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

Abstract

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. 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. 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. 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.