Effectiveness and safety of plasma exchange for anti‐MDA5 antibody–positive clinically amyopathic dermatomyositis with rapidly progressive interstitial lung disease refractory to intensive immune suppression therapy: A case series.

Introduction: Clinically amyopathic dermatomyositis (CADM) with anti‐melanoma differentiation‐associated gene 5 (MDA5) antibody (Ab) with rapidly progressive interstitial lung disease (RP‐ILD) is often refractory for intensive immunosuppression. In this study, we verified the effectiveness and safety of plasma exchange (PEx) for this lethal disease. Methods: We retrospectively examined the clinical course and adverse effect (AE) of 12 patients with anti‐MDA5 Ab–positive CADM between January 2017 and December 2021 in our hospital. Results: Five out of six patients treated with simple PEx using fresh frozen plasma or 5% albumin survived with or without home oxygen therapy. Multiple PEx (15–20 times) were required to achieve satisfactory improvement as well as remission of CADM. The AEs caused by PEx were resolved using conventional methods. Conclusion: PEx might be a promising option for controlling the disease activity of anti‐MDA5 Ab–positive CADM with severe RP‐ILD and may contribute to better survival. [ABSTRACT FROM AUTHOR]