Predictors of quality of life, functional status, depression and fatigue in early arthritis: comparison between clinically suspect arthralgia, unclassified arthritis and rheumatoid arthritis.

BACKGROUND: Rheumatoid arthritis (RA) is often preceded by symptomatic phases during which classification criteria are not fulfilled. The health burden of these "at-risk" stages is not well described. This study assessed health-related quality of life (HRQoL), function, fatigue and depression in newly presenting patients with clinically suspect arthralgia (CSA), unclassified arthritis (UA) or RA. METHODS: Cross-sectional analysis of baseline Patient-Reported Outcome Measures (PROMs) was conducted in patients from the Birmingham Early Arthritis Cohort. HRQoL, function, depression and fatigue at presentation were assessed using EQ-5D, HAQ-DI, PHQ-9 and FACIT-F. PROMs were compared across CSA, UA and RA and with population averages from the HSE with descriptive statistics. Multivariate linear regression assessed associations between PROMs and clinical and sociodemographic variables. RESULTS: Of 838 patients included in the analysis, 484 had RA, 200 had CSA and 154 had UA. Patients with RA reported worse outcomes for all PROMs than those with CSA or UA. However, "mean EQ-5D utilities were 0.65 (95%CI: 0.61 to 0.69) in CSA, 0.61 (0.56 to 0.66) in UA and 0.47 (0.44 to 0.50) in RA, which was lower than in general and older (≥ 65 years) background populations." In patients with CSA or UA, HRQoL was comparable to chronic conditions such as heart failure, severe COPD or mild angina. Higher BMI and older age (≥ 60 years) predicted worse depression (PHQ-9: -2.47 (-3.85 to -1.09), P < 0.001) and fatigue (FACIT-F: 5.05 (2.37 to 7.73), P < 0.001). Women were more likely to report worse function (HAQ-DI: 0.13 (0.03 to 0.21), P = 0.01) and fatigue (FACIT-F: -3.64 (-5.59 to -1.70), P < 0.001), and residents of more deprived areas experienced decreased function (HAQ-DI: 0.23 (0.10 to 0.36), P = 0.001), greater depression (PHQ-9: 1.89 (0.59 to 3.18), P = 0.004) and fatigue (FACIT-F: -2.60 (-5.11 to 0.09), P = 0.04). After adjustments for confounding factors, diagnostic category was not associated with PROMs, but disease activity and polypharmacy were associated with poorer performance across all PROMs. CONCLUSIONS: Patient-reported outcomes were associated with disease activity and sociodemographic characteristics. Patients presenting with RA reported a higher health burden than those with CSA or UA, however HRQoL in the pre-RA groups was significantly lower than population averages.

Navigating the path of progress: The OMERACT 2023 emerging leaders program.

OBJECTIVES: The Outcome Measures in Rheumatology Clinical Trials (OMERACT) Emerging Leaders Program (ELP) aims to cultivate a cohort of skilled leaders within the OMERACT community empowering them with expertise and knowledge to help shape and steer the organization into the future. This publication highlights the significance of the ELP in driving leadership excellence, its impact on OMERACT's evolution, and the outcomes and learnings from the OMERACT 2023 ELP. METHODS: Insights from the 2018 ELP report informed 2023 program improvements. Engagement was measured by attendance and WhatsApp interactions. Positive program aspects, areas for improvement and ideas for enhancing future ELPs were captured via anonymous survey and participant focus groups. RESULTS: Engagement with the ELP was high with 9 participants, 96 % attendance at all workshops, 154 WhatsApp interactions. All program components were highly rated, with the highest being the 'Psychological Safety' and 'Methodology/Process/Politics' workshops. Future enhancements included creating further networking, connection and support activities, practical leadership and methodological skill development opportunities, and a new stream focussing on organisational advancement. CONCLUSIONS: The 2023 OMERACT ELP was well received and successfully addressed areas previously identified as requiring improvement. New educational enhancements were valued, and the importance of fostering psychological safety at all levels was highlighted. The ELP fortifies OMERACT by nurturing a diverse array of skilled leaders who embody OMERACTs core values. Continuing to refine and evolve the ELP over time will help OMERACT sustain its global influence in patient-centered outcome research.

The Sjögren's Working Group: The 2023 OMERACT meeting and provisional domain generation.

Sjögren's disease (SjD) is a systemic autoimmune exocrinopathy with key features of dryness, pain, and fatigue. SjD can affect any organ system with a variety of presentations across individuals. This heterogeneity is one of the major barriers for developing effective disease modifying treatments. Defining core disease domains comprising both specific clinical features and incorporating the patient experience is a critical first step to define this complex disease. The OMERACT SjD Working Group held its first international collaborative hybrid meeting in 2023, applying the OMERACT 2.2 filter toward identification of core domains. We accomplished our first goal, a scoping literature review that was presented at the Special Interest Group held in May 2023. Building on the domains identified in the scoping review, we uniquely deployed multidisciplinary experts as part of our collaborative team to generate a provisional domain list that captures SjD heterogeneity.

Deconstruction of rheumatoid arthritis synovium defines inflammatory subtypes.

Rheumatoid arthritis is a prototypical autoimmune disease that causes joint inflammation and destruction1. There is currently no cure for rheumatoid arthritis, and the effectiveness of treatments varies across patients, suggesting an undefined pathogenic diversity1,2. Here, to deconstruct the cell states and pathways that characterize this pathogenic heterogeneity, we profiled the full spectrum of cells in inflamed synovium from patients with rheumatoid arthritis. We used multi-modal single-cell RNA-sequencing and surface protein data coupled with histology of synovial tissue from 79 donors to build single-cell atlas of rheumatoid arthritis synovial tissue that includes more than 314,000 cells. We stratified tissues into six groups, referred to as cell-type abundance phenotypes (CTAPs), each characterized by selectively enriched cell states. These CTAPs demonstrate the diversity of synovial inflammation in rheumatoid arthritis, ranging from samples enriched for T and B cells to those largely lacking lymphocytes. Disease-relevant cell states, cytokines, risk genes, histology and serology metrics are associated with particular CTAPs. CTAPs are dynamic and can predict treatment response, highlighting the clinical utility of classifying rheumatoid arthritis synovial phenotypes. This comprehensive atlas and molecular, tissue-based stratification of rheumatoid arthritis synovial tissue reveal new insights into rheumatoid arthritis pathology and heterogeneity that could inform novel targeted treatments.

Is symptom duration before DMARD therapy a determinant of direct and indirect costs in DMARD-naïve RA patients? A systematic review.

Objective: Early treatment of RA improves clinical outcomes; however, the impact on health economic outcomes is unclear. This review sought to investigate the relationship between symptom/disease duration and resource utilization/costs and the responsiveness of costs following RA diagnosis. Methods: A systematic search was performed on Pubmed, EMBASE, CINAHL and Medline. Studies were eligible if patients were DMARD-naïve and fulfilled 1987 ACR or 2010 ACR/EULAR RA classification criteria. Studies had to report symptom/disease duration and resource utilization or direct/indirect costs as health economic outcomes. The relationships between symptom/disease duration and costs were explored. Results: Three hundred and fifty-seven records were identified in a systematic search; nine were eligible for analysis. The mean/median of symptom/disease duration in studies ranged between 25 days and 6 years. Annual direct costs of RA following diagnosis showed a U-shaped distribution in two studies. Longer symptom duration before starting a DMARD (>180 days) was associated with lower health-care utilization in the first year of RA diagnosis in one study. Annual direct and indirect costs 6 months before RA diagnosis were higher in patients with shorter symptom duration (<6 months) in one study. Given the clinical and methodological heterogeneities, the association between symptom/disease duration and costs after diagnosis was not computed. Conclusion: The association between symptom/disease duration at the time of DMARD initiation and resource utilization/cost in patients with RA remains unclear. Health economic modelling with clearly defined symptom duration, resource utilization and long-term productivity is vital to address this evidence gap.

The value of ultrasound-defined tenosynovitis and synovitis in the prediction of persistent arthritis.

OBJECTIVES: The value of US-defined tenosynovitis in predicting the persistence of inflammatory arthritis is not well described. In particular, the predictive utility of US-defined tenosynovitis of larger tendons is yet to be reported. We assessed the value of US-defined tenosynovitis alongside US-defined synovitis and clinical and serological variables in predicting persistent arthritis in an inception cohort of DMARD-naïve patients with early arthritis. METHODS: One hundred and fifty DMARD-naïve patients with clinically apparent synovitis of one or more joints and a symptom duration of ≤3 months underwent baseline clinical, laboratory and US (of 19 bilateral joints and 16 bilateral tendon compartments) assessments. Outcomes were classified as persistent or resolving arthritis after 18 months' follow-up. The predictive value of US-defined tenosynovitis for persistent arthritis was compared with those of US-defined synovitis, and clinical and serological variables. RESULTS: At 18 months, 99 patients (66%) had developed persistent arthritis and 51 patients (34%) had resolving disease. Multivariate logistic regression analysis showed that US-detected digit flexor tenosynovitis [odds ratio (OR): 6.6, 95% CI: 2.0 , 22.1, P = 0.002] provided independent predictive data for persistence over and above the presence of US-detected joint synovitis and RF antibodies. In the RF/ACPA-negative subcohort, US-defined digit flexor tenosynovitis remained a significant predictive variable (OR: 4.7, 95% CI: 1.4, 15.8, P = 0.012), even after adjusting for US-defined joint synovitis. CONCLUSION: US-defined tenosynovitis provided independent predictive data for the development of persistent arthritis. The predictive role of US-defined digit flexor tenosynovitis should be further assessed; investigators should consider including this tendon site as a candidate variable when designing imaging-based predictive algorithms for persistent inflammatory arthritis development.

Very low prevalence of ultrasound-detected tenosynovial abnormalities in healthy subjects throughout the age range: OMERACT ultrasound minimal disease study.

OBJECTIVES: This study aimed to determine the prevalence of ultrasound-detected tendon abnormalities in healthy subjects (HS) across the age range. METHODS: Adult HS (age 18-80 years) were recruited in 23 international Outcome Measures in Rheumatology ultrasound centres and were clinically assessed to exclude inflammatory diseases or overt osteoarthritis before undergoing a bilateral ultrasound examination of digit flexors (DFs) 1-5 and extensor carpi ulnaris (ECU) tendons to detect the presence of tenosynovial hypertrophy (TSH), tenosynovial power Doppler (TPD) and tenosynovial effusion (TEF), usually considered ultrasound signs of inflammatory diseases. A comparison cohort of patients with rheumatoid arthritis (RA) was taken from the Birmingham Early Arthritis early arthritis inception cohort. RESULTS: 939 HS and 144 patients with RA were included. The majority of HS (85%) had grade 0 for TSH, TPD and TEF in all DF and ECU tendons examined. There was a statistically significant difference in the proportion of TSH and TPD involvement between HS and subjects with RA (HS vs RA p<0.001). In HS, there was no difference in the presence of ultrasound abnormalities between age groups. CONCLUSIONS: Ultrasound-detected TSH and TPD abnormalities are rare in HS and can be regarded as markers of active inflammatory disease, especially in newly presenting RA.

Relationship Between Inflammation and Metabolism in Patients With Newly Presenting Rheumatoid Arthritis.

Background: Systemic inflammation in rheumatoid arthritis (RA) is associated with metabolic changes. We used nuclear magnetic resonance (NMR) spectroscopy-based metabolomics to assess the relationship between an objective measure of systemic inflammation [C-reactive protein (CRP)] and both the serum and urinary metabolome in patients with newly presenting RA. Methods: Serum (n=126) and urine (n=83) samples were collected at initial presentation from disease modifying anti-rheumatic drug naïve RA patients for metabolomic profile assessment using 1-dimensional 1H-NMR spectroscopy. Metabolomics data were analysed using partial least square regression (PLS-R) and orthogonal projections to latent structure discriminant analysis (OPLS-DA) with cross validation. Results: Using PLS-R analysis, a relationship between the level of inflammation, as assessed by CRP, and the serum (p=0.001) and urinary (p<0.001) metabolome was detectable. Likewise, following categorisation of CRP into tertiles, patients in the lowest CRP tertile and the highest CRP tertile were statistically discriminated using OPLS-DA analysis of both serum (p=0.033) and urinary (p<0.001) metabolome. The most highly weighted metabolites for these models included glucose, amino acids, lactate, and citrate. These findings suggest increased glycolysis, perturbation in the citrate cycle, oxidative stress, protein catabolism and increased urea cycle activity are key characteristics of newly presenting RA patients with elevated CRP. Conclusions: This study consolidates our understanding of a previously identified relationship between serum metabolite profile and inflammation and provides novel evidence that there is a relationship between urinary metabolite profile and inflammation as measured by CRP. Identification of these metabolic perturbations provides insights into the pathogenesis of RA and may help in the identification of therapeutic targets.

Vitamin D and early rheumatoid arthritis.

BACKGROUND: Previous studies have linked rheumatoid arthritis (RA) risk and disease activity with vitamin D-deficiency (low serum 25-hydroxyvitamin D (25OHD)), but a causal role for vitamin D in RA is still unclear, with conflicting results from many previous studies, partly due to heterogeneity in study design and patient populations. In this study we aimed to (1) analyse serum 25OHD in early inflammatory arthritis, (2) compare 25OHD with disease activity and fatigue in early RA and (3) determine whether low 25OHD is associated with progression to RA. METHODS: An analysis of 790 patients recruited to the Birmingham Early Inflammatory Arthritis Cohort and followed longitudinally to determine clinical outcomes. The following were recorded at baseline: demographic data, duration of symptoms, duration of early morning stiffness (EMS), tender and swollen joint counts, Visual Analogue Scale (VAS) pain/fatigue/EMS, PHQ-9, HAQ and FACIT-Fatigue scores, DAS28-ESR, DAS28-CRP, CRP, ESR, anti-CCP antibody status, rheumatoid factor status, and serum 25OHD (ng/ml). Diagnosis was recorded at 0 and 12 months onwards as either RA, Undifferentiated Inflammatory Arthritis (UIA; synovitis not meeting other classification/diagnostic criteria), Clinically Suspect Arthralgia (CSA; arthralgia of an inflammatory type without synovitis), or Other. RESULTS: Baseline demographic data were similar between all groups, with median symptom duration of 16.8-34.0 days. Baseline 25OHD was not significantly different between groups [median, interquartile range (IQR): RA 46.7, 30.0-73.3; UIA 51.4, 30.0-72.3; CSA 47.7, 30.3-73.0; Other 39.9, 28.6-62.2]. In RA (n = 335), there were no significant differences between 25OHD and measures of disease activity or fatigue. No association between 25OHD and progression from UIA or CSA to RA was observed. CONCLUSIONS: There was no clear association between serum 25OHD and baseline diagnosis, RA disease activity, or progression from UIA or CSA to RA. Future studies of other vitamin D metabolites may better define the complex role of vitamin D in RA.

Bilateral Anterior Thigh Thickness: A New Diagnostic Tool for the Identification of Low Muscle Mass?

OBJECTIVES: To develop an ultrasonographic scanning protocol that included an assessment of muscle size [the proposed Bilateral Anterior Thigh Thickness (BATT)] and quality (echogenicity) to support the diagnosis of sarcopenia in a clinical setting. To determine the relationship of BATT and ultrasound echogenicity with physical function parameters of sarcopenia and test the reliability of ultrasound echogenicity measurements. DESIGN: Observational study. SETTING AND PARTICIPANTS: The BATT criteria were determined from a reference population of 113 healthy younger adults and tested in 39 healthy older adults and 31 frail older adults. METHODS: Ultrasonography was used to measure the thickness of rectus femoris and vastus intermedius bilaterally; the thickness measurements were summed to calculate the BATT. Diagnostic criteria for low muscle size were calculated from the reference population. Echogenicity was assessed using freeze-frame images. All individuals underwent anthropological, frailty, and physical performance assessments. RESULTS: The mean (standard deviation) BATTs for the subsamples were as follows: healthy young women (n = 54), 60.6 mm (±11.1); healthy young men (n = 59), 75.8 mm (±10.71); healthy older women (n = 27), 38.4 mm (±7.18); healthy older men (n = 13), 47.5 mm (±10.8); frail older women (n = 17), 29.2 mm (±11.4); and frail older men (n = 14), 27.3 mm (±13.9). The calculated cutoffs for low muscle size in older adults using the BATT criteria were 38.5 mm in women and 54.4 mm in men in this population. The BATT was correlated with grip strength (ρ = 0.750, P < .001 for women; ρ = 0.619, P < .001 for men) and walk speed (ρ = -0.599, P < .001 for women; ρ = -0.324, P = .003 for men). Ultrasound echogenicity increased with age and frailty. Lay sonographers were able to reliably reproduce the same muscle thickness measurements but not the same muscle echogenicity measurements. CONCLUSIONS/IMPLICATIONS: The data support the use of ultrasonography to identify low muscle size in sarcopenia. Ultrasonography provides a pragmatic diagnostic tool that is noninvasive, without radiation exposure, and usable in both community and hospital settings. The proposed BATT criteria could be used to identify low muscle size in clinical practice and research, and in this study have excellent correlation with physical parameters of muscle health. However, this now needs testing in a validation cohort. Ultrasound echogenicity has been demonstrated to be an important surrogate marker of muscle health, but difficulties with reproducibility preclude its widespread clinical use.

The OMERACT Emerging Leaders Program: The Good, the Bad, and the Future.

OBJECTIVE: To describe the experience of the first OMERACT Emerging Leaders Program (ELP). METHODS: A Delphi process identified positive aspects, areas for improvement, and future directions. Core items were defined as essential if they received ≥ 70% ratings. RESULTS: Participants valued relatable/accessible mentors (100%), including an OMERACT Executive mentor (100%), and a support network of peers (90%). Key items for future development were funding support (100%) and developing knowledge about OMERACT processes (90%) and politics (80%). CONCLUSION: The ELP has the potential to provide targeted training for early career researchers to develop relevant skills for future leadership roles within OMERACT.

Targeting early changes in the synovial microenvironment: a new class of immunomodulatory therapy?

OBJECTIVES: Controlled immune responses rely on integrated crosstalk between cells and their microenvironment. We investigated whether targeting proinflammatory signals from the extracellular matrix that persist during pathological inflammation provides a viable strategy to treat rheumatoid arthritis (RA). METHODS: Monoclonal antibodies recognising the fibrinogen-like globe (FBG) of tenascin-C were generated by phage display. Clones that neutralised FBG activation of toll-like receptor 4 (TLR4), without impacting pathogenic TLR4 activation, were epitope mapped by crystallography. Antibodies stained synovial biopsies of patients at different stages of RA development. Antibody efficacy in preventing RA synovial cell cytokine release, and in modulating collagen-induced arthritis in rats, was assessed. RESULTS: Tenascin-C is expressed early in the development of RA, even before disease diagnosis, with higher levels in the joints of people with synovitis who eventually developed RA than in people whose synovitis spontaneously resolved. Anti-FBG antibodies inhibited cytokine release by RA synovial cells and prevented disease progression and tissue destruction during collagen-induced arthritis. CONCLUSIONS: Early changes in the synovial microenvironment contribute to RA progression; blocking proinflammatory signals from the matrix can ameliorate experimental arthritis. These data highlight a new drug class that could offer early, disease-specific immune modulation in RA, without engendering global immune suppression.

New headaches with normal inflammatory markers: an early atypical presentation of giant cell arteritis.

An 80-year-old man presented repeatedly to his general practitioner with 3 months of unexplained persistent frontal headaches. CT head revealed no diagnosis. His dentist diagnosed his co-existing jaw pain as bruxism. Three months later, the patient happened to attend a routine ophthalmology follow-up appointment. During this routine appointment, features of giant cell arteritis (GCA) including worrying visual complications were first noted. His inflammatory markers (C-reactive protein and erythrocyte sedimentation rate) were not significantly raised-contrary to the norm. A temporal artery ultrasound and biopsy were performed, in light of the history. This confirmed GCA. He was commenced on high-dose oral prednisolone and was managed by ophthalmology and rheumatology. At 4 weeks, symptoms resolved with no permanent visual loss despite a prolonged initial symptomatic period. Multiple symptomatic presentations to different specialties should therefore alert clinicians to a unifying diagnosis, for example, vasculitis. Serious illnesses may present with severe symptoms despite normal screening investigations.

Initial validation and results of the Symptoms in Persons At Risk of Rheumatoid Arthritis (SPARRA) questionnaire: a EULAR project.

OBJECTIVES: To describe the development and assess the psychometric properties of the novel 'Symptoms in Persons At Risk of Rheumatoid Arthritis' (SPARRA) questionnaire in individuals at risk of rheumatoid arthritis (RA) and to quantify their symptoms. METHODS: The questionnaire items were derived from a qualitative study in patients with seropositive arthralgia. The questionnaire was administered to 219 individuals at risk of RA on the basis of symptoms or autoantibody positivity: 74% rheumatoid factor and/or anticitrullinated protein antibodies positive, 26% seronegative. Validity, reliability and responsiveness were assessed. Eighteen first degree relatives (FDR) of patients with RA were used for comparison. RESULTS: Face and content validity were high. The test-retest showed good agreement and reliability (1 week and 6 months). Overall, construct validity was low to moderate, with higher values for concurrent validity, suggesting that some questions reflect symptom content not captured with regular Visual Analogue Scale pain/well-being. Responsiveness was low (small subgroup). Finally, the burden of symptoms in both seronegative and seropositive at risk individuals was high, with pain, stiffness and fatigue being the most common ones with a major impact on daily functioning. The FDR cohort (mostly healthy individuals) showed a lower burden of symptoms; however, the distribution of symptoms was similar. CONCLUSIONS: The SPARRA questionnaire has good psychometric properties and can add information to currently available clinical measures in individuals at risk of RA. The studied group had a high burden and impact of symptoms. Future studies should evaluate whether SPARRA data can improve the prediction of RA in at risk individuals.

The role of ultrasound-defined tenosynovitis and synovitis in the prediction of rheumatoid arthritis development.

OBJECTIVES: Tenosynovitis (TS) is common in early arthritis. However, the value of US-defined TS in predicting RA development is unclear. We assessed the predictive utility of US-defined TS alongside US-defined synovitis and clinical and serological variables in a prospective cohort of early arthritis patients. METHODS: One hundred and seven patients with clinically apparent synovitis of one or more joint and symptom duration ⩽3 months underwent baseline clinical, laboratory and US assessment of 19 bilateral joint sites and 16 bilateral tendon compartments. Diagnostic outcome was determined after 18 months, applying the 2010 ACR/EULAR classification criteria for RA. The predictive values of US-defined TS for persistent RA were compared with those of US-defined synovitis, clinical and serological variables. RESULTS: A total of 4066 US joint sites and 3424 US tendon compartments were included in the analysis. Forty-six patients developed persistent RA, 17 patients developed non-RA persistent disease and 44 patients had resolving disease at follow-up. US-defined TS in at least one tendon compartment at baseline was common in all groups (RA 85%, non-RA persistent disease 71% and resolving 70%). On multi-variate analysis, US-defined digit flexor TS provided independent predictive data over and above the presence of ACPA and US-defined joint synovitis. CONCLUSION: US-defined digit flexor TS provided independent predictive data for persistent RA development in patients with early arthritis. The predictive utility of this tendon site should be further assessed in a larger cohort; investigators designing imaging-based predictive algorithms for RA development should include this tendon component as a candidate variable.

Immunoglobulin characteristics and RNAseq data of FcRL4+ B cells sorted from synovial fluid and tissue of patients with rheumatoid arthritis.

This manuscript is a companion paper to Amara et al. [1]. Data shown here include detailed clinical characteristics from anonymized patients, the Ig subclass data generated from B cells sorted from four individual patients, tables detailing variable gene region sequences from sorted cells linked to the patient information and the sequence yields from individual patients. Furthermore a URL link to the RNAseq datasets submitted to GEO is included.

B cells expressing the IgA receptor FcRL4 participate in the autoimmune response in patients with rheumatoid arthritis.

The clinical efficacy of B cell targeting therapies highlights the pathogenic potential of B cells in inflammatory diseases. Expression of Fc Receptor like 4 (FcRL4) identifies a memory B cell subset, which is enriched in the joints of patients with rheumatoid arthritis (RA) and in mucosa-associated lymphoid tissue. The high level of RANKL production by this B cell subset indicates a unique pathogenic role. In addition, recent work has identified a role for FcRL4 as an IgA receptor, suggesting a potential function in mucosal immunity. Here, the contribution of FcRL4+ B cells to the specific autoimmune response in the joints of patients with RA was investigated. Single FcRL4+ and FcRL4- B cells were sorted from synovial fluid and tissue from RA patients and their immunoglobulin genes characterized. Levels of hypermutation in the variable regions in both populations were largely consistent with memory B cells selected by an antigen- and T cell-dependent process. Recombinant antibodies were generated based on the IgH and IgL variable region sequences and investigated for antigen specificity. A significantly larger proportion of the recombinant antibodies generated from individual synovial FcRL4+ B cells showed reactivity towards citrullinated autoantigens. Furthermore, both in analyses based on heavy chain sequences and flow cytometric detection, FcRL4+ B cells have significantly increased usage of the IgA isotype. Their low level of expression of immunoglobulin and plasma cell differentiation genes does not suggest current antibody secretion. We conclude that these activated B cells are a component of the local autoimmune response, and through their RANKL expression, can contribute to joint destruction. Furthermore, their expression of FcRL4 and their enrichment in the IgA isotype points towards a potential role for these cells in the link between mucosal and joint inflammation.

The OMERACT Ultrasound Group: A Report from the OMERACT 2016 Meeting and Perspectives.

OBJECTIVE: To provide an update from the Outcome Measures in Rheumatology (OMERACT) Ultrasound Working Group on the progress for defining ultrasound (US) minimal disease activity threshold at joint level in rheumatoid arthritis (RA) and for standardization of US application in juvenile idiopathic arthritis (JIA). METHODS: For minimal disease activity, healthy controls (HC) and patients with early arthritis (EA) who were naive to disease-modifying antirheumatic drugs were recruited from 2 centers. US was performed of the hands and feet, and scored semiquantitatively (0-3) for synovial hypertrophy (SH) and power Doppler (PD). Synovial effusion (SE) was scored a binary variable. For JIA, a Delphi approach and subsequent validation in static images and patient-based exercises were used to developed preliminary definitions for synovitis and a scoring system. RESULTS: For minimal disease activity, 7% HC had at least 1 joint abnormality versus 30% in the EA group. In HC, the findings of SH and PD were predominantly grade 1 whereas all grades were seen in the EA cohort, but SE was rare. In JIA, synovitis can be diagnosed based on B-mode findings alone because of the presence of physiological vascularization. A semiquantitative scoring system (0-3) for synovitis for both B-mode and Doppler were developed in which the cutoff between Doppler grade 2 and grade 3 was 30%. CONCLUSION: The first step has been taken to define the threshold for minimal disease activity in RA by US and to define and develop a scoring system for synovitis in JIA. Further steps are planned for the continuous validation of US in these areas.