LAUSR

OBJECTIVES In the present study, we aimed to assess the prevalence and clinical significance of anti-Ro52 antibodies in a cohort of patients with idiopathic inflammatory myopathy-associated interstitial lung disease (IIM-ILD) with different myositis-specific autoantibodies (MSAs). METHODS A cohort of 267 IIM-ILD patients, including 62 patients with polymyositis (PM), 126 patients with dermatomyositis (DM), and 79 patients with clinically amyopathic dermatomyositis (CADM), were retrospectively analysed in this study. Clinical and laboratory findings, pulmonary function tests (PFTs), HRCT patterns and treatment information were compared between patients with and without anti-Ro52 antibodies. The association between prognosis and anti-Ro52 antibodies was also evaluated based on different MSA subgroups. RESULTS Anti-Ro52 antibodies were more frequent in patients with anti-MDA5 (62.1%, p< 0.01) and anti-Jo1 (64.9%, p< 0.01) antibodies than in those with other MSAs. The proportion of patients with anti-Jo1 antibodies was higher in the anti-Ro52 antibody-positive group than in the anti-Ro52 antibody-negative group. Patients with anti-Ro52 antibodies were more likely to exhibit the Gottron sign than the anti-Ro52 antibody-negative group (p< 0.001). Furthermore, it was a predictive factor for rapid progression interstitial lung disease (RP-ILD) (p= 0.001) and was also associated with a higher mortality rate (log-rank test, p< 0.01). Furthermore, RP-ILD was more frequently exhibited in anti-MDA5- and anti-Ro52-positive patients. Moreover, anti-Ro52 antibody positivity was closely associated with a higher mortality rate in anti-MDA5-ILD patients (log-rank test, p< 0.05). CONCLUSIONS Anti-Ro52 antibodies were highly prevalent in patients with anti-MDA5 and anti-Jo1 antibodies. Within all patients with IIM-ILD, those with anti-Ro52 autoantibodies had a higher frequency of RP-ILD and a poorer prognosis, especially in the anti-MDA5 antibody subgroup.