Autoimmune interstitial lung disease in Latin-America

Information about the prognosis and natural history of autoimmune interstitial lung diseases (Ai-ILD) is limited. The aim of the study was to evaluate the characteristics of patients diagnosed with Ai-ILD in Latin-America. We conducted an ambispective multicenter cohort study in 25 centers of Argentina, Colombia, and Uruguay between January 2015 and April 2018. Participants were included in the study if they had diagnosis of Ai-ILD performed by a multidisciplinary team. Patients were classified into the following sub-groups: connective tissue disease-associated ILD (ILD-CTD), interstitial pneumonia with autoimmune features (IPAF), and positive antineutrophils cytoplasmatic antibodies associated ILD (ILD-ANCA). All images were reviewed by a blinded thoracic radiologist. Out of the 381 patients included during the study period, 282 (74%; 95% CI; 69.39-78.16) were women. Mean age was 58 years old (SD 16). Three-hundred and twenty-five (85.1%; 95% CI 81.39-88.5) patients were classified as ILD-CTD (rheumatoid arthritis 31%, systemic sclerosis 29%, dermatomyositis 15%). Thirty-six patients were classified as IPAF (9.5%; 95% CI 6.9-12.8), and 13 (3.5%; 95% CI 2-5.75) as ILD-ANCA. Fifty percent of patients (95% CI 45.12-55.43) had a mild decrease of the forced vital capacity at the time of diagnosis. The most common treatment strategy was the combination of steroids and cyclophosphamide (30.1%; 95% CI 25.32-35.34) followed by azathioprine (20,3%; 95% CI 16.32-25.14). In conclusion, to the best of our knowledge, this is the first study to evaluate the characteristics and treatment strategies used in patients affected by Ai-ILD in Latin-America. Future studies should to evaluate the prognosis and impact of current treatment strategies in patients with Ai-ILD.