Abstract:

Objective: To investigate the clinical characteristics, treatment regimens, and the efficacy and safety of antifibrotic agents in elderly patients with connective tissue disease-associated interstitial lung disease (CTD-ILD). Methods: This single-center retrospective cohort study enrolled 129 elderly patients (≥60 years) with a confirmed diagnosis of CTD-ILD at Beijing Hospital from June 2016 to June 2024. Baseline data, including comorbidities and CTD subtypes, treatment regimens (glucocorticoids, immunosuppressants, antifibrotic agents), pulmonary function parameters, high-resolution computed tomography (HRCT) imaging features, and adverse events were retrieved from the electronic medical record system. Treatment efficacy was evaluated according to the 2022 American Thoracic Society/European Respiratory Society criteria for progressive pulmonary fibrosis. Statistical analyses were performed using SPSS 26.0, with χ² tests or t-tests applied for between-group comparisons. Results: (1) Clinical characteristics: The predominant CTD subtypes were rheumatoid arthritis (RA), primary Sjögren syndrome (pSS), and polymyositis or dermatomyositis (PM/DM). Hypertension was present in 45.7% of the patients, reflecting the characteristics of multiple comorbidities in the elderly population. (2) CTD treatment regimens: 76.0% of the patients received glucocorticoid therapy, 83.7% used immunosuppressants (IS)/conventional synthetic disease-modifying antirheumatic drugs (csDMARDs), among which cyclophosphamide had the highest usage rate (47.3%); 31.8% of the patients were combined with antifibrotic drugs (nintedanib 16.3%, pirfenidone 10.1%, and 5.4% used both). (3) Efficacy of antifibrotic therapy: There was no statistically significant difference in the 6-month HRCT progression rate between the antifibrotic and non-antifibrotic groups (31.3% vs. 45.2%, P=0.193). However, the proportion of the patients with pulmonary function deterioration in the antifibrotic group was significantly lower than that in the non-antifibrotic group (34.1% vs. 53.4%, P=0.041), suggesting a potential role in delaying pulmonary function deterioration. (4) Safety of antifibrotic agents: Gastrointestinal adverse events occurred in 39.0% of the patients receiving antifibrotics (26.8% diarrhea, 22.0% nausea), and abnormal liver function was observed in 17.1%. (5) Long-term outcomes: During a 2-year follow-up, 67.4% of the patients experienced infections (47.3% pulmonary infections), 14.0% progressed to respiratory failure, and the all-cause mortality rate was 2.3%. Conclusion: The main subtypes of CTD-ILD in the elderly are RA, pSS, and PM/DM, which are often complicated with hypertension. Antifibrotic agents may significantly delay the deterioration of pulmonary function, but attention should be paid to the risks of gastrointestinal adverse effects and hepatotoxicity. Infection remains the primary complication, emphasizing the need to balance benefits of immunosuppressive therapy and the risk of infection to formulate treatment strategies.

Key words: Elderly, Connective tissue disease-associated interstitial lung disease, Antifibrotic agents