Rapidly Progressive Interstitial Lung Disease Associated with Melanoma Differentiation-Associated Gene 5 Antibody.

Anti-melanoma differentiation-associated gene-5 (MDA-5) antibody is an autoantibody found in patients with dermatomyositis. These antibody-positive patients are clinically characterized by complications of rapidly progressive interstitial pneumonia resistant to treatment and with poor prognosis. We describe herein a patient with MDA-5 antibody-positive interstitial lung disease, which progressed rapidly to death after a period of slow progress. Recently, attention has been paid to the similarities in clinical courses and CT images between MDA-5 antibody-positive interstitial lung disease and coronavirus disease 2019 (COVID-19)-associated pneumonia. Patients with MDA-5 antibody do not always have diffuse and evenly distributed bilateral opacities at the time of first presentation. This patient had significant laterality of such opacities. It should be considered that MDA-5 antibody-positive patients with such laterality in opacities might progress rapidly. Chest physicians, dermatologists, and dermatologists need to be aware of the characteristics of the disease for optimal treatment choices.