Pharmacologic Treatment of Anti-MDA5 Rapidly Progressive Interstitial Lung Disease

Purpose of the Review Idiopathic inflammatory myopathies are a heterogeneous group of autoimmune disorders. The presence of different autoantibodies allows clinicians to define distinct phenotypes. Antibodies against the melanoma differentiation-associated protein 5 gene, also called anti-MDA5 antibodies, are associated with a characteristic phenotype, the clinically amyopathic dermatomyositis with rapidly progressive interstitial lung disease. This review aims to analyze the different pharmacological options for the treatment of rapidly progressive interstitial lung disease in patients with anti-MDA5 antibodies. Recent Findings Evidence-based therapeutic recommendations suggest that the best initial approach to treat these patients is an early combination of immunosuppressive drugs including either glucocorticoids and calcineurin inhibitors or a triple therapy adding intravenous cyclophosphamide. Tofacitinib, a Janus kinase inhibitor, could be useful according to recent reports. High ferritin plasma levels, generalized worsening of pulmonary infiltrates, and ground-glass opacities should be considered predictive factors of a bad outcome. In this scenario, clinicians should consider rescue therapies such as therapeutic plasma exchange, polymyxin-B hemoperfusion, veno-venous extracorporeal membrane oxygenation, or even lung transplantation. Combined immunosuppressive treatment should be considered the first-line therapy for patients with anti-MDA5 rapidly progressive interstitial lung disease. Aggressive rescue therapies may be useful in refractory patients.