Emergent role of complement inhibitors in myasthenic crisis: Understanding why, when and how

Abstract

We report the case of a 32-year-old woman with an 11-year history of thymomatous AChR antibody-positive generalized myasthenia gravis (gMG, MGFA IIIb) who experienced a myasthenic crisis (MC) during the postpartum period, requiring mechanical ventilation (MV). Initial treatment with therapeutic plasma exchange (TPE) and high-dose prednisone was ineffective, and pyridostigmine worsened airway secretions. Due to contraindications for IVIg, she was treated with the complement inhibitor eculizumab, following prophylactic meningococcal vaccination and antibiotic therapy. Six days after starting eculizumab, the patient showed marked improvement in muscle strength, respiratory function, and was successfully extubated. She was discharged from the intensive care unit (ICU) and continued bi-weekly Eculizumab infusions without adverse events. A systematic literature review identified 19 additional cases of MC treated with eculizumab, examining response timing, treatment efficacy, adverse events, and follow-up data. This case, along with the literature review, supports the possibility of using anti-complement therapy in patients unresponsive to conventional therapies in MC setting.

Keywords: Complement inhibitor therapy; Eculizumab; Myasthenia gravis; Myasthenic crisis.