Dermatomyositis with Rapidly Progressive Interstitial Lung Disease Treated with Rituximab: A Report of 3 Cases in Japan.

We performed a retrospective chart review of three patients with hypomyopathic dermatomyositis and rapidly progressive interstitial lung disease. The patients were Japanese women of 71, 69, and 65 years of age. Two patients were anti-melanoma differentiation-associated gene 5 (anti-MDA5) antibody-positive and 1 was anti-aminoacyl-tRNA synthetase (anti-ARS) antibody-positive. Their respiratory statuses deteriorated despite the administration of glucocorticoid, calcineurin inhibitors, and intravenous cyclophosphamide therapy. We subsequently administered rituximab. The anti-ARS antibody-positive patient survived, while 2 anti-MDA5 antibody-positive patients died.