Country-level socioeconomic status relates geographical latitude to the onset of RA: a worldwide cross-sectional analysis in the METEOR registry.

OBJECTIVE: Age at rheumatoid arthritis (RA) onset varies by geographical latitude. We have investigated to what extent differences in patient-specific factors and country-level socioeconomic indicators explain this variability. METHODS: Patients with RA from the worldwide METEOR registry were included. Bayesian multilevel structural equation models were used to study the relationship between the absolute value of (hospital) geographical latitude and age at diagnosis (as a proxy for age at RA onset). We examined to what extent this effect is mediated by individual patient characteristics and by country-specific socioeconomic indicators and disentangled whether the observed effects occurred at the patient, hospital, or country levels. RESULTS: We included 37 981 patients from 93 hospitals in 17 geographically widespread countries. Mean age at diagnosis per country ranged from 39 (Iran) to 55 (Netherlands) years. Per degree increase in country latitude (between 9.9° and 55.8°), mean age at diagnosis increased by 0.23 years (95% credibility interval: 0.095 to 0.38) (reflecting >10 years difference in age at RA onset). For hospitals within a country, this latitude effect was negligible. Inclusion of patient-specific factors (eg, gender, anticitrullinated protein antibodies status) in the model augmented the main effect from 0.23 to 0.36 years. Inclusion of country-level socioeconomic indicators (eg, gross domestic product per capita) in the model almost effaced the main effect (from 0.23 to 0.051 (-0.37 to 0.38)). CONCLUSIONS: Patients living closer to the equator get RA at a younger age. This latitude gradient was not explained by individual patient characteristics, but rather by countries' socioeconomic status, providing a direct link between countries' level of welfare and the clinical onset of RA.

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.

Hand function is already reduced before RA development and reflects subclinical tenosynovitis.

BACKGROUND: Clinically suspect arthralgia (CSA) is characterised by arthralgia of small joints and considered a risk stage for development of rheumatoid arthritis (RA). However, it remains unknown if the function of the hands is already affected and what mechanisms underlie impaired hand-function in CSA. METHODS: We studied various measures of hand function in two CSA populations. CSA patients in the TREAT EARLIER-trial (n=236) were evaluated at baseline for: grip strength on a dynamometer (GS), patient-reported difficulties in the grip domain of the Health Assessment Questionnaire (HAQ) questionnaire and incomplete fist closure at physical examination. Findings were validated in an independent CSA cohort (n=600) where hand function was measured as: GS evaluated by squeezing the examiner's fingers, grip domain of the HAQ questionnaire and fist closure. Contrast-enhanced MRI of the hands measured synovitis, tenosynovitis and bone marrow oedema (summed as subclinical inflammation) in both cohorts. RESULTS: GS (on a dynamometer) was reduced in 75% compared with reference values in healthy controls, 60% reported grip difficulties and 13% had incomplete fist closure. Reduced GS was associated with subclinical inflammation (-0.38 kg/point inflammation, 95% CI -0.68 to -0.08). Studying separate MRI features, GS reduction was independently associated with tenosynovitis, decreasing with -2.63 kg (95% CI -2.26 to -0.33)/point tenosynovitis (range observed tenosynovitis scores: 0-20). Similar relations with tenosynovitis were seen for patient-reported grip difficulties (OR 1.12/point, 95% CI 1.07 to 1.42) and incomplete fist closure (OR 1.36/point, 95% CI 1.03 to 1.79). In the validation cohort, 36% had decreased examiner-assessed GS, 51% reported grip difficulties and 14% incomplete fist closure: all were associated with tenosynovitis. Decreased dynamometer-measured GS was most sensitive for detecting tenosynovitis (75%), while incomplete fist closure was most specific (88%-90%). CONCLUSION: Hand function is already often affected before RA development. These limitations are related to subclinical inflammation and tenosynovitis in particular.

Frequency of joint inflammation is associated with local joint damage progression in rheumatoid arthritis despite long-term targeted treatment.

OBJECTIVES: To investigate whether in rheumatoid arthritis (RA) frequency of local joint inflammation is associated with radiographic joint damage progression in that joint. METHODS: Data from 473 patients with RA and available radiographs from the BeSt study were used. Patients were treated to target (Disease Activity Score of ≤2.4) for a median of 10 years. At each study visit every 3 months, joints were assessed for swelling and tenderness. Radiographs of hands and feet were made yearly. A generalised linear mixed model was used to assess the association between the percentage of study visits at which clinical inflammation was observed in a joint (cumulative inflammation) and radiographic joint damage in that same joint. Clinical inflammation was primarily defined as joint swelling (with or without joint tenderness). For secondary analyses, we also investigated joint tenderness without joint swelling. Damage was measured as the percentage of the maximum possible Sharp-Van der Heijde score in a particular joint. RESULTS: Cumulative local joint swelling was associated with local progression of radiographic damage in the same joint (ß=0.14, 95% CI 0.13 to 0.15). This association was also found in a subset of joints that were swollen at least once. Cumulative local joint tenderness without concurrent local joint swelling was less strongly associated with local radiographic joint damage progression (ß=0.04, 95% CI 0.03 to 0.05). CONCLUSIONS: In RA, long-term cumulative local joint inflammation is associated with joint damage progression in the same joint.

ACPA-negative and ACPA-positive RA patients achieving disease resolution demonstrate distinct patterns of MRI-detected joint-inflammation.

OBJECTIVES: Although sustained DMARD-free remission (SDFR; sustained absence of clinical-synovitis after DMARD-discontinuation) is increasingly achievable in RA, prevalence differs between ACPA-negative (40%) and ACPA-positive RA (5-10%). Additionally, early DAS remission (DAS4months<1.6) is associated with achieving SDFR in ACPA-negative, but not in ACPA-positive RA. Based on these differences, we hypothesized that longitudinal patterns of local tissue inflammation (synovitis/tenosynovitis/osteitis) also differ between ACPA-negative and ACPA-positive RA patients achieving SDFR. With the ultimate aim being to increase understanding of disease resolution in RA, we studied MRI-detected joint inflammation over time in relation to SDFR development in ACPA-positive RA and ACPA-negative RA. METHODS: A total of 198 RA patients (94 ACPA-negative, 104 ACPA-positive) underwent repeated MRIs (0/4/12/24 months) and were followed on SDFR development. The course of MRI-detected total inflammation, and synovitis/tenosynovitis/osteitis individually were compared between RA patients who did and did not achieve SDFR, using Poisson mixed models. In total, 174 ACPA-positive RA patients from the AVERT-1 were studied as ACPA-positive validation population. RESULTS: In ACPA-negative RA, baseline MRI-detected inflammation levels of patients achieving SDFR were similar to patients without SDFR but declined 2.0 times stronger in the first year of DMARD treatment [IRR 0.50 (95% CI; 0.32, 0.77); P < 0.01]. This stronger decline was seen in tenosynovitis/synovitis/osteitis. In contrast, ACPA-positive RA-patients achieving SDFR, had already lower inflammation levels (especially synovitis/osteitis) at disease presentation [IRR 0.45 (95% CI; 0.24, 0.86); P = 0.02] compared with patients without SDFR, and remained lower during subsequent follow-up (P = 0.02). Similar results were found in the ACPA-positive validation population. CONCLUSION: Compared with RA patients without disease resolution, ACPA-positive RA patients achieving SDFR have less severe joint inflammation from diagnosis onwards, while ACPA-negative RA patients present with similar inflammation levels but demonstrate a stronger decline in the first year of DMARD therapy. These different trajectories suggest different mechanisms underlying resolution of RA chronicity in both RA subsets.

Walking Disabilities in Association With Tenosynovitis at the Metatarsophalangeal Joints: A Longitudinal Magnetic Resonance Imaging Study in Early Arthritis.

OBJECTIVE: The relationship between functional disability and magnetic resonance imaging (MRI) inflammation has been studied for the hands, but has not been well established for the feet, even though walking difficulties are common. Therefore, our objective was to study whether walking difficulties were associated with MRI inflammation at metatarsophalangeal (MTP) joints in early arthritis patients, at diagnosis and during 24 months of follow-up. METHODS: A total of 532 consecutive patients presenting with early arthritis reported on the presence and severity of walking difficulties (Health Assessment Questionnaire question 4a, scale 0-3), and underwent unilateral contrast-enhanced MRI of MTP joints 1-5 at baseline. In total, 107 patients had clinical and MRI data at follow-up (4, 12, and 24 months). MRI inflammation (synovitis, tenosynovitis, and osteitis) was scored in line with the Rheumatoid Arthritis Magnetic Resonance Imaging Scoring system. At baseline, the association of walking disability with MRI inflammation was assessed using regression. Longitudinally, the association between a change in walking disability with a change in MRI inflammation was studied with linear mixed models. RESULTS: At baseline, 81% of patients with walking disabilities had MRI inflammation at MTP joints, versus 68% without walking disabilities (P < 0.001). Total MRI inflammation (i.e., the sum of tenosynovitis, synovitis, and osteitis) was associated with severity of walking disability (ß = 0.023, P < 0.001). Studying the MRI features separately, tenosynovitis, synovitis, and osteitis were all univariably associated with severity of walking disability (P < 0.001, P < 0.001, and P = 0.014, respectively). In multivariable analysis, the association was strongest for tenosynovitis. During follow-up, a decrease in MTP inflammation was associated with a decrease in walking disability (ß = 0.029, P = 0.001); in multivariable analyses only, tenosynovitis was independently associated (ß = 0.073, P = 0.049). CONCLUSION: Of the different inflamed tissues in MTP joints, predominantly MRI-detected tenosynovitis was associated with walking disabilities. Likewise a reduction in tenosynovitis related to a decrease in walking disabilities. These results increase our understanding of the involvement of tenosynovitis in walking disabilities in early arthritis.

Undifferentiated arthritis: a changing population who did not benefit from enhanced disease-modifying anti-rheumatic drug strategies-results from a 25 year longitudinal inception cohort.

OBJECTIVES: International guidelines stress timely DMARD initiation in early arthritis as well as when classification criteria are not yet fulfilled. Consequently, undifferentiated arthritis (UA) patients may be increasingly treated with DMARDs. Since UA is a diagnosis of exclusion, the introduction of the 2010 classification criteria presumably decreased the UA population, as former UA patients became regarded as RA. Consequently, the contemporary definition of UA has changed into: no clinical diagnosis and not fulfilling the 1987 nor 2010 RA-criteria. Importantly, placebo-controlled trials on DMARD efficacy in contemporary UA are absent. We aimed to study whether enhanced treatment strategies across the last 25 years improved outcomes in contemporary UA, whereby inclusion period was used as instrumental variable for DMARD treatment. METHODS: UA was defined, retrospectively, as clinical arthritis (joint swelling at physical examination) neither fulfilling the 1987 nor 2010 RA-criteria or any other clinical diagnosis. In total, 1132 UA patients consecutively included in the Leiden Early Arthritis Clinic between 1993 and 2019 were divided into five inclusion periods: 1993-1997, 1998-2005, 2006-2010, 2011-2014 and 2015-2019. The frequency of DMARD initiation was compared across the inclusion periods, as were the following outcomes: 28-joint DAS with CRP (DAS28-CRP) and the HAQ Disability Index (HAQ-DI) during follow-up, prevalence of DMARD-free-status within 10 years (DFS; spontaneous remission or sustained remission after DMARD stop) and progression to RA (according 1987/2010 criteria). RESULTS: The contemporary UA population is mainly autoantibody negative, with a median swollen joint count of 2, tender joint count of 3 and HAQ score of 0.6. These characteristics were similar across the inclusion periods. DMARD treatment increased from 17% (1993-1997) to 52% (2015-2019) and methotrexate became more common. The DAS28-CRP during follow-up improved from 2011 onwards (-0.18 to -0.25 DAS units; P < 0.05). Disability scores during follow-up did not significantly improve. DFS prevalence also remained similar: 58%, 57% and 61% for 1993-1997, 1998-2005 and 2006-2010, respectively (P = 0.77). Likewise, the percentages of RA development did not decrease (14%, 21%, 26%, 18% and 27%, respectively). CONCLUSION: Although intensified DMARD treatment slightly improved disease activity scores, physical functioning and long-term outcomes did not improve. This suggests overtreatment in the contemporary UA population and underlines the importance of developing stratification methods suitable for this patient-population.

Intermetatarsal Bursitis, a Novel Feature of Juxtaarticular Inflammation in Early Rheumatoid Arthritis Related to Clinical Signs: Results of a Longitudinal Magnetic Resonance Imaging Study.

OBJECTIVE: Intermetatarsal bursae in the forefeet possess a synovial lining similar to joints and tendon sheaths. Inflammation of these bursae (intermetatarsal bursitis [IMB]) was recently identified as specific for early rheumatoid arthritis (RA). The present study was undertaken to determine if IMB is indeed an RA feature by assessing the following: 1) the association with other local inflammatory measures (synovitis, tenosynovitis, and osteitis), 2) the association with clinical signs, and 3) whether it responds to disease-modifying antirheumatic drug (DMARD) therapy similarly to other local inflammatory measures. METHODS: One hundred fifty-seven consecutive early RA patients underwent unilateral contrast-enhanced 1.5T forefoot magnetic resonance imaging (MRI) at diagnosis. MRIs were evaluated for IMB presence and for synovitis, tenosynovitis, and osteitis in line with the RA MRI Scoring (RAMRIS) system (summed as RAMRIS inflammation). MRIs at 4, 12, and 24 months were evaluated for IMB presence and size in patients who had IMB at baseline and received early DMARD therapy. Logistic regression and generalized estimating equations were used. Anti-citrullinated protein antibody (ACPA) stratification was performed. RESULTS: Sixty-nine percent of RA patients had ≥1 IMB. In multivariable analysis on bursa level, presence of IMB was independently associated with local presence of synovitis and tenosynovitis, with odds ratios (OR) of 1.69 (95% confidence interval [95% CI] 1.12, 2.57) and 2.83 (95% CI 1.80, 4.44), respectively, but not osteitis. On the patient level, IMB presence was most strongly associated with tenosynovitis (OR 2.92 [95% CI 1.62, 5.24]). IMB presence was associated with local joint swelling (OR 2.7 [95% CI 1.3, 5.3]) and tenderness (OR 1.7 [95% CI 1.04, 2.9]) independent of RAMRIS inflammation. During treatment, IMB size decreased between 0 and 12 months. This decrease associated with decrease in RAMRIS inflammation, which was driven by synovitis decrease. Within ACPA-positive and ACPA-negative RA, similar results were obtained. CONCLUSION: IMB particularly accompanies inflammation of the synovial lining of joints and tendon sheaths, showed a similar treatment response after DMARD initiation, and associates with typical clinical signs. These findings suggest that IMB represents a frequently present novel RA feature of juxtaarticular synovial inflammation.

Joint inflammation tends to recur in the same joints during the rheumatoid arthritis disease course.

OBJECTIVES: We investigated whether local joint swelling recurs in the same joints over time in patients with rheumatoid arthritis (RA) who are treated to target. METHODS: Patients with newly diagnosed RA participating in the Behandel-Strategieën, "treatment strategies" (BeSt) study (n=508) were followed for median 10 years while receiving Disease Activity Score (DAS) ≤2.4 steered treatment. Every 3 months 68 joints were assessed for the presence of swelling. We evaluated whether baseline local joint swelling was predictive for swelling in the same joint during follow-up using a multilevel mixed-effect logistic regression model. Different strategies were used to account for missing data. A permutation test was performed to assess if joint swelling was better predicted by baseline swelling of the joint itself than by baseline swelling of randomly selected other joints. RESULTS: In 46% of the joints that were swollen at baseline, joint swelling later recurred at least once during follow-up. Joint swelling at baseline was statistically significantly associated with swelling in the same joint during follow-up (OR 2.37, 95% CI 2.30 to 2.43, p<0.001), and also specifically with recurrent swelling in the same joint (OR 1.73, 95% CI 1.37 to 1.59, p<0.001). Local joint swelling was better predicted by baseline swelling of that particular joint than by baseline swelling of other joints (p<0.001). CONCLUSION: Joint swelling tends to recur locally in the joints swollen at RA onset. This suggests that local factors influence the manifestation of joint inflammation over time.

Determining in which pre-arthritis stage HLA-shared epitope alleles and smoking exert their effect on the development of rheumatoid arthritis.

OBJECTIVES: The human leukocyte antigen-shared epitope (HLA-SE) alleles and smoking are the most prominent genetic and environmental risk factors for rheumatoid arthritis (RA). However, at which pre-arthritis stage (asymptomatic/symptomatic) they exert their effect is unknown. We aimed to determine whether HLA-SE and smoking are involved in the onset of autoantibody positivity, symptoms (clinically suspect arthralgia (CSA)) and/or progression to clinical arthritis. METHODS: We performed meta-analyses on results from the literature on associations of HLA-SE and smoking with anti-citrullinated protein antibodies (ACPAs) in the asymptomatic population. Next, we studied associations of HLA-SE and smoking with autoantibody positivity at CSA onset and with progression to clinical inflammatory arthritis (IA) during follow-up. Associations in ACPA-positive patients with CSA were validated in meta-analyses with other arthralgia cohorts. Analyses were repeated for rheumatoid factor (RF), anti-carbamylated protein antibodies (anti-CarP) and anti-acetylated protein antibodies (AAPA). RESULTS: Meta-analyses showed that HLA-SE is not associated with ACPA positivity in the asymptomatic population (OR 1.06 (95% CI:0.69 to 1.64)), whereas smoking was associated (OR 1.37 (95% CI: 1.15 to 1.63)). At CSA onset, both HLA-SE and smoking associated with ACPA positivity (OR 2.08 (95% CI: 1.24 to 3.49), OR 2.41 (95% CI: 1.31 to 4.43)). During follow-up, HLA-SE associated with IA development (HR 1.86 (95% CI: 1.23 to 2.82)), in contrast to smoking. This was confirmed in meta-analyses in ACPA-positive arthralgia (HR 1.52 (95% CI: 1.08 to 2.15)). HLA-SE and smoking were not associated with RF, anti-CarP or AAPA-positivity at CSA onset. Longitudinally, AAPA associated with IA development independent from ACPA and RF (HR 1.79 (95% CI: 1.02 to 3.16)), anti-CarP did not. CONCLUSIONS: HLA-SE and smoking act at different stages: smoking confers risk for ACPA and symptom development, whereas HLA-SE mediates symptom and IA development. These data enhance the understanding of the timing of the key risk factors in the development of RA.

Differing time-orders of inflammation decrease between ACPA subsets in RA patients suggest differences in underlying inflammatory pathways.

OBJECTIVES: Advanced imaging modalities have shown that not only joints but also bones and tendon sheaths can be inflamed at diagnosis of RA. We aimed to better understand the time-order in which the inflamed tissues respond to DMARD treatment. Also, because ACPA status may reflect a different pathophysiology, differences in time-order of inflammation decrease were hypothesized between these disease types. METHODS: A total of 216 consecutive patients presenting with RA (n = 176) or undifferentiated arthritis (n = 40), who all started with conventional synthetic DMARD treatment, were studied. 1.5T contrast-enhanced hand and foot MRIs were performed before treatment and after 4, 12 and 24 months. Cross-lagged models evaluated the influence of two time patterns: a simultaneous pattern ('change in one inflammatory feature associated with change in another feature') and a subsequent pattern ('change in one inflammatory feature preceded change in another feature'). ACPA stratification was performed. RESULTS: The median symptom duration at presentation was 13 weeks. Forty-four percent of patients was ACPA-positive. All pairs of inflammatory features decreased simultaneously in all time intervals (0-4/4-12/12-24 months; P < 0.05). Moreover, time-orders were identified: synovitis decrease preceded tenosynovitis decrease (0-4 to >4-12 months; P = 0.02 and 4-12 to >12-24 months; P = 0.03). Largely similar results were obtained in both ACPA subgroups. Additionally, in ACPA-positive but not ACPA-negative patients, synovitis decrease preceded osteitis decrease (4-12 to >12-24 moths; P = 0.002). CONCLUSION: This study increased the understanding of the response to treatment on the tissue level. In addition to simultaneous decrease of inflammation, synovitis decrease preceded tenosynovitis decrease. Differences in time-order of inflammation decrease between ACPA subgroups suggest differences in underlying inflammatory pathways.

Enhanced treatment strategies and distinct disease outcomes among autoantibody-positive and -negative rheumatoid arthritis patients over 25 years: A longitudinal cohort study in the Netherlands.

BACKGROUND: Based on different genetic and environmental risk factors and histology, it has been proposed that rheumatoid arthritis (RA) consists of 2 types: autoantibody-positive and autoantibody-negative RA. However, until now, this remained hypothetical. To assess this hypothesis, we studied whether the long-term outcomes differed for these 2 groups of RA patients. METHODS AND FINDINGS: In the Leiden Early Arthritis Clinic cohort, 1,285 consecutive RA patients were included between 1993 and 2016 and followed yearly. Treatment protocols in routine care improved over time, irrespective of autoantibody status, and 5 inclusion periods were used as instrumental variables: 1993-1996, delayed mild disease-modifying antirheumatic drug (DMARD) initiation (reference period); 1997-2000, early mild DMARDs; 2001-2005, early methotrexate; 2006-2010, early methotrexate followed by treat-to-target adjustments; 2011-2016, similar to 2006-2010 plus additional efforts for very early referral. Three long-term outcomes were studied: sustained DMARD-free remission (SDFR) (persistent absence of clinical synovitis after DMARD cessation), mortality, and functional disability measured by yearly Health Assessment Questionnaire (HAQ). Treatment response in the short term (disease activity) was measured by Disease Activity Score-28 with erythrocyte sedimentation rate (DAS28-ESR). Linear mixed models and Cox regression were used, stratified for autoantibody positivity, defined as IgG anti-CCP2 and/or IgM rheumatoid factor positivity. In total, 823 patients had autoantibody-positive RA (mean age 55 years, 67% female); 462 patients had autoantibody-negative RA (age 60 years, 64% female). Age, gender, and percentage of autoantibody-positive patients were stable throughout the inclusion periods. Disease activity significantly decreased over time within both groups. SDFR rates increased after introduction of treat-to-target (hazard ratio [HR] 2006-2010 relative to 1993-1996: 3.35 [95% CI 1.46 to 7.72; p = 0.004]; HR 2011-2016: 4.57 [95% CI 1.80 to 11.6; p = 0.001]) in autoantibody-positive RA, but not in autoantibody-negative RA. In autoantibody-positive RA, mortality decreased significantly after the introduction of treat-to-target treatment adjustments (HR 2006-2010: 0.56 [95% CI 0.34 to 0.92; p = 0.023]; HR 2011-2016: 0.33 [95% CI 0.14 to 0.77; p = 0.010]), but not in autoantibody-negative RA (HR 2006-2010: 0.79 [95% CI 0.40 to 1.56; p = 0.50]; HR 2011-2016: 0.36 [95% CI 0.10 to 1.34; p = 0.13]). Similarly, functional disability improved in autoantibody-positive RA for the periods after 2000 relative to 1993-1996 (range -0.16 [95% CI -0.29 to -0.03; p = 0.043] to -0.32 [95% CI -0.44 to -0.20; p < 0.001] units of improvement), but not in autoantibody-negative RA (range 0.10 [95% CI -0.12 to 0.31; p = 0.38] to -0.13 [95% CI -0.34 to 0.07; p = 0.20] units of improvement). Limitations to note were that treatment was not randomized-but it was protocolized and instrumental variable analysis was used to obtain comparable groups-and that a limited spread of ethnicities was included. CONCLUSIONS: Although disease activity has improved in both autoantibody-positive and autoantibody-negative RA in recent decades, the response in long-term outcomes differed. We propose that it is time to subdivide RA into autoantibody-positive RA (type 1) and autoantibody-negative RA (type 2), in the hope that this leads to stratified treatment in RA.

Reliability of Magnetic Resonance Imaging (MRI) Scoring of the Metatarsophalangeal Joints of the Foot according to the Rheumatoid Arthritis MRI Score.

OBJECTIVE: The Rheumatoid Arthritis Magnetic Resonance Imaging Score (RAMRIS) is validated for hand MRI. Its reliability applied to metatarsophalangeal (MTP 1-5) joints is unknown and was studied in early arthritis and clinically suspect arthralgia. METHODS: Patients underwent 1.5 Tesla MRI of MTP, metacarpophalangeal (MCP 2-5), and wrist joints. Two paired readers scored bone marrow edema (BME), synovitis, tenosynovitis, and erosions. Interreader reliability was assessed of 441 consecutive early arthritis patients at baseline, 215 by 2 readers, and the remaining 226 by 2 different readers. Two readers scored baseline MRI of 82 consecutive patients with clinically suspect arthralgia, and 40 randomly selected patients by 9 readers. Intrareader reliability was determined on a random set of 15 early arthritis patients, scored twice by 2 readers. For change scores, 30 early arthritis patients with baseline and 1-year followup MRI were scored by 2 readers. Intraclass correlation coefficients (ICC), Bland-Altman (BA) plots, and smallest detectable change (SDC) were determined. MRI data of MTP joints were compared to wrist and MCP joints. RESULTS: Interreader ICC and mean scores in early arthritis were BME ICC 0.91-0.92 (mean 1.5 ± SD 2.6), synovitis 0.90-0.92 (1.3 ± 1.7), tenosynovitis 0.80-0.85 (1.1 ± 1.8), and erosions 0.88-0.89 (0.7 ± 1.0). In patients with clinically suspect arthralgia, ICC were comparable. Intrareader ICC for inflammatory MRI features were 0.84-0.98, for erosions 0.71 (reader 1), and 0.92 (reader 2). Change score ICC were ≥ 0.90, except erosions (0.77). SDC were ≤ 1.0. BA plots showed no systematic bias. Reliability scores of MTP joints were similar to MCP and wrist joints. CONCLUSION: Status and change MRI scores of BME, synovitis, tenosynovitis, and erosions of MTP joints can be assessed reliably by RAMRIS.

A search to the target tissue in which RA-specific inflammation starts: a detailed MRI study to improve identification of RA-specific features in the phase of clinically suspect arthralgia.

OBJECTIVE: Based on a unique cohort of clinically suspect arthralgia (CSA) patients, we analysed which combinations of MRI features at onset were predictive for rheumatoid arthritis (RA) development. This was done to increase our comprehension of locations of RA onset and improve the predictive accuracy of MRI in CSA. METHODS: In the discovery cohort, 225 CSA patients were followed on clinical arthritis development. Contrast-enhanced 1.5 T MRIs were made of unilateral metacarpophalangeal (MCP) (2-5), wrist, and metatarsophalangeal (1-5) joints at baseline and scored for synovitis, tenosynovitis, and bone marrow edema. Severity, number, and combinations of locations (joint/tendon/bone) with subclinical inflammation were determined, with symptom-free controls of similar age category as reference. Cox regression was used for predictor selection. Predictive values were determined at 1 year follow-up. Results were validated in 209 CSA patients. RESULTS: In both cohorts, 15% developed arthritis < 1 year. The multivariable Cox model selected presence of MCP-extensor peritendinitis (HR 4.38 (2.07-9.25)) and the number of locations with subclinical inflammation (1-2 locations HR 2.54 (1.11-5.82); ≥ 3 locations HR 3.75 (1.49-9.48)) as predictors. Severity and combinations of inflammatory lesions were not selected. Based on these variables, five risk categories were defined: no subclinical inflammation, 1-2 locations, or ≥ 3 locations, with or without MCP-extensor peritendinitis. Positive predictive values (PPVs) ranged 5% (lowest category; NPV 95%) to 67% (highest category). Similar findings were obtained in the validation cohort; PPVs ranged 4% (lowest category; NPV 96%) to 63% (highest category). CONCLUSION: Tenosynovitis, particularly MCP-extensor peritendinitis, is among the first tissues affected by RA. Incorporating this feature and number of locations with subclinical inflammation improved prediction making with PPVs up to 63-67%.