Defining inflammatory cell states in rheumatoid arthritis joint synovial tissues by integrating single-cell transcriptomics and mass cytometry.

To define the cell populations that drive joint inflammation in rheumatoid arthritis (RA), we applied single-cell RNA sequencing (scRNA-seq), mass cytometry, bulk RNA sequencing (RNA-seq) and flow cytometry to T cells, B cells, monocytes, and fibroblasts from 51 samples of synovial tissue from patients with RA or osteoarthritis (OA). Utilizing an integrated strategy based on canonical correlation analysis of 5,265 scRNA-seq profiles, we identified 18 unique cell populations. Combining mass cytometry and transcriptomics revealed cell states expanded in RA synovia: THY1(CD90)+HLA-DRAhi sublining fibroblasts, IL1B+ pro-inflammatory monocytes, ITGAX+TBX21+ autoimmune-associated B cells and PDCD1+ peripheral helper T (TPH) cells and follicular helper T (TFH) cells. We defined distinct subsets of CD8+ T cells characterized by GZMK+, GZMB+, and GNLY+ phenotypes. We mapped inflammatory mediators to their source cell populations; for example, we attributed IL6 expression to THY1+HLA-DRAhi fibroblasts and IL1B production to pro-inflammatory monocytes. These populations are potentially key mediators of RA pathogenesis.

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

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

How to treat patients with rheumatoid arthritis when methotrexate has failed? The use of a multiple propensity score to adjust for confounding by indication in observational studies.

OBJECTIVES: To compare consecutive disease modifying antirheumatic drug (DMARD)-treatment regimes in daily practice in patients with rheumatoid arthritis (RA) who failed on initial methotrexate, while using a multiple propensity score (PS) method to control for the spurious effects of confounding by indication. METHODS: Patients with newly diagnosed RA who had failed initial treatment with methotrexate were selected from METEOR, an international, observational registry. Subsequent DMARD-treatment regimens were categorised as: (1) conventional synthetic DMARD(s) (csDMARD(s)) only (143 patients), (2) csDMARD(s)+glucocorticoid (278 patients) and (3) biological DMARD (bDMARD)±csDMARD(s) (89 patients). Multiple PS that reflect the likelihood of treatment with each treatment-regime were estimated per patient using multinomial regression. Linear mixed model analyses were performed to analyse treatment responses per category (Disease Activity Score (DAS)) after a maximum follow-up duration of 6 and 12 months, and results were presented with adjustment for the multiple PS. RESULTS: After 6 months, follow-up PS-adjusted treatment responses yielded a change in DAS per year (95% CI) of -2.00 (-2.65 to -1.36) if patients received a bDMARD; of -0.96 (-1.33 to -0.59) if patients received csDMARD(s)+glucocorticoids and of -0.73 (-1.21 to -0.25) if patients received csDMARDs only. These changes were -0.91 (-1.23 to -0.60); -0.43 (-0.62 to -0.23) and -0.39 (-0.66 to -0.13), respectively after 1 year of follow-up. CONCLUSIONS: In this analysis of worldwide common practice data with adjustment for multiple PS, patients with RA who had failed initial treatment with methotrexate monotherapy had a better DAS-response after a subsequent switch to a bDMARD-containing treatment regimen than to a regimen with csDMARD(s) only, with or without glucocorticoids.

Autoantibody status is not associated with early treatment response to first-line methotrexate in patients with early rheumatoid arthritis.

Objectives: In RA, the relationship between autoantibody status and treatment response to MTX remains unclear. We investigated the association between autoantibody status and early remission in newly diagnosed RA patients treated with MTX using real-world data. Methods: RA-patients initially treated with MTX were selected from an international observational database (METEOR). Patients were stratified into autoantibody-positive (RF- and/or ACPA-positive) or autoantibody negative (RF- and ACPA-negative). The effect of autoantibody status on the chance of achieving remission within 3 to 6 months was analysed using Cox-proportional hazards regression. Results: Data from 1826 RA patients were available for analysis. DAS remission was achieved in 17% (318/1826). This was similar in autoantibody-positive [17% (282/1629)] and -negative patients [18% (36/197)]. Hence, autoantibody positivity was not associated with remission [hazard ratio (HR) 0.89, 95% CI 0.57, 1.38]. Similar findings were found when stratified for MTX monotherapy (HR 0.75, 95% CI 0.41, 1.37) or combination treatment (HR 0.76, 95% CI 0.37, 1.54). Good physical function (HAQ < 0.5) was achieved in 33% (530/1590) of all patients. Autoantibody-positivity was also not associated with HAQ < 0.5 (HR 1.05, 95% CI 0.71, 1.57). Conclusion: Autoantibody status is not associated with early remission in newly diagnosed RA-patients receiving MTX. This indicates that MTX is effective as an initial treatment strategy regardless of autoantibody status.

Inequity in access to bDMARD care and how it influences disease outcomes across countries worldwide: results from the METEOR-registry.

OBJECTIVE: To establish in a global setting the relationships between countries' socioeconomic status (SES), measured biological disease modifying antirheumatic drug (bDMARD)-usage and disease outcomes. To assess if prescription and reimbursement rules and generic access to medication relates to a countries' bDMARD-usage. METHODS: Data on disease activity and drug use from countries that had contributed at least 100 patients were extracted from the METEOR database. Mean disease outcomes of all available patients at the final visit were calculated on a per-country basis. A questionnaire was sent to at least two rheumatologists per country inquiring about DMARD-prices, access to treatment and valid regulations for prescription and reimbursement. RESULTS: Data from 20 379 patients living in 12 different countries showed that countries' SES was positively associated with measured disease activity (meanDAS28), but not always with physical functioning (HAQ-score). A lower country's SES, stricter rules for prescription and reimbursement of bDMARDs as well as worse affordability of bDMARDs were associated with lower bDMARD-usage. bDMARD-usage was negatively associated with disease activity (although not with physical functioning), but the association was moderate at best. CONCLUSIONS: Disease activity in patients with rheumatoid arthritis as well as bDMARD-usage varies across countries worldwide. The (negative) relationship between countries' bDMARD-usage and level of disease activity is complex and under the influence of many factors, including-but not limited to-countries' SES, affordability of bDMARDs and valid prescription and reimbursement rules for bDMARDs.

Dynamic changes in the infrapatellar knee structures with quadriceps muscle contraction. An in vivo study.

OBJECTIVE: To determine the effect of knee flexion and submaximal isometric quadriceps muscle (Q) contraction on the patellar tendon (PT), the infrapatellar fat pad (IPFP), and the deep infrapatellar bursa (IPB) from extension to full flexion. METHODS: In Study 1, the dominant knee of seven healthy subjects was studied in full extension and at 60° flexion during relaxation and Q contraction. Each knee was inspected and palpated, the transverse infrapatellar diameter was measured by plicometry, and measurements of the anteroposterior (AP) thickness of the IPFP were made by ultrasound (US). In Study 2, the dominant knee of seven healthy subjects was studied by US in full flexion, and then, at 15° decrements, down to 60° flexion during relaxation and Q contraction. Both studies had IRB approval. Results were analyzed with the Wilcoxon test and descriptive statistics. RESULTS: In Study 1, Q contraction caused straightening of the patellar tendon (PT), a statistically significant widening of the IPFP by plicometry, and an increased AP thickness of the IPFP by US, in both knee positions. In Study 2, in full knee flexion, the PT contacted the tibial cortex in all seven subjects. Upon increasing extension, the PT-tibial cortex contact was lost in all subjects nearing 90° flexion. The contraction of the Q made the concave PT straight, grew the width of the underlying IPFP, and the apron of the IPFP moved distally within the IPB in all knee positions. A small amount of bursal fluid was present in all seven subjects. CONCLUSION: Q contraction makes the IPFP bulge anteriorly, on both sides of the PT, and distally into the IPB, with possible biomechanical implications. In full knee flexion, the PT contacted the tibia, confirming a fulcrum at this site.

Association of 17 Definitions of Remission with Functional Status in a Large Clinical Practice Cohort of Patients with Rheumatoid Arthritis.

OBJECTIVE: To compare the association between different remission criteria and physical function in patients with rheumatoid arthritis followed in clinical practice. METHODS: Longitudinal data from the METEOR database were used. Seventeen definitions of remission were tested: American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) Boolean-based; Simplified/Clinical Disease Activity Index (SDAI/CDAI); and 14 Disease Activity Score (DAS)-based definitions. Health Assessment Questionnaire (HAQ) ≤ 0.5 was defined as good functional status. Associations were investigated using generalized estimating equations. Potential confounders were tested and sensitivity analyses performed. RESULTS: Data from 32,915 patients (157,899 visits) were available. The most stringent definition of remission was the ACR/EULAR Boolean-based definition (1.9%). The proportion of patients with HAQ ≤ 0.5 was higher for the most stringent definitions, although it never reached 100%. However, this also meant that, for the most stringent criteria, many patients in nonremission had HAQ ≤ 0.5. All remission definitions were associated with better function, with the strongest degree of association observed for the SDAI (adjusted OR 3.36, 95% CI 3.01-3.74). CONCLUSION: The 17 definitions of remission confirmed their validity against physical function in a large international clinical practice setting. Achievement of remission according to any of the indices may be more important than the use of a specific index. A multidimensional approach, targeted at wider goals than disease control, is necessary to help all patients achieve the best possible functional status.

Body mass index and treatment survival in patients with RA starting treatment with TNFα-inhibitors: long-term follow-up in the real-life METEOR registry.

OBJECTIVES: To study whether there is an association between body mass index (BMI) category and survival of various tumour necrosis factor inhibitors (TNFi) in rheumatoid arthritis (RA) patients in a real-life longitudinal international registry. METHODS: Data from 5230 patients with RA starting treatment with any TNFi were selected from the METEOR registry. Patients were divided into six BMI categories: 3.7% underweight, BMI<18.5 kg/m2; 46% normal weight, BMI 18.5-25 kg/m2; 32% pre-obesity, BMI 25-30 kg/m2; 13% obesity class I, BMI 30-35 kg/m2; 3.4% obesity class II, BMI 35-40 kg/m2; and 1.6% obesity class III, BMI >40 kg/m2. Time on treatment in the different BMI categories was compared for all TNFi combined and for the infliximab, adalimumab and etanercept separately, using Kaplan-Meier curves and Cox regression analyses. Cox regression analyses were adjusted for potential confounders, with follow-up censored at 5000 days. RESULTS: Patients in obesity class II (HR 1.28, 95% CI 1.06 to 1.54) and III (HR 1.67, 95% CI 1.29 to 2.18) and underweight patients (HR 1.30, 95% CI 1.07 to 1.58) showed statistically significantly shorter TNFi survival than normal weight patients. The effect in underweight patients was strongest for infliximab (HR 1.82, 95% CI 1.20 to 2.76), the effect in overweight patients was strongest for infliximab (category II (HR 1.49, 95% CI 0.98 to 2.26); category III (HR 1.46, 95% CI 0.79 to 2.71)) and etanercept (category II (HR 1.27 95% CI 0.98 to 1.65); category III (HR 1.79, 95% CI 1.25 to 2.55)). No significant effect modification from reported pain was found. CONCLUSION: Both underweight and overweight patients discontinued TNFi treatment earlier than normal weight patients, without evidence of reported pain as the main determinant. It remains uncertain what determines TNFi survival in individual patients.

The "Treat to Target" Approach to Rheumatoid Arthritis.

Treatment of rheumatoid arthritis has evolved significantly over the past decades. Therapeutic advances have made clinical remission a feasible goal. Systematic treatment approaches taking into account objective measures of disease activity ("treat-to-target"/"T2T") have been shown to result in better outcomes. This article reviews the latest information regarding T2T in rheumatoid arthritis, including a synopsis of the different disease activity scores available, new definitions of remission used in clinical trials and in routine clinical care, studies supporting a T2T approach, the role of imaging to guide treatment, and areas in which uncertainty remains.

Impact of the combined presence of erosions and ACPA on rheumatoid arthritis disease activity over time: results from the METEOR registry.

Objective: To investigate associations between baseline presence of erosions and/or anti-citrullinated protein antibodies (ACPA) on functional ability, disease activity and treatment survival over time. Methods: Real life data from newly diagnosed rheumatoid arthritis patients were identified in the international METEOR registry. Patients were grouped according to presence/absence of ACPA and/or erosions at baseline. Associations between the presence of ACPA and/or erosions (four groups) with the change of Disease Activity Score (DAS) and Health Assessment Questionnaire (HAQ) over time were assessed using linear mixed models during maximum 6 or maximum 12 months from baseline. Treatment survival was assessed using multiple failure-times Cox regression. Results: Data were included from 701 ACPA‒/erosions‒, 334 ACPA‒/erosions+, 1585 ACPA+/erosions‒ and 1993 ACPA+/erosions+ patients. We found statistically significant differences in DAS and HAQ change over time between the four groups, both after maximum follow-up durations of 6 and of 12 months, but after stratification differences proved small and not clinically meaningful. Patients in the ACPA‒/erosions‒ group were less likely to switch treatment compared with the ACPA+/erosions‒ reference group (p<0.001). The other two ACPA/erosions groups did not differ from the reference group. Conclusions: In this analysis of worldwide real life data, we found statistically significant, but clinically irrelevant differences in treatment response to initial disease modifying anti-rheumatic drug therapies as measured by DAS and HAQ in ACPA‒/erosions‒, ACPA‒/erosions+, ACPA+/erosions‒ and ACPA+/erosions+ rheumatoid arthritis patients. However, after maximum follow-up durations of 6 and 12 months all groups had a similar response to initial treatment, but with a lower likelihood to switch treatment for ACPA‒/erosions‒ patients during the first year of follow-up.

Gastrointestinal and Hepatic Disease in Sjogren Syndrome.

Sjogren syndrome (SS) is a lymphocyte-mediated, infiltrative autoimmune disorder characterized by destruction of exocrine glands leading to secretory dysfunction. The typical manifestations include xerostomia and xerophthalmia; however, extensive gastrointestinal involvement is increasingly being recognized, emphasizing the variable and systemic nature of SS.

The conundrum of indeterminate QuantiFERON-TB Gold results before anti-tumor necrosis factor initiation.

BACKGROUND: Tumor necrosis factor alpha (TNFα) is a key cytokine in both the pathogenesis of inflammatory bowel disease (IBD) and rheumatoid arthritis (RA) and the host defense against tuberculosis (TB). Consequently, anti-TNFα medications result in an increased risk of latent TB infection (LTBI) reactivation. Here, we sought to evaluate the factors affecting the results of QuantiFERON-TB Gold In-Tube (QFT-GIT) assay as a screening tool for LTBI. METHODS: We conducted an observational, retrospective study in patients with IBD and RA who underwent LTBI screening using QFT-GIT at UMass Memorial Medical Center between 2008 and 2016 prior to initiation of anti-TNF medications. RESULTS: We included 107 and 89 patients with IBD and RA, respectively. We found that a higher proportion of IBD patients had indeterminate QFT-GIT result compared to RA patients. Furthermore, we found that the majority of patients with indeterminate results were tested during an acute flare of IBD (88%) and while taking corticosteroids. Of all patients receiving ≥20 mg equivalent prednisone dose (n=32), 63% resulted in indeterminate QFT-GIT, compared to only 6% indeterminate testing in patients receiving <20 mg of equivalent prednisone dose (n=164, P<0.001). There was no correlation between indeterminate results and age, gender, disease duration, or distribution, or smoking status within each population. CONCLUSION: We observed that high-dose corticosteroids may affect QFT-GIT outcomes leading to a high proportion of indeterminate results. We propose that IBD patients should be tested prior to initiation of corticosteroids to avoid equivocal results and prevent potential delays in initiation of anti-TNF medications.

Assessment of control of rheumatoid arthritis disease activity.

As very effective targeted biological therapies have become available to treat rheumatoid arthritis (RA), remission is now the goal of treatment. Since 1981, efforts have been undertaken to develop criteria for clinical remission in RA. Although several different measures of disease activity have been proposed, many issues remain unresolved. Active joint inflammation, even if involving only a few joints, negatively impacts a patient's quality of life and may ultimately result in structural damage. Thus, a low disease activity state (LDAS), which has been adopted as the target in clinical trials of 'treat to target', may not be the optimal treatment target in clinical practice. Similarly, the definitions of remission used in clinical trials may not be appropriate for use in daily clinical practice because some allow for the presence of several tender and swollen joints. Measures of disease activity do not necessarily correlate with structural remission, which implies halting progression of radiographic evidence of damage over time. Because no single measure of RA disease activity fully quantifies the global burden of disease, rheumatologists must follow multiple parameters to assess disease activity thoroughly and to adjust treatment optimally.