Anti-MDA5 Antibody Spectrum in Western World.

PURPOSE OF REVIEW: Anti-melanoma differentiation-associated gene 5 (anti-MDA5) is a novel and highly specific myositis-associated autoantibody, which defines a unique phenotype among patients with dermatomyositis (DM).

RECENT FINDINGS: Anti-MDA5 was originally characterized in Japan in DM patients with hallmark cutaneous features and no proximal muscle weakness and termed clinically amyopathic DM (CADM). Anti-MDA5 has characteristic cutaneous manifestations which include tender palmar papules and cutaneous ulcerations, along with an increased frequency of interstitial lung disease (ILD) that can be rapidly progressive (RPILD) and fatal. This review will highlight the clinical significance of anti-MDA5 autoantibodies in Caucasian DM patients.