Comprehensive analysis of patients with rheumatoid arthritis associated interstitial lung disease.

Background/aims: To investigate the demographics, disease characteristics, and treatment modalities of patients with rheumatoid arthritis (RA) associated interstitial lung disease (ILD), focusing on ILD exacerbation and mortality.

Methods: This retrospective study included individuals aged ≥ 18 years diagnosed with RA-ILD at Ajou University Hospital from January 1999 to March 2022. Diagnosis was based on chest computed tomography (CT) scans; progression was monitored based on available follow-up pulmonary function tests (PFTs) and chest CTs. Logistic regression analysis identified factors associated with ILD progression and mortality.

Results: The study included participants with a mean age of 64.3 years, 48.3% of whom were male. Smoking status: 13.2% ex-smokers, 25.2% current smokers, 61.6% non-smokers. Mean RA and ILD duration were 134.0 and 87.5 months, respectively. Mean Disease Activity Score in 28 joints was 4.9. The usual interstitial pneumonia (UIP) pattern was seen in 60.3%. Baseline PFT showed a mean FVC of 81.9 L, diffusing capacity for carbon monoxide (DLco) of 58.7 mL/min/mm, and DLco corrected for alveolar volume of 83.4 mL/min. With a mean follow-up of 4 years, ILD progressed in 58.3% of patients, with a mortality rate of 21.2%. ILD progression and UIP pattern significantly influenced mortality. Methotrexate use did not impact progression or mortality.

Conclusion: RA-ILD patients showed diverse clinical profiles, with ILD duration and UIP pattern significantly affecting prognosis. Personalized management and vigilant monitoring are essential to improve outcomes for RA-ILD patients.