Patients with obesity have more inflamed joints and higher CRP levels during the disease course in ACPA-positive RA but not in ACPA-negative RA.

BACKGROUND: Obese RA patients have higher disease activity scores (DAS). Previous research showed that obese RA patients have higher tender joint count (TJC) and VAS general health. However, it remains unclear whether DAS components measuring local and systemic inflammation (swollen joint count (SJC), CRP) are increased and if this is present in the total RA population or confined to an ACPA subgroup. As ACPA is suggested to enhance inflammatory responses, we hypothesized that the association of obesity with SJC and CRP is present especially in ACPA-positive RA. We therefore studied associations of obesity with courses of DAS components in ACPA subgroups. METHODS: We studied 649 RA patients (291 ACPA-positive), included in the Leiden Early Arthritis Clinic. Five-year courses of DAS44 and DAS44 components (SJC-44, TJC-53, CRP, VAS (0-100)) were compared between RA patients with normal weight (BMI 18.5-24.9), overweight (25.0-29.9), and obesity (≥ 30.0), stratified for ACPA. Linear/Poisson mixed models with a knot at 4 months were used. RESULTS: Obese RA patients had + 0.32 higher DAS compared to normal weight during the 5-year follow-up. In ACPA-positive RA, obese patients had + 0.43 (95% CI: 0.22, 0.64) higher DAS, whereas in ACPA-negative RA, this difference was smaller and not statistically significant: + 0.19 (95% CI: - 0.01, 0.38). In ACPA-positive RA, all DAS components were significantly higher in obese patients compared to normal weight: SJC + 60% (IRR1.60; 95% CI: 1.18, 2.16), CRP + 3.7 mg/L (95% CI:0.95, 6.53), TJC + 55% (IRR1.55; 95% CI:1.15, 2.10), and VAS + 9 (95% CI: 4.0, 14.2). ACPA-negative obese RA patients tended to have higher TJC (IRR1.22; 95% CI: 0.96, 1.55) and VAS (ß4.3; 95% CI: - 0.4, 9.0), while SJC (IRR1.07; 95% CI:0.85, 1.33) and CRP (ß0.24; 95% CI: - 1.29, 3.32) were unaffected. CONCLUSION: The association of obesity with a worse DAS course is mainly present in ACPA-positive RA; especially SJC and CRP levels remain higher in ACPA-positive RA patients with obesity but not ACPA-negative RA patients. This is the first demonstration that obesity influences the disease course of ACPA-positive and ACPA-negative RA differently.

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

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

Arthroscopic synovectomy versus intra-articular injection of corticosteroids for the management of refractory psoriatic or rheumatoid arthritis of the wrist: study protocol for a randomized controlled trial (ARCTIC trial).

BACKGROUND: Rheumatoid arthritis (RA) and psoriatic arthritis (PsA) are inflammatory diseases that often affect the wrist and, when affected, can lead to impaired wrist function and progressive joint destruction if inadequately treated. Standard care consists primarily of disease-modifying anti-rheumatic drugs (DMARDs), often supported by systemic corticosteroids or intra-articular corticosteroid injections (IACSI). IACSI, despite their use worldwide, show poor response in a substantial group of patients. Arthroscopic synovectomy of the wrist is the surgical removal of synovitis with the goal to relieve pain and improve wrist function. The primary objective of this study is to evaluate wrist function following arthroscopic synovectomy compared to IACSI in therapy-resistant patients with rheumatoid or psoriatic arthritis. Secondary objectives include radiologic progress, disease activity, health-related quality of life, work participation and cost-effectiveness during a 1-year follow-up. METHODS: This protocol describes a prospective, randomized controlled trial. RA and PsA patients are eligible with prominent wrist synovitis objectified by a rheumatologist, not responding to at least 3 months of conventional DMARDs and naïve to biological DMARDs. For 90% power, an expected loss to follow-up of 5%, an expected difference in mean Patient-Rated Wrist Evaluation score (PRWE, range 0-100) of 11 and α = 0.05, a total sample size of 80 patients will be sufficient to detect an effect size. Patients are randomized in a 1:1 ratio for arthroscopic synovectomy with deposition of corticosteroids or for IACSI. Removed synovial tissue will be stored for an ancillary study on disease profiling. The primary outcome is wrist function, measured with the PRWE score after 3 months. Secondary outcomes include wrist mobility and grip strength, pain scores, DAS28, EQ-5D-5L, disease progression on ultrasound and radiographs, complications and secondary treatment. Additionally, a cost-effectiveness analysis will be performed, based on healthcare costs (iMCQ questionnaire) and productivity loss (iPCQ questionnaire). Follow-up will be scheduled at 3, 6 and 12 months. Patient burden is minimized by combining study visits with regular follow-ups. DISCUSSION: Persistent wrist arthritis continues to be a problem for patients with rheumatic joint disease leading to disability. This is the first randomized controlled trial to evaluate the effect, safety and feasibility of arthroscopic synovectomy of the wrist in these patients compared to IACSI. TRIAL REGISTRATION: Dutch trial registry (CCMO), NL74744.100.20. Registered on 30 November 2020. CLINICALTRIALS: gov NCT04755127. Registered after the start of inclusion on 15 February 2021.

Unraveling heterogeneity within ACPA-negative rheumatoid arthritis: the subgroup of patients with a strong clinical and serological response to initiation of DMARD treatment favor disease resolution.

BACKGROUND: Rheumatoid arthritis (RA) is a heterogeneous disease, as evidenced by the differences in long-term outcomes. This applies especially to anti-citrullinated protein antibodies (ACPA)-negative RA, where a proportion achieves sustained DMARD-free remission (SDFR; sustained absence of synovitis after DMARD cessation). Differentiation of RA patients who will achieve SDFR can guide personalized treatment/tapering strategies. Although this subgroup remains scarcely discerned, previous research demonstrated that these RA patients are characterized by an early clinical response (DAS remission after 4 months) after DMARD start. We studied whether, in addition to this clinical response, a specific biomarker response can further distinguish the subgroup of RA patients most likely to achieve SDFR. METHODS: In 266 RA patients, levels of 12 biomarkers (SAA/CRP/MMP-1/MMP-3/resistin/leptin/IL-6/TNF-R1/YKL-40/EGF/VEGF/VCAM-1), in the first 2 years after diagnosis, were studied in relation to SDFR, stratified for ACPA status. Subsequently, biomarkers associated with SDFR development were combined with early DAS remission to study its additional value in defining subgroups. Since most biomarker levels are not routinely measured in clinical practice, we explored how this subgroup can be clinically recognized. RESULTS: ACPA-negative RA patients achieving SDFR were characterized by high baseline levels and stronger decline in MMP-1/MMP-3/SAA/CRP after DMARD-start, respectively 1.30×/1.44×/2.12×/2.24× stronger. This effect was absent in ACPA-positive RA. In ACPA-negative RA, a strong biomarker decline is associated with early DAS remission. The combination of both declines (clinical, biomarker) was present in a subgroup of ACPA-negative RA patients achieving SDFR. This subgroup can be clinically recognized by the combination of high baseline CRP levels (≥ 3 times ULN), and early DAS remission (DAS4 months < 1.6). This latter was replicated in independent ACPA-negative RA patients. CONCLUSIONS: ACPA-negative RA patients with early DAS remission and a strong biomarker response (or baseline CRP levels ≥ 3× ULN) are most likely to achieve SDFR later on. This could guide personalized decisions on DMARD tapering/cessation in ACPA-negative RA.

Value of imaging detected joint inflammation in explaining fatigue in RA at diagnosis and during the disease course: a large MRI study.

OBJECTIVE: Fatigue in rheumatoid arthritis (RA) is hypothesised to be caused by inflammation. Still ~50% of the variance of fatigue in RA cannot be explained by the Disease Activity Score (DAS), nor by background or psychological factors. Since MRI can detect joint inflammation more sensitively than the clinical joint counts as incorporated in the DAS, we hypothesised that inflammation detected by MRI could aid in explaining fatigue in RA at diagnosis and during the follow-up. METHODS: 526 consecutive patients with RA were followed longitudinally. Fatigue was assessed yearly on a Numerical Rating Scale. Hand and foot MRIs were performed at inclusion, after 12 and 24 months in 199 patients and were scored for inflammation (synovitis, tenosynovitis and osteitis combined). We studied whether patients with RA with more MRI-inflammation were more fatigued at diagnosis (linear regression), whether the 2-year course of MRI-inflammation associated with the course of fatigue (linear mixed models) and whether decrease in MRI-inflammation in year 1 associated with subsequent improvement in fatigue in year 2 (cross-lagged models). Similar analyses were done with DAS as inflammation measure. RESULTS: At diagnosis, higher DAS scores were associated with more severe fatigue (p<0.001). However, patients with more MRI-inflammation were not more fatigued (p=0.94). During 2-year follow-up, DAS decrease associated with improvement in fatigue (p<0.001), but MRI-inflammation decrease did not (p=0.96). DAS decrease in year 1 associated with fatigue improvement in year 2 (p=0.012), as did MRI-inflammation decrease (p=0.039), with similar effect strength. CONCLUSION: Sensitive measurements of joint inflammation did not explain fatigue in RA at diagnosis and follow-up. This supports the concept that fatigue in RA is partly uncoupled from inflammation.

Handwork vs machine: a comparison of rheumatoid arthritis patient populations as identified from EHR free-text by diagnosis extraction through machine-learning or traditional criteria-based chart review.

BACKGROUND: Electronic health records (EHRs) offer a wealth of observational data. Machine-learning (ML) methods are efficient at data extraction, capable of processing the information-rich free-text physician notes in EHRs. The clinical diagnosis contained therein represents physician expert opinion and is more consistently recorded than classification criteria components. OBJECTIVES: To investigate the overlap and differences between rheumatoid arthritis patients as identified either from EHR free-text through the extraction of the rheumatologist diagnosis using machine-learning (ML) or through manual chart-review applying the 1987 and 2010 RA classification criteria. METHODS: Since EHR initiation, 17,662 patients have visited the Leiden rheumatology outpatient clinic. For ML, we used a support vector machine (SVM) model to identify those who were diagnosed with RA by their rheumatologist. We trained and validated the model on a random selection of 2000 patients, balancing PPV and sensitivity to define a cutoff, and assessed performance on a separate 1000 patients. We then deployed the model on our entire patient selection (including the 3000). Of those, 1127 patients had both a 1987 and 2010 EULAR/ACR criteria status at 1 year after inclusion into the local prospective arthritis cohort. In these 1127 patients, we compared the patient characteristics of RA cases identified with ML and those fulfilling the classification criteria. RESULTS: The ML model performed very well in the independent test set (sensitivity=0.85, specificity=0.99, PPV=0.86, NPV=0.99). In our selection of patients with both EHR and classification information, 373 were recognized as RA by ML and 357 and 426 fulfilled the 1987 or 2010 criteria, respectively. Eighty percent of the ML-identified cases fulfilled at least one of the criteria sets. Both demographic and clinical parameters did not differ between the ML extracted cases and those identified with EULAR/ACR classification criteria. CONCLUSIONS: With ML methods, we enable fast patient extraction from the huge EHR resource. Our ML algorithm accurately identifies patients diagnosed with RA by their rheumatologist. This resulting group of RA patients had a strong overlap with patients identified using the 1987 or 2010 classification criteria and the baseline (disease) characteristics were comparable. ML-assisted case labeling enables high-throughput creation of inclusive patient selections for research purposes.

Early DAS response after DMARD-start increases probability of achieving sustained DMARD-free remission in rheumatoid arthritis.

BACKGROUND: Sustained DMARD-free remission (SDFR) is increasingly achievable. The pathogenesis underlying SDFR development is unknown and patient characteristics at diagnosis poorly explain whether SDFR will be achieved. To increase the understanding, we studied the course of disease activity scores (DAS) over time in relation to SDFR development. Subsequently, we explored whether DAS course could be helpful identifying RA patients likely to achieve SDFR. METHODS: 772 consecutive RA patients, promptly treated with csDMARDs (mostly methotrexate and treat-to-target treatment adjustments), were studied for SDFR development (absence of synovitis, persisting minimally 12 months after DMARD stop). The course of disease activity scores (DAS) was compared between RA patients with and without SDFR development within 7 years, using linear mixed models, stratified for ACPA. The relation between 4-month DAS and the probability of SDFR development was studied with logistic regression. Cumulative incidence of SDFR within DAS categories (< 1.6, 1.6-2.4, 2.4-3.6, ≥ 3.6) at 4 months was visualized using Kaplan-Meier curves. RESULTS: In ACPA-negative RA patients, those achieving SDFR showed a remarkably stronger DAS decline within the first 4 months, compared to RA patients without SDFR; - 1.73 units (95%CI, 1.28-2.18) versus - 1.07 units (95%CI, 0.90-1.23) (p < 0.001). In APCA-positive RA patients, such an effect was not observed, yet SDFR prevalence in this group was low. In ACPA-negative RA, DAS decline in the first 4 months and absolute DAS levels at 4 months (DAS4 months) were equally predictive for SDFR development. Incidence of SDFR in ACPA-negative RA patients was high (70.2%) when DAS4 months was < 1.6, whilst SDFR was rare (7.1%) when DAS4 months was ≥ 3.6. CONCLUSIONS: In ACPA-negative RA, an early response to treatment, i.e., a strong DAS decline within the first 4 months, is associated with a higher probability of SDFR development. DAS values at 4 months could be useful for later decisions to stop DMARDs.

DMARD-free remission as novel treatment target in rheumatoid arthritis: A systematic literature review of achievability and sustainability.

OBJECTIVES: Although current treatment guidelines for rheumatoid arthritis (RA) suggest tapering disease-modifying anti-rheumatic drugs (DMARDs), it is unclear whether DMARD-free remission (DFR) is an achievable and sustainable outcome. Therefore, we systematically reviewed the literature to determine the prevalence and sustainability of DFR and evaluated potential predictors for DFR. METHODS: A systematic literature search was performed in March 2019 in multiple databases. All clinical trials and observational studies reporting on discontinuation of DMARDs in RA patients in remission were included. Our quality assessment included a general assessment and assessment of the description of DFR. Prevalence of DFR and its sustainability and flares during tapering and after DMARD stop were summarised. Also, potential predictors for achieving DFR were reviewed. RESULTS: From 631 articles, 51 were included, comprising 14 clinical trials and 5 observational studies. DFR definition differed, especially for the duration of DMARD-free state. Considering only high- and moderate-quality studies, DFR was achieved in 5.0%-24.3% and sustained DFR (duration>12 months) in 11.6%-19.4% (both relative to the number of patients eligible for tapering). Flares occurred frequently during DMARD tapering (41.8%-75.0%) and in the first year after achieving DFR (10.4%-11.8%), while late flares, >1 year after DMARD-stop, were infrequent (0.3%-3.5%). Many patient characteristics lacked association with DFR. Absence of autoantibodies and shared epitope alleles increased the chance of achieving DFR. CONCLUSIONS: DFR is achievable in RA and is sustainable in ~10%-20% of patients. DFR can become an important outcome measure for clinical trials and requires consistency in the definition. Considering the high rate of flares in the first year after DMARD stop, a DMARD-free follow-up of >12 months is advisable to evaluate sustainability.

The impact of a disease flare during tapering of DMARDs on the lives of rheumatoid arthritis patients.

OBJECTIVES: To determine the impact of a disease flare on patient reported outcome measures (PROMs) in rheumatoid arthritis (RA) patients, who are tapering treatment. METHODS: Data were used from the TARA trial; a multicenter, randomized controlled trial in which RA patients, with a well-controlled disease (DAS≤2.4 and SJC≤1) for at least 6 months, gradually tapered their DMARDs. PROMs of patients with a flare (DAS>2.4 and/or SJC>1) were compared every three months before and after a flare with their own norm values. Linear Mixed Models were used to investigate whether a disease flare influenced functional ability (HAQ-DI), fatigue (BRAF-MDQ), quality of life (EQ-5D and SF36), anxiety and depression (HADS), morning stiffness, general health (GH) and worker productivity, and if so, the duration was determined. For unemployment and sick leave we used descriptive statistics. RESULTS: A flare negatively influenced GH, morning stiffness, HAQ-DI, EQ-5D, BRAF-MDQ, and the SF36 physical component scale and this effect lasted >3 months. Except for the HAQ-DI, effect sizes exceeded the minimum clinically important differences (MCIDs). For the physical outcomes effects lasted >6 months. Worker productivity was not significantly affected by a flare. CONCLUSION: A disease flare influenced patients' lives, the largest effect was seen in the physical outcomes, and lasted 6 months. Although on a group level effect sizes for the separate PROMs were not always significant or larger than specific MCIDs, a disease flare can still be of great importance for individual patients.

Does treatment strategy influence the ability to achieve and sustain DMARD-free remission in patients with RA? Results of an observational study comparing an intensified DAS-steered treatment strategy with treat to target in routine care.

OBJECTIVES: To study the impact of treatment strategy on achieving and sustaining disease-modifying antirheumatic drug (DMARD)-free remission in patients with rheumatoid arthritis (RA). METHODS: Two hundred seventy-nine RA patients (median follow-up 7.8 years) were studied. Of these, 155 patients participated in a disease activity score (DAS) < 1.6 steered trial aimed at DMARD-free remission. Initial treatment comprised methotrexate with high-dose prednisone (60 mg/day) and a possibility to start biologicals after 4 months. In the same period and hospital, 124 patients were treated according to routine care, comprising DAS < 2.4 steered treatment. Percentages of DMARD-free remission (absence of synovitis for ≥ 1 year after DMARD cessation), late flares (recurrence of clinical synovitis ≥ 1 year after DMARD cessation), and DMARD-free sustained remission (DMARD-free remission sustained during complete follow-up) were compared between both treatment strategies. RESULTS: Patients receiving intensive treatment were younger and more often ACPA-positive. On a group level, there was no significant association between intensive treatment and DMARD-free remission (35% vs 29%, corrected hazard ratio (HR) 1.4, 95%CI 0.9-2.2), nor in ACPA-negative RA (49% versus 44%). In ACPA-positive RA intensive treatment resulted in more DMARD-free remission (25% vs 6%, corrected HR 4.9, 95%CI 1.4-17). Intensive treatment was associated with more late flares (20% versus 8%, HR 2.3, 95%CI 0.6-8.3). Subsequently, there was no difference in DMARD-free sustained remission on a group level (28% versus 27%), nor in the ACPA-negative (43% versus 42%) or ACPA-positive stratum (17% versus 6%, corrected HR 3.1, 95%CI 0.9-11). CONCLUSIONS: Intensive treatment did not result in more DMARD-free sustained remission, compared to routine up-to-date care. The data showed a tendency towards an effect of intensive treatment in ACPA-positive RA; this needs further investigation.

What is the additional value of MRI of the foot to the hand in undifferentiated arthritis to predict rheumatoid arthritis development?

BACKGROUND: MRI-detected subclinical joint inflammation in the hand joints of patients with undifferentiated arthritis (UA) predicts progression to rheumatoid arthritis (RA). It is unknown if adding MRI of the foot increases predictive accuracy compared to the hand alone. METHODS: 1.5-T contrast-enhanced MRI of the unilateral foot (MTP-1-5) and hand (MCP-2-5 and wrist) was performed in 123 patients presenting with UA (not fulfilling the 2010 RA criteria) and scored for bone marrow edema (BME), synovitis and tenosynovitis. Symptom-free controls (n = 193) served as a reference for defining an abnormal MRI. Patients were followed for RA development ≤ 1 year, defined as fulfilling the classification criteria or initiation of disease-modifying antirheumatic drugs because of the expert opinion of RA. The added predictive value of foot MRI to hand MRI was evaluated. RESULTS: Fifty-two percent developed RA. Foot tenosynovitis was predictive (OR 2.55, 95% CI 1.01-6.43), independent of BME and synovitis (OR 3.29, 95% CI 1.03-10.53), but not independent of CRP and number of swollen joints (OR 2.14, 95% CI 0.77-5.95). Hand tenosynovitis was also predictive independent of BME and synovitis (OR 3.99, 95% CI 1.64-9.69) and independent of CRP and swollen joints (OR 2.36, 95% CI 1.04-5.38). Adding foot tenosynovitis to hand tenosynovitis changed the sensitivity from 72 to 73%, specificity from 59 to 54% and AUC from 0.66 to 0.64; the net reclassification index was - 3.5. CONCLUSION: MRI-detected tenosynovitis of the foot predicts progression to RA. However, adding MRI of the foot does not improve the predictive accuracy compared to MRI of the hand alone. In view of cost reduction, the performance of foot MRI for prognostic purposes in UA can be omitted.

Sequence of joint tissue inflammation during rheumatoid arthritis development.

OBJECTIVE: Subclinical joint inflammation in patients with arthralgia is predictive for progression to rheumatoid arthritis (RA). However, the time course of progression for bone marrow edema (osteitis), synovitis, and/or tenosynovitis is unsettled. This longitudinal study assessed the course of magnetic resonance imaging (MRI)-detected subclinical joint inflammation during progression to RA. METHODS: Patients that progressed from clinically suspect arthralgia (CSA) to RA underwent 1.5-T MRI of the metacarpophalangeal (MCP), wrist, and metatarsophalangeal (MTP) joints at presentation with arthralgia and at first identification of synovitis assessed through physical examination (n = 31). MRIs were evaluated for osteitis, synovitis, tenosynovitis, and erosions by two readers, blinded for clinical data and order in time. To estimate changes in MRI scores between the asymptomatic state and CSA onset, scores of MRI features at CSA baseline were compared with scores from age-matched symptom-free persons. RESULTS: At presentation with CSA, synovitis and tenosynovitis scores were higher than scores from age-matched symptom-free persons (p = 0.004 and p = 0.001, respectively). Anti-citrullinated protein antibody (ACPA)-positive arthralgia patients also had increased osteitis scores (p = 0.04). Median duration between presentation with arthralgia and RA development was 17 weeks. During progression to RA, synovitis and osteitis increased significantly (p = 0.001 and p = 0.036, respectively) in contrast to tenosynovitis and erosion scores. This pattern was similar in both ACPA subsets, although statistical significance was reached for synovitis and osteitis in ACPA-negative but not ACPA-positive RA. CONCLUSION: Increased tenosynovitis and synovitis scores at CSA onset and the increase in synovitis and osteitis during progression to RA suggest an 'outside-in' temporal relationship of arthritis development, in particular for ACPA-negative RA. For ACPA-positive RA, further studies are needed.

Inflammation functions as a key mediator in the link between ACPA and erosion development: an association study in Clinically Suspect Arthralgia.

BACKGROUND: Anti-citrullinated protein antibodies (ACPA) are associated with more severe joint erosions in rheumatoid arthritis (RA), but the underlying mechanism is unclear. Recent in vitro and murine studies indicate that ACPAs can directly activate osteoclasts leading to bone erosions and pain. This study sought evidence for this hypothesis in humans and evaluated whether in patients with arthralgia who are at risk of RA, ACPA is associated with erosions (detected by magnetic resonance imaging (MRI)) independent of inflammation, and also independent of the presence of rheumatoid factor (RF). METHODS: Patients with Clinically Suspect Arthralgia (n = 507) underwent determination of ACPA and RF and 1.5 T contrast-enhanced MRI of the metacarpophalangeal, wrist and metatarsophalangeal joints at baseline. MRIs were scored for presence of local inflammation and erosions. Comparisons of erosion scores were performed using the Kruskal-Wallis test. To evaluate if inflammation is, in statistical terms, intermediary in the causal path of ACPA and erosions, three-step mediation analysis was performed using linear regression. RESULTS: ACPA-positive patients had higher erosion scores than ACPA-negative patients (p = 0.006). ACPA-positive patients without subclinical inflammation did not have higher erosion scores than ACPA-negative patients (p = 0.68), in contrast to ACPA-positive patients with local inflammation (p < 0.001). Mediation analyses suggested that local inflammation is in the causal path of ACPA leading to higher erosion scores. Compared to ACPA-negative/RF-negative patients, ACPA-positive/RF-negative patients did not differ (p = 0.30), but ACPA-positive/RF-positive patients had higher erosion scores (p = 0.006). CONCLUSIONS: The effect of ACPA on erosions is mediated by inflammation and is not independent of RF.

Does the presence of magnetic resonance imaging-detected osteitis at diagnosis with rheumatoid arthritis lower the risk for achieving disease-modifying antirheumatic drug-free sustained remission: results of a longitudinal study.

BACKGROUND: Although infrequent, some rheumatoid arthritis (RA) patients achieve disease-modifying antirheumatic drug (DMARD)-free sustained remission. The absence of RA-specific autoantibodies, such as anticitrullinated protein antibodies (ACPA), is known to be associated with this outcome but further mechanisms underlying the chronic nature of RA are largely unknown. Magnetic resonance imaging (MRI)-detected bone marrow edema (BME), or osteitis, strongly predicts erosive progression and is associated with ACPA positivity. Therefore, we hypothesized that the presence of MRI-detected osteitis is also predictive of not achieving DMARD-free sustained remission and that the presence of osteitis mediates the association between ACPA and DMARD-free sustained remission. METHODS: A 1.5 T unilateral hand and foot MRI was performed at disease presentation in 238 RA patients, evaluating BME, synovitis, and tenosynovitis (summed as MRI inflammation score). DMARD-free sustained remission, defined as the absence of clinical synovitis after DMARD cessation that persisted during the total follow-up, was assessed (median follow-up 3.8 years). Associations between the different MRI-detected inflammatory features and this outcome were studied. A mediation analysis was performed to study whether the presence of BME mediated the association between ACPA and DMARD-free sustained remission. Finally, patterns of MRI-detected inflammation with regard to DMARD-free sustained remission were studied using partial least squares (PLS) regression. RESULTS: Forty-six (19.3%) patients achieved DMARD-free sustained remission. ACPA positivity associated independently with remission (hazard ratio (HR) 0.16, 95% confidence interval (CI) 0.06-0.39). In contrast, no associations were observed between MRI-detected BME (HR 0.99, 95% CI 0.94-1.03), or other MRI inflammatory features, and achieving DMARD-free sustained remission. Thus, the presence of BME did not mediate the association between ACPA and DMARD-free sustained remission. Furthermore, a PLS analysis revealed that patients who did or did not achieve remission could not be distinguished by patterns of MRI-detected inflammation. CONCLUSIONS: At disease presentation, osteitis, as well as other MRI-detected inflammatory features, was not associated with achieving DMARD-free sustained remission over time. Thus, imaging predictors for joint damage and disease persistence differ. The processes mediating RA chronicity remain largely unsolved.

Inflammatory genes TNFα and IL6 display no signs of increased H3K4me3 in circulating monocytes from untreated rheumatoid arthritis patients.

Innate immune cells, such as monocytes, can adopt a long-lasting pro-inflammatory phenotype, a phenomenon called 'trained immunity'. In trained immunity, increased cytokine levels of genes, like interleukin (IL)-6 and tumor necrosis factor (TNF)-α, are observed, which are associated with increased histone 3 lysine 4 trimethylation (H3K4me3) in the promoter region. As systemic IL6 and TNFα levels are increased in rheumatoid arthritis (RA) patients and monocytes are known to be the primary producers of TNFα and IL6, we hypothesized that 'trained immunity' signals may be observed at these genes in monocytes from RA patients. CD14+ monocytes were isolated from untreated RA patients and paired age-matched healthy controls. H3K4me3, mRNA, protein and serum levels of IL6 and TNFα were evaluated by chromatin immunoprecipitation, reverse-transcription quantitative PCR and enzyme-linked immunosorbent assays. Despite elevated serum levels of TNFα and IL6 in the tested RA patients (P<0.05), ex vivo isolated monocytes displayed similar H3K4me3 levels to healthy controls in the promoter region of TNFα and IL6. Concordantly, mRNA and protein levels of IL6 and TNFα were similar before and after lipopolysaccharide stimulation between patients and controls. Together, with the current number of individuals tested we have not detected enhanced trained immunity signals in circulating monocytes from untreated RA patients, despite increased IL6 and TNFα serum levels.

Rheumatoid arthritis phenotype at presentation differs depending on the number of autoantibodies present.

OBJECTIVES: In rheumatoid arthritis (RA), seropositive and seronegative disease may be two entities with different underlying pathophysiological mechanisms, long-term outcomes and disease presentations. However, the effect of the conjoint presence of multiple autoantibodies, as proxy for a more pronounced humoral autoimmune response, on clinical phenotype remains unclear. Therefore, this study investigates the association between the number of autoantibodies and initial clinical presentation in two independent cohorts of patients with early RA. METHODS: Autoantibody status (rheumatoid factor, anticitrullinated protein antibodies and anticarbamylated protein antibodies) was determined at baseline in the Leiden Early Arthritis Cohort (n=828) and the Swedish BARFOT (Better Anti-Rheumatic Farmaco-Therapy, n=802) study. The association between the number of autoantibodies and baseline clinical characteristics was investigated using univariable and multivariable ordinal regression. RESULTS: In both cohorts, the following independent associations were found in multivariable analysis: patients with a higher number of RA-associated antibodies were younger, more often smokers, had a longer symptom duration and a higher erythrocyte sedimentation rate at presentation compared with patients with few autoantibodies. CONCLUSIONS: The number of autoantibodies, reflecting the breadth of the humoral autoimmune response, is associated with the clinical presentation of RA. Predisease pathophysiology is thus reflected by the initial clinical phenotype.