a prediction model into low risk, increased risk, and high risk of developing persistent, clinically apparent inflammatory arthritis. The primary outcome was development of rheumatoid arthritis, defined as the presence of clinically apparent inflammatory arthritis and clinical diagnosis of rheumatoid arthritis, and was assessed in all TREAT EARLIER participants. Severity of subclinical joint inflammation, physical functioning, and grip strength in ACPA-negative participants was studied in each risk group over a period of 2 years.

FINDINGS

901 people with clinically suspect arthralgia were assessed for eligibility and 236 were enrolled in TREAT EARLIER. All 236 participants were included in the intention-to-treat analysis and 217 (92%) completed 4-year follow-up. 154 (65%) of 236 participants were women and 82 (35%) were men, 182 (77%) were ACPA-negative and 54 (23%) were ACPA-positive. Of the 182 randomly assigned ACPA-negative participants, none were predicted to be at high risk of developing persistent, clinically apparent inflammatory arthritis, 66 (36%) at increased risk, and 116 (64%) at low risk. Of the 54 ACPA-positive participants, 24 (44%) were predicted to be at high risk, 30 (56%) at increased risk, and none at low risk. After 4 years, 52 (22%) of 236 participants had developed the primary outcome of rheumatoid arthritis (25 [21%] of 119 in the treatment group and 27 [23%] of 117 in the placebo group). Of the 66 ACPA-negative participants predicted to be at increased risk, three (9%) of 35 in the treatment group developed the primary outcome compared with nine (29%) of 31 in the placebo group (hazard ratio 0·27, 95% CI 0·07-0·99; p=0·034). Of the 116 ACPA-negative participants predicted to be at low risk, four (8%) of 53 in the treatment group met the primary outcome compared with six (10%) of 63 in the placebo group (0·79, 0·22-2·80; p=0·71). Thus, after risk stratification, a 1-year course of methotrexate was associated with a reduced rate of development of ACPA-negative rheumatoid arthritis in participants with predicted increased risk of developing the disease. Subclinical joint inflammation, physical functioning, and grip strength persistently improved upon treatment in ACPA-negative participants with increased risk of developing rheumatoid arthritis, but not in those with low risk.

INTERPRETATION

Risk stratification can be helpful in trials of ACPA-negative people with clinically suspect arthralgia to identify participants who could benefit from treatment to prevent development of rheumatoid arthritis.

FUNDING

Dutch Research Council-ZonMw, Dutch Arthritis Society.

Environment and systemic autoimmune rheumatic diseases: an overview and future directions

Introduction

Despite progress in our understanding of disease pathogenesis for systemic autoimmune rheumatic diseases (SARD), these diseases are still associated with high morbidity, disability, and mortality. Much of the strongest evidence to date implicating environmental factors in the development of autoimmunity has been based on well-established, large, longitudinal prospective cohort studies.

Methods

Herein, we review the current state of knowledge on known environmental factors associated with the development of SARD and potential areas for future research.

Results

The risk attributable to any particular environmental factor ranges from 10-200%, but exposures are likely synergistic in altering the immune system in a complex interplay of epigenetics, hormonal factors, and the microbiome leading to systemic inflammation and eventual organ damage. To reduce or forestall the progression of autoimmunity, a better understanding of disease pathogenesis is still needed.

Conclusion

Owing to the complexity and multifactorial nature of autoimmune disease, machine learning, a type of artificial intelligence, is increasingly utilized as an approach to analyzing large datasets. Future studies that identify patients who are at high risk of developing autoimmune diseases for prevention trials are needed.

Patient burden and joint inflammation during development of RA from arthralgia: is it similar in ACPA-positive and ACPA-negative disease?

OBJECTIVES

ACPA-positive and ACPA-negative RA differ in underlying risk factors but have a similar clinical presentation at RA diagnosis. It is unknown what the ACPA-associated differences or similarities are during the symptomatic at-risk stage of RA, i.e. clinically suspect arthralgia (CSA). To deepen insights into these differences/similarities, we compared the course of symptoms/impairments and subclinical joint inflammation in the CSA phase during progression to inflammatory arthritis (IA) or to CSA resolution.

METHODS

A total of 845 CSA patients were followed for a median of 24 months; 136 patients developed IA and an additional 355/505 patients had resolution of CSA according to rheumatologists. Patient burden (pain, morning stiffness, fatigue, functional disabilities, presenteeism) was assessed at baseline and 4, 12 and 24 months and at IA development. Subclinical joint inflammation in the hands and feet was assessed over time with 1.5T MRI. Linear and Poisson mixed models were used.

RESULTS

In both ACPA-positive and ACPA-negative patients, patient burden increased towards IA development and decreased towards CSA resolution. However, patient burden was lower in ACPA-positive vs ACPA-negative disease at all timepoints. Conversely, subclinical joint inflammation tended to increase more rapidly during development of ACPA-positive IA [incidence rate ratio (IRR) 1.52 (95% CI 0.94, 2.47), P = 0.089] and remained higher over time in ACPA-positive CSA patients achieving resolution compared with ACPA-negative patients [IRR 1.52 (95% CI 1.07, 2.15), P = 0.018]. Although correlation coefficients between changes in patient burden and subclinical joint inflammation during progression to IA were weak, they were consistently higher in ACPA-positive than ACPA-negative disease, e.g. ρ = 0.29 vs 0.12 for functional disabilities.

CONCLUSION

During RA development and CSA resolution, ACPA-positive CSA patients have lower patient burden but more subclinical joint inflammation than ACPA-negative CSA patients. These data strengthen the notion that the development of ACPA-positive and ACPA-negative RA is pathophysiologically different and encourage further research on these differences.

Predicting autoimmune diseases: A comprehensive review of classic biomarkers and advances in artificial intelligence

Autoimmune diseases comprise a spectrum of disorders characterized by the dysregulation of immune tolerance, resulting in tissue or organ damage and inflammation. Their prevalence has been on the rise, significantly impacting patients' quality of life and escalating healthcare costs. Consequently, the prediction of autoimmune diseases has recently garnered substantial interest among researchers. Despite their wide heterogeneity, many autoimmune diseases exhibit a consistent pattern of paraclinical findings that hold predictive value. From serum biomarkers to various machine learning approaches, the array of available methods has been continuously expanding. The emergence of artificial intelligence (AI) presents an exciting new range of possibilities, with notable advancements already underway. The ultimate objective should revolve around disease prevention across all levels. This review provides a comprehensive summary of the most recent data pertaining to the prediction of diverse autoimmune diseases and encompasses both traditional biomarkers and the latest innovations in AI.

Connective Tissue Disease Associated Interstitial Lung Disease

Connective tissue disease associated interstitial lung disease (CTD-ILD) is a heterogenous collection of conditions with a diverse spectrum of interstitial lung disease (ILD) manifestations. Currently, clinical practice of lung-directed immunosuppression in CTD-ILD is supported by several randomized, placebo-controlled trials (RCTs) in patients with scleroderma and several observational, retrospective studies in other autoimmune conditions. However, given the harm of immunosuppression in idiopathic pulmonary fibrosis, there is an urgent need for RCTs of immunosuppression and antifibrotic agents in fibrotic CTD-ILD populations as well as the study of intervention in patients with subclinical CTD-ILD.

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.

Ultrasound in anti-CCP+ at-risk individuals without clinical synovitis: development of a novel 6-joint protocol for feasible risk prediction

OBJECTIVES

To investigate, in anti-CCP antibody-positive individuals with musculoskeletal symptoms but no clinical synovitis (CCP+ at-risk), the additional value of US for the prediction of inflammatory arthritis. Furthermore, to define a concise US protocol for feasible risk prediction.

METHODS

Demographic and clinical data were collected in 417 CCP+ at-risk (Leeds CCP cohort) with a baseline US scan assessing synovitis and bone erosions in 36 joints, and a follow-up duration ≥24 months. Multivariable binary regression models for inflammatory arthritis development at 24 months evaluated routine clinical variables associated with inflammatory arthritis alone ('clinical' model) and combined with a 36-joint US scanning protocol ('clinical-US extended' model). A 'clinical-US short' model was also developed.

RESULTS

At 24 months, 92/417 (22.1%) CCP+ at-risk developed inflammatory arthritis (median time 7 months, interquartile range 3-12). The 'clinical-US extended' model performed better than the 'clinical' model [area under the curve (AUC) 0.788 vs AUC 0.731, respectively, P < 0.001] with an odds ratio for inflammatory arthritis development of 3.18 (95% CI 1.80-5.63) for US synovitis and 2.54 (95% CI 1.21-5.37) for bone erosions. The 'clinical-US short' model, which retained the wrists, knees and MTP5 joints, performed better (AUC 0.782) than the 'clinical' model (P < 0.001) and similarly (difference in Akaike information criteria <2) to the 'clinical-US extended' model.

CONCLUSIONS

US provides valuable information for predicting progression to inflammatory arthritis in CCP+ individuals both alone and in addition to clinical variables. US synovitis was associated with a 3-fold increase risk of inflammatory arthritis development. A concise US protocol of six joints provides clinically feasible risk prediction in CCP+ at-risk.

The Impact of Rheumatoid Arthritis on First Nations and How We Can Work With Communities to Prevent It

Rheumatoid arthritis (RA) is prevalent in many Indigenous North American First Nations (FN) and tends to be seropositive, familial, and disabling, as well as associated with highly unfavorable outcomes such as early mortality. The risk of developing RA is based on a perfect storm of gene-environment interactions underpinning this risk. The gene-environment interactions include a high frequency of shared epitope encoding HLA alleles, particularly HLA-DRB1*1402, in the background population, and prevalent predisposing environmental factors such as smoking and periodontal disease. Together, these provide a compelling rationale for an RA prevention agenda in FN communities. Our research team has worked in partnership with several FN communities to prospectively follow the first-degree relatives of FN patients with RA, with the aim of better understanding the preclinical stages of RA in this population. We have focused on specific features of the anticitrullinated protein antibodies (ACPA) and other proteomic biomarkers as predictors of future development of RA. These studies have now led us to consider interventions having a favorable risk-benefit ratio if applied at a stage prior to a hypothetical "point of no return," when the autoimmunity potentially becomes irreversible. Based on a supportive mouse model and available human studies of curcumin, omega-3, and vitamin D supplements, we are undertaking studies where we screen communities using dried blood spot technology adapted for the detection of ACPA, and then enrolling ACPA-positive individuals in studies that use a combination of these supplements. These studies are guided by shared decision-making principles.

Multi-Autoantibody Testing Identifies Expansion of Reactivity to Targeted Antigens Before a Diagnosis of Rheumatoid Arthritis

OBJECTIVE

Rheumatoid arthritis (RA) has a "pre-RA" period in which multiple autoantibodies, including antibodies to citrullinated (cit) proteins (ACPA), rheumatoid factor (RF), anti-peptidyl arginine deiminase (anti-PAD), among others, have been described; however, few studies have tested all autoantibodies in a single pre-RA cohort. This study aims to evaluate the prevalence of multiple autoantibodies in pre-RA and potentially identify an autoantibody profile in pre-RA that indicates imminent onset of clinical RA.

METHODS

We evaluated 148 individuals with two pre- and one post-RA diagnosis samples available from the Department of Defense Serum Repository and matched controls. Samples were tested for immuglobulin (Ig) G anti-cyclic cit peptide-3 (anti-CCP3), five ACPA fine specificities, five anti-PAD isoforms, as well as RF IgA and RF IgM using commercial platforms; cutoffs were determined using levels present in <1% of controls.

RESULTS

Positivity of anti-CCP3, RF IgA and RF IgM, anti-PAD1, anti-cit-vimentin 2, anti-cit-fibrinogen, and anti-cit-histone 1 increased over time in pre-RA, although anti-PAD and ACPA fine specificities were predominately present within anti-CCP3-positive individuals. Within anti-CCP3-positive samples from the pre-RA period, positivity for RFs as well as anti-PAD and ACPA fine specificities classified samples as being closer to the time of RA diagnosis.

CONCLUSION

Multiple autoantibodies are present in pre-RA and increase in positivity as the time of RA diagnosis approaches. These results confirm previous findings predicting imminent RA and provide a pathway using commercial-grade assays to assess the risk for and timing of development of clinical RA.

Expansion of HLA-DR Positive Peripheral Helper T and Naive B Cells in Anticitrullinated Protein Antibody-Positive Individuals At Risk for Rheumatoid Arthritis

OBJECTIVE

To investigate immune dysregulation in the peripheral blood that contributes to the pre-rheumatoid arthritis (RA) stage of RA development in anticitrullinated protein antibody (ACPA)+ individuals.

METHODS

Using 37 markers by mass cytometry, we investigated peripheral blood mononuclear cells (PBMCs) from ACPA+ at-risk individuals, ACPA+ early untreated patients with RA, and ACPA- controls in the Tokyo Women's Medical University cohort (n = 17 in each group). Computational algorithms, FlowSOM and Optimized t-Distributed Stochastic Neighbor Embedding, were employed to explore specific immunologic differences between study groups. These findings were further evaluated, and longitudinal changes were explored, using flow cytometry and PBMCs from the US-based Targeting Immune Responses for Prevention of RA cohort that included 11 ACPA+ individuals who later developed RA (pre-RA), of which 9 had post-RA diagnosis PBMCs (post-RA), and 11 ACPA- controls.

RESULTS

HLA-DR+ peripheral helper T (Tph) cells, activated regulatory T cells, PD-1hi CD8+ T cells, and CXCR5-CD11c-CD38+ naive B cells were significantly expanded in PBMCs from at-risk individuals and patients with early RA from the Tokyo Women's Medical University cohort. Expansion of HLA-DR+ Tph cells and CXCR5-CD11c-CD38+ naive B cells was likewise found in both pre-RA and post-RA time points in the Targeting Immune Responses for Prevention of RA cohort.

CONCLUSION

The expansion of HLA-DR+ Tph cells and CXCR5-CD11c-CD38+ naive B cells in ACPA+ individuals, including those who developed inflammatory arthritis and classified RA, supports a key role of these cells in transition from pre-RA to classified RA. These findings may identify a new mechanistic target for treatment and prevention in RA.

Immune response to post-translationally modified proteins in rheumatoid arthritis: what makes it special?

Rheumatoid arthritis (RA) exhibits common characteristics with numerous other autoimmune diseases, including the presence of susceptibility genes and the presence of disease-specific autoantibodies. Anti-citrullinated protein antibodies (ACPA) are the hallmarking autoantibodies in RA and the anti-citrullinated protein immune response has been implicated in disease pathogenesis. Insight into the immunological pathways leading to anti-citrullinated protein immunity will not only aid understanding of RA pathogenesis, but may also contribute to elucidation of similar mechanisms in other autoantibody-positive autoimmune diseases. Similarly, lessons learnt in other human autoimmune diseases might be relevant to understand potential drivers of RA. In this review, we will summarise several novel insights into the biology of the anti-citrullinated protein response and their clinical associations that have been obtained in recent years. These insights include the identification of glycans in the variable domain of ACPA, the realisation that ACPA are polyreactive towards other post-translational modifications on proteins, as well as new awareness of the contributing role of mucosal sites to the development of the ACPA response. These findings will be mirrored to emerging concepts obtained in other human (autoimmune) disease characterised by disease-specific autoantibodies. Together with an updated understanding of genetic and environmental risk factors and fresh perspectives on how the microbiome could contribute to antibody formation, these advancements coalesce to a progressively clearer picture of the B cell reaction to modified antigens in the progression of RA.

Polymorphic Analysis of Genes PADI4 (rs2240340, rs1748033) and HLA-DRB1 (rs2395175) in Arthritis Patients in Pakistani Population

Genes are an important factor for the initiation of any disease. Many genes are associated with rheumatoid arthritis (RA) other than environmental factors. The main objective of the study was to evaluate the association of genes PADI4 (peptidylarginine deiminases 14) (rs2240340, rs1748033) and Human leukocyte antigen class II histocompatibility, D-related beta chain (HLA-DRB1) (rs2395175) polymorphisms in RA patients from Punjab, Pakistan. Blood samples of RA patients were collected from different hospitals of Sargodha. DNA was extracted, followed by PCR. Polymorphic analysis was performed in 300 rheumatoid arthritis patients and 300 healthy controls on PADI4 (rs2240340, rs1748033) and HLA-DRB1 (rs2395175). In PADI4 gene, both homozygous mutant genotype (TT) and heterozygous (CT) of SNP rs2240340 showed significant association by increasing the risk of RA up to two fold (OR 2.55; 95% CI 1.57-4.15; p = 0.0002). In case of rs1748033 polymorphism, homozygous mutant genotype (TT) showed significant association with RA by increasing the risk of disease up to three fold (OR 3.46; 95% CI 1.97-6.07; p = 0.0001), while heterozygous genotype (CT) of the same SNP showed significant association with RA by playing a protective role (OR 0.57; 95% CI 0.36-0.91; p = 0.0197). In HLA-DRB1 gene, homozygous mutant genotype (GG) of SNP rs2395175 showed no significant association with RA, while heterozygous genotype (AG) of the same SNP showed significant association with RA by playing a protective role (OR 0.44; 95% CI 0.27-0.71; p = 0.0009). Highly significance association of genes PADI4 (rs2240340, rs1748033) and HLA-DRB1 (rs2395175) polymorphisms with RA was observed in Pakistani population.

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.

Rheumatoid arthritis: prediction of future clinically-apparent disease, and prevention

PURPOSE OF REVIEW

This review discusses updates in the prediction and prevention of future rheumatoid arthritis (RA).

RECENT FINDINGS

In individuals with musculoskeletal symptoms and elevated antibodies to citrullinated proteins (ACPA) without clinical inflammatory arthritis (IA), a 'simple' score has a positive predictive value (PPV) of ∼28% for clinical IA/RA within 1 year, and a comprehensive score (including ultrasound) has a PPV of ∼71% for clinical RA within 5 years. Controlled clinical trials in individuals at-risk for future RA have been performed using corticosteroids, rituximab, atorvastatin, methotrexate, hydroxychloroquine and abatacept. Abatacept modestly reduced rates of incident clinical RA and imaging inflammation within the trials, rituximab delayed clinical IA, and methotrexate improved function, symptoms and imaging inflammation. Vitamin D with or without omega 3 fatty acids reduced incidence of autoimmune diseases, including RA. While not proven in controlled clinical trials, observational studies suggest exercise, weight loss and smoking cessation may reduce progression to clinical RA.

SUMMARY

Prediction and prevention of RA is advancing although there are no currently approved interventions for prevention. Future studies should include deeper evaluation of the pathophysiology of RA development to improve prediction and identify key pathways to target in future clinical trials, as well as develop infrastructure to support prevention-related research.

Rheumatoid Arthritis: The Continuum of Disease and Strategies for Prediction, Early Intervention, and Prevention

Rheumatoid arthritis (RA) is known to include a pre-RA stage that can be defined as the presence of familial or genetic risk factors, biomarker abnormalities (eg, anticitrullinated protein antibodies [ACPA]), symptoms, and even abnormal imaging findings prior to the development of the onset of clinical RA with inflammatory arthritis that is apparent on physical examination. Indeed, there are multiple completed or ongoing retrospective case-control as well as prospective observational studies to identify the key biologic drivers of disease. Further, building on the predictive ability of combinations of biomarkers, symptoms, and imaging for future RA, there are multiple clinical trials completed, underway, or in development to identify approaches that may prevent, delay, or ameliorate future clinical RA in at-risk individuals. Importantly, however, although an effective preventive intervention has not yet been identified, at-risk individuals are being increasingly identified in clinical care; this presents a challenge of how to manage these individuals in clinical practice. This review will discuss the current understanding of the biology and natural history of RA development, nomenclature, and current models for prediction of future RA, as well as evaluate the current and ongoing clinical prevention trials with the overall goal to provide insights into the challenges and opportunities in the field of RA prevention. Moreover, this review will provide up-to-date options for clinical management of individuals at risk for RA.

Rheumatoid arthritis and the intestinal microbiome: probiotics as a potential therapy

Rheumatoid arthritis (RA) is a systemic autoimmune disorder characterized by swollen joints, discomfort, stiffness, osteoporosis, and reduced functionality. Genetics, smoking, dust inhalation, high BMI, and hormonal and gut microbiota dysbiosis are all likely causes of the onset or development of RA, but the underlying mechanism remains unknown. Compared to healthy controls, patients with RA have a significantly different composition of gut microbiota. It is well known that the human gut microbiota plays a key role in the initiation, maintenance, and operation of the host immune system. Gut microbiota dysbiosis has local or systematic adverse effects on the host immune system, resulting in host susceptibility to various diseases, including RA. Studies on the intestinal microbiota modulation and immunomodulatory properties of probiotics have been reported, in order to identify their potential possibility in prevention and disease activity control of RA. This review summarized current studies on the role and potential mechanisms of gut microbiota in the development and progression of RA, as well as the preventative and therapeutic effects and potential mechanisms of probiotics on RA. Additionally, we proposed the challenges and difficulties in the application of probiotics in RA, providing the direction for the research and application of probiotics in the prevention of RA.

Methotrexate treatment strategies for rheumatoid arthritis: a scoping review on doses and administration routes

BACKGROUND

To describe the evidence of methotrexate (MTX) initiation strategies in patients with rheumatoid arthritis (RA) and, in the case of non-responders, analyse the efficacy and safety of route and dose optimisation.

METHODS

We conducted a comprehensive scoping review of randomised controlled trials according to PRISMA Scoping Reviews Checklist and the framework proposed by Arksey and O'Malley. PubMed, EMBASE, and Cochrane were searched without language restriction, and hand searches of relevant articles were examined.

RESULTS

We identified 1,367 potentially eligible studies, of which 12 were selected based on the titles and abstracts and then on the full-length articles. In naïve-MTX patients, a linear dose-response relationship for starting dose was found between 5 mg/m2/week (7.5-10 mg/week) and 10 mg/m2/week (15-22 mg/week), without toxicity correlation. A higher initial dose of MTX (25 mg vs. 15 mg) was more effective, resulting in fewer dose increases due to ineffectiveness and more dose reductions due to higher remission rates. There was also a trend towards increased gastrointestinal toxicity. Comparing different routes of administration of MTX, subcutaneous MTX showed a statistically higher ACR20 response (85%) in comparison with oral MTX (77%) (p < 0.05). The clinical efficacy and safety of accelerated and conventional start MTX regimens were comparable between 7.5 and 15 mg with a 2,5 mg dose increase every two weeks. In RA patients who have failed the initial treatment with MTX, the stepwise increase in MTX doses is associated with a higher ACR20 response and sustained remission rate than other strategies. In MTX non-responders, optimisation to SC MTX was associated with improvements in ACR20 and ACR50 rates with similar toxicity between groups. In the early RA patients subgroup, SC MTX showed higher ACR20 response rates than oral MTX, and intensive oral methods have a much higher sustained remission rate, shorter mean time to remission, and better clinical disease activity measures than conventional treatments.

CONCLUSIONS

Higher starting doses of MTX and initial subcutaneous MTX made better performance in improving the ACR20 response, although the clinical effectiveness and safety of other MTX start regimens are comparable. This scoping review provides evidence in support of optimising MTX treatment in terms of route and dose prior to concluding that MTX treatment in RA patients has failed.

Abatacept inhibits inflammation and onset of rheumatoid arthritis in individuals at high risk (ARIAA): a randomised, international, multicentre, double-blind, placebo-controlled trial

BACKGROUND

Individuals with anti-citrullinated protein antibodies (ACPAs) and subclinical inflammatory changes in joints are at high risk of developing rheumatoid arthritis. Treatment strategies to intercept this pre-stage clinical disease remain to be developed. We aimed to assess whether 6-month treatment with abatacept improves inflammation in preclinical rheumatoid arthritis.

METHODS

The abatacept reversing subclinical inflammation as measured by MRI in ACPA positive arthralgia (ARIAA) study is a randomised, international, multicentre, double-blind, placebo-controlled trial done in 14 hospitals and community centres across Europe (11 in Germany, two in Spain, and one in the Czech Republic). Adults (aged ≥18 years) with ACPA positivity, joint pain (but no swelling), and signs of osteitis, synovitis, or tenosynovitis in hand MRI were randomly assigned (1:1) to weekly subcutaneous abatacept 125 mg or placebo for 6 months followed by a double-blind, drug-free, observation phase for 12 months. The primary outcome was the proportion of participants with any reduction in inflammatory MRI lesions at 6 months. The primary efficacy analysis was done in the modified intention-to-treat population, which included participants who were randomly assigned and received study medication. Safety analyses were conducted in participants who received the study medication and had at least one post-baseline observation. The study was registered with the EUDRA-CT (2014-000555-93).

FINDINGS

Between Nov 6, 2014, and June 15, 2021, 139 participants were screened. Of 100 participants, 50 were randomly assigned to abatacept 125 mg and 50 to placebo. Two participants (one from each group) were excluded due to administration failure or refusing treatment; thus, 98 were included in the modified intention-to-treat population. 70 (71%) of 98 participants were female and 28 (29%) of 98 were male. At 6 months, 28 (57%) of 49 participants in the abatacept group and 15 (31%) of 49 participants in the placebo group showed improvement in MRI subclinical inflammation (absolute difference 26·5%, 95% CI 5·9-45·6; p=0·014). Four (8%) of 49 participants in the abatacept group and 17 (35%) of 49 participants in the placebo group developed rheumatoid arthritis (hazard ratio [HR] 0·14 [0·04-0·47]; p=0·0016). Improvement of MRI inflammation (25 [51%] of 49 participants in the abatacept group, 12 [24%] of 49 in the placebo group; p=0·012) and progression to rheumatoid arthritis (17 [35%] of 49, 28 [57%] of 49; HR 0·14 [0·04-0·47]; p=0·018) remained significantly different between the two groups after 18 months, 12 months after the end of the intervention. There were 12 serious adverse events in 11 participants (four [8%] of 48 in the abatacept group and 7 [14%] of 49 in the placebo group). No deaths occurred during the study.

INTERPRETATION

6-month treatment with abatacept decreases MRI inflammation, clinical symptoms, and risk of rheumatoid arthritis development in participants at high risk. The effects of the intervention persist through a 1-year drug-free observation phase.

FUNDING

Innovative Medicine Initiative.

Abatacept in individuals at high risk of rheumatoid arthritis (APIPPRA): a randomised, double-blind, multicentre, parallel, placebo-controlled, phase 2b clinical trial

BACKGROUND

Individuals with serum antibodies to citrullinated protein antigens (ACPA), rheumatoid factor, and symptoms, such as inflammatory joint pain, are at high risk of developing rheumatoid arthritis. In the arthritis prevention in the pre-clinical phase of rheumatoid arthritis with abatacept (APIPPRA) trial, we aimed to evaluate the feasibility, efficacy, and acceptability of treating high risk individuals with the T-cell co-stimulation modulator abatacept.

METHODS

The APIPPRA study was a randomised, double-blind, multicentre, parallel, placebo-controlled, phase 2b clinical trial done in 28 hospital-based early arthritis clinics in the UK and three in the Netherlands. Participants (aged ≥18 years) at risk of rheumatoid arthritis positive for ACPA and rheumatoid factor with inflammatory joint pain were recruited. Exclusion criteria included previous episodes of clinical synovitis and previous use of corticosteroids or disease-modifying antirheumatic drugs. Participants were randomly assigned (1:1) using a computer-generated permuted block randomisation (block sizes of 2 and 4) stratified by sex, smoking, and country, to 125 mg abatacept subcutaneous injections weekly or placebo for 12 months, and then followed up for 12 months. Masking was achieved by providing four kits (identical in appearance and packaging) with pre-filled syringes with coded labels of abatacept or placebo every 3 months. The primary endpoint was the time to development of clinical synovitis in three or more joints or rheumatoid arthritis according to American College of Rheumatology and European Alliance of Associations for Rheumatology 2010 criteria, whichever was met first. Synovitis was confirmed by ultrasonography. Follow-up was completed on Jan 13, 2021. All participants meeting the intention-to-treat principle were included in the analysis. This trial was registered with EudraCT (2013-003413-18).

FINDINGS

Between Dec 22, 2014, and Jan 14, 2019, 280 individuals were evaluated for eligibility and, of 213 participants, 110 were randomly assigned to abatacept and 103 to placebo. During the treatment period, seven (6%) of 110 participants in the abatacept group and 30 (29%) of 103 participants in the placebo group met the primary endpoint. At 24 months, 27 (25%) of 110 participants in the abatacept group had progressed to rheumatoid arthritis, compared with 38 (37%) of 103 in the placebo group. The estimated proportion of participants remaining arthritis-free at 12 months was 92·8% (SE 2·6) in the abatacept group and 69·2% (4·7) in the placebo group. Kaplan-Meier arthritis-free survival plots over 24 months favoured abatacept (log-rank test p=0·044). The difference in restricted mean survival time between groups was 53 days (95% CI 28-78; p<0·0001) at 12 months and 99 days (95% CI 38-161; p=0·0016) at 24 months in favour of abatacept. During treatment, abatacept was associated with improvements in pain scores, functional wellbeing, and quality-of-life measurements, as well as low scores of subclinical synovitis by ultrasonography, compared with placebo. However, the effects were not sustained at 24 months. Seven serious adverse events occurred in the abatacept group and 11 in the placebo group, including one death in each group deemed unrelated to treatment.

INTERPRETATION

Therapeutic intervention during the at-risk phase of rheumatoid arthritis is feasible, with acceptable safety profiles. T-cell co-stimulation modulation with abatacept for 12 months reduces progression to rheumatoid arthritis, with evidence of sustained efficacy beyond the treatment period, and with no new safety signals.

FUNDING

Bristol Myers Squibb.

'What is my risk really?': a qualitative exploration of preventive interventions among individuals at risk of rheumatoid arthritis

Objectives

Intervention in the pre-arthritis phase of RA could prevent or delay the onset of disease. The primary aim of this study was to explore perspectives of being at risk and potential preventive interventions among individuals at risk of developing RA and to identify factors influencing their engagement with prevention. A secondary aim, established during the analytical process, was to understand and compare different approaches to health-related behaviours related to prevention of RA.

Methods

Anti-CCP-positive (CCP+) at-risk individuals with musculoskeletal symptoms but no synovitis participated in semi-structured interviews. Data were analysed using reflexive thematic analysis, followed by a secondary ideal-type analysis.

Results

Nineteen CCP+ at-risk individuals (10 women; age range 35-70 years) participated. Three overarching themes were identified: being CCP+ at risk; aiming to prevent RA; and influencers of engagement. Participants described distress related to symptoms and uncertainty about disease progression. Many participants had concerns about medication side effects. In contrast, most participants expressed willingness to make lifestyle changes with the aim of preventing RA. Engagement with preventive measures was influenced by symptom severity, personal risk level, co-morbidities, experiences of taking other medications/supplements, knowledge of RA, risk factors and medications, and perceived effort. Three types of participants were identified from the data: proactive preventers, change considerers and fearful avoiders. Overall orientation to health behaviours also impacted the attitude towards preventing RA.

Conclusion

Findings could inform recruitment and retention in RA prevention research and promote uptake of preventive interventions in clinical practice.

Rheumatology tolerance for cure (RTCure) - an IMI project aimed at prevention and cure of RA

The RT Cure project, supported from the Innovative Medicines Initiative (IMI) has been active for 6 years and involved several European and one Australian rheumatology institutions, six major pharma companies and a few small companies. The present report describes the major aims and results of the project which include new understanding of specificity and regulation a of adaptive immunity that precedes RA and is active in established disease. use this understanding to predict risk for RA and establish registers of at risk for RA cohorts. support for clinical trials aimed at prevention of RA with knowledge and tools for immune surveillance. The progress in these areas, including the support to successful clinical trials for prevention will provide a basis for further development of prevention of RA using increasingly specific immunotherapies.

Therapeutic advances in rheumatoid arthritis

Rheumatoid arthritis (RA) is one of the most common immune mediated inflammatory diseases. People with rheumatoid arthritis present with pain, swelling, and stiffness that typically affects symmetrically distributed small and large joints. Without effective treatment, significant joint damage, disability, and work loss develop, owing to chronic inflammation of the joint lining (synovium). Over the past 25 years, the management of this condition has been revolutionized, resulting in substantially higher levels of disease remission and better long term outcomes. This improvement reflects a paradigm shift towards early and aggressive pharmacological intervention coupled with a proliferation in treatment choice, in turn related to enhanced pathobiological understanding and the advent of new drugs for rheumatoid arthritis. Following an overview of these developments from a historical perspective, and with a general audience in mind, this review focuses on newer, targeted treatments in an ever evolving landscape. The review highlights ongoing areas of debate and unmet need, including the proportion of patients with persistent, difficult-to-treat disease, despite recent advances. Also discussed are personalized, strategic approaches to individual patients, the role for imaging in clinical decision making, and the goal of sustained, drug free remission and disease prevention in the future.

When does obesity exert its effect in conferring risk of developing RA: a large study in cohorts of symptomatic persons at risk

OBJECTIVES

Obesity is a known risk factor for developing rheumatoid arthritis (RA). However, it is unclear whether obesity exerts its risk effect during the asymptomatic or the symptomatic clinically suspect arthralgia (CSA) phase of risk. To improve understanding of the effect of obesity on RA development, we aimed to (1) compare body mass index (BMI) at CSA onset to BMI of the general population and (2) study within CSA patients if obesity increases the risk for progression to RA.

METHODS

1107 symptomatic persons at risk for RA from four cohorts (CSA Leiden, CSA Rotterdam, SONAR and TREAT EARLIER placebo arm) were studied. For the first aim, baseline BMI was compared with age-matched/sex-matched BMI of the general population. Patients were stratified for anticitrullinated protein antibody (ACPA) status. Regarding the second aim, the association between BMI and inflammatory arthritis (IA) development during 2 years was studied with Cox regression analysis within each cohort and via meta-analysis in all cohorts.

RESULTS

CSA patients of all cohorts were more often obese than the general population (respectively 21.9% vs 14.0%, 25.7% vs 14.5%, 26.7% vs 14.5% and 33.3% vs 14.9%, in CSA Leiden, CSA Rotterdam, SONAR, TREAT EARLIER placebo arm). Both ACPA-positive and ACPA-negative CSA patients had a higher frequency of obesity. Within CSA, obesity was not associated with IA development compared to normal weight (pooled effect in meta-analysis of four cohorts HR 1.01 (95% CI 0.93 to 1.08)).

CONCLUSIONS

Obesity is not associated with RA development within CSA patients but BMI has already increased in CSA compared to the general population. Obesity, therefore, presumably exerts its risk effect at an early asymptomatic phase of RA development, rather than being associated with the disease processes that ultimately result in clinical arthritis.

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.

Rheumatoid arthritis

Rheumatoid arthritis is a chronic, systemic, autoimmune inflammatory disease that mainly affects the joints and periarticular soft tissues. In this Seminar, we provide an overview of the main aspects of rheumatoid arthritis. Epidemiology and advances in the understanding of rheumatoid arthritis pathogenesis will be reviewed. We will discuss the clinical manifestations of rheumatoid arthritis, classification criteria, and the value of imaging in the diagnosis of the disease. The advent of new medications and the accumulated scientific evidence demand continuous updating regarding the diagnosis and management, including therapy, of rheumatoid arthritis. An increasing number of patients are now able to reach disease remission. This major improvement in the outcome of patients with rheumatoid arthritis has been determined by a combination of different factors (eg, early diagnosis, window of opportunity, treat-to-target strategy, advent of targeted disease-modifying antirheumatic drugs, and combination therapy). We will discuss the updated recommendations of the two most influential societies for rheumatology worldwide (ie, the American College of Rheumatology and European Alliance of Associations for Rheumatology) for the management of rheumatoid arthritis. Furthermore, controversies (ie, the role of glucocorticoids in the management of rheumatoid arthritis and safety profile of Janus kinase inhibitors) and outstanding research questions, including precision medicine approach, prevention, and cure of rheumatoid arthritis will be highlighted.

Multifaceted immune dysregulation characterizes individuals at-risk for rheumatoid arthritis

Molecular markers of autoimmunity, such as antibodies to citrullinated protein antigens (ACPA), are detectable prior to inflammatory arthritis (IA) in rheumatoid arthritis (RA) and may define a state that is 'at-risk' for future RA. Here we present a cross-sectional comparative analysis among three groups that include ACPA positive individuals without IA (At-Risk), ACPA negative individuals and individuals with early, ACPA positive clinical RA (Early RA). Differential methylation analysis among the groups identifies non-specific dysregulation in peripheral B, memory and naïve T cells in At-Risk participants, with more specific immunological pathway abnormalities in Early RA. Tetramer studies show increased abundance of T cells recognizing citrullinated (cit) epitopes in At-Risk participants, including expansion of T cells reactive to citrullinated cartilage intermediate layer protein I (cit-CILP); these T cells have Th1, Th17, and T stem cell memory-like phenotypes. Antibody-antigen array analyses show that antibodies targeting cit-clusterin, cit-fibrinogen and cit-histone H4 are elevated in At-Risk and Early RA participants, with the highest levels of antibodies detected in those with Early RA. These findings indicate that an ACPA positive at-risk state is associated with multifaceted immune dysregulation that may represent a potential opportunity for targeted intervention.

Mitochondrion-NLRP3 inflammasome activation in macrophages: A novel mechanism of the anti-inflammatory effect of Notopterygium in rheumatoid arthritis treatment

OBJECTIVE

The mechanism by which Notopterygium (NE) regulates the nucleotide-binding, oligomerization domain (NOD)-like receptor family and pyrin domain-containing 3 (NLRP3) inflammasome to treat rheumatoid arthritis (RA) was investigated to reveal the scientific implications of NE in RA treatment.

METHODS

Adjuvant arthritis (AA) rats were replicated. After NE intervention, the anti-inflammatory efficacy of NE in vivo was determined. The mechanism of NE in RA treatment was predicted by network pharmacology, and the key target for further experiments was found through the analysis of Kyoto Encyclopedia of Genes and Genomes (KEGG). The effect of NE on the NLRP3 inflammasome in AA rats was verified. Furthermore, with the induction of inflammation in RAW264.7 cells by lipopolysaccharide (LPS), several techniques, such as Griess assay, enzyme linked immunosorbent assays, electron microscopy, and fluorescence probe technology, were used to investigate the anti-inflammatory and related mechanisms of NE in RA treatment.

RESULTS

NE could inhibit inflammation in AA rats. KEGG results showed that NLRP3 participated in the top three pathways of NE in RA treatment. Through Western blotting and immunofluorescence assays, this study demonstrated that NE can regulate NLRP3, pro-Caspase-1, Caspase-1, and CD11b in the ankle joint of AA rats. NE may significantly reduce the LPS-induced inflammatory response of RAW264.7 cells by alleviating mitochondrial damage, reducing the number of mitochondrial deoxyribonucleic Acid and mitochondrial reactive oxygen species, inhibiting NLRP3 inflammasome activation.

CONCLUSION

The anti-inflammatory and antirheumatic effect of NE may involve regulating NLRP3 inflammasome activation through mitochondria. NLRP3 is probably the key target molecule of NE in the treatment of RA.

Beyond very early systemic sclerosis: deciphering pre‑scleroderma and its trajectories to open new avenues for preventive medicine

The identification of individuals with systemic sclerosis in an oligosymptomatic phase preceding the very early manifestations of the disease represents a challenge in the search for a new window of opportunity in systemic sclerosis. This phase could be identified in a clinical scenario as the pre-scleroderma phase, in which the disease would still be far from systemic sclerosis-related fibrotic or irreversible manifestations in skin or organs. In this Personal View, we discuss parameters and candidate definitions for a conceptual framework of pre-scleroderma, from the identification of populations at risk to autoantibodies and their potential functional activities. We discuss how this new paradigm of pre-scleroderma could represent a game-changing approach in the management of systemic sclerosis, allowing the treatment of patients at high risk of organ involvement or skin fibrosis before such events occur.

Global, regional, and national incidence of six major immune-mediated inflammatory diseases: findings from the global burden of disease study 2019

Background

The causes for immune-mediated inflammatory diseases (IMIDs) are diverse and the incidence trends of IMIDs from specific causes are rarely studied. The study aims to investigate the pattern and trend of IMIDs from 1990 to 2019.

Methods

We collected detailed information on six major causes of IMIDs, including asthma, inflammatory bowel disease, multiple sclerosis, rheumatoid arthritis, psoriasis, and atopic dermatitis, between 1990 and 2019, derived from the Global Burden of Disease study in 2019. The average annual percent change (AAPC) in number of incidents and age standardized incidence rate (ASR) on IMIDs, by sex, age, region, and causes, were calculated to quantify the temporal trends.

Findings

In 2019, rheumatoid arthritis, atopic dermatitis, asthma, multiple sclerosis, psoriasis, inflammatory bowel disease accounted 1.59%, 36.17%, 54.71%, 0.09%, 6.84%, 0.60% of overall new IMIDs cases, respectively. The ASR of IMIDs showed substantial regional and global variation with the highest in High SDI region, High-income North America, and United States of America. Throughout human lifespan, the age distribution of incident cases from six IMIDs was quite different. Globally, incident cases of IMIDs increased with an AAPC of 0.68 and the ASR decreased with an AAPC of -0.34 from 1990 to 2019. The incident cases increased across six IMIDs, the ASR of rheumatoid arthritis increased (0.21, 95% CI 0.18, 0.25), while the ASR of asthma (AAPC = -0.41), inflammatory bowel disease (AAPC = -0.72), multiple sclerosis (AAPC = -0.26), psoriasis (AAPC = -0.77), and atopic dermatitis (AAPC = -0.15) decreased. The ASR of overall and six individual IMID increased with SDI at regional and global level. Countries with higher ASR in 1990 experienced a more rapid decrease in ASR.

Interpretation

The incidence patterns of IMIDs varied considerably across the world. Innovative prevention and integrative management strategy are urgently needed to mitigate the increasing ASR of rheumatoid arthritis and upsurging new cases of other five IMIDs, respectively.

Funding

The Global Burden of Disease Study is funded by the Bill and Melinda Gates Foundation. The project funded by Scientific Research Fund of Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital (2022QN38).

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.

Modifiable risk factors linked to the development of rheumatoid arthritis: evidence, immunological mechanisms and prevention

Rheumatoid Arthritis (RA) is a common autoimmune disease that targets the synovial joints leading to arthritis. Although the etiology of RA remains largely unknown, it is clear that numerous modifiable risk factors confer increased risk to developing RA. Of these risk factors, cigarette smoking, nutrition, obesity, occupational exposures and periodontal disease all incrementally increase RA risk. However, the precise immunological mechanisms by which these risk factors lead to RA are not well understood. Basic and translational studies have provided key insights into the relationship between inflammation, antibody production and the influence in other key cellular events such as T cell polarization in RA risk. Improving our general understanding of the mechanisms which lead to RA will help identify targets for prevention trials, which are underway in at-risk populations. Herein, we review the modifiable risk factors that are linked to RA development and describe immune mechanisms that may be involved. We highlight the few studies that have sought to understand if modification of these risk factors reduces RA risk. Finally, we speculate that modification of risk factors may be an appealing avenue for prevention for some at-risk individuals, specifically those who prefer lifestyle interventions due to safety and economic reasons.

The Natural Sequence in Which Subclinical Inflamed Joint Tissues Subside or Progress to Rheumatoid Arthritis: A Study of Serial MRIs in the TREAT EARLIER Trial

OBJECTIVE

The natural trajectory of clinical arthritis progression at the tissue level remains elusive. We hypothesized that subclinical inflammation in different joint tissues (synovitis, tenosynovitis, osteitis) increases in a distinct temporal order in patients with clinically suspect arthralgia (CSA) who develop rheumatoid arthritis (RA) and subsides in a different sequence when CSA spontaneously resolves.

METHODS

We studied 185 serial magnetic resonance images (MRIs) from CSA patients with subclinical joint inflammation from the placebo arm of the TREAT EARLIER trial: 52 MRIs from 21 RA progressors (MRIs conducted at 1 year before, at 4 months before, and upon RA development), and 133 MRIs from 35 patients with spontaneous resolution of pain (MRIs conducted at baseline and at 4, 12, and 24 months). MRIs were scored for osteitis, synovitis, and tenosynovitis. We used cross-lagged models to evaluate 2 types of time patterns between pairs of inflamed tissues: a simultaneous pattern (coinciding changes) and a subsequent pattern (inflammatory changes in 1 tissue preceding changes in another tissue).

RESULTS

In patients who developed RA, synovitis, tenosynovitis, and osteitis increased simultaneously. Increasing osteitis occurred in the final 4 months before RA diagnosis, following incremental tenosynovitis and synovitis changes during the 1 year to 4 months before diagnosis (P < 0.01). In anti-citrullinated protein antibody (ACPA)-positive and ACPA-negative patients who progressed to RA, osteitis increased just before RA development. In patients with pain resolution, simultaneous decreases in synovitis, tenosynovitis, and osteitis occurred, with tenosynovitis decreasing in the first 4 months after CSA onset preceding decreasing synovitis and osteitis during 4-12 months (P = 0.02 and P < 0.01).

CONCLUSION

We identified natural sequences of subclinical inflammation in different joint tissues, which deepens our understanding of clinical arthritis and RA development. During RA progression, increasing osteitis followed previous increases in tenosynovitis and synovitis. During pain resolution, tenosynovitis decreased first, followed by decreasing synovitis and osteitis.

To treat or not to treat? Current attitudes on treatment aimed at modifying the disease burden in clinically suspect arthralgia: a survey among participants of the TREAT EARLIER trial and healthcare professionals

OBJECTIVES

While awaiting therapies accomplishing rheumatoid arthritis (RA)-prevention in individuals at-risk, recent evidence supports that a 1-year methotrexate treatment may lead to sustained reduction in disease burden and subclinical joint inflammation in patients with clinically suspect arthralgia (CSA). We aimed to study the previously unexplored attitudes of CSA patients and rheumatologists on 1-year DMARD treatment in the arthralgia phase to reduce the disease burden, while not preventing RA.

METHODS

CSA patients who participated in the TREAT EARLIER trial, thus being expert by experience, were informed on the trial results. Thereafter they completed an anonymous questionnaire about their attitudes on treatment in the CSA phase. We used the same approach for Dutch healthcare professionals in rheumatology.

RESULTS

The majority of trial participants (85%) considered the effects of the 1-year treatment as found in the TREAT EARLIER trial, beneficial in the symptomatic at-risk stage. 79% would recommend a 1-year methotrexate course to others with comparable joint complaints. Two-thirds indicated RA prevention and improving disease burden to be equally important treatment goals in the CSA phase. Most healthcare professionals (88%) were inclined to prescribe 1-year treatment to CSA patients aimed at long-term improvement of symptoms and functioning, while not preventing RA development. 59% believed the profits of a 1-year methotrexate course to outweigh disadvantages, for example, side effects.

CONCLUSIONS

A considerable willingness exists among CSA patients and rheumatologists to start a 1-year treatment resulting in long-term improvement of symptoms and functioning, while not preventing RA. This emphasises the need for more research optimising treatment regimens and disease monitoring in individuals at-risk to facilitate such treatment decisions in the future, while avoiding an intervention, either limited or for a prolonged period, which may have harms that outweigh benefits.

TRIAL REGISTRATION NUMBER

The Netherlands Trials Registry (NTR4853-trial-NL4599). EudraCT number: NL2014-004472-35.

Predicting Inflammatory Arthritis in At-Risk Persons: Development of Scores for Risk Stratification

BACKGROUND

Inflammatory arthritis (IA) is an immune-related condition defined by the presence of clinical synovitis. Its most common form is rheumatoid arthritis.

OBJECTIVE

To develop scores for predicting IA in at-risk persons using multidimensional biomarkers.

DESIGN

Prospective observational cohort study.

SETTING

Single-center, Leeds, United Kingdom.

PARTICIPANTS

Persons with new musculoskeletal symptoms, a positive test result for anticitrullinated protein antibodies, and no clinical synovitis and followed for 48 weeks or more or until IA occurred.

MEASUREMENTS

A simple score was developed using logistic regression, and a comprehensive score was developed using the least absolute shrinkage and selection operator Cox proportional hazards regression. Internal validation with bootstrapping was estimated, and a decision curve analysis was done.

RESULTS

Of 455 participants, 32.5% (148 of 455) developed IA, and 15.4% (70 of 455) developed it within 1 year. The simple score identified 249 low-risk participants with a false negative rate of 5% (and 206 high-risk participants with a false-positive rate of 72%). The comprehensive score identified 119 high-risk participants with a false-positive rate of 29% (and 336 low-risk participants with a false-negative rate of 19%); 40% of high-risk participants developed IA within 1 year and 71% within 5 years.

LIMITATIONS

External validation is required. Recruitment occurred over 13 years, with lower rates of IA in later years. There was geographic variation in laboratory testing and recruitment availability.

CONCLUSION

The simple score identified persons at low risk for IA who were less likely to need secondary care. The comprehensive score identified high-risk persons who could benefit from risk stratification and preventive measures. Both scores may be useful in clinical care and should also be useful in clinical trials.

PRIMARY FUNDING SOURCE

National Institute for Health and Care Research Leeds Biomedical Research Centre.

Diagnostic performance of double inversion recovery MRI sequence for synovitis of the wrist joints in rheumatoid arthritis

PURPOSE

To assess the diagnostic accuracy of double inversion recovery (DIR) magnetic resonance imaging (MRI) sequences for synovitis of the wrist joints in patients with rheumatoid arthritis (RA).

MATERIAL AND METHODS

Participants with newly diagnosed RA were enrolled between November 2019 and November 2020. MRI examinations of the wrist joints were performed using a contrast-enhanced T1-weighted imaging sequence (CE-T1WI) and DIR sequence. We measured synovitis score, number of synovial areas, synovial volume, mean synovium-to-bone signal ratio (SBR), and synovial contrast-to-noise ratio (SNR). The inter-reviewer agreement rated on a four-point scale was evaluated by calculating the weighted k statistics. Two MRI sequences were assessed using Bland-Altman analyses, and the diagnostic performance of DIR images was calculated using the chi-square test.

RESULTS

A total of 47 participants were evaluated, and 282 joint regions in 5076 images were reviewed by two readers. There was no significant difference in synovitis scores (P = 0.67), number of synovial areas (P = 0.89), and synovial volume (P = 0.086) between the two MRI sequences. DIR images showed better SBR and SNR (all P < 0.01). There was good agreement between the two reviewers in terms of synovitis distribution (κ = 0.79). The synovitis was well agreed upon by the two readers according to Bland-Altman analyses. Using CE-T1WI as the reference standard, DIR imaging demonstrated a sensitivity of 94.1% and a specificity of 84.6% at the patient level.

CONCLUSION

The non-contrast DIR sequence showed good consistency with CE-T1WI and potential for evaluating synovitis in patients with RA.

Preventive interventions in individuals at risk for Rheumatoid Arthritis: State of the art and perspectives

During the last decade, the outlook for patients with rheumatoid arthritis (RA) has improved greatly, especially for patients with autoantibody-positive RA. To further improve long-term disease outcomes, the field has turned to investigating the efficacy of treatment initiated in the pre-arthritic phase of RA, based on the adage "the sooner the better." In this review, the concept of prevention is evaluated and different risk stages are being examined for their pre-test risks of RA development. These risks affect the post-test risk of biomarkers used at these stages and, consequently, the accuracy with which the risk of RA can be estimated. Furthermore, through their effect on accurate risk stratification, these pre-test risks ultimately also associate with the likelihood of false-negative trial results (the so-called "clinicostatistical tragedy"). Outcome measures to assess preventive effects are evaluated and relate to either the occurrence of disease itself or to the severity of risk factors for RA development. Results of recently completed prevention studies are discussed in the light of these theoretical considerations. The results vary, but clear prevention of RA has not been demonstrated. While some treatments (e.g. methotrexate) persistently reduced symptom severity, physical disability, and the severity of imaging joint inflammation, other treatments were not reported to produce long-lasting effects (hydroxychloroquine, rituximab, atorvastatin). The review concludes with future perspectives regarding the design of new prevention studies and considerations and requirements before findings can be implemented in daily practice in individuals at risk of RA attending rheumatology practices.

Interosseous tendon inflammation in the hands of patients with clinically suspect arthralgia: analysis of MRI data from a prospective cohort study

BACKGROUND

Inflammation around the tendons of interosseous muscles of the hand (interosseous tendon inflammation) was recently observed with MRI for the first time in patients with rheumatoid arthritis and in at-risk individuals with detectable anti-citrullinated protein antibodies, generating the hypothesis that interosseous tendon inflammation precedes clinical arthritis. To better understand the role of interosseous tendon inflammation during the development of rheumatoid arthritis, we studied the frequency of interosseous tendon inflammation in healthy individuals and in those with arthralgia that was suspected of progressing to rheumatoid arthritis (ie, clinically suspect arthralgia) and the association of interosseous tendon inflammation with other symptoms of inflamed joint tissues and with clinical arthritis development.

METHODS

Adult (age ≥18 years) patients who presented with clinically suspect arthralgia and symptom-free (control) individuals underwent contrast-enhanced hand MRI. MRIs were evaluated for interosseous tendon inflammation on the radial and ulnar sides of the second to fifth metacarpophalangeal joints, and for synovitis, tenosynovitis, and osteitis using the rheumatoid arthritis MRI scoring system. Patients with clinically suspect arthralgia were followed up for clinical arthritis development. The presence of local tenosynovium was examined using immunohistochemistry for anti-CD55 and anti-CD68 on tissue from the hands of three embalmed bodies donated for scientific research. The primary outcome for the cross-sectional part of the study was the presence of interosseous tendon inflammation on MRI. The primary outcome for the longitudinal part of the study was development of clinical arthritis.

FINDINGS

Between April 3, 2012, and May 20, 2020, 667 patients with clinically suspect arthralgia (mean age 44 years [SD 13], 504 [76%] were women and 163 [24%] were men) underwent contrast-enhanced hand MRI. Between Nov 1, 2013, and Nov 30, 2014, 193 symptom-free controls were recruited (mean age 50 years [SD 16], 136 [70%] were women and 57 [30%] were men). Two (1%) of 193 symptom-free controls had interosseous tendon inflammation. Immunohistochemistry of cadaveric hand tissues showed no tenosynovium surrounding interosseous tendons. At inclusion, 67 (10%) of 667 patients with clinically suspect arthralgia had interosseous tendon inflammation (p<0·0001 vs symptom-free controls). Interosseous tendon inflammation occurred more frequently if synovitis (odds ratio [OR] 2·2 [95% CI 1·2-4·2]), or tenosynovitis (OR 9·7 [5·5-17·0]), was present at metacarpophalangeal joints. A three-dimensional MRI reconstruction suggested confluency of interosseous tendon inflammation with metacarpophalangeal-flexor-tenosynovitis. 91 (16%) of 558 patients with clinically suspect arthralgia developed clinical arthritis during follow-up (median total follow-up 25·3 months [95% CI 25·1-25·5]). Patients with clinically suspect arthralgia with interosseous tendon inflammation had a higher risk of developing clinical arthritis (hazard ratio [HR] 4·5 [2·8-7·2]), which was attenuated but still significant after adjusting for concomitant synovitis, tenosynovitis, or osteitis (HR 1·7 [1·02-2·8]).

INTERPRETATION

Interosseous tendon inflammation is almost absent in symptom-free individuals but occurs in people with clinically suspect arthralgia, in whom it correlates with symptoms and is associated with the development of clinical arthritis. The absence of local tenosynovium suggests that interosseous tendon inflammation arises from expanding local subclinical inflammation in the pre-arthritis phase of rheumatoid arthritis.

FUNDING

European Research Council and the Dutch Arthritis Society.

Joint involvement in RA starts predominantly in the hands: functional, clinical and imaging studies in clinically suspect arthralgia and during progression to RA

OBJECTIVES

It is unknown whether rheumatoid arthritis (RA) starts in hands or feet. To investigate this, we performed functional, clinical and imaging studies during progression from clinically suspect arthralgia (CSA) to RA. Additionally, we studied whether functional disabilities of hands/feet at CSA onset contribute to predicting RA development.

METHODS

600 patients with CSA were followed for clinical inflammatory arthritis (IA) during median follow-up of 25 months, during which 99 developed IA. Functional disabilities were measured at baseline/4/12/24 months with the Health Assessment Questionnaire Disability Index (HAQ); HAQ items assessing hand disabilities and foot disabilities were selected. The course of disabilities towards IA development (here considered as t=0) was depicted by increasing incidences and analysed using linear mixed models. To evaluate robustness of findings, tender hand/foot joints and subclinical joint inflammation (measured with CE-1.5TMRI) of hand/foot were additionally studied. Associations between disabilities at CSA presentation (here t=0) and future IA development were studied using Cox regression in the total CSA population.

RESULTS

During IA development, hand disabilities occurred earlier and more frequently than foot disabilities. Despite both hand disabilities and foot disabilities rose significantly towards IA development, hand disabilities were more severe during this course (mean difference over time: 0.41 units, 95% CI 0.28 to 0.55, p<0.001, on a range 0-3). Similar to functional disabilities, tender joints and subclinical joint inflammation occurred earlier in the hands than feet. In the total CSA population, a single HAQ question on difficulties with dressing (hand functioning) was independently predictive for IA development: HR=2.2, 95% CI 1.4 to 3.5, p=0.001.

CONCLUSION

Evaluation of functional disabilities, supported by clinical and imaging findings, revealed that joint involvement starts predominantly in the hands during RA development. Additionally, a single question on dressing difficulties adds value to risk stratification in patients with CSA.

Pathogenesis of autoimmune disease

Autoimmune diseases are a diverse group of conditions characterized by aberrant B cell and T cell reactivity to normal constituents of the host. These diseases occur widely and affect individuals of all ages, especially women. Among these diseases, the most prominent immunological manifestation is the production of autoantibodies, which provide valuable biomarkers for diagnosis, classification and disease activity. Although T cells have a key role in pathogenesis, they are technically more difficult to assay. In general, autoimmune disease results from an interplay between a genetic predisposition and environmental factors. Genetic predisposition to autoimmunity is complex and can involve multiple genes that regulate the function of immune cell populations. Less frequently, autoimmunity can result from single-gene mutations that affect key regulatory pathways. Infection seems to be a common trigger for autoimmune disease, although the microbiota can also influence pathogenesis. As shown in seminal studies, patients may express autoantibodies many years before the appearance of clinical or laboratory signs of disease - a period called pre-clinical autoimmunity. Monitoring autoantibody expression in at-risk populations may therefore enable early detection and the initiation of therapy to prevent or attenuate tissue damage. Autoimmunity may not be static, however, and remission can be achieved by some patients treated with current agents.

Connective Tissue Disease Associated Interstitial Lung Disease

Connective tissue disease associated interstitial lung disease (CTD-ILD) is a heterogenous collection of conditions with a diverse spectrum of interstitial lung disease (ILD) manifestations. Currently, clinical practice of lung-directed immunosuppression in CTD-ILD is supported by several randomized, placebo-controlled trials (RCTs) in patients with scleroderma and several observational, retrospective studies in other autoimmune conditions. However, given the harm of immunosuppression in idiopathic pulmonary fibrosis, there is an urgent need for RCTs of immunosuppression and antifibrotic agents in fibrotic CTD-ILD populations as well as the study of intervention in patients with subclinical CTD-ILD.