Complement Inhibition for Acute Neuromyelitis Optica Spectrum Disorder Attacks: Insights From an International Case...

Area of Science:

• Neurology
• Immunology
• Autoimmune Diseases

Background:

• Neuromyelitis optica spectrum disorder (NMOSD) is a severe autoimmune condition driven by aquaporin-4 antibodies (AQP4-IgG).
• Acute NMOSD attacks involve complement system activation, leading to astrocyte destruction and irreversible neurological damage.
• Terminal complement inhibitors are approved for relapse prevention but their role in acute attacks is less understood.

Purpose of the Study:

• To investigate the efficacy of complement component 5 (C5) inhibition in managing acute NMOSD attacks.
• To evaluate the potential of eculizumab and ravulizumab in mitigating disability during NMOSD relapses.

Main Methods:

• A multinational retrospective case series of 33 patients with AQP4-IgG-positive NMOSD treated with C5 inhibitors during acute relapse.
• Analysis of treatment timing, lesion locations (myelitis, optic neuritis), disability scores (EDSS), and recovery rates.
• Comparison of outcomes based on treatment initiation time and use of adjunctive therapies like plasma exchange.

Main Results:

• Patients treated with C5 inhibition showed clinical stabilization and improved Expanded Disability Status Scale (EDSS) scores post-relapse.
• Earlier treatment (within 21 days) was associated with better response, though not statistically significant in this series.
• Most patients experienced moderate to good recovery, with 20 continuing C5 inhibition for attack prevention.

Conclusions:

• C5 inhibition demonstrates potential as a treatment for acute NMOSD attacks, especially in patients with suboptimal response to standard therapies.
• The observed clinical stabilization and recovery suggest further investigation into C5 inhibition for acute NMOSD management is warranted.
• This study provides Class IV evidence supporting the use of C5 inhibitors in acute NMOSD relapse management.