Splicing factor proline/glutamine-rich is a novel autoantigen of dermatomyositis and associated with anti-melanoma differentiation-associated gene 5 antibody

Anti-MDA5 antibody positive dermatomyositis (DM) and clinically amyopathic DM (CADM) often develop into rapidly progressive interstitial lung disease, but their pathogenesis remains unclear. We observed that sera from DM/CADM patients immunoprecipitated a common 110 kDa polypeptide. We investigated this autoantigen and its clinical significance.Autoantibodies were screened in 333 patients with various connective tissue diseases (CTDs) and 20...