Objective Interstitial lung disease (ILD) is common in idiopathic inflammatory myositis (IIM), particularly in antisynthetase syndrome (ASyS), antimelanoma differentiation‐associated protein 5 (anti‐MDA5) syndrome, and scleromyositis. ILD can progress despite resolution of extrapulmonary symptoms, termed postmyopathic progressive pulmonary fibrosis (PmPPF). We outlined ILD trajectories in these subgroups of IIM, focusing on PmPPF. Methods A retrospective review of patients with IIM (ASyS, anti‐MDA5+ dermatomyositis DM, scleromyositis) from a British Columbia cohort (2019–2024) assessed demographics, auto‐antibodies, treatments, and ILD progression. Results Among 111 patients with ASyS, anti‐MDA5+ DM, and scleromyositis (median age 51 years, follow‐up 35.5 months), ILD prevalence was highest in ASyS (87.5%), followed by anti‐MDA5+ DM (84.6%), and scleromyositis (65.5%). PmPPF occurred in 13.5% of the cohort, predominantly in anti‐MDA5+ DM (23.1%) and ASyS (16.1%) but not in scleromyositis. Patients with PmPPF had higher rates of active disease (46.7% vs 9.3%), rapidly progressive ILD (33.3% vs 5.3%), and lung transplantation (20% vs 1.3%). Anti‐MDA5+ DM exhibited the highest remission rate (88.5%) but also the highest transplant requirement (11.5%). Organizing pneumonia (OP)/nonspecific interstitial pneumonia (NSIP) overlap on high‐resolution computed tomography was more common in PmPPF (33.3% vs 9.3%). PmPPF showed a nonsignificant trend toward higher mortality compared to non‐PmPPF (20% vs 4%). Rituximab use was greater in PmPPF (73.3% vs 37.3%). Conclusion This study highlights distinct ILD patterns across three idiopathic inflammatory myopathy subtypes, with PmPPF occurring more frequently in ASyS and anti‐MDA5+ DM but not in scleromyositis. The persistence of ILD progression independent of extrapulmonary disease activity underscores the importance of ongoing pulmonary monitoring and multidisciplinary management. image
Clark et al. (Thu,) studied this question.