The significance of myositis autoantibodies in idiopathic inflammatory myopathy concomitant with interstitial lung disease

Aim: This study identified factors associated with interstitial lung disease (ILD) in patients with idiopathic inflammatory myopathy (IIM) based on the latest classification and recent advances in autoantibody serology. Methods: We retrospectively analyzed data of 173 patients who underwent complete myositis autoantibody serology examination in a medical center in Taiwan from July 2018 to February 2020. After exclusion of patients who did not receive a final diagnosis of IIM, clinical features, serology data, concomitant diseases, treatment, presence of respiratory failure, and mortality rate of the remaining 97 patients were analyzed. Results: Of IIM patients in our cohort, 47.4% had ILD. ILD was significantly associated with subtypes of IIM, older age of onset, presence of mechanic’s hand, and presence of anti-Jo-1 and anti-Ro52 antibodies. Among five IIM subtypes, overlap myositis (OM) and dermatomyositis (DM) were significantly associated with a higher prevalence rate of ILD (67.5% in OM and 53.3% in DM). Among patients with OM, the presence of anti-Jo-1 (100%), anti-PL-7 (100%), and anti-EJ antibodies (77.8%) was most significantly associated with ILD. Conclusion: The latest classification of IIM, older age of onset, presence of mechanic’s hand, and presence of anti-Jo-1 and anti-Ro52 antibodies were significantly associated with ILD. Among five IIM subtypes, OM and DM had higher prevalence rate of ILD. Among OM patients, the presence of anti-Jo-1, anti-EJ, and anti-PL-7 antibodies was significantly associated with ILD. The study results may help physicians to timely screen and monitor pulmonary function in high-risk groups.