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.

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.

The prognostic value of IgA anti-citrullinated protein antibodies and rheumatoid factor in an early arthritis population with a treat-to-target approach.

The mucosal origin hypothesis of rheumatoid arthritis has renewed the interest in IgA autoantibodies, but their added value over IgG anti-citrullinated protein antibody (ACPA) and IgM rheumatoid factor (RF) for modern treatment outcomes remains unknown. We aimed to investigate the prognostic value of IgA-ACPA and IgA-RF for treatment outcomes in an early arthritis population. IgA-ACPA/RF isotypes were measured in baseline sera from 480 inflammatory arthritis (IA) patients, who were included in the treatment in the Rotterdam Early Arthritis Cohort trial (tREACH). The tREACH trial was a multicentre, stratified, single-blinded trial with a treat-to-target approach. The prognostic value of IgA-ACPA/RF was determined by evaluating differences in (1) quick-attained (< 6 months after diagnosis) and persistent remission rates, (2) DMARD-free remission and (3) biological use between IA patients with and without IgA-ACPA/RF over 3 years of follow-up. IgA-ACPA was present in 23% of patients and overlapped with IgG-ACPA positivity in 94%. Similarly, IgA-RF overlapped with IgM-RF in 90% of patients. IgA-ACPA positivity was associated with lower DFR rates and more biological use, but this effect was largely mediated by the presence of IgG-ACPA, since this effect disappeared after stratification for IgG-ACPA (HR 0.6, 95%CI 0.2-1.6 for DFR). No differences were observed in 'quick-attained and persistent remission' rates and for IgA-RF. Their seems to be no additional value of IgA-ACPA and IgA-RF for modern, long-term clinical outcomes. The effects of IgA-ACPA seen in our study are largely mediated by the presence of IgG-ACPA. Based on these results, there is no rationale for measuring these isotypes in daily practice.

Early identification of rheumatoid arthritis: does it induce treatment-related cost savings?

OBJECTIVE: Early diagnosis and treatment-start is key for rheumatoid arthritis (RA), but the economic effect of an early versus a later diagnosis has never been investigated. We aimed to investigate whether early diagnosis of RA is associated with lower treatment-related costs compared with later diagnosis. METHODS: Patients with RA consecutively included in the Leiden Early Arthritis Clinic between 2011 and 2017 were studied (n=431). Symptom duration was defined as the time between symptom onset and first presentation at the outpatient clinic; early treatment start was defined as symptom duration <12 weeks. Information on disease-modifying anti-rheumatic drug use per patient over 5 years was obtained from prescription data from patient records. Prices were used from 2022 and 2012 (proxy of time of prescription) to study the impact of changes in drug costs. Autoantibody-positive and autoantibody-negative RA were studied separately because differences in disease severity may influence costs. RESULTS: Within autoantibody-negative RA, costs were 316% higher in the late compared with the early group (ß=4.16 (95% CI 1.57 to 11.1); €4856 vs €1159). When using 2012 prices, results were similar. For autoantibody-positive RA, costs were 19% higher in the late group (€9418 vs €7934, ß=1.19, 0.57 to 2.47). This effect was present but smaller when using 2012 prices. Within patients with autoantibody-positive RA using biologicals, late treatment start was associated with 46% higher costs (ß=1.46 (0.91 to 2.33)); higher costs were also seen when using 2012 prices. CONCLUSION: When RA is detected within 12 weeks after symptom onset, treatment-related costs were lower in both autoantibody-negative and autoantibody-positive RA. This study is the first to report how early diagnosis and treatment start impact treatment-related costs.

Clinically suspect arthralgia and rheumatoid arthritis: patients' perceptions of illness.

OBJECTIVES: Clinically suspect arthralgia (CSA) is an at-risk stage of rheumatoid arthritis (RA), in which patients experience symptoms and physical limitations. Perceptions of CSA-patients have remained largely unknown. Therefore, we aimed to map perceptions of CSA-patients and compare these to RA-patients. Additionally, we studied changes in perceptions in CSA over time. METHODS: Three hundred and ninety-nine consecutively included CSA-patients from the Leiden and Rotterdam CSA-cohorts and 100 recently diagnosed RA-patients from the Leiden Early Arthritis Clinic were included. Patients' illness perceptions (IP) were assessed using the Brief Illness Perception Questionnaire (BIPQ), consisting of 8 questions (scale 0-10; higher score indicating more negative IP) covering cognitive, emotional and comprehensibility domains, and one open question about causes of disease. IP were measured at baseline in both populations and during 2years follow-up in the CSA-cohorts. RESULTS: Total BIPQ-scores were comparable at CSA-presentation and RA-diagnosis (40±11 and 40±10; range 0-80). Comparing dimensions separately revealed that CSA-patients were less worried about physical complaints compared to RA-patients. However, CSA-patients were more negative about expected treatment-effect on symptoms. IP over time in CSA improved in patients without development of clinical arthritis (from 38±11 to 34±14; P=0.005) but remained similar in CSA-patients who progressed to arthritis/RA (mean 40 at both timepoints). CSA-patients mainly perceived physical strain and heredity as causes of their complaints. CONCLUSIONS: Although CSA-patients have not developed clinical arthritis, illness perceptions at CSA-presentation and RA-diagnosis are equally severe. Knowledge on worries and expectations may contribute to improving patient-contact and care in patients at risk of RA.

Ultrasound of the forefeet besides the hands in patients at risk for rheumatoid arthritis: is it worth the effort? A longitudinal cohort study.

OBJECTIVE: Ultrasound (US) can detect subclinical joint-inflammation in patients with clinically suspect arthralgia (CSA), which is valuable as predictor for rheumatoid arthritis (RA) development. In most research protocols both hands and forefeet are scanned, but it is unclear if US of the forefeet has additional value for predicting RA, especially since synovial hypertrophy in MTP-joints of healthy individuals is also common. To explore the possibility to omit scanning of the forefeet we determined if US of the forefeet is of additional predictive value for RA-development in CSA patients. METHODS: CSA patients of two independent cohorts underwent US of the hands and forefeet. We analyzed the association between RA-development and US-positivity for the full US-protocol, the full US-protocol with correction for Gray Scale(GS)-findings in the forefeet of healthy and the protocol without-forefeet. RESULTS: In total, 298 CSA patients were studied. In patients with a positive US, subclinical joint-inflammation was mostly present in the hands (90-86%). Only 10-14% of patients had subclinical joint-inflammation solely in the forefeet. US-positivity was associated with inflammatory arthritis development in both cohorts, with HRs 2.6(95%CI 0.9-7.5) and 3.1(95%CI 1.5-6.4) for the full protocol, 3.1(95%CI 1.3-7.7) and 2.7(95%CI 1.3-5.4) for the full US-protocol with correction, and 3.1(95%CI 1.4-6.9) and 2.8(95%CI 1.4-5.6) without the forefeet. AUROCs were equal across both cohorts. CONCLUSION: The forefeet can be omitted when US is used for the prediction of RA-development in CSA patients. This is due to the finding that subclinical joint-inflammation in the forefeet without concomitant inflammation in the hands is infrequent.

RPA3-UMAD1 rs12702634 and rheumatoid arthritis-associated interstitial lung disease in European ancestry.

Objective: Recently, a genome-wide association study identified an association between RA-associated interstitial lung disease (ILD) and RPA3-UMAD1 rs12702634 in the Japanese population, especially for patients with a usual interstitial pneumonia (UIP) pattern. We aimed to replicate this association in a European population and test for interaction with MUC5B rs35705950. Methods: In this genetic case-control association study, patients with RA and ILD and controls with RA and no ILD were included from France, the USA and the Netherlands. Only cases and controls from European genetic ancestries determined by principal components analysis were included in the analyses. RA was defined by the 1987 ACR or 2010 ACR/EULAR criteria and ILD by chest high-resolution CT scan, except in the control dataset from the Netherlands, where the absence of ILD was determined by chart review. Patients were genotyped for RPA3-UMAD1 rs12702634 and MUC5B rs35705950. Associations were tested using logistic regression adjusted for sex, age at RA onset, age at ILD onset or at certified absence of ILD, tobacco smoking status and country of origin. Results: Among the 883 patients included, 322 were RA-ILD cases (36.5%). MUC5B rs35705950 was strongly associated with RA-ILD in all datasets {combined adjusted odds ratio [OR] 2.9 [95% CI 2.1, 3.9], P = 1.1 × 10-11. No association between RPA3-UMAD1 rs12702634 and RA-ILD was observed [combined OR 1.2 (95% CI 0.8, 1.6), P = 0.31. No interaction was found between RPA3-UMAD1 rs12702634 and MUC5B rs35705950 (P = 0.70). Conclusion: Our findings did not support a contribution of RPA3-UMAD1 rs12702634 to the overall RA-ILD susceptibility in the European population.

Responsiveness and sensitivity of PROMs to change in disease activity status in early and established rheumatoid arthritis.

OBJECTIVES: To determine whether patient reported outcome measures (PROMs) capturing activity limitations, health impact, pain, fatigue and work ability are responsive and sensitive to changes in disease activity status in patients with early and established rheumatoid arthritis (RA). METHODS: All early RA patients (n = 557) from the tREACH-trial and established RA patients (n = 188) from the TARA-trial were included. Both studies were multicentre, single-blinded trials with a treat-to-target management approach. The following PROMs were studied: Health Assessment Questionnaire Disability Index(HAQ-DI), morning stiffness severity, EQ-5D, general health, 36-item short form(SF-36), joint pain, fatigue and productivity loss. Mean changes in PROMs between two consecutive visits were compared with changes in disease activity status(remission, low disease activity and active disease) using linear mixed models and standardised response means. Additionally, the proportion of individual observations that showed an expected PROM response to disease activity status alterations was calculated. RESULTS: HAQ-DI, morning stiffness severity, general health, EQ-5D and joint pain demonstrated responsiveness to improvement or worsening of disease activity status in both early and established RA. SF-36 physical and mental component scale, fatigue and productivity loss did not show this effect in both groups. Across nearly all PROMs, the magnitude of change and the proportion of individual observations that reflect a shift from and to active disease remained low. CONCLUSION: HAQ-DI, morning stiffness severity, EQ-5D, general health and joint pain are responsive to disease activity status alterations on a group level in both early and established RA. For the individual patient the responsiveness of these PROMs is poor. CLINICAL TRIAL REGISTRATION: tREACH trial (www.isrctn.com, ISRCTN26791028) and TARA trial (www.onderzoekmetmensen.nl, NTR2754).

Work-related physical strain and development of joint inflammation in the trajectory of emerging inflammatory and rheumatoid arthritis: a prospective cohort study.

OBJECTIVES: Rheumatoid arthritis (RA) mainly affects small joints. Despite the mechanical function of joints, the role of mechanical stress in the development of arthritis is insufficiently understood. We hypothesised that mechanical stress/physical strain is a risk factor for joint inflammation in RA. Therefore, we studied work-related physical strain in subjects with clinically suspected arthralgia (CSA) as a risk factor for the presence of imaging-detected subclinical joint inflammation and the development of clinical arthritis/RA. METHODS: In 501 CSA patients and 155 symptom-free persons' occupation-related physical strain was quantified using the International Standard Classification of Occupations. Contrast-enhanced hand-MRIs were made and evaluated for joint inflammation (sum of synovitis/tenosynovitis/osteitis). CSA patients were followed on RA development. Age relationship was studied using an interaction term of physical strain with age. RESULTS: The degree of physical strain in CSA is associated with the severity of joint inflammation, independent of educational-level/BMI/smoking (interaction physical strain-age p=0.007; indicating a stronger association with increasing age). Physical strain is associated with higher tenosynovitis scores, in particular. In symptom-free persons, physical strain was not associated with imaging-detected joint inflammation. Higher degrees of physical strain also associated with higher risks for RA development in an age-dependent manner (HR=1.20 (1.06-1.37)/10-year increase in age), independent of educational-level/BMI/smoking. This association was partly mediated by an effect via subclinical joint inflammation. CONCLUSIONS: Work-related physical strain increases the risk of subclinical joint inflammation and of developing RA. The age relationship suggests an effect of long-term stress or that tenosynovium is more sensitive to stress at older age. Together, the data indicate that mechanical stress contributes to the development of arthritis in RA.

EULAR recommendations for the management of psoriatic arthritis with pharmacological therapies: 2023 update.

OBJECTIVE: New modes of action and more data on the efficacy and safety of existing drugs in psoriatic arthritis (PsA) required an update of the EULAR 2019 recommendations for the pharmacological treatment of PsA. METHODS: Following EULAR standardised operating procedures, the process included a systematic literature review and a consensus meeting of 36 international experts in April 2023. Levels of evidence and grades of recommendations were determined. RESULTS: The updated recommendations comprise 7 overarching principles and 11 recommendations, and provide a treatment strategy for pharmacological therapies. Non-steroidal anti-inflammatory drugs should be used in monotherapy only for mild PsA and in the short term; oral glucocorticoids are not recommended. In patients with peripheral arthritis, rapid initiation of conventional synthetic disease-modifying antirheumatic drugs is recommended and methotrexate preferred. If the treatment target is not achieved with this strategy, a biological disease-modifying antirheumatic drug (bDMARD) should be initiated, without preference among modes of action. Relevant skin psoriasis should orient towards bDMARDs targeting interleukin (IL)-23p40, IL-23p19, IL-17A and IL-17A/F inhibitors. In case of predominant axial or entheseal disease, an algorithm is also proposed. Use of Janus kinase inhibitors is proposed primarily after bDMARD failure, taking relevant risk factors into account, or in case bDMARDs are not an appropriate choice. Inflammatory bowel disease and uveitis, if present, should influence drug choices, with monoclonal tumour necrosis factor inhibitors proposed. Drug switches and tapering in sustained remission are also addressed. CONCLUSION: These updated recommendations integrate all currently available drugs in a practical and progressive approach, which will be helpful in the pharmacological management of PsA.

Window of opportunity in psoriatic arthritis: the earlier the better?

OBJECTIVES: To investigate whether there is a window of opportunity for psoriatic arthritis (PsA) patients and to assess which patient characteristics are associated with a longer diagnostic delay. METHODS: All newly diagnosed, disease-modifying antirheumatic drug-naïve PsA patients who participated in the Dutch southwest Early PsA cohoRt and had ≥3 years of follow-up were studied. First, total delay was calculated as the time period between symptom onset and PsA diagnosis made by a rheumatologist and then split into patient and physician delays. The total delay was categorised into short (<12 weeks), intermediate (12 weeks to 1 year) or long (>1 year). These groups were compared on clinical (Minimal Disease Activity (MDA) and Disease Activity index for PSoriatic Arthritis (DAPSA) remission) and patient-reported outcomes during 3 years follow-up. RESULTS: 708 PsA patients were studied of whom 136 (19%), 237 (33%) and 335 (47%) had a short, intermediate and long total delay, respectively. Patient delay was 1.0 month and physician delay was 4.5 months. Patients with a short delay were more likely to achieve MDA (OR 2.55, p=0.003) and DAPSA remission (OR 2.35,p=0.004) compared with PsA patients with a long delay. Patient-reported outcomes showed numerical but non-significant differences between the short and long delay groups. Female patients and those presenting with enthesitis, chronic back pain or normal C-reactive protein (CRP) had a longer delay. CONCLUSIONS: In PsA, referral and diagnosis within 1 year is associated with better clinical outcomes, suggesting the presence of a window of opportunity. The most gain in referral could be obtained in physician delay and in females, patients with enthesitis, chronic back pain or normal CRP.

Patient-reported outcomes and radiographic progression in patients with rheumatoid arthritis in sustained remission versus low disease activity.

OBJECTIVE: To compare clinical and patient-reported outcomes (PROs) over 5 years between patients with rheumatoid arthritis (RA) in sustained remission (sREM), sustained low disease activity (sLDA) or active disease (AD) in the first year after diagnosis. METHODS: All patients with RA from the treatment in the Rotterdam Early Arthritis CoHort trial, a multicentre, stratified, single-blinded trial with a treat-to-target approach, aiming for LDA (Disease Activity Score (DAS) ≤2.4), were studied. Patients were categorised into: (1) sREM (mean DAS from 6 to 12 months <1.6) (n=173); (2) sLDA (mean DAS from 6 to 12 months 1.6-2.4) (n=142); and (3) AD (mean DAS from 6 to 12 months >2.4) (n=59). Pain, fatigue, functional impairment, health-related quality of life (HRQoL), health status and productivity loss during 5 years were compared between groups. Radiographic progression (modified Total Sharp Score (mTSS)) was compared over 2 years. RESULTS: Patients in sLDA in the first year had worse PROs during follow-up, compared with patients in sREM: pain (0-10 Likert) was 0.90 units higher (95% CI 0.52 to 1.27), fatigue (Visual Analogue Scale) was 12.10 units higher (95% CI 7.27 to 16.92), functional impairment (Health Assessment Questionnaire-Disability Index) was 0.28 units higher (95% CI 0.17 to 0.39), physical HRQoL (36-item Short Form Health Survey (SF-36) Physical Component Summary score) was 4.42 units lower (95% CI -6.39 to -2.45), mental HRQoL (SF-36 Mental Component Summary score (MCS)) was 2.95 units lower (95% CI -4.83 to -1.07), health status (European Quality of life 5-Dimensions 3-Levels (EQ-5D-3L)) was 0.06 units lower (95% CI -0.09 to -0.03) and productivity loss (0%-100%) was 7.76% higher (95% CI 2.76 to 12.75). Differences between the AD and sREM group were even larger, except for the SF-36 MCS and EQ-5D-3L. No differences in mTSS were found between groups. CONCLUSION: Patients with RA who reach sREM in the first year have better HRQoL and function, and less pain, fatigue and productivity loss in the years thereafter, compared with patients with RA who are in sLDA or AD in the first year.

Deep learning in rheumatological image interpretation.

Artificial intelligence techniques, specifically deep learning, have already affected daily life in a wide range of areas. Likewise, initial applications have been explored in rheumatology. Deep learning might not easily surpass the accuracy of classic techniques when performing classification or regression on low-dimensional numerical data. With images as input, however, deep learning has become so successful that it has already outperformed the majority of conventional image-processing techniques developed during the past 50 years. As with any new imaging technology, rheumatologists and radiologists need to consider adapting their arsenal of diagnostic, prognostic and monitoring tools, and even their clinical role and collaborations. This adaptation requires a basic understanding of the technical background of deep learning, to efficiently utilize its benefits but also to recognize its drawbacks and pitfalls, as blindly relying on deep learning might be at odds with its capabilities. To facilitate such an understanding, it is necessary to provide an overview of deep-learning techniques for automatic image analysis in detecting, quantifying, predicting and monitoring rheumatic diseases, and of currently published deep-learning applications in radiological imaging for rheumatology, with critical assessment of possible limitations, errors and confounders, and conceivable consequences for rheumatologists and radiologists in clinical practice.

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.

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.