Comparative Efficacy of Double-Filtration Plasmapheresis Versus Intravenous Methylprednisolone in Acute Attacks of Neuromyelitis Optica Spectrum Disorder: A Prospective Cohort Study.

INTRODUCTION: While double-filtration plasmapheresis (DFPP) and intravenously administered methylprednisolone (IVMP) are both established treatments for acute attacks of neuromyelitis optica spectrum disorder (NMOSD), their comparative efficacy and safety profiles remain a critical area of investigation. This study aimed to evaluate the clinical outcomes and adverse events of DFPP versus IVMP in patients with NMOSD, with a focus on disability improvement and treatment tolerability. METHODS: A prospective single-center cohort study was performed with 146 patients with NMOSD, who were treated with DFPP, IVMP, and combination therapy (DFPP + IVMP). Primary efficacy was measured by changes in Expanded Disability Status Scale (EDSS) scores (ΔEDSS). Secondary outcomes included Modified Rankin Scale (mRS) scores. Safety profiles, including liver enzyme elevation and infection rates, were monitored. RESULTS: The DFPP group (n = 81) demonstrated a significant clinical response, with a median EDSS improvement of 0.5 (IQR 0.0-1.0) points. The response rate (defined as ΔEDSS > 0) was 66.7%, with 33.3% (27/81), 18.5% (15/81), and 14.8% (12/81) of patients achieving improvements of 0.5, 1.0, and ≥ 1.5 points, respectively. This was accompanied by a marked reduction in serum immunoglobulins (IgG: 11.87 ± 4.39 to 3.13 ± 1.76 g/L, p < 0.001). The DFPP group and IVMP monotherapy group showed comparable efficacy, with 66.7% (54/81) and 69.2% (45/65) of patients achieving EDSS improvement, respectively (OR 0.89, 95% CI 0.45-1.77, p = 0.742). The magnitude of EDSS improvement was identical between groups (median ΔEDSS 0.5 points). Combination therapy demonstrated particular utility in severe cases (median baseline EDSS 5.0 [IQR 3.5-6.5]). Adverse events were fewer with DFPP than with IVMP (19.8% vs. 33.8%, p = 0.059). CONCLUSION: DFPP exhibited comparable effectiveness to IVMP in improving disability during NMOSD acute attacks, with a trend towards a more favorable safety profile. The combination of DFPP and IVMP may benefit severe cases. These findings support DFPP as a viable therapeutic option, particularly for patients with high baseline disability or steroid-refractory disease.