Abstract
INTRODUCTION: Adult-onset Still's disease (AOSD) complicated by macrophage activation syndrome (MAS) carries substantial mortality. The role of therapeutic plasma exchange (TPE) remains uncertain. METHODS: We retrospectively analyzed patients with AOSD-MAS treated with TPE at a single-center. RESULTS: All five patients had arthralgia, a salmon-pink rash, extreme hyperferritinemia, and multiorgan dysfunction including liver dysfunction. Prior to TPE, all patients received pulse glucocorticoids; three also received calcineurin inhibitors and one tocilizumab. TPE was initiated at a median of 12.0 days after diagnosis; the patients underwent a median of six sessions without major adverse events. Following TPE, fever and rash resolved; C-reactive protein (CRP), ferritin, and liver enzyme levels decreased without further corticosteroid escalation during and immediately after TPE. At 1 month, four patients achieved CRP < 1.0 mg/dL, four recovered with tapered immunosuppression. One patient died from cytomegalovirus infection despite MAS improvement. CONCLUSIONS: Adjunctive TPE was associated with rapid clinical and biochemical improvement.