Frequency and clinical relevance of anti-Mi-2 autoantibody in adult Brazilian patients with dermatomyositis

Abstract Background: To analyze the frequency and clinical relevance of anti-Mi-2 autoantibody in a representative sample of patients with dermatomyositis. Methods: This longitudinal inception cohort study, from 2001 to 2017, included 87 definite adult dermatomyositis. Anti-Mi-2 analysis was performed using a commercial kit. Results: Seventeen patients (19.5%) had anti-Mi-2 and 70 (80.5%) did not have this autoantibody. The following parameters were equally distributed between the patients with versus without anti-Mi-2: mean age at the disease diagnosis onset, median follow-up time, constit...