Abstract Introduction Interstitial lung disease (ILD) is a common complication of idiopathic inflammatory myopathies, with a prevalence of 20-43%. Currently, myositis-specific antibodies (MSAs) are available, which have facilitated phenotying. Methods Descriptive case series of clinical features and ouctomes of patients with ILD and positive for at least one MSA in three centers of Colombia. Results 21 cases were included, of which 71.4% were female, with a median age of 56 years (interquartile range IQR 47-65), and a median age at clinical presentation of 50 years (42-64). A history of smoking was noted in 46.7%. The predominant radiological patterns were nonspecific interstitial pneumonia (NSIP) (61.9%), organizing pneumonia (14.28%), lymphoid interstitial pneumonia (LIP), and usual interstitial pneumonia (UIP), with one case each (4.76%). Pulmonary fibrosis was present in 53.3%.Initial mean forced vital capacity (FVC) was 77.5% (68-84, diffusing capacity for carbon monoxide (DLCO) was 65% (51-97). Initial 6-minute walk test median distance was 487 meters, and 449 meters at follow-up.Polioautoimmunity was observed in 28.5%, and Sjögren’s syndrome in 19%. Antinuclear antibodies (ANA) were detected in 71.4%, with a median titer of 1:320 (1:160-1:1280). Concerning the MSA panel, the most frequently detected antibody was anti-Ro52 (N = 7), all of which were associated with other autoantibodies (see Figure 1).Initial clinical involvement was pulmonary in 33.3% (N = 7), muscular in 23.8% (N = 5), cutaneous in 23.8% (N = 5), and combined in a smaller proportion (N = 2; 9.5%). The most common symptoms included muscle weakness in 66.7% (N = 14), joint pain in 38.1% (N = 8), and skin involvement in 61.9% (N = 13). One case of associated pulmonary neoplasia was identified.All patients received more than one immunosuppressive agent: 66.7% received corticosteroids, 42.8% azathioprine, 38.1% rituximab, and 28.5% cyclophosphamide. Pulmonary progression was documented in 23.8%, and exacerbation in 19%. Overall mortality was 28.5% (N = 6); all deceased patients had combinations including either anti-Ro52 or anti-MDA5. Conclusions In patients with ILD and MSAs, the predominant radiological pattern was NSIP and a serological profile characterized by combinations of anti-Ro52 with other MSAs. This, along with the presence of polioautoimmunity—particularly related to Sjögren’s syndrome—warrants further investigation into potential associations between these conditions. The MSAs combination with higher mortality involved the presence of anti-Ro52 or anti-MDA5. Additionally, the high frequency of interstitial involvement as the initial manifestation and the observed mortality—despite relatively preserved pulmonary function—highlight the importance of early diagnosis, molecular panel testing, and prompt intervention to improve outcomes, especially in the setting of developing countries. This abstract is funded by: None
Rojas et al. (Fri,) studied this question.