Prevalence and clinical significance of anti-MDA5 antibodies in European patients with polymyositis/dermatomyositis

Polymyositis/dermatomyositis (PM/DM) is an autoimmune disease characterised by skin and muscle inflammation, internal organ involvement and serum disease-specific autoantibodies. The recently identified anti-MDA5 (melanoma differentiation-associated gene 5) antibodies are associated with clinically amyopathic DM (CADM), rapidly progressive interstitial lung disease, severe skin manifestations, and poor prognosis. Our objective was to examine the clinical significance of anti-MDA5 antibodies in a cohort of European Caucasian patients with PM/DM, considering that data on anti-MDA5 serology are limited to Asian and US cohorts.