Interstitial Lung Disease Associated with Autoimmune Rheumatic Diseases: An Experience from Türkiye.

Objective: Interstitial lung disease (ILD) is one of the most challenging involvement of autoimmune rheumatic diseases (ARDs) and could lead to significant morbidity and mortality. In this article, a collaborative work of tertiary rheumatology and pulmonology centers describing demographic, serological, and radiological findings of patients with ARD associated with ILD (ARD-ILD) is presented. Methods: A descriptive, retrospective study, and data related to demographics, clinical, laboratory, radiologic, or histopathological findings of ILD were collected from the study participants' charts. Results: Around 212 patients with ARD-ILD were evaluated. Of the patients, 172 (81.1%) were female and 40 (18.9%) were male. The distribution of the rheumatic diseases was as follows: systemic sclerosis in 114 (53.8%), rheumatoid arthritis in 47 (22.2%), Sjögren's syndrome in 14 (6.6%), inflammatory myopathy in 16 (7.5%) patients, interstitial pneumonia with autoimmune features (IPAF) in 9 (4%) patients, undifferentiated connective tissue disease in 8 (3.8%), and systemic lupus erythematosus in 4 (1.9%). According to the radiological patterns, 71.7% of the patients had nonspecific interstitial pneumonia (NSIP), 13.7% had definite usual interstitial pneumonia (UIP), 8.5% had probable UIP, 3.8% had lymphocytic interstitial pneumonia, 1.9% had organizing pneumonia, and 0.5% had an atypical pattern. Conclusion: This study showed that the most common rheumatic disease causing ILD is still systemic sclerosis, and NSIP is more prominent as a radiological pattern. IPAF, a disease that has entered the literature in recent years, is also an important type of ILD. Given the multisystemic involvement of ARDs, collaboration among different disciplines is undoubtedly crucial in the diagnosis and management of these diseases.