Clinically Amyopatic Dermatomyositis with Anti-MDA5 Antibody Treated by Combination Therapy Including Intravenous Immunoglobulin

Abstract

A 56-year-old woman presented with violaceous erythema on her bilateral eyelids and mechanic's hands without myogenic change. The patient was diagnosed with amyopathic dermatomyositis (ADM) with highly positive anti-MDA5 antibody. Although anti-MDA5 antibody positive DM is often accompanied by rapidly progressive interstitial lung disease, the patient had no pulmonary abnormalities. We first treated her with oral prednisolone (PSL) alone at 1 mg/kg/day, because severe adverse effect of a combination immunosuppressive therapy were a concern. However, even after the initiation of PSL treatment, serum biomarkers, such as ferritin, KL-6, and anti-MDA5 antibody, increased progressively. Moreover, pulmonary ground-glass opacities were detected on a CT examination. Therefore, we switched the treatment to a combination with PSL, tacrolimus, intravenous cyclophosphamide, and intravenous immunoglobulin. The combination therapy ameliorated her skin symptoms without worsening of the pulmonary lesions. We conclude that a combination immunosuppressive therapy should be recommended for anti-MDA5 antibody highly positive DM patients.