Are cleaning activities a source of exposure to crystalline silica in women with rheumatoid arthritis? A case-control study.

INTRODUCTION: Inhalation of crystalline silica (silicon dioxide, SiO2) is associated with a wide range of acute and chronic diseases, including rheumatoid arthritis (RA). The objectives of this work were to identify the main sources of exposure to SiO2 in a series of patients with RA not selected on the basis of their professional activity, compared with a representative sample of the French general population, and to assess the association between silica exposure and disease features. METHODS: The Dust Exposure Life-Course Questionnaire (DELCQ) is a tool that enables retrospective quantification of both occupational and non-occupational lifetime exposure to SiO2. DELCQ-previously validated in a large representative sample of the French general population-was administered to 97 consecutive RA patients, and exposure scores were compared between cases and age, gender and smoking status-matched controls (1:4). The main sources of SiO2 exposure were identified in cases and controls, and source-specific exposure levels were compared. The association between DELCQ scores and disease variables in cases was tested via univariable and multivariable analyses. RESULTS: In women with RA, the main sources of SiO2 exposure were cleaning activities and dusty clothes laundry, with higher exposure levels from these sources versus the general population (p<0.005). Across the whole series of RA patients, high SiO2 exposure was independently associated with mediastinal lymphadenopathy (OR 6.3, 95% CI 1.4 to 27.7). CONCLUSION: Cleaning activities and dusty clothes laundry may be underestimated sources of SiO2 exposure in women with RA.

Crystalline silica exposure in patients with rheumatoid arthritis and systemic sclerosis: a nationwide cross-sectional survey.

OBJECTIVES: Develop and validate a thorough exposure questionnaire to comprehensively explore crystalline silica (SiO2) exposure in the general population (gender-specific, occupational and non-occupational) and in patients with autoimmune diseases (rheumatoid arthritis (RA), systemic sclerosis (SSc)). METHODS: Lifetime exposures to SiO2 in occupational and non-occupational settings were assessed using a thorough exposure questionnaire. The questionnaire was applied to a general population panel (n = 2911) sampled from the French rolling census, and to unselected patients with SSc (n = 100) and RA (n = 97). Global (GES), occupational (OES) and non-occupational (NOES) exposure scores were assessed in SSc and RA patients, and compared with up to four controls from the general population, matched by age group, sex and tobacco consumption. RESULTS: Patients had higher GES than their matched controls (SSc: P = 0.001; RA: P < 0.0001) due to higher OES (P < 0.0001 for SSc and RA). Men had higher GES than women (SSc: P < 0.0001; RA: P = 0.002) due to higher OES (P < 0.0001 for SSc and RA). The NOES did not differ between men and women. In SSc patients: Men had higher GES than controls (P < 0.0001). Men and women with SSc had higher OES than controls (P < 0.0001). In RA patients: GES and OES were higher in both men (P = 0.00521; P < 0.0001) and women (P < 0.0001; P < 0.0001) than in their respective controls. Women had higher NOES than controls (P = 0.045). CONCLUSION: The lifetime SiO2 exposure gap between RA and SSc patients and controls was substantially due to occupational exposure. In both diseases, men had higher exposure scores than women.

The exposome in rheumatoid arthritis.

The exposome integrates the variety and accumulation of exposures (external and internal) to which an individual is submitted to from conception to death. Exposome may therefore be a useful tool for understanding the diversity of these factors and their role in the pathophysiology of rheumatoid arthritis (RA). Life is perceived as a continuum of cumulative changes, with key periods of disruption (e.g. birth, adolescence, pregnancy, prolonged treatment). The combination of these changes and the external signals that cause them constitute an individual's exposome, which is constantly changing and expanding throughout life. Thus, measuring the exposome requires specific tools and approaches as well as a global perspective. RA, a complex, heterogeneous, pro-inflammatory autoimmune disease with a genetic component and for which a large number of environmental factors have already been incriminated is an appropriate field of application for the exposome. The aim of this review is to define the exposome concept, outline the different analytic tools available for its study and finally apply them to the field of RA.

Serum Fatty Acid Profiles Are Associated with Disease Activity in Early Rheumatoid Arthritis: Results from the ESPOIR Cohort.

BACKGROUND: Long-chain omega-3 and omega-6 fatty acids (n-3, n-6 FAs) may modulate inflammation and affect the risk of developing rheumatoid arthritis (RA). However, whether n-3/n-6 FA status affects RA after disease onset is unknown. This study aimed to assess whether FA profiles are independently associated with disease activity in a large prospective cohort of patients with early RA. METHODS: Baseline serum FAs were quantified in 669 patients in the ESPOIR cohort. Principal component analysis identified three serum FA patterns that were rich in n-7-9, n-3 and n-6 FAs (patterns ω7-9, ω3 and ω6), respectively. The association of pattern tertiles with baseline variables and 6-month disease activity was tested using multivariable logistic regression. RESULTS: Pattern ω3 was associated with low baseline and pattern ω6 with high baseline C-reactive protein level and disease activity. Both patterns ω3 and ω6 were associated with reduced odds of active disease after 6 months of follow-up (pattern ω3: odds ratio, tertile three vs. one, 0.49 [95% CI 0.25 to 0.97] and pattern ω6: 0.51 [0.28 to 0.95]; p = 0.04 and 0.03, respectively). CONCLUSIONS: In a cohort of early RA patients, a serum lipid profile rich in n-3 FAs was independently associated with persistently reduced disease activity between baseline and 6-month follow-up. An n-6 FA profile was also associated with lower 6-month disease activity.

Interleukin 27 is a novel cytokine with anti-inflammatory effects against spondyloarthritis through the suppression of Th17 responses.

Introduction: Spondylarthritis (SpA) development in HLA-B27/human ß2-microglobulin transgenic rat (B27-rat) is correlated with altered conventional dendritic cell (cDC) function that promotes an inflammatory pattern of CD4+T cells, including a biased expansion of pro-inflammatory Th17 population and imbalance of regulatory T cells cytokine profile. Transcriptomic analysis revealed that cDCs from B27-rats under express IL-27, an anti-inflammatory cytokine which induces the differentiation of IL-10+ regulatory T cells and inhibits Th17 cells. Methods: Here, we first investigated whether in vitro addition of exogenous IL-27 could reverse the inflammatory pattern observed in CD4+ T cells. Next, we performed preclinical assay using IL-27 to investigate whether in vivo treatment could prevent SpA development in B27-rats. Results: in vitro addition of IL-27 to cocultures of cDCs and CD4+ T cell subsets from B27-rats reduced IL-17 and enhanced IL-10 production by T cells. Likewise, IL-27 inhibited the production of IL-17 by CD4+ T cells from SpA patients. Interestingly, in vivo treatment with recombinant IL-27 starting before SpA onset, inhibited SpA development in B27-rats through the suppression of IL-17/TNF producing CD4+ T cells. Discussion: Overall, our results reveal a potent inhibitory effect of IL-27 and highlight this cytokine as a promising new therapeutic target in SpA, especially for SpA patients non responders to currently approved biotherapies.

MUC5B promoter variant rs35705950 and rheumatoid arthritis associated interstitial lung disease survival and progression.

BACKGROUND: The major risk factor for idiopathic pulmonary fibrosis (IPF), MUC5B rs35705950, was found to be associated with rheumatoid arthritis-associated interstitial lung disease (RA-ILD). Whilst the MUC5B rs35705950 T risk allele has been associated with better survival in IPF, its impact on RA-ILD prognosis remains to be determined. Our objective was to explore the influence of MUC5B rs35705950 on survival and progression in RA-ILD. METHODS: Through an international retrospective observational study, patients with RA-ILD were genotyped for the MUC5B rs35705950 variant and consecutive pulmonary function tests (PFTs) findings were collected. Longitudinal data up to a 10-year follow-up were considered and analyzed using mixed regression models. Proportional hazards and joint proportional hazards models were used to analyze the association of baseline and longitudinal variables with lung transplant-free survival. Significant progression of RA-ILD was defined as at least an absolute or relative 10% decline of forced vital capacity at 2 years from baseline. RESULTS: Out of 321 registered patients, 261 were included in the study: 139 women (53.3%), median age at RA-ILD diagnosis 65 years (interquartile range [IQR] 57 to 71), 151 ever smokers (59.2%). Median follow-up was 3.5 years (IQR 1.3 to 6.6). Mortality rate was 32% (95%CI 19 to 42) at 10 years. The MUC5B rs35705950 variant did not impact lung transplant-free survival (HR for the T risk allele carriers=1.26; 95%CI 0.61 to 2.62; P=0.53). Decline in pulmonary function at 2 years was not influenced by MUC5B rs35705950 (OR=0.95; 95%CI 0.44 to 2.05; P=0.89), irrespective of the HRCT pattern. CONCLUSION: In this study, the MUC5B rs35705950 promoter variant did not influence transplant- free survival or decline in pulmonary function in patients with RA-ILD.

Mitral valve granulomatosis: A paradoxical reaction complicating etanercept treatment in rheumatoid arthritis. A case report.

BACKGROUND: "Sarcoidosis-like" paradoxical reactions to Antitumor necrosis factor α (anti-TNFα) treatment have been reported. The clinical presentations are varied, most of the time, with a relatively typical picture of mediastinopulmonary involvement. More rarely, isolated granulomatous locations from various organs are described, leading to difficulties in diagnosis. CASE PRESENTATION: We report a granulomatous cardiac valve location complicating etanercept treatment in a 26-years-old caucasian male with rheumatoid arthritis. The patient received leflunomide and low-dose corticosteroids, then etanercept was introduced because of persistent disease activity. He had no history of tuberculosis infection or contact, chest CT-scan was normal. At 3 months, he showed complete remission. After 6 months of etanercept treatment, the patient suddenly complained of headache with scotomas of the right visual field and vertigo, without fever. Cerebral MRI revealed 3 recent infarcts. Cardiac ultrasonography revealed a mobile mass on the posterior mitral leaflet. C-reactive protein level was 8mg/L, and all analyses were negative for an infectious agent. Leflunomide and etanercept were discontinued, and antibiotic therapy was started. Mitral valve resection and plasty were performed 2 days later. Histology of the valve revealed large non-caseating epithelioid granulomas with a suppurative-like necrotic center. After ruling out infectious endocarditis, sarcoidosis, rheumatoid valvulitis or lupus-like reaction induced by anti-TNF therapy, the diagnosis of a paradoxical reaction to etanercept was finally retained. Tocilizumab monotherapy was introduced to treat RA flare, no antibiotic preventive treatment was added. After 2 years, the patient was in remission. CONCLUSION: This case raises for the first time the possibility of a paradoxical adverse event with an isolated granulomatous reaction on the heart valve occurring with anti-TNF treatment, namely etanercept.

Methotrexate and rheumatoid arthritis associated interstitial lung disease.

QUESTION ADDRESSED BY THE STUDY: Methotrexate (MTX) is a key anchor drug for rheumatoid arthritis (RA) management. Fibrotic interstitial lung disease (ILD) is a common complication of RA. Whether MTX exposure increases the risk of ILD in patients with RA is disputed. We aimed to evaluate the association of prior MTX use with development of RA-ILD. METHODS: Through a case-control study design with discovery and international replication samples, we examined the association of MTX exposure with ILD in 410 patients with chronic fibrotic ILD associated with RA (RA-ILD) and 673 patients with RA without ILD. Estimates were pooled over the different samples using meta-analysis techniques. RESULTS: Analysis of the discovery sample revealed an inverse relationship between MTX exposure and RA-ILD (adjusted OR 0.46, 95% CI 0.24-0.90; p=0.022), which was confirmed in the replication samples (pooled adjusted OR 0.39, 95% CI 0.19-0.79; p=0.009). The combined estimate using both the derivation and validation samples revealed an adjusted OR of 0.43 (95% CI 0.26-0.69; p=0.0006). MTX ever-users were less frequent among patients with RA-ILD compared to those without ILD, irrespective of chest high-resolution computed tomography pattern. In patients with RA-ILD, ILD detection was significantly delayed in MTX ever-users compared to never-users (11.4±10.4 years and 4.0±7.4 years, respectively; p<0.001). ANSWER TO THE QUESTION: Our results suggest that MTX use is not associated with an increased risk of RA-ILD in patients with RA, and that ILD was detected later in MTX-treated patients.

Involvement of Tumor Necrosis Factor Receptor Type II in FoxP3 Stability and as a Marker of Treg Cells Specifically Expanded by Anti-Tumor Necrosis Factor Treatments in Rheumatoid Arthritis.

OBJECTIVE: To study the involvement of Treg cells expressing tumor necrosis factor receptor type II (TNFRII) in exerting control of inflammation in experimental models and in the response to anti-TNF treatments in patients with rheumatoid arthritis (RA) or spondyloarthritis (SpA). METHODS: The role of TNFRII in Treg cells was explored using a multilevel translational approach. Treg cell stability was evaluated by analyzing the methylation status of the Foxp3 locus using bisulfite sequencing. Two models of inflammation (imiquimod-induced skin inflammation and delayed-type hypersensitivity arthritis [DTHA]) were induced in TNFRII-/- mice, with or without transfer of purified CD4+CD25+ cells from wild-type (WT) mice. In patients with RA and those with SpA, the evolution of the TNFRII+ Treg cell population before and after targeted treatment was monitored. RESULTS: Foxp3 gene methylation in Treg cells was greater in TNFRII-/- mice than in WT mice (50% versus 36.7%). In cultured Treg cells, TNF enhanced the expression, maintenance, and proliferation of Foxp3 through TNFRII signaling. Imiquimod-induced skin inflammation and DTHA were aggravated in TNFRII-/- mice (P < 0.05 for mice with skin inflammation and P < 0.0001 for mice with ankle swelling during DTHA compared to WT mice). Adoptive transfer of WT mouse Treg cells into TNFRII-/- mice prevented aggravation of arthritis. In patients with RA receiving anti-TNF treatments, but not those receiving tocilizumab, the frequency of TNFRII+ Treg cells was increased at 3 months of treatment compared to baseline (mean ± SEM 65.2 ± 3.1% versus 49.1 ± 5.5%; P < 0.01). In contrast, in anti-TNF-treated patients with SpA, the frequency of TNFRII+ Treg cells was not modified. CONCLUSION: TNFRII expression identifies a subset of Treg cells that are characterized by stable expression of Foxp3 via gene hypomethylation, and adoptive transfer of TNFRII-expressing Treg cells ameliorates inflammation in experimental models. Expansion and activation of TNFRII+ Treg cells may be one of the mechanisms by which anti-TNF agents control inflammation in RA, but not in SpA.

Thoracic aorta involvement in giant cell arteritis: a case-control analysis of morphological data at diagnosis.

OBJECTIVES: Giant cell arteritis (GCA) is a cause of potentially fatal aortic aneurysms. Descriptive data on thoracic aorta measurements at the beginning of the disease are lacking. We aimed to compare aortic diameters between a recently diagnosed GCA population and an age- and sex-matched control group. METHODS: Patients with GCA and with an available thoracic CT concomitant with diagnosis were included. Controls were patients matched for age and sex and hospitalised in the same care centre for pneumonia. The main criteria were the anteroposterior and lateral diameters of the ascending thoracic aorta, which were measured by a blinded evaluator. RESULTS: 90 cases and 90 controls were included. Each group comprised 30 males and 60 females for a mean age of 75.1±9 and 75.7±10.1 years old. At the time of GCA diagnosis no difference was found between the two groups (anteroposterior diameter 37.1±5 mm for cases vs. 36.7±5 mm for controls, p=0.6; lateral diameter 36.6±5 mm for cases vs. 35.9±4 mm for controls, p=0.3). Thoracic aorta diameter was not significantly higher in patients with aortitis at diagnosis (n=44) than in cases without aortitis (n=46). CONCLUSIONS: Morphologic comparison of thoracic aorta at diagnosis of GCA with an age- and sex-matched control population showed no significant difference. Morphologic evaluation of aorta cannot predict accurately the occurrence of aortic aneurysm. Systematic follow-up according to current recommendations is thus justified.

Origins of rheumatoid arthritis.

While the exact cause of rheumatoid arthritis is unknown, several mechanisms have been described extensively. The genetic predisposition for this autoimmune disease is largely attributed to MHC class II genes, especially the main polymorphism in the HLA shared epitope. Non-genetic factors account for the rest. The best known are autoantigens to citrullinated or carbmylated proteins, although there are many others. They are recognized by an immune system with defective control mechanisms, in which regulator T-cells are unable to prevent inflammation and the destruction of tissue, joint and vascular structures (among others). Polymorphonuclear neutrophils, which are very abundant at sites of inflammation, interfere with attempts at regulation. Cell metabolism, which typically participates in fighting against the autoantigen attack, does not respond correctly to the demands, making the inflammatory phenomenon worse. This is also the case for environmental factors such as atmospheric pollution, dust, diet (especially salt intake) and infections. Inflammatory cytokines such as TNF-α, IL-1 and IL-17, are certain implicated, but not initially. They appear as a common execution pathway for a lengthy sentence following an unfortunate encounter between genetic predisposition and a harmful environment.

High prevalence of spondyloarthritis in sarcoidosis patients with chronic back pain.

INTRODUCTION: Chronic back pain (CBP) is a frequent complaint in patients with sarcoidosis, which challenges the clinician as multiples causes may potentially underlie this symptom. Interestingly, some reports suggest that the coexistence of sarcoidosis and spondyloarthritis (SpA) may be frequent. This study aimed to determine the prevalence of axial radiographic and non-radiographic SpA in patients with sarcoidosis and CBP and assess the association between patient characteristics and SpA. METHODS: This cross-sectional study enrolled 64 patients with a diagnosis of sarcoidosis and CBP. Patients describing CBP underwent a full spine MRI and radiography. All patients with inflammatory CBP underwent complementary sacroiliac joint MRI. The diagnosis of axial SpA was based on the Assessment of SpondyloArthritis International Society classification criteria. RESULTS: Among the 64 patients (49 women) with sarcoidosis and CBP, 29 had inflammatory pain; 15/64 had a diagnosis of SpA (23.4% [95% CI: 13.7-35.6], 14/29 (48.3% [95% CI: 29.5-67.5] of those with inflammatory back pain). MRI sacroiliitis was found in 13 patients. On both univariate and multivariate analysis, SpA diagnosis was associated with inflammatory CBP (OR=28.5, 95% CI: 1.91-425.4) and sarcoidosis limited to the thorax (OR=6.74, 95% CI: 1.08-42.1). SpA was associated with young age (p = 0.0093) and male sex (p = 0.021) only on univariate analysis. Besides, 12/64 patients (18.8%, 95% CI: 10.1-30.5) had a diagnosis of sarcoidosis spine bone lesions, 7/64 (10.9%, 95% CI: 4.5-21.2) symptomatic vertebral fracture and 30/64 (46.9%, 95% CI: 34.3-59.8) degenerative spine. CONCLUSIONS: The prevalence of SpA is increased in sarcoidosis patients with inflammatory back pain. The systematic use of spine and sacroiliac MRI in this subgroup is justified. The association between other patient features and SpA needs further confirmation.

Microenvironment tailors nTreg structure and function.

Natural regulatory T cells (nTregs) ensure the control of self-tolerance and are currently used in clinical trials to alleviate autoimmune diseases and graft-versus-host disease after hematopoietic stem cell transfer. Based on CD39/CD26 markers, blood nTreg analysis revealed the presence of five different cell subsets, each representing a distinct stage of maturation. Ex vivo added microenvironmental factors, including IL-2, TGFß, and PGE2, direct the conversion from naive precursor to immature memory and finally from immature to mature memory cells, the latest being a no-return stage. Phenotypic and genetic characteristics of the subsets illustrate the structural parental maturation between subsets, which further correlates with the expression of regulatory factors. Regarding nTreg functional plasticity, both maturation stage and microenvironmental cytokines condition nTreg activities, which include blockade of autoreactive immune cells by cell-cell contact, Th17 and IL-10 Tr1-like activities, or activation of TCR-stimulating dendritic cell tolerization. Importantly, blood nTreg CD39/CD26 profile remained constant over a 2-y period in healthy persons but varied from person to person. Preliminary data on patients with autoimmune diseases or acute myelogenous leukemia illustrate the potential use of the nTreg CD39/CD26 profile as a blood biomarker to monitor chronic inflammatory diseases. Finally, we confirmed that naive conventional CD4 T cells, TCR-stimulated under a tolerogenic conditioned medium, could be ex vivo reprogrammed to FOXP3 lineage Tregs, and further found that these cells were exclusively committed to suppressive function under all microenvironmental contexts.

Neutrophil extracellular traps exert both pro- and anti-inflammatory actions in rheumatoid arthritis that are modulated by C1q and LL-37.

OBJECTIVE: Neutrophil extracellular traps (NET), produced by activated polymorphonuclear neutrophils (PMN), are supposed to play a role in the pathogenesis of rheumatoid arthritis (RA), a chronic inflammatory autoimmune disease characterized by anti-citrullinated protein antibodies (ACPA). Indeed, NET contain citrullinated autoantigens and some RA autoantibodies recognize NET. However, the mechanisms by which NET trigger or perpetuate the inflammatory process in RA are hitherto not elucidated. We hypothesized that, in addition to citrullination, NET might also contain stimulatory proteins and directly activate inflammatory target cells, as PMN and macrophages. METHODS: NET antigenic and inflammatory properties were analyzed in 157 healthy donors (HD) and RA patients, the largest analysis reported so far. Primary PMN and monocyte-derived macrophages were isolated and immunoglobulin G (IgG) purified. NET were induced (NETosis), isolated and quantified. NET antigenicity was analyzed by fluorescence microscopy. PMN and macrophages were stimulated with NET with/without ACPA, C1q, LL-37 or lipopolysaccharide (LPS) and cell activation was estimated by flow cytometry and ELISA. RESULTS: PMN from RA patients produced more NET than HD PMN. We next dissected how NET mechanistically affect inflammatory cells. Particularly, we show for the first time that RA and HD NET activated both resting macrophages and PMN, but importantly RA NET were more stimulatory, leading to secretion of inflammatory cytokines and up-regulation of HLA/CD86/CD11b. IgG from ACPA-positive RA patients specifically recognized RA and even HD NET. Nevertheless, NET-induced cell activation occurs independently of immune complex formation with ACPA. Likewise, endosomal acidification was not required. Notably, we also report that complement C1q increased the NET stimulatory activity on macrophages only, due to higher expression of C1q receptors, which was further supported by the LL-37 antimicrobial peptide. In contrast, NET specifically inhibited interleukin (IL)-6 secretion by LPS-activated macrophages and not PMN, especially with C1q/LL-37. This inhibition was not mediated by NET-derived proteases or LPS neutralization and was associated with the simultaneous induction of IL-10 secretion. CONCLUSION: We show that NET possess both pro- and anti-inflammatory properties depending on target cells, their activation levels and C1q/LL-37. Thus, independently of ACPA, NET modulate RA chronic inflammation via this new dual activity we identified. In addition, NET may trigger autoimmunity in RA as ACPA recognize NET antigens but not non-activated PMN. Therefore, we conclude that excess of NETosis together with enhanced NET activity participate to RA pathogenesis at different levels.