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.

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.

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.

Evaluating the participation of junior members and patient and healthcare professionals representatives in EULAR task forces: results from an international survey.

OBJECTIVE: European Alliance of Associations for Rheumatology (EULAR) task forces (TF) requires participation of ≥2 junior members, a health professional in rheumatology (HPR) and two patient research partners for the development of recommendations or points to consider. In this study, participation of these junior and representative members was compared with the one of traditional TF members (convenor, methodologist, fellow and expert TF members). METHODS: An online survey was developed and emailed to previous EULAR TF members. The survey comprised multiple-choice, open-ended and 0-100 rating scale (fully disagree to fully agree) questions. RESULTS: In total, 77 responded, 48 (62%) women. In total, 46 (60%) had participated as a junior or representative TF member. Most junior/representative members reported they felt unprepared for their first TF (10/14, 71%). Compared with traditional members, junior/representative members expressed a significantly higher level of uncertainty about their roles within the TF (median score 23 (IQR 7.0-52.0) vs 7 (IQR 0.0-21.0)), and junior/representative members felt less engaged by the convenor (54% vs 71%). Primary factors that facilitated interaction within a TF were experience, expertise and preparation (54%), a supportive atmosphere (42%) and a clear role (12%). CONCLUSION: Juniors, patients and HPR experience various challenges when participating in a EULAR TF. These challenges differ from and are generally less pronounced than those experienced by traditional TF members. The convenor should introduce the participants to the tasks, emphasise the value of their contributions and how to prepare accordingly for the TF meeting.

Characterisation of airway disease associated with Sjögren disease.

OBJECTIVE: Although airway disease associated with Sjögren's disease (Sjo-AD) is common, it is poorly studied compared with interstitial lung disease (ILD). In this study, we aimed to assess factors associated with Sjo-AD, the characteristics and prognosis of this manifestation. METHODS: We performed a retrospective multicentric study involving nine centres. We included Sjo-AD patients confirmed by at least one clinician and one CT scan report. Clinical and biological data, pulmonary function test (PFT), and CT scans were collected. A single radiologist specialist in thoracic diseases reviewed CT scans. Sjo-AD patients were compared with Sjo controls without pulmonary involvement, randomly selected after matching for age and disease duration. RESULTS: We included 31 Sjo-AD and 62 Sjo controls without pulmonary history. Sjo-AD had a higher disease activity (ESSDAI) compared with controls, even when excluding the pulmonary domain of the score (7 vs 3.8, p<0.05), mainly due to the biological activity. Sjo-AD was multilobar (72%) and associated with signs of both bronchiectasis and bronchiolitis (60%). Obstructive lung disease occurred in 32% at the time of Sjo-AD diagnosis. Overall, PFT was stable after 8.7±7 years follow-up but repeated CT scans showed extended lesions in 41% of cases within 6±3.2 years. No patient developed Sjo-ILD. Sjo-AD progression was independent of the global disease activity. CONCLUSIONS: Sjo-AD preferentially affects Sjo patients with higher biological activity. It is often characterised as a diffuse disease, affecting both proximal and distal airways, with a slow evolution over time and no progression to Sjo-ILD.

Articular manifestations related to anti-interleukin-5 therapies in severe asthma: a case series.

Articular manifestations should be screened before and during anti-IL-5/5R biologic treatment in severe asthma. Rigorous multidisciplinary team discussion should be carried out to assess the risk-benefit balance of withholding effective treatment. https://bit.ly/3vfPn4k.

Short peripheral blood leukocyte telomere length in rheumatoid arthritis-interstitial lung disease.

Shortened telomere lengths (TLs) can be caused by single nucleotide polymorphisms and loss-of-function mutations in telomere-related genes (TRG), as well as ageing and lifestyle factors such as smoking. Our objective was to determine if shortened TL is associated with interstitial lung disease (ILD) in individuals with rheumatoid arthritis (RA). This is the largest study to demonstrate and replicate that shortened peripheral blood leukocytes-TL is associated with ILD in patients with RA compared with RA without ILD in a multinational cohort, and short PBL-TL was associated with baseline disease severity in RA-ILD as measured by forced vital capacity percent predicted.

Effectiveness and tolerability of antifibrotics in rheumatoid arthritis-associated interstitial lung disease.

OBJECTIVE: Our aim was to investigate the effectiveness and tolerability of antifibrotics in a real-world cohort of patients with rheumatoid arthritis-associated interstitial lung diseases (RA-ILD). METHODS: In this retrospective cohort study, we identified RA-ILD patients initiating antifibrotics at Mass General Brigham Integrated Health Care System, a large multi-hospital healthcare system in Boston, MA, USA. We used electronic query to identify all patients with at least 2 RA diagnosis codes and a prescription for either nintedanib or pirfenidone (2014-2023). All analyzed patients met 2010 American College of Rheumatology/European Alliance of Associations for Rheumatology classification criteria for RA and had definite RA-ILD according to Bongartz criteria. Data regarding pulmonary function test (PFT) results, adverse events (AEs), tolerability, and clinical data were collected. A linear mixed model with random intercept was used to compare the within-patient trajectory of the percent predicted forced vital capacity (FVCpp) within 18-months before to 18-months after antifibrotic initiation among those with these PFT data. Lung transplant-free survival and drug retention was estimated in a Kaplan-Meier analysis and a Cox regression analysis was performed to identify independent baseline factors associated with lung transplant or mortality. RESULTS: We analyzed 74 patients with RA-ILD that initiated antifibrotics (mean age 67.8 years, 53 % male); 40 patients initiated nintedanib and 34 initiated pirfenidone. Median follow-up was 89 weeks (min 4, max 387). There was a significant improvement in the estimated slope of FVCpp after antifibrotic initiation (-0.3 % per year after initiation compared to -6.2 % per year before antifibrotic initiation, p = 0.03). Nintedanib and pirfenidone had similar FVCpp trajectory. Twenty-six patients (35 %) died and 4 (5 %) had undergone lung transplantation during follow-up. Male sex and heavy smoking were each associated with the composite outcome of lung transplant or mortality. AEs were reported in 41 (55 %) patients, with gastrointestinal (GI) AEs being most common (n = 30). The initial antifibrotic was discontinued in 34 (46 %) patients mostly due to GI AEs (n = 19). The median drug retention time was 142 weeks (95 %CI 56, 262) with no difference between nintedanib and pirfenidone (p = 0.68). CONCLUSION: In this first real-world study of antifibrotic use dedicated to RA-ILD, antifibrotic initiation was associated with a modestly improved trajectory of FVCpp. AEs were frequently reported, particularly GI, and discontinuation was common. However, lung transplant and mortality rates were still high, emphasizing the need for further therapeutic strategies in patients with severe RA-ILD. These real-world data complement previous trial data that investigated efficacy and safety.

Increased mortality in patients with RA-associated interstitial lung disease: data from a French administrative healthcare database.

OBJECTIVES: Interstitial lung disease (ILD) is a severe extra-articular manifestation of rheumatoid arthritis (RA). The objectives of this study were to estimate mortality rate in patients with RA-ILD and identify factors affecting mortality. METHODS: Data from a French national claims database (Système National des Données de Santé) from 2013 to 2018 were analysed. Adults with an RA diagnosis (International Classification of Diseases (ICD)-10 codes M05, M06.0, M06.8 and M06.9) were included. ILD diagnosis was defined with ICD-10 code J84. Mortality rates were compared between patients with RA with and without ILD, using Cox proportional hazards regression, after matching 1:1 for age, sex, age at RA-ILD onset and RA duration. RESULTS: Among 173 132 patients with RA, 4330 (3%) also had ILD (RA-ILD). After matching, RA-ILD was associated with an increased mortality rate (HR 3.4, 95% CI 3.1 to 3.9). The HR for mortality was greater for: patients aged <75 years (HR 4.8, 95% CI 3.9 to 5.9) versus ≥75 years (HR 3.0, 95% CI 2.6 to 3.5); patients with ILD onset occurring before RA onset (HR 8.4, 95% CI 5.5 to 13.0) versus ILD onset occurring after RA onset (HR 2.9, 95% CI 2.6 to 3.3); and men (HR 5.2, 95% CI 4.4 to 6.2) versus women (HR 3.6, 95% CI 3.0 to 4.2). CONCLUSION: In this nationwide cohort study, RA-ILD was associated with increased mortality rate (vs in patients with RA without ILD), notably for those aged <75 years, those whose ILD preceded RA onset and men.

Rheumatoid arthritis, quantitative parenchymal lung features, and mortality among smokers.

OBJECTIVES: There have been limited investigations of the prevalence and mortality impact of quantitative computed tomography (QCT) parenchymal lung features in rheumatoid arthritis (RA). We examined the cross-sectional prevalence and mortality associations of QCT features, comparing RA and non-RA participants. METHODS: We identified participants with and without RA in COPDGene, a multicentre cohort study of current or former smokers. Using a k-nearest neighbor quantifier, high resolution CT chest scans were scored for percentage of normal lung, interstitial changes, and emphysema. We examined associations between QCT features and RA using multivariable linear regression. After dichotomizing participants at the 75th percentile for each QCT feature among non-RA participants, we investigated mortality associations by RA/non-RA status and quartile 4 vs quartiles 1-3 of QCT features using Cox regression. We assessed for statistical interactions between RA and QCT features. RESULTS: We identified 82 RA cases and 8820 non-RA comparators. In multivariable linear regression, RA was associated with higher percentage of interstitial changes (ß = 1.7 ± 0.5, p= 0.0008) but not emphysema (ß = 1.3 ± 1.7, p= 0.44). Participants with RA and >75th percentile of emphysema had significantly higher mortality than non-RA participants (HR 5.86, 95%CI 3.75-9.13) as well as RA participants (HR 5.56, 95%CI 2.71-11.38) with ≤75th percentile of emphysema. There were statistical interactions between RA and emphysema for mortality (multiplicative p= 0.014; attributable proportion 0.53, 95%CI 0.30-0.70). CONCLUSIONS: Using machine learning-derived QCT data in a cohort of smokers, RA was associated with higher percentage of interstitial changes. The combination of RA and emphysema conferred >5-fold higher mortality.

Gene-respiratory disease interactions for rheumatoid arthritis risk.

OBJECTIVE: We aimed to identify gene by respiratory tract disease interactions that increase RA risk. METHODS: In this case-control study using the Mass General Brigham Biobank, we matched incident RA cases, confirmed by ACR/EULAR criteria, to four controls on age, sex, and electronic health record history. Genetic exposures included a validated overall genetic risk score (GRS) for RA, a Human Leukocyte Antigen (HLA) GRS for RA, and the MUC5B promoter variant, an established risk factor for RA-associated interstitial lung disease (ILD). Preceding respiratory tract diseases came from diagnosis codes (positive predictive value 86%). We estimated attributable proportions (AP) and multiplicative odds ratios (OR) with 95% confidence intervals (CI) for RA for each genetic and respiratory exposure using conditional logistic regression models, adjusting for potential confounders. RESULTS: We identified 653 incident RA cases and 2,607 matched controls (mean 54 years, 76% female). The highest tertile of the overall GRS and the HLA GRS were both associated with increased RA risk (OR 2.28, 95% CI 1.89,2.74; OR 2.02, 95% CI 1.67-2.45). ILD and the HLA GRS exhibited a synergistic relationship for RA risk (OR for both exposures 4.30, 95% CI 1.28,14.38; AP 0.51, 95% CI-0.16,1.18). Asthma and the MUC5B promoter variant also exhibited a synergistic interaction for seropositive RA (OR for both exposures 2.58, 95% CI 1.10,6.07; AP 0.62, 95% CI 0.24,1.00). CONCLUSION: ILD-HLA GRS and asthma-MUC5B promoter variant showed synergistic interactions for RA risk. Such interactions may prove useful for RA prevention and screening.

Fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography in polymyalgia rheumatica: an observational study.

OBJECTIVES: Polymyalgia rheumatica (PMR) is an inflammatory disease with a diagnosis that is sometimes difficult to establish. Fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) might be helpful. We analysed the usefulness of 18F-FDG PET/CT for the diagnosis of PMR. METHODS: This was an observational retrospective study of individuals with PMR who underwent 18F-FDG PET/CT and a control group. We assessed clinical and 18F-FDG PET/CT characteristics. Sixteen sites were studied. The number of sites with significant FDG uptake, the mean maximum standardised uptake value (SUVmax) and the highest SUVmax value were assessed for each patient. RESULTS: Data for 123 patients with PMR (37 with corticosteroids [CSTs] use) were analysed; 85 had new-onset PMR. As compared with the 75 controls, patients with new-onset PMR had higher mean ± SD number of sites with significant FDG uptake (11.3 ± 3.3 vs. 0.9 ± 1.1, p<0.001) and higher SUVmax scores (p<0.001). A cut-off of 5 hypermetabolic sites provided sensitivity of 96.5% and specificity 100%. For the total SUVmax score, a cut-off of 3 had the best sensitivity (92.6%) and specificity (86.1%). As compared with PMR patients using CSTs, those who were CST-naive had significantly higher CRP level (p<0.001), number of sites with significant FDG uptake (p<0.001) and SUVmax scores (p<0.01). In contrast, large-vessel vasculitis was more frequent in patients receiving CSTs than CST-naive patients (27% vs. 8%, p<0.01). CONCLUSIONS: The number of hypermetabolic sites or SUVmax quantification might be useful for PMR diagnosis, and CSTs might affect the results of 18F-FDG PET/CT.

A Risk Score to Detect Subclinical Rheumatoid Arthritis-Associated Interstitial Lung Disease.

OBJECTIVE: Patients at high risk of rheumatoid arthritis-associated interstitial lung disease (RA-ILD) would benefit from being identified before the onset of respiratory symptoms; this can be done by screening patients with the use of chest high-resolution computed tomography (HRCT). Our objective was to develop and validate a risk score for patients who have subclinical RA-ILD. METHODS: Our study included a discovery population and a replication population from 2 prospective RA cohorts (ESPOIR and TRANSLATE2, respectively) without pulmonary symptoms who had received chest HRCT scans. All patients were genotyped for MUC5B rs35705950. After multiple logistic regression, a risk score based on independent risk factors for subclinical RA-ILD was developed in the discovery population and tested for validation in the replication population. RESULTS: The discovery population included 163 patients with RA, and the replication population included 89 patients with RA. The prevalence of subclinical RA-ILD was 19.0% and 16.9%, respectively. In the discovery population, independent risk factors for subclinical RA-ILD were presence of the MUC5B rs35705950 T allele (odds ratio [OR] 3.74 [95% confidence interval (95% CI) 1.37, 10.39]), male sex (OR 3.93 [95% CI 1.40, 11.39]), older age at RA onset (for each year, OR 1.10 [95% CI 1.04, 1.16]), and increased mean Disease Activity Score in 28 joints using the erythrocyte sedimentation rate (for each unit, OR 2.03 [95% CI 1.24, 3.42]). We developed and validated a derived risk score with receiver operating characteristic areas under the curve of 0.82 (95% CI 0.70-0.94) for the discovery population and 0.78 (95% CI 0.65-0.92) for the replication population. Excluding MUC5B rs35705950 from the model provided a lower goodness of fit (likelihood ratio test, P = 0.01). CONCLUSION: We developed and validated a risk score that could help identify patients at high risk of subclinical RA-ILD. Our findings support an important contribution of MUC5B rs35705950 to subclinical RA-ILD risk.

Salivary gland ultrasonography in patients with connective tissue diseases: a multi-centre observational study.

OBJECTIVE: US of salivary glands (SGUS) is a non-invasive tool that allows for diagnosing primary SS (pSS) or secondary SS (sSS). However, little is known about the prevalence of US findings of SS in other CTDs. The aim of this multi-centre observational study was to evaluate, in CTD patients with or without SS, the prevalence of abnormal SGUS findings and the possible association of the findings with clinical or biological phenotypes. METHODS: B-Mode SGUS was performed by one operator blinded to clinical data. Each SG was semi-quantitatively rated on a scale from 0 to 4 according to the Jousse-Joulin score; a score ≥2 was considered pathological. RESULTS: Data for 194 patients were analysed (pSS, n = 30; sSS, n = 39; other CTDs, n = 77; controls, n = 48). SGUS findings were abnormal in 80%, 67%, 25% and 2% of patients, respectively. Independent of the underlying disease, age and sex, abnormal SGUS findings were significantly associated with presence of anti-SSA antibodies (P < 0.001), pSS (P < 0.001) and sSS (P < 0.01). Among SS patients, abnormal SGUS findings were associated with the presence of hypergammaglobulinemia, anti-SSA antibodies, objective eye dryness and increased anti-nuclear antibody level, with no difference in EULAR SS Disease Activity Index. CONCLUSION: Abnormal SGUS findings were associated with anti-SSA antibody positivity independent of the underlying disease. In SS patients, abnormal findings were associated with immunologic features and mouth involvement. Among CTD patients, SGUS changes may be associated with a particular immune profile.

Clinical features and outcomes of patients with myositis associated-interstitial lung disease.

Introduction: Myositis associated interstitial lung disease (ILD) seems to be an under-recognized entity. Methods: In this multicenter, retrospective study, we recorded between 9/12/2019 and 30/9/2021 consecutive patients who presented in five different ILD centers from two European countries (Greece, France) and received a multidisciplinary diagnosis of myositis associated-ILD. The primary outcome was all-cause mortality over 1 year in specific subgroups of patients. Secondary outcomes included comparison of disease characteristics between patients diagnosed with the amyopathic subtype and patients with evidence of myopathy at diagnosis. Results: We identified 75 patients with myositis associated-ILD. Median age (95% CI) at the time of diagnosis was 64.0 (61.0-65.0) years. Antinuclear antibody testing was positive in 40% of the cohort (n = 30/75). Myopathy onset occurred first in 40.0% of cases (n = 30), ILD without evidence of myopathy occurred in 29 patients (38.7%), while 16 patients (21.3%) were diagnosed concomitantly with ILD and myopathy. The commonest radiographic pattern was cellular non-specific interstitial pneumonia (NSIP) and was observed in 29 patients (38.7%). The radiographic pattern of organizing pneumonia was significantly more common in patients diagnosed with the amyopathic subtype compared to patients that presented with myopathy [24.1% (n = 7/29) vs. 6.5% (n = 3/46), p = 0.03]. One year survival was 86.7% in the overall population. Kaplan-Meier analysis demonstrated significantly higher all-cause 1-year mortality in patients with the amyopathic subtype compared to patients with evidence of myopathy [H R 4.24 (95% CI: 1.16-15.54), p = 0.03]. Patients diagnosed following hospitalization due to acute respiratory failure experienced increased risk of 1-year all-cause mortality compared to patients diagnosed in outpatient setting [HR 6.70 (95% CI: 1.19-37.81), p = 0.03]. Finally, patients with positive anti-MDA5 presented with higher 1-year all-cause mortality compared to anti-MDA5 negative patients [HR 28.37 (95% CI: 5.13-157.01), p = 0.0001]. Conclusion: Specific ILD radiographic patterns such as NSIP and organizing pneumonia may herald underlying inflammatory myopathies. Hospitalized patients presenting with bilateral organizing pneumonia refractory to antibiotics should be meticulously evaluated for myositis associated-ILD even if there is no overt muscular involvement. Incorporation of ILD radiological patterns in the diagnostic criteria of inflammatory myopathies may lead to timely therapeutic interventions and positively impact patients' survival.

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.