BACKGROUND Given the phenotypic similarities between rheumatoid arthritis (RA)–associated interstitial lung disease (ILD) (hereafter, RA-ILD) and idiopathic pulmonary fibrosis, we hypothesized that the strongest risk factor for the development of idiopathic pulmonary fibrosis, the gain-of-function MUC5B promoter variant rs35705950, would also contribute to the risk of ILD among patients with RA. METHODS Using a discovery population and multiple validation populations, we tested the association of the MUC5B promoter variant rs35705950 in 620 patients with RA-ILD, 614 patients with RA without ILD, and 5448 unaffected controls. RESULTS Analysis of the discovery population revealed an association of the minor allele of the MUC5B promoter variant with RA-ILD when patients with RA-ILD were compared with unaffected controls (adjusted odds ratio, 3.8; 95% confidence interval [CI], 2.8 to 5.2; P = 9.7×10−17). The MUC5B promoter variant was also significantly overrepresented among patients with RA-ILD, as compared with unaffected controls, in an analysis of the multi-ethnic case series (adjusted odds ratio, 5.5; 95% CI, 4.2 to 7.3; P = 4.7×10−35) and in a combined analysis of the discovery population and the multiethnic case series (adjusted odds ratio, 4.7; 95% CI, 3.9 to 5.8; P = 1.3×10−49). In addition, the MUC5B promoter variant was associated with an increased risk of ILD among patients with RA (adjusted odds ratio in combined analysis, 3.1; 95% CI, 1.8 to 5.4; P = 7.4×10−5), particularly among those with evidence of usual interstitial pneumonia on high-resolution computed tomography (adjusted odds ratio in combined analysis, 6.1; 95% CI, 2.9 to 13.1; P = 2.5×10−6). However, no significant association with the MUC5B promoter variant was observed for the diagnosis of RA alone. CONCLUSIONS We found that the MUC5B promoter variant was associated with RA-ILD and more specifically associated with evidence of usual interstitial pneumonia on imaging. (Funded by Société Française de Rhumatologie and others.)

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Rheumatoid arthritis-associated interstitial lung disease (RA-ILD) has a heterogeneous clinical presentation and disease course. Establishing prognosis for these patients is challenging. Identifying the factors that predict mortality in patients with RA-ILD could help guide management. A detailed systematic review was conducted in order to identify individual variables that predict mortality in RA-ILD. A literature review was performed using keywords and medical subject headings to identify all articles relating to the prognosis of RA-ILD. Studies were included if they identified predictors of mortality in adults with RA-ILD, were published in English, and included at least 10 patients with RA-ILD. Two authors independently reviewed each citation and extracted data from all studies meeting inclusion criteria. Any differences were then resolved by consensus. A total of 10 studies met our inclusion criteria. All were observational cohort studies of variable quality. Mean age of reported patients ranged from 55 to 69 years, and 41.7% of all patients were male. Median survival ranged from 3.2 to 8.1 years. Significant predictors of mortality on multivariate analysis were older age, male gender, lower diffusion capacity for carbon monoxide, extent of fibrosis, and the presence of usual interstitial pneumonia pattern. Mortality in RA-ILD is associated with several patient-and ILD-specific variables; however, previous studies are of low quality.

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RationaleProgressive fibrosing interstitial lung disease (PF-ILD) is characterised by progressive physiologic, symptomatic, and/or radiographic worsening. The real-world prevalence and characteristics of PF-ILD remain uncertain.MethodsPatients were enrolled from the Canadian Registry for Pulmonary Fibrosis between 2015–2020. PF-ILD was defined as a relative forced vital capacity (FVC) decline ≥10%, death, lung transplantation, or any 2 of: relative FVC decline ≥5 and <10%, worsening respiratory symptoms, or worsening fibrosis on computed tomography of the chest, all within 24 months of diagnosis. Time-to-event analysis compared progression between key diagnostic subgroups. Characteristics associated with progression were determined by multivariable regression.ResultsOf 2746 patients with fibrotic ILD (mean age 65±12 years, 51% female), 1376 (50%) met PF-ILD criteria in the first 24 months of follow-up. PF-ILD occurred in 427 (59%) patients with idiopathic pulmonary fibrosis (IPF), 125 (58%) with fibrotic hypersensitivity pneumonitis (HP), 281 (51%) with unclassifiable ILD (U-ILD), and 402 (45%) with connective tissue disease-associated ILD (CTD-ILD). Compared to IPF, time to progression was similar in patients with HP (hazard ratio [HR] 0.96, 95% confidence interval, CI 0.79–1.17), but was delayed in patients with U-ILD (HR 0.82, 95% CI 0.71–0.96) and CTD-ILD (HR 0.65, 95% CI 0.56–0.74). Background treatment varied across diagnostic subtypes with 66% of IPF patients receiving antifibrotic therapy, while immunomodulatory therapy was utilised in 49%, 61%, and 37% of patients with CHP, CTD-ILD, and U-ILD respectively. Increasing age, male sex, gastroesophageal reflux disease, and lower baseline pulmonary function were independently associated with progression.InterpretationProgression is common in patients with fibrotic ILD, and is similarly prevalent in HP and IPF. Routinely collected variables help identify patients at risk for progression and may guide therapeutic strategies.

The coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2, has affected virtually all aspects of patient care. Health-care systems around the world are trying simultaneously to treat patients with COVID-19, prepare for its longterm impacts, and treat patients with other acute and chronic diseases. There are multiple ways that the COVID-19 pandemic will directly affect patients with fibrotic interstitial lung disease (ILD), particularly given their common risk factors for poor outcomes. Major issues for patients with ILD will include restricted access to key components of the diagnostic process, new uncertainties in the use of common ILD pharmacotherapies, limited ability to monitor both disease severity and the presence of medication adverse effects, and significantly curtailed research activities. The purpose of this review is to summarize how COVID-19 has impacted key components of the diagnosis and management of fibrotic ILD as well as to provide strategies to mitigate these challenges. We further review major obstacles for researchers and identify priority areas for future ILD research related to COVID-19. Our goals are to provide practical considerations to support the care of patients with ILD during the COVID-19 pandemic and to provide a road map for clinicians caring for these patients during future infectious disease outbreaks.

The objective of this study was to develop a diagnostic model that allows for a highly specific diagnosis of chronic hypersensitivity pneumonitis using clinical and radiological variables alone. Chronic hypersensitivity pneumonitis and other interstitial lung disease cases were retrospectively identified from a longitudinal database. High-resolution CT scans were blindly scored for radiographic features (eg, ground-glass opacity, mosaic perfusion) as well as the radiologist’s diagnostic impression. Candidate models were developed then evaluated using clinical and radiographic variables and assessed by the cross-validated C-statistic. Forty-four chronic hypersensitivity pneumonitis and eighty other interstitial lung disease cases were identified. Two models were selected based on their statistical performance, clinical applicability and face validity. Key model variables included age, down feather and/or bird exposure, radiographic presence of ground-glass opacity and mosaic perfusion and moderate or high confidence in the radiographic impression of chronic hypersensitivity pneumonitis. Models were internally validated with good performance, and cut-off values were established that resulted in high specificity for a diagnosis of chronic hypersensitivity pneumonitis.

Purpose:To determine the accuracy of computed tomography (CT) in identifying the histopathologic usual interstitial pneumonia (UIP) pattern in rheumatoid arthritis-associated interstitial lung disease (RA-ILD). Materials and Methods:All patients were enrolled into institutional review boardapproved longitudinal cohorts at their respective institution, and informed consent was obtained at the time of enrollment. Images of patients with surgical lung biopsyproved RA-ILD (n = 69) were collected from three tertiary care centers. Two experienced thoracic radiologists independently reviewed the CT scans. The CT pattern was categorized as definite UIP, possible UIP, or inconsistent with UIP in accordance with published criteria. Findings of biopsies were reviewed by an experienced lung pathologist. The sensitivity and specificity of definite CT UIP pattern to histopathologic UIP pattern were determined. The agreement between radiologists was assessed by calculating a k score. Results:The histopathologic UIP pattern was present in 42 of 69 (61%) patients. Men were more likely than women to have a histopathologic UIP pattern (P = .02). Twenty patients (29%, 20 of 69) had a definite UIP pattern on CT scans. The specificity of CT UIP pattern was 96% (26 of 27; 95% confidence interval [CI]: 81%, 100%), with a negative predictive value of 53% (26 of 49). The sensitivity of CT UIP pattern was 45% (19 of 42; 95% CI: 30%, 61%), with a positive predictive value of 95% (19 of 20).The agreement between radiologists for definite UIP pattern versus not was 87% (k = 0.67, P , .0001). Conclusion:Definite UIP pattern on a CT scan in RA-ILD is highly specific and moderately sensitive for histopathologic UIP pattern. CT can therefore help accurately identify the UIP pattern in RA-ILD.q RSNA, 2013