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.

Persistently activated, proliferative memory autoreactive B cells promote inflammation in rheumatoid arthritis.

Autoreactive B cells mediate autoimmune pathology, but exactly how remains unknown. A hallmark of rheumatoid arthritis (RA), a common autoimmune disease, is the presence of disease-specific anticitrullinated protein antibodies (ACPAs). Here, we showed that ACPA-positive B cells in patients with RA strongly expressed T cell-stimulating ligands, produced abundant proinflammatory cytokines, and were proliferative while escaping inhibitory signals. This activated state was found at different degrees in different stages of disease: highest in patients with recent-onset RA, moderate in patients with established RA, and far less pronounced in ACPA-positive individuals "at risk" for developing disease. The activated autoreactive B cell response persisted in patients who achieved clinical remission with conventional treatment. ACPA-positive B cells in blood and synovial fluid secreted increased amounts of the chemoattractant interleukin-8, which attracted neutrophils, the most abundant immune cell in arthritic joints. Tetanus toxoid-specific B cells from the same patients exhibited properties of memory B cells without the activation and proliferation phenotype, but these cells transiently acquired a similar proliferative phenotype upon booster vaccination. Together, these data indicated that continuous antigenic triggering of autoreactive B cells occurs in human autoimmune disease and support the emerging concept of immunological activity that persists under treatment even in clinical remission, which may revise our current concept of treatment targets for future therapeutic interventions. In addition, our data pointed to a pathogenic role of ACPA-positive B cells in the inflammatory disease process underlying RA and favor approaches that aim at their antigen-specific inactivation or depletion.

Improvement of symptoms in clinically suspect arthralgia and resolution of subclinical joint inflammation: a longitudinal study in patients that did not progress to clinical arthritis.

INTRODUCTION: Arthralgia and MRI-detected subclinical inflammation can precede the development of clinically evident rheumatoid arthritis (RA). However, part of the patients presenting with clinically suspect arthralgia (CSA) do not progress to RA. In these 'non-progressors', we aimed to study the frequencies of spontaneous improvement of arthralgia and its relation with the course of subclinical inflammation. METHODS: Between April 2012 and April 2015, 241 patients were considered at risk for RA based on the clinical presentation and included in the CSA cohort. One hundred fifty-two patients with complete data on clinical follow-up did not develop clinical arthritis, of which 98 underwent serial 1.5T MRI scans (wrist, MCP2-5, and MTP1-5 joints) at baseline and after 2 years. MRI scans were scored for synovitis, tenosynovitis, and bone marrow oedema (summed: MRI inflammation score). MRI scores were compared to scores of symptom-free persons. RESULTS: After a 2-year follow-up, 33% of the 'non-progressors' had complete resolution of symptoms; 67% had no symptom resolution and were diagnosed as persistent CSA (44%), osteoarthritis (10%), and tendinomuscular complaints (13%). With symptom-free controls as a reference, patients without resolution did not have increased MRI scores at any time point. However, patients achieving resolution of symptoms had increased MRI inflammation scores at baseline (4.0 vs. 2.6, p = 0.037), but not after 2 years (3.0 vs. 2.6; p = 0.57), and during follow-up, their MRI inflammation score decreased significantly (p = 0.036). CONCLUSIONS: A subgroup of CSA patients that did not progress to RA had spontaneous improvement of symptoms and resolution of subclinical joint inflammation. This time relationship suggests that symptoms and inflammation were causally related in these patients. Further research is needed to identify the mechanisms underlying the resolution of inflammation.

Do musculoskeletal ultrasound and magnetic resonance imaging identify synovitis and tenosynovitis at the same joints and tendons? A comparative study in early inflammatory arthritis and clinically suspect arthralgia.

OBJECTIVE: Ultrasound (US) and magnetic resonance imaging (MRI) are recommended in the diagnostic process of rheumatoid arthritis. Research on its comparability in early disease phases is scarce. Therefore, we compared synovitis and tenosynovitis detected by US and MRI on joint/tendon level. METHODS: Eight hundred forty joints and 700 tendons of 70 consecutive patients, presenting with inflammatory arthritis or clinically suspect arthralgia, underwent US and MRI of MCP (2-5), wrist and MTP (1-5) joints at the same day. Greyscale (GS) and power Doppler (PD) synovitis were scored according to the modified Szkudlarek method (combining synovial effusion and hypertrophy) and the recently published EULAR-OMERACT method (synovial hypertrophy regardless of the presence of effusion) on static images. US-detected tenosynovitis was scored according to the OMERACT. MRI scans were scored according to the RAMRIS. Test characteristics were calculated on joint/tendon level with MRI as reference. Cut-off for US scores were ≥ 1 and ≥ 2 and for MRI ≥ 1. RESULTS: Compared to MRI, GS synovitis according to EULAR-OMERACT (cut-off ≥ 1) had a sensitivity ranging from 29 to 75% for the different joint locations; specificity ranged from 80 to 98%. For the modified Szkudlarek method, the sensitivity was 68-91% and specificity 52-71%. PD synovitis had a sensitivity of 30-54% and specificity 97-99% compared to MRI. The sensitivity to detect GS tenosynovitis was 50-78% and the specificity 80-94%. For PD tenosynovitis, the sensitivity was 19-58% and specificity 98-100%. CONCLUSION: Current data showed that US is less sensitive than MRI in the early detection of synovitis and tenosynovitis, but resulted in only few non-specific findings. The higher sensitivity of MRI is at the expense of less accessibility and higher costs.

Development and validation of a clinical rule for recognition of early inflammatory arthritis.

OBJECTIVES: National and international guidelines recommend prompt referral of patients presenting with inflammatory arthritis (IA), but general practitioners (GPs) feel uncertain in their proficiency to detect synovitis through joint examination, the method of choice to identify IA. Our objective was to develop and validate a rule composed of clinical characteristics to assist GPs and other physicians in identifying IA when in doubt. DESIGN: Split-sample derivation and validation study. SETTING: The Leiden Early Arthritis Recognition Clinic (EARC), a screening clinic for patients in whom GPs suspected but were unsure of the presence of IA. PARTICIPANTS: 1288 consecutive patients visiting the EARC. PRIMARY AND SECONDARY OUTCOME MEASURES: Associations of clinical characteristics with presence of IA were determined using logistic regression in 644 patients, while validating the results in the other 644 patients (split-sample validation). To facilitate application in clinical practice, a simplified rule (with scores ranging from 0 to 7.5) was derived and validated. RESULTS: IA was identified by a rheumatologist in 41% of patients. In univariable analysis, male gender, age ≥60 years, symptom duration <6 weeks, morning stiffness >60 min, a low number of painful joints (1-3 joints), presence of patient-reported joint swelling and difficulty with making a fist were associated with IA in the derivation data set. Using multivariable analysis, a simplified rule consisting of these seven items was derived and validated, yielding an area under the receiver operator characteristic curve (AUC) of 0.74 (95% CI 0.70 to 0.78) in the derivation data set. Validation yielded an AUC of 0.71 (95% CI 0.67 to 0.75). Finally, the model was repeated to study predicted probabilities with a lower prevalence of inflammatory arthritis to simulate performance in primary care settings. CONCLUSIONS: Our rule, composed of clinical parameters, had reasonable discriminative ability for IA and could assist physicians in decision-making in patients with suspected IA, increasing appropriateness of healthcare utilisation.

Identifying MRI-detected inflammatory features specific for rheumatoid arthritis: two-fold feature reduction maintains predictive accuracy in clinically suspect arthralgia patients.

OBJECTIVE: MRI-detected inflammation is considered of diagnostic value for rheumatoid arthritis (RA), but its evaluation involves a time-consuming scoring of 61 joint-level features. It is not clear, however, which of these features are specific for RA and whether evaluating a subset of specific features is sufficient to differentiate RA patients. This study aimed to identify a subset of RA-specific features in a case-control setting and validate them in a longitudinal cohort of arthralgia patients. METHODS: The difference in frequency of MRI-detected inflammation (bone marrow edema, synovitis, and tenosynovitis) between 199 RA patients and 193 controls was studied in 61 features across the wrist, metacarpophalangeal, and metatarsophalangeal joints. A subset of RA-specific features was obtained by applying a cutoff on the frequency difference while maximizing discriminative performance. For validation, this subset was used to predict arthritis development in 225 clinically suspect arthralgia (CSA) patients. Diagnostic performance was compared to a reference method that uses the complete set of 61 features normalized for inflammation levels in age-matched controls. RESULTS: Subset of 30 features, mainly (teno)synovitis, was obtained from the case-control setting. Validation in CSA patients yielded an area of 0.69 (95% CI: 0.59-0.78) under the ROC curve and a positive predictive value (PPV) of 31%, compared to 0.68 (95% CI: 0.60-0.77) and 29% PPV of the reference method with 61 features. CONCLUSION: Subset of 30 MRI-detected inflammatory features, dominated by (teno)synovitis, offers a considerable reduction of scoring efforts without compromising accuracy for prediction of arthritis development in CSA patients.

Is joint pain in patients with arthralgia suspicious for progression to rheumatoid arthritis explained by subclinical inflammation? A cross-sectional MRI study.

Objectives: The development of RA includes a phase of arthralgia preceding clinical arthritis. The aetiology of symptoms of arthralgia is unclear. Since subclinical joint inflammation is expected to be causally related to pain, we aimed to study associations between subclinical MRI-detected inflammation and pain in patients with arthralgia suspicious for progression to RA. Methods: Unilateral MRIs of the wrist, MCP (2-5) and MTP (1-5) joints of 325 patients who fulfilled the EULAR definition of arthralgia suspicious for progression to RA were scored by two readers on subclinical inflammation (synovitis, bone marrow oedema and tenosynovitis). Associations between MRI-detected inflammation and overall pain severity at patient level (measured using the visual analogue scale), as well as with local joint tenderness, were studied. Analyses were stratified for ACPA. Results: At patient level, synovitis (ß = 0.10, P = 0.048) and tenosynovitis (ß = 0.11, P = 0.026) associated with the visual analogue scale pain. Of the 1620 imaged joints, 447 (28%) were tender. MRI-detected synovitis associated independently with joint tenderness in all patients (odds ratio 1.74, P < 0.001), and in the ACPA-negative stratum (odds ratio 1.96, P < 0.001). In the ACPA-positive stratum only bone marrow oedema (osteitis) was independently associated with tenderness (odds ratio 2.39, P = 0.005). Sensitivity analyses in patients who developed inflammatory arthritis during follow-up (n = 61) revealed similar associations. Subclinical inflammation was present in 51% of tender joints and 39% of non-tender joints. Conclusion: In patients with arthralgia suspicious for progression to RA, MRI-detected subclinical inflammation is associated with overall pain and local joint tenderness. However, the association is partial, indicating that subclinical inflammation is not the sole explanation of the arthralgia.

Development of clinically apparent synovitis: a longitudinal study at the joint level during progression to inflammatory arthritis.

INTRODUCTION: Subclinical inflammation, detected by MRI, in patients with arthralgia is predictive for development of inflammatory arthritis (IA). However, within patients that develop IA, the course of inflammation at the joint level during this transition is unknown. This longitudinal study assessed progression of inflammation at the joint level. METHODS: 350 joints (unilateral metacarpophalangeals (MCPs), wrist, metatarsophalangeal (MTP) joints) of 35 patients presenting with clinically suspect arthralgia (CSA) that progressed to IA were studied at presentation with CSA and subsequently when clinical synovitis was first identified at joint examination (median time interval 17 weeks). At both time points, subclinical inflammation (bone marrow oedema, synovitis, tenosynovitis) was evaluated with MRI and joint examination was performed. RESULTS: At presentation with CSA, 71 joints showed subclinical inflammation. During progression to IA, 20% of these joints had resolution of inflammation, 60% had persistent inflammation and 20% progressed to clinical synovitis. Of all joints that had developed clinical synovitis (n = 45), no prior subclinical inflammation was detected in 69%. Similar results were observed for anticitrullinated protein antibodies (ACPA)-positive and ACPA-negative patients. CONCLUSIONS: This longitudinal study demonstrated moderate correlations between joints with subclinical inflammation and joints that developed clinical synovitis. These data imply that IA development is a more systemic rather than a locally outgrowing process.

Does psychological stress in patients with clinically suspect arthralgia associate with subclinical inflammation and progression to inflammatory arthritis?

BACKGROUND: Within established rheumatoid arthritis (RA), stress can have pro-inflammatory effects by activating the immune system via the hypothalamic-pituitary-adrenal axis and the autonomic nervous system. It is unknown if stress levels also promote inflammation during RA development. We studied whether the psychological stress response was increased in clinically suspect arthralgia (CSA) and if this associated with inflammation at presentation with arthralgia and with progression to clinical arthritis. METHODS: In 241 CSA patients, psychological stress was measured by the Mental Health Inventory (MHI-5) and the Perceived Stress Scale (PSS-10) at first presentation and during follow-up. Systemic inflammation was measured by C-reactive protein (CRP) and joint inflammation by 1.5 T-MRI of wrist, MCP, and MTP joints. RESULTS: At baseline, 12% (24/197) of CSA patients had a high psychological stress response according to the MHI-5. This was not different for patients presenting with or without an elevated CRP, with or without subclinical MRI-detected inflammation and for patients who did or did not develop arthritis. Similar findings were obtained with the PSS-10. When developing clinical arthritis, the percentage of patients with 'high psychological stress' increased to 31% (p = 0.025); during the first year of treatment this decreased to 8% (p = 0.020). 'High psychological stress' in non-progressors remained infrequent over time (range 7-13%). Stress was associated with fatigue (p = 0.003) and wellbeing (p < 0.001). CONCLUSIONS: Psychological stress was not increased in the phase of arthralgia, raised at the time of diagnoses and decreased thereafter. The lack of an association with inflammation in arthralgia and this temporal relationship, argue against psychological stress having a significant contribution to progression from CSA to inflammatory arthritis.

Validation of the EULAR definition of arthralgia suspicious for progression to rheumatoid arthritis.

Objectives: Recently a EULAR-taskforce defined arthralgia suspicious for progression to RA, in order to allow inclusion of homogeneous sets of arthralgia patients in clinical studies. This longitudinal study aimed (i) to validate this definition in arthralgia patients in whom rheumatologists felt that imminent RA was more likely than other arthralgias [clinically suspect arthralgia (CSA)], that is, the target population fulfilling the entry criterion, and (ii) to explore the performance in arthralgia patients who were referred to secondary care prior to rheumatological evaluation, hence ignoring the entry criterion. Methods: The definition was assessed in 241 Dutch patients identified with CSA by rheumatologists and 113 patients referred to the Umeå university hospital with recent-onset arthralgia in small joints. The external reference was arthritis development <2 years' follow-up. Results: CSA patients with a positive definition (⩾3/7 parameters present) had an increased risk for developing arthritis compared with definition-negative CSA patients (hazard ratio = 2.1, 95% CI: 0.9, 4.7). The sensitivity was 84% and the positive predictive value 30%. In arthralgia patients in whom the definition was applied before rheumatological evaluation, a positive definition was neither sensitive (10%) nor predictive (positive predictive value 3%). Conclusion: The EULAR definition of arthralgia suspicious for progression to RA is sensitive when used to support the rheumatologist's opinion on imminent RA. This validation study shows that the definition, when used as designed, further homogenizes patients that rheumatologists consider at risk for RA. To arrive at a high specificity, the clinical definition needs to be combined with biomarkers.

The risk of individual autoantibodies, autoantibody combinations and levels for arthritis development in clinically suspect arthralgia.

Objectives: Autoantibody testing is helpful for predicting the risk of progression to clinical arthritis in subjects at risk. Previous longitudinal studies have mainly selected autoantibody-positive arthralgia patients, and consequently the predictive values of autoantibodies were evaluated relative to one another. This study assessed the risks for arthritis development of ACPA, RF and/or anti-carbamylated protein antibodies (anti-CarP) in arthralgia patients considered at risk for RA by rheumatologists, based on clinical characteristics (clinically suspect arthralgia, CSA). Methods: The baseline ACPA, RF and anti-CarP autoantibody status of 241 patients, consecutively included in the CSA cohort, was studied for risk of developing clinical arthritis during a median follow-up of 103 (interquartile range: 81-114) weeks. Results: Univariable associations for arthritis development were observed for ACPA, RF and anti-CarP antibodies; hazard ratios (HRs) (95% CI) were 8.5 (4.7-15.5), 5.1 (2.8-9.3) and 3.9 (1.9-7.7), respectively. In multivariable analysis, only ACPA was independently associated (HR = 5.1; 2.0-13.2). Relative to autoantibody-negative CSA patients, ACPA-negative/RF-positive patients had HRs of 2.6 (1.04-6.6), ACPA-positive/RF-negative patients 8.0 (2.4-27.4) and ACPA-positive/RF-positive patients 10.5 (5.4-20.6). Positive predictive values for development of clinical arthritis within 2 years were: 38% for ACPA-negative/RF-positive, 50% for ACPA-positive/RF-negative and 67% for ACPA-positive/RF-positive patients. Higher ACPA levels were not significantly associated with increased progression to clinical arthritis, in contrast to higher RF levels. Autoantibody levels were stable during follow-up. Conclusion: ACPA conferred the highest risk for arthritis development and had an additive value to RF. However, >30% of ACPA-positive/RF-positive CSA patients did not develop arthritis during the 2-year follow-up. Thus, CSA and information on autoantibodies is insufficient for accurately identifying imminent autoantibody-positive RA.

Using a reference when defining an abnormal MRI reduces false-positive MRI results-a longitudinal study in two cohorts at risk for rheumatoid arthritis.

Objectives: The use of hand and foot MRI in the diagnostic process of RA has been advocated. Recent studies showed that MRI is helpful in predicting progression from clinically suspect arthralgia (CSA) to clinical arthritis, and from undifferentiated arthritis (UA) to RA. Symptom-free persons can also show inflammation on MRI. This study aimed to evaluate if MRI findings in symptom-free volunteers are relevant when defining a positive MRI. Methods: Two hundred and twenty-five CSA patients and two hundred and one UA patients underwent MRI of MCP, wrist and MTP joints at baseline and were followed for 1 year on progression to arthritis and RA, respectively, as reported previously. MRI was considered positive if ⩾ 1 joint showed inflammation (called uncorrected definition), or if ⩾ 1 joint had inflammation that was present in < 5% of persons of the same age category at the same location (called 5% corrected definition). Test characteristics were compared for both definitions. Results: By using MRI data of symptom-free volunteers as reference, specificity of MRI-detected inflammation increased from 22 to 56% in CSA patients, and from 10 to 36% in UA patients. The sensitivity was not affected; it was 88 and 85% in CSA patients and 93 and 93% in UA patients. The accuracy also increased, from 32 to 60% in CSA patients and 22 to 44% in UA patients. Conclusion: The use of a reference population resulted in a substantial reduction of false-positive results, without influencing the sensitivity. Although common for other tests in medicine, this phenomenon is novel for MRI in the early detection of RA.

Functional limitations in the phase of clinically suspect arthralgia are as serious as in early clinical arthritis; a longitudinal study.

INTRODUCTION: A phase of arthralgia may precede the emergence of rheumatoid arthritis (RA). Although several studies have focused on biomarkers, the relevance of this phase for patients is less studied. It is unknown if patients already have functional limitations and if this is correlated to the extent of subclinical inflammation. Therefore, we assessed functional disability in patients with clinically suspect arthralgia (CSA), its association with MRI-detected subclinical inflammation and its course during progression to clinical arthritis. METHODS: From April 2012 to March 2015, 241 patients had arthralgia for <1 year and were, based on clinical presentation, considered at risk for RA by their rheumatologists. At baseline, Health Assessment Questionnaire (HAQ) scores were determined and unilateral 1.5 T MRI of metacarpophalangeal, wrist and metatarsophalangeal joints were made. Presence of MRI-detected subclinical inflammation was assessed by summing synovitis, tenosynovitis and bone marrow oedema scores (range 0-189). Patients were followed on arthritis development and HAQ scores were repeated when clinical arthritis had developed. RESULTS: The median HAQ score at presentation with CSA was 0.50. Higher MRI-inflammation scores were associated with higher HAQ scores (ß=0.017, 95% CI=0.004 to 0.030). During median 103 weeks follow-up, 44 patients progressed to clinical arthritis. HAQ scores ≥1.0 were associated with arthritis development (HR=2.50, 95% CI=1.03 to 6.10). Within converters, median HAQ scores did not increase from presentation with CSA to arthritis development (0.88 and 0.75, p=0.36). CONCLUSIONS: HAQ scores ≥1.0 at presentation were associated with the development of clinical arthritis. Functional limitations in the prearthritis phase of CSA were as serious as in the early clinical phase, demonstrating the relevance of CSA from patients' perspectives.

Differences in the symptomatic phase preceding ACPA-positive and ACPA-negative RA: a longitudinal study in arthralgia during progression to clinical arthritis.

OBJECTIVE: Although anticitrullinated protein antibody (ACPA)-positive and ACPA-negative rheumatoid arthritis (RA) have different aetiopathology, the clinical presentation at the time of diagnosis is similar. This study evaluated whether there are phenotypic differences in the symptomatic pre-RA phase. METHODS: Patients with arthralgia included in the Leiden clinically suspect arthralgia cohort who developed arthritis during follow-up were studied (n=67). Symptoms at symptom onset, symptoms and signs at presentation with arthralgia and time to arthritis development were compared between ACPA-positive and ACPA-negative patients. RESULTS: In ACPA-negative patients (n=37), the location of initial symptoms less often included the lower extremities (22% vs 50%, p=0.014). At presentation with arthralgia, ACPA-positive patients had a longer symptom duration (median 22 vs 14 weeks, p=0.005), less tender joints (mean 5 vs 9, p=0.007) and less difficulty making a fist (11% vs 43%, p=0.004). However, after presentation with arthralgia, ACPA-positive patients developed arthritis more quickly (median 6 vs 18 weeks, p=0.015). A partial least squares regression analysis showed clustering of ACPA-positive and ACPA-negative patients based on the above-mentioned clinical variables. CONCLUSION: This study is the first showing that ACPA-positive and ACPA-negative patients have clinical differences in the symptomatic phase preceding clinical arthritis. This contributes to the notion that ACPA-positive and ACPA-negative RA develop differently.