Myositis-specific antibodies (MSA) are detected in over 80% of patients with dermatomyositis (DM). 1 Anti-Mi-2 antibodies were found to be specific for DM. 2 We encountered a patient in whom anti-Mi-2 autoantibodies were detected 3 months before the clinical diagnosis of DM and in whom steroid treatment was promptly initiated when myositis developed.

Myositis-specific antibodies (MSAs) are antibodies that against cytoplasmic or nuclear component involved in the regulation of protein synthesis in patients with idiopathic inflammatory myopathies (IIMs). They have been shown to be highly specific, be able to predict clinical features, and have prognostic implications in patients with IIMs. [1][2][3] In Japan, an enzyme-linked immunosorbent