Background:  Rheumatoid arthritis (RA) can present both chronic arthritis and extra-articular involvement. Pulmonary involvement is the most frequent extra-articular manifestation and can lead to high morbidity and mortality. Interstitial lung disease (ILD) is the most common lung manifestation of RA.

Methods: A retrospective cohort study extracted RA patients from an electronic database of Songklanagarind Hospital from January 2013 to December 2022. We aimed to identify clinical characteristics, imaging patterns, and identify risk factors of RA-associated lung diseases. Risk factors of lung involvement were analyzed by univariate and multivariate logistic regression analyses.

Results: Overall 2,350 RA patients were included and a total of 269 RA patients who had high-resolution computed tomography (HRCT) of the chest were reviewed. Most of the patients (80.7%) were female, with a mean age of 60.1±13.5. The prevalence of RA-ILD and airway diseases were 17.5% and 23.8%, respectively. The most common type of ILD was usual interstitial pneumonia (UIP) about 51%, whereas bronchiectasis was the leading pattern of airway diseases. FEV₁, FEV₁/FVC, and FVC were significantly declined overtime in RA-associated lung disease. Older age, elevated levels of rheumatoid factor (RF), and elevated erythrocyte sedimentation rate (ESR) were significant risk factors of RA-associated lung diseases.

Conclusion: RA-ILD and RA-related airway diseases are the two common pulmonary manifestations in RA patients. Pulmonary function parameters significantly declined overtime in RA-associated lung disease.