Anti-mda5 antibody-positive dermatomyositis complicated by autoimmune-associated hemophagocytic syndrome that was successfully treated with immunosuppressive therapy and plasmapheresis

Abstract

A 56-year-old Japanese woman with muscle weakness, increased creatine kinase and aldolase levels, and characteristic cutaneous lesions was diagnosed with anti-melanoma differentiation-associated gene 5 antibody (anti-MDA5 antibody)-positive dermatomyositis. She also had interstitial lung disease (ILD). After corticosteroid and tacrolimus combination therapy was started, bicytopenia and elevated serum ferritin and trans-aminase emerged. Because the bone marrow tissues were hypoplastic with hemophagocytes, she was diagnosed with concomitant autoimmune-associated hemophagocytic syndrome (HPS). Intravenous cyclophosphamide pulse therapy and plasmapheresis were performed. The laboratory findings indicated improved abnormalities, and the ILD did not progress. Anti-MDA5 antibody-positive dermatomyositis can be complicated by HPS.