Disease-modifying antirheumatic drugs and risk of incident interstitial lung disease among patients with rheumatoid arthritis: A systematic review and meta-analysis.

OBJECTIVE: To investigate the association of disease-modifying antirheumatic drugs (DMARDs) and risk of incident interstitial lung disease (ILD) among patients with rheumatoid arthritis (RA) using a systematic literature review and meta-analysis. METHODS: We performed a systematic literature review and meta-analysis of studies examining the association of DMARDs with incident RA-ILD. PubMed, Embase, Web of Science, and Cochrane Library were searched from inception to November 2023 for randomized controlled trials (RCTs), observational studies, and post-marketing surveillance studies that investigated adults with RA and compared DMARDs of interest with placebo, no DMARDs, or other DMARDs. The outcome was incident ILD. We summarized the literature on DMARDs and incident RA-ILD risk. Among studies with sufficient quality, we performed meta-analyses to obtain odds ratios (OR) and 95 % confidence intervals (95 %CI) using the Mantel-Haenszel method. RESULTS: Among 3,612 studies, we identified a total of 40 papers that encompassed 486,465 patients with RA and 3,928 incident ILD outcomes that were included in the final systematic review and meta-analysis. Among the studies, 24 were RCTs, 4 were prospective cohort studies, 9 were retrospective cohort studies, 2 were case-control studies, and 1 was a post-marketing surveillance study. The pooled analysis from RCTs revealed no statistically significant difference in the odds of ILD development for any specific DMARD across all comparisons examined. The largest identified RCT (Oral Surveillance trial) of tofacitinib (n = 2,911) vs. tumor necrosis factor inhibitor (TNFi, n = 1,451) found no relationship with incident ILD (OR 0.94, 95 %CI 0.52 to 1.69, p = 0.828). In 7 observational studies, the use of methotrexate (MTX) yielded a pooled OR for ILD of 0.49 (95 %CI 0.32 to 0.76, p < 0.001) compared to those not using MTX. In a single observational study, tofacitinib users had an OR for ILD of 0.36 (95 %CI 0.15 to 0.87, p = 0.024) compared to TNFi users. CONCLUSION: Observational data suggest no increased risk for any DMARD for incident RA-ILD risk, and perhaps a potential protective role of MTX and tofacitinib. However, these studies may be susceptible to bias, and no specific DMARD showed associations with incident RA-ILD in RCTs. Further well-designed prospective studies are warranted for definitive conclusions on the potential relationship between DMARDs and RA-ILD risk.

Genomic and Serological Rheumatoid Arthritis Biomarkers, MUC5B Promoter Variant, and Interstitial Lung Abnormalities.

RATIONALE: Rheumatoid arthritis (RA) has been implicated in interstitial lung disease (ILD) as majority of studies have been comprised of patients with known RA. However, it remains unclear whether an underlying risk for RA in combination with genetic risk for pulmonary fibrosis is associated with radiological markers of early lung injury and fibrosis in broader population samples. OBJECTIVE: Determine whether genetic and serological biomarkers of RA risk in combination with the MUC5B (rs35705950) risk allele (T) are associated with interstitial lung abnormalities (ILA) on computed tomography (CT) scans. METHODS: Associations of RA-risk HLA-DRB1 alleles (*04:01, *04:08, *04:05, *04:04, *10:01) and serum RA autoantibodies with ILA in the Multi-Ethnic Study of Atherosclerosis (MESA, n=4,018) and COPDGene (n=5,963) cohorts were modeled using logistic regression and adjusted for age, sex, self-reported race and ethnicity, smoking history, body mass index, and principal components of genetic ancestry. RESULTS: The prevalence of an RA risk HLA-DRB1 allele was 16.5% and 21.9% in MESA and COPDGene, respectively. ILA was present in 3.9% and 11% in MESA and COPDGene, respectively. An RA risk HLA-DRB1 allele was not significantly associated with ILA in MESA and COPDGene. In MESA, higher serum levels of IgA rheumatoid factor (RF) and anti-cyclic citrullinated peptide were associated with an odds ratio (OR) for ILA of 1.20 (95% CI 1.07-1.35) and 1.19 (95% CI 1.04-1.37), respectively. Among smokers without baseline ILA, per doubling of IgM RF was associated with an OR for ILA 10 years later of 1.25 (95% CI 1.08-1.43). Associations were not significantly different by MUC5B risk allele status. CONCLUSIONS: RA-related HLA-DRB1 alleles were not associated with ILA, whereas higher serum levels of IgM RF among smokers without baseline ILA were associated with subsequent ILA.

Interstitial Pneumonia with Autoimmune Features: Aiming to Define, Refine, and Treat.

Interstitial pneumonia with autoimmune features (IPAF) was defined for research purposes as interstitial lung disease (ILD) associated with features of autoimmunity without diagnosed rheumatic disease. Since publication of the IPAF criteria in 2015, there have been multiple studies of IPAF. However, much remains unknown regarding pathogenesis, prognosis, and treatment in IPAF. This narrative review details the history and classification of IPAF, lists challenges associated with classifying patients as IPAF, and explores the prevalence, epidemiology and presentation of IPAF. We also examine prognosis and important features determining IPAF clinical course, outline pathogenesis, and review treatment strategies.

La neumonía intersticial con características autoinmunes (IPAF) se definió para fines de investigación como enfermedad pulmonar intersticial (EPI) con hallazgos de autoinmunidad sin evidencia de enfermedad reumática (ER) diagnosticada. Desde la publicación de los criterios de clasificación de IPAF en 2015, se han venido realizando múltiples estudios acerca de esta enfermedad. Sin embargo, aún queda mucho por conocer sobre la patogénesis, el pronóstico y el tratamiento de la IPAF. Esta revisión narrativa detalla la historia y la clasificación de la IPAF, enumera los desafíos asociados con la clasificación de los pacientes como IPAF y explora la prevalencia, la epidemiología y manifestaciones clínicas de la enfermedad. Asimismo, explicamos la patogenia, el pronóstico junto con las características importantes que determinan el curso clínico de IPAF y revisamos las estrategias de tratamiento.

Emerging SARS-CoV-2 Resistance After Antiviral Treatment.

Importance: Previous studies have identified mutations in SARS-CoV-2 strains that confer resistance to nirmatrelvir, yet how often this resistance arises and its association with posttreatment virologic rebound is not well understood. Objective: To examine the prevalence of emergent antiviral resistance after nirmatrelvir treatment and its association with virologic rebound. Design, Setting, and Participants: This cohort study enrolled outpatient adults with acute COVID-19 infection from May 2021 to October 2023. Participants were divided into those who received antiviral therapy and those who did not. The study was conducted at a multicenter health care system in Boston, Massachusetts. Exposure: Treatment regimen, including none, nirmatrelvir, and remdesivir. Main Outcomes and Measures: The primary outcome was emergent SARS-CoV-2 antiviral resistance, defined as the detection of antiviral resistance mutations, which were not present at baseline, were previously associated with decreased antiviral efficacy, and emerged during or after completion of a participant's treatment. Next-generation sequencing was used to detect low frequency mutations down to 1% of the total viral population. Results: Overall, 156 participants (114 female [73.1%]; median [IQR] age, 56 [38-69] years) were included. Compared with 63 untreated individuals, the 79 who received nirmatrelvir were older and more commonly immunosuppressed. After sequencing viral RNA from participants' anterior nasal swabs, nirmatrelvir resistance mutations were detected in 9 individuals who received nirmatrelvir (11.4%) compared with 2 of those who did not (3.2%) (P = .09). Among the individuals treated with nirmatrelvir, those who were immunosuppressed had the highest frequency of resistance emergence (5 of 22 [22.7%]), significantly greater than untreated individuals (2 of 63 [3.1%]) (P = .01). Similar rates of nirmatrelvir resistance were found in those who had virologic rebound (3 of 23 [13.0%]) vs those who did not (6 of 56 [10.7%]) (P = .86). Most of these mutations (10 of 11 [90.9%]) were detected at low frequencies (<20% of viral population) and reverted to the wild type at subsequent time points. Emerging remdesivir resistance mutations were only detected in immunosuppressed individuals (2 of 14 [14.3%]) but were similarly low frequency and transient. Global Initiative on Sharing All Influenza Data analysis showed no evidence of increased nirmatrelvir resistance in the United States after the authorization of nirmatrelvir. Conclusions and Relevance: In this cohort study of 156 participants, treatment-emergent nirmatrelvir resistance mutations were commonly detected, especially in individuals who were immunosuppressed. However, these mutations were generally present at low frequencies and were transient in nature, suggesting a low risk for the spread of nirmatrelvir resistance in the community with the current variants and drug usage patterns.

Modeling suggests SARS-CoV-2 rebound after nirmatrelvir-ritonavir treatment is driven by target cell preservation coupled with incomplete viral clearance.

In a subset of SARS-CoV-2 infected individuals treated with the oral antiviral nirmatrelvir-ritonavir, the virus rebounds following treatment. The mechanisms driving this rebound are not well understood. We used a mathematical model to describe the longitudinal viral load dynamics of 51 individuals treated with nirmatrelvir-ritonavir, 20 of whom rebounded. Target cell preservation, either by a robust innate immune response or initiation of nirmatrelvir-ritonavir near the time of symptom onset, coupled with incomplete viral clearance, appear to be the main factors leading to viral rebound. Moreover, the occurrence of viral rebound is likely influenced by time of treatment initiation relative to the progression of the infection, with earlier treatments leading to a higher chance of rebound. Finally, our model demonstrates that extending the course of nirmatrelvir-ritonavir treatment, in particular to a 10-day regimen, may greatly diminish the risk for rebound in people with mild-to-moderate COVID-19 and who are at high risk of progression to severe disease. Altogether, our results suggest that in some individuals, a standard 5-day course of nirmatrelvir-ritonavir starting around the time of symptom onset may not completely eliminate the virus. Thus, after treatment ends, the virus can rebound if an effective adaptive immune response has not fully developed. These findings on the role of target cell preservation and incomplete viral clearance also offer a possible explanation for viral rebounds following other antiviral treatments for SARS-CoV-2.

Therapeutic single-cell landscape: methotrexate exacerbates interstitial lung disease by compromising the stemness of alveolar epithelial cells under systemic inflammation.

BACKGROUND: Interstitial lung disease (ILD) poses a serious threat in patients with rheumatoid arthritis (RA). However, the impact of cornerstone drugs, including methotrexate (MTX) and TNF inhibitor, on RA-associated ILD (RA-ILD) remains controversial. METHODS: Using an SKG mouse model and single-cell transcriptomics, we investigated the effects of MTX and TNF blockade on ILD. FINDINGS: Our study revealed that MTX exacerbates pulmonary inflammation by promoting immune cell infiltration, Th17 activation, and fibrosis. In contrast, TNF inhibitor ameliorates these features and inhibits ILD progression. Analysis of data from a human RA-ILD cohort revealed that patients with ILD progression had persistently higher systemic inflammation than those without progression, particularly among the subgroup undergoing MTX treatment. INTERPRETATION: These findings highlight the need for personalized therapeutic approaches in RA-ILD, given the divergent outcomes of MTX and TNF inhibitor. FUNDING: This work was funded by GENINUS Inc., and the National Research Foundation of Korea, and Seoul National University Hospital.

Therapeutic interception in individuals at risk of rheumatoid arthritis to prevent clinically impactful disease.

Multiple clinical trials for rheumatoid arthritis (RA) prevention have been completed. Here, we set out to report on the lessons learnt from these studies. Researchers who conducted RA prevention trials shared the background, rationale, approach and outcomes and evaluated the lessons learnt to inform the next generation of RA prevention trials. Individuals at risk of RA can be identified through population screening, referrals to musculoskeletal programmes and by recognition of arthralgia suspicious for RA. Clinical trials in individuals at risk for future clinical RA have demonstrated that limited courses of corticosteroids, atorvastatin and hydroxychloroquine do not alter incidence rates of clinical RA; however, rituximab delays clinical RA onset, and methotrexate has transient effects in individuals who are anticitrullinated protein antibody-positive with subclinical joint inflammation identified by imaging. Abatacept delays clinical RA onset but does not fully prevent onset of RA after treatment cessation. Additionally, subclinical joint inflammation and symptoms appear responsive to interventions such as methotrexate and abatacept. To advance prevention, next steps include building networks of individuals at risk for RA, to improve risk stratification for future RA and to understand the biological mechanisms of RA development, including potential endotypes of disease, which can be targeted for prevention, thus adopting a more precision-based approach. Future trials should focus on interceptions aimed at preventing clinical RA onset and which treat existing symptoms and imaging-defined subclinical inflammation. These trials may include advanced designs (eg, adaptive) and should be combined with mechanistic studies to further define pathophysiological drivers of disease development.

Screening, diagnosis, and monitoring of interstitial lung disease in autoimmune rheumatic diseases: A narrative review.

Interstitial lung disease (ILD) is a common and serious manifestation of autoimmune rheumatic diseases. While the prevalence of ILD differs among the individual autoimmune rheumatic diseases, ILD remains an important cause of morbidity and mortality in systemic sclerosis, systemic lupus erythematosus, mixed connective tissue disease, primary Sjögren's disease, rheumatoid arthritis, and idiopathic inflammatory myositis. The present review summarizes recent literature on autoimmune-associated ILD with a focus on screening and monitoring for ILD progression. Reflecting on the currently available evidence, the authors propose a guideline for monitoring for progression in patients with newly diagnosed autoimmune-associated ILD. This review also highlights clinical and biological predictors of progressive pulmonary fibrosis and describes opportunity for further study in the rapidly evolving area of rheumatology and pulmonology.

La enfermedad pulmonar intersticial (EPI) es una manifestación común y seria de las enfermedades autoinmunes. Aunque la prevalencia de EPI difiere de acuerdo a cada enfermedad, continúa siendo una causa importante de morbilidad y mortalidad en la esclerosis sistémica, la artritis reumatoide, el síndrome de Sjögren, la enfermedad mixta del tejido conjuntivo y las miopatías inflamatorias. Este artículo de revisión resume la literatura reciente sobre la EPI asociada con autoinmunidad, con enfoque en la búsqueda y el monitoreo de la progresión de la EPI. Con base en la evidencia disponible, los autores proponen una guía para el monitoreo de la progresión en pacientes con la EPI asociada con autoinmunidad de reciente diagnóstico. Esta revisión también aborda los predictores clínicos y biológicos de la fibrosis pulmonar progresiva y resalta la oportunidad para estudios adicionales en áreas de rápida evolución como la reumatología y la neumología.

Impact of Sex, Serostatus, and Smoking on Risk for Rheumatoid Arthritis-Associated Interstitial Lung Disease Subtypes.

OBJECTIVE: Rheumatoid arthritis-associated interstitial lung disease (RA-ILD) includes multiple subtypes with varying histopathology, prognosis, and potential treatments. Limited research has investigated risk factors for different RA-ILD subtypes. Therefore, we examined demographic, serologic, and lifestyle associations with RA-ILD subtypes. METHODS: We systematically identified RA-ILD cases and RA controls without ILD (RA-noILD) in the Brigham RA Sequential Study and Mass General Brigham Biobank RA cohort. We determined RA-ILD subtype (usual interstitial pneumonia [UIP], nonspecific interstitial pneumonia [NSIP], and other/indeterminate) through chest high-resolution computed tomography imaging pattern. We investigated associations of demographic, lifestyle, and serologic factors with major RA-ILD subtypes using multivariable logistic regression. RESULTS: Among 3,328 patients with RA, we identified 208 RA-ILD cases and 547 RA-noILD controls. RA-UIP was associated with older age (odds ratio [OR] 1.03 per year, 95% confidence interval [95% CI] 1.01-1.05), male sex (OR 2.15, 95% CI 1.33-3.48), and seropositivity (OR 2.08, 95% CI 1.24-3.48), whereas RA-NSIP was significantly associated only with seropositive status (OR 3.21, 95% CI 1.36-7.56). Nonfibrotic ILDs were significantly associated with smoking (OR 2.81, 95% CI 1.52-5.21). Having three RA-ILD risk factors (male, seropositive, smoking) had an OR of 6.89 (95% CI 2.41-19.7) for RA-UIP compared with having no RA-ILD risk factors. CONCLUSION: Older age, seropositivity, and male sex were strongly associated with RA-UIP, whereas RA-related autoantibodies were associated with RA-NSIP. These findings suggest RA-ILD sex differences may be driven by RA-UIP and emphasize the importance of further studies to clarify RA-ILD heterogeneity and optimize screening and treatment approaches.

High-throughput identification of functional regulatory SNPs in systemic lupus erythematosus.

Genome-wide association studies implicate multiple loci in risk for systemic lupus erythematosus (SLE), but few contain exonic variants, rendering systematic identification of non-coding variants essential to decoding SLE genetics. We utilized SNP-seq and bioinformatic enrichment to interrogate 2180 single-nucleotide polymorphisms (SNPs) from 87 SLE risk loci for potential binding of transcription factors and related proteins from B cells. 52 SNPs that passed initial screening were tested by electrophoretic mobility shift and luciferase reporter assays. To validate the approach, we studied rs2297550 in detail, finding that the risk allele enhanced binding to the transcription factor Ikaros (encoded by IKZF1), thereby modulating expression of IKBKE. Correspondingly, primary cells from genotyped healthy donors bearing the risk allele expressed higher levels of the interferon / NF-κB regulator IKKε. Together, these findings define a set of likely functional non-coding lupus risk variants and identify a regulatory pathway involving rs2297550, Ikaros, and IKKε implicated by human genetics in risk for SLE.

Air Pollution and Rheumatoid Arthritis Risk and Progression: Implications for the Mucosal Origins Hypothesis and Climate Change for RA Pathogenesis.

PURPOSE OF REVIEW: The goal of this review paper is to summarize the main research and findings regarding air pollution and its association with the risk and progression of rheumatoid arthritis (RA). RECENT FINDINGS: The most studied components of air pollution included particulate matter of ≤ 2.5 microns in diameter (PM2.5), PM10, carbon monoxide (CO), nitrogen dioxide (NO2), nitric oxide (NOx), sulfur dioxide (SO2), and ozone (O3). In addition, specific occupations and occupational inhalants have been investigated for RA risk. Several studies showed that increased exposure to air pollutants increased the risk of developing RA, particularly seropositive RA. There was evidence of gene-inhalant interactions for seropositive RA risk. Fewer studies have been conducted on RA disease activity and bone erosions. Some studies suggest that patients with RA-associated interstitial lung disease may have worse outcomes if exposed to air pollution. We summarized associations between air pollution and increased RA risk, including RA-associated interstitial lung disease. Relatively few studies investigated air pollution and RA disease activity or other outcomes. These results suggest an important role of air pollution for seropositive RA development and suggest that climate change could be a driver in increasing RA incidence as air pollution increases.

Immune mechanisms in fibrotic interstitial lung disease.

Fibrotic interstitial lung diseases (fILDs) have poor survival rates and lack effective therapies. Despite evidence for immune mechanisms in lung fibrosis, immunotherapies have been unsuccessful for major types of fILD. Here, we review immunological mechanisms in lung fibrosis that have the potential to impact clinical practice. We first examine innate immunity, which is broadly involved across fILD subtypes. We illustrate how innate immunity in fILD involves a complex interplay of multiple cell subpopulations and molecular pathways. We then review the growing evidence for adaptive immunity in lung fibrosis to provoke a re-examination of its role in clinical fILD. We close with future directions to address key knowledge gaps in fILD pathobiology: (1) longitudinal studies emphasizing early-stage clinical disease, (2) immune mechanisms of acute exacerbations, and (3) next-generation immunophenotyping integrating spatial, genetic, and single-cell approaches. Advances in these areas are essential for the future of precision medicine and immunotherapy in fILD.

Forced vital capacity trajectories and risk of lung transplant and ILD-related mortality among patients with rheumatoid arthritis-associated interstitial lung disease.

We aimed to determine the prevalence and outcomes for forced vital capacity percent predicted (FVCpp) decline among patients with rheumatoid arthritis-associated interstitial lung disease (RA-ILD). We identified patients with RA-ILD in the Mass General Brigham Healthcare system. RA-ILD diagnosis was determined by review of high-resolution computed tomography (HRCT) imaging by up to three thoracic radiologists. We abstracted FVCpp measurements, covariates, lung transplant, and ILD-related death from the medical record. We employed a relative FVCpp decline cutoff of > 10% within 24 months. We also used a group-based trajectory model to obtain patterns of change from RA-ILD diagnosis. We then assessed for associations of each FVC decline definition with risk of lung transplant or ILD-related death using multivariable logistic regression. We analyzed 172 patients with RA-ILD with a median of 6 FVCpp measurements per patient over 6.5 years of follow-up (mean age 62.2 years, 36% male). There were seven (4%) lung transplants and 44 (26%) ILD-related deaths. Ninety-eight (57%) patients had relative decline of FVCpp by > 10% in 24 months. We identified three trajectory groups of FVCpp change: rapidly declining (n = 24/168 [14%]), slowly declining (n = 90/168 [54%]), and stable/improving (n = 54/168 [32%]). The rapidly declining group and FVCpp > 10% had adjusted odds ratios (aOR) for lung transplant/ILD-related death of 19.2 (95%CI 4.9 to 75.5) and 2.8 (95%CI 1.3 to 6.1) respectively. Over half of patients with RA-ILD had declining FVCpp. The different trajectory patterns demonstrate the importance of FVC monitoring for identifying patients at the highest risk of poor outcomes. Key Points • Over half of patients with RA-ILD had declining FVCpp over a median of 6.5 years of follow-up. • The rapidly declining FVCpp trajectory group had stronger associations with lung transplant and ILD-related death compared to those with FVCpp decline by > 10%. • Clinicians can employ FVC monitoring to proactively treat patients who are at risk of poor outcomes.

Ultraprocessed Food Intake and Risk of Systemic Lupus Erythematosus Among Women Observed in the Nurses' Health Study Cohorts.

OBJECTIVE: We assessed ultraprocessed food (UPF) intake and systemic lupus erythematosus (SLE) incidence within the prospective Nurses' Health Study (NHS) cohorts. METHODS: A total of 204,175 women were observed (NHS 1984-2016; NHSII 1991-2017). Semiquantitative food frequency questionnaires were completed every two to four years. UPF intake was determined as per the Nova classification. Nurses self-reported new doctor-diagnosed SLE, confirmed by medical records. Time-varying Cox regressions estimated hazard ratios (HRs; 95% confidence intervals [CIs]) for patients with incident SLE and SLE by anti-double-stranded DNA (dsDNA) antibody at diagnosis, according to cumulatively updated daily (a) UPF servings, (b) total intake (in grams and milliliters), and (c) percentage of total intake. Analyses adjusted for age, race, cohort, caloric and alcohol intakes, household income, smoking, body mass index (BMI), physical activity, menarchal age, and oral contraceptive use. We tested for interaction with BMI and examined UPF categories. RESULTS: Mean baseline age was ~50 years (NHS) and ~36 years (NHSII); 93% self-reported White race. A total of 212 patients with incident SLE were identified. SLE risk was higher in the third versus first UPF tertile (servings per day pooled multivariable [MV] HR 1.56, 95% CI 1.04-2.32; P = 0.03). Results were stronger for dsDNA antibody in patients with SLE (servings per day pooled MV HR 2.05, 95% CI 1.15-3.65; P = 0.01) and for absolute (servings or total) than percentage of total intake. Sugar-sweetened/artificially sweetened beverages were associated with SLE risk (third vs first tertile MV HR 1.45, 95% CI 1.01-2.09). No BMI interactions were observed. CONCLUSION: Higher cumulative average daily UPF intake was associated with >50% increased SLE risk and with doubled risk for anti-dsDNA antibody in patients with SLE. Many deleterious effects on systemic inflammation and immunity are postulated.

High Interleukin-13 level is associated with disease stability in interstitial Lung disease.

Purpose: Cytokines can help predict prognosis in interstitial lung disease (ILD) and to differentiate between ILD subtypes. The objectives of our study were to evaluate association of baseline cytokine levels with time to ILD progression and to compare baseline cytokine levels between ILD subtypes. Methods: We quantified 27 cytokines using a multiplex assay in peripheral blood samples from 77 patients. Cox proportional hazards regression analysis was performed to evaluate cytokine impact on the time to progression in the total cohort and within each ILD type. We evaluated for significant differences in cytokine levels between ILD types using ANOVA, Wilcoxon signed-rank test and Tukey method. Results: Higher IL-13 level was associated with longer time to progression (hazard ratio 0.52 [0.33-0.81], p-value 0.004). FGF-ß, GM-CSF, and IL-17 levels differed significantly between fibrotic and inflammatory ILD subgroups. Conclusion: IL-13 may be a useful biomarker predicting ILD stability.

RPA3-UMAD1 rs12702634 and rheumatoid arthritis-associated interstitial lung disease in European ancestry.

Objective: Recently, a genome-wide association study identified an association between RA-associated interstitial lung disease (ILD) and RPA3-UMAD1 rs12702634 in the Japanese population, especially for patients with a usual interstitial pneumonia (UIP) pattern. We aimed to replicate this association in a European population and test for interaction with MUC5B rs35705950. Methods: In this genetic case-control association study, patients with RA and ILD and controls with RA and no ILD were included from France, the USA and the Netherlands. Only cases and controls from European genetic ancestries determined by principal components analysis were included in the analyses. RA was defined by the 1987 ACR or 2010 ACR/EULAR criteria and ILD by chest high-resolution CT scan, except in the control dataset from the Netherlands, where the absence of ILD was determined by chart review. Patients were genotyped for RPA3-UMAD1 rs12702634 and MUC5B rs35705950. Associations were tested using logistic regression adjusted for sex, age at RA onset, age at ILD onset or at certified absence of ILD, tobacco smoking status and country of origin. Results: Among the 883 patients included, 322 were RA-ILD cases (36.5%). MUC5B rs35705950 was strongly associated with RA-ILD in all datasets {combined adjusted odds ratio [OR] 2.9 [95% CI 2.1, 3.9], P = 1.1 × 10-11. No association between RPA3-UMAD1 rs12702634 and RA-ILD was observed [combined OR 1.2 (95% CI 0.8, 1.6), P = 0.31. No interaction was found between RPA3-UMAD1 rs12702634 and MUC5B rs35705950 (P = 0.70). Conclusion: Our findings did not support a contribution of RPA3-UMAD1 rs12702634 to the overall RA-ILD susceptibility in the European population.

Rheumatoid arthritis and changes on spirometry by smoking status in two prospective longitudinal cohorts.

OBJECTIVE: To compare longitudinal changes in spirometric measures between patients with rheumatoid arthritis (RA) and non-RA comparators. METHODS: We analysed longitudinal data from two prospective cohorts: the UK Biobank and COPDGene. Spirometry was conducted at baseline and a second visit after 5-7 years. RA was identified based on self-report and disease-modifying antirheumatic drug use; non-RA comparators reported neither. The primary outcomes were annual changes in the per cent-predicted forced expiratory volume in 1 s (FEV1%) and per cent predicted forced vital capacity (FVC%). Statistical comparisons were performed using multivariable linear regression. The analysis was stratified based on baseline smoking status and the presence of obstructive pattern (FEV1/FVC <0.7). RESULTS: Among participants who underwent baseline and follow-up spirometry, we identified 233 patients with RA and 37 735 non-RA comparators. Among never-smoking participants without an obstructive pattern, RA was significantly associated with more FEV1% decline (ß=-0.49, p=0.04). However, in ever smokers with ≥10 pack-years, those with RA exhibited significantly less FEV1% decline than non-RA comparators (ß=0.50, p=0.02). This difference was more pronounced among those with an obstructive pattern at baseline (ß=1.12, p=0.01). Results were similar for FEV1/FVC decline. No difference was observed in the annual FVC% change in RA versus non-RA. CONCLUSIONS: Smokers with RA, especially those with baseline obstructive spirometric patterns, experienced lower FEV1% and FEV1/FVC decline than non-RA comparators. Conversely, never smokers with RA had more FEV1% decline than non-RA comparators. Future studies should investigate potential treatments and the pathogenesis of obstructive lung diseases in smokers with RA.