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.