Distinctive cutaneous and systemic features associated with specific antimyositis antibodies in adults with dermatomyositis: a prospective multicentric study of 117 patients

International audienceBACKGROUND:Identification of myositis-specific autoantibodies (MSAs) for dermatomyositis (DM) could allow the characterization of an antibody-associated clinical phenotype.OBJECTIVE:We sought to define the clinical phenotype of DM and the risk of cancer, interstitial lung disease (ILD) and calcinosis based on MSA.METHODS:A 3.5-year multicentre prospective study of adult DM patients was conducted to determine the clinical phenotype associated with MSAs and the presence of cancer, ILD and calcinosis.RESULTS:MSAs were detected in 47.1% of 117 included patients. Patients with antimelanoma differentiation-associated protein-5 antibodies (13.7%) had significantly more palmar violaceous macules/papules [odds ratio (OR) 9.9], mechanic's hands (OR 8), cutaneous necrosis (OR 3.2), articular involvement (OR 15.2) and a higher risk of ILD (OR 25.3). Patients with antitranscriptional intermediary factor-1 antibodies (11.1%), antinuclear matrix protein-2 antibodies (6.8%) and antiaminoacyl-transfer RNA synthetase (5.1%) had, respectively, significantly more poikiloderma (OR 5.9), calcinosis (OR 9.8) and articular involvement (OR 15.2). Cutaneous necrosis was the only clinical manifestation significantly associated with cancer (OR 3.1).CONCLUSION:Recognition of the adult DM phenotype associated with MSAs would allow more accurate appraisal of the risk of cancer, ILD and calcinosis