Plasma exchange in adult idiopathic inflammatory myositis: a systematic review and meta-analysis

OBJECTIVES: To systematically evaluate the efficacy and safety of plasma exchange (PE) in adult patients with idiopathic inflammatory myopathies (IIM). METHODS: A systematic review was conducted in accordance with PRISMA guidelines and registered on PROSPERO. MEDLINE, Embase and Web of Science were searched from inception to 17 January 2025. Studies involving adult patients with IIM treated with PE were included. Baseline demographics, clinical characteristics, treatment outcomes and adverse events were extracted. RESULTS: = 70%). In immune-mediated necrotising myopathy, PE was frequently associated with clinical improvement and reductions in anti-HMGCR antibody titres. Reported adverse events were generally mild to moderate, with no procedure-related mortality. CONCLUSION: PE has a biologically plausible but clinically selective role in adult IIM and is most commonly used as an adjunctive therapy in severe or refractory disease. Evidence is heterogeneous and largely observational, limiting causal inference. Prospective studies with standardised outcome measures are required to better define the role of PE in IIM.