Sabbagh S, et al. - In a large cohort of patients with juvenile myositis, researchers defined the prevalence and clinical characteristics correlated with anti-Ro52 autoantibodies. Sera were screened for anti-Ro52 autoantibodies by ELISA in 302 patients with juvenile dermatomyositis, 25 patients with juvenile polymyositis and 44 patients with juvenile connective tissue disease–myositis overlap. Among myositis patients with and without anti-Ro52 autoantibodies, clinical features were compared. In 14% of patients with juvenile myositis, anti-Ro52 autoantibodies are present and strongly linked to anti-MDA5 and antiaminoacyl tRNA synthetase autoantibodies. Those with anti-Ro52 autoantibodies were more probable to have interstitial lung disease in all juvenile myositis patients. In addition, anti-Ro52 autoantibodies patients have more severe disease and poorer prognosis.