Efficacy and tolerability of intravenous immunoglobulin versus intravenous methylprednisolone treatment in anti‐N‐methyl‐d‐aspartate receptor encephalitis

The aim was to compare the effectiveness and safety of intravenous immunoglobulin (IVIg) or intravenous methylprednisolone (IVMP) versus IVIg plus IVMP (IPI) as initial therapy in anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis.This was a multicenter study of prospectively identified NMDAR encephalitis individuals who presented from October 2011 to August 2020 to the study hospitals of western China, with a median follow-up of 3.9 years. Prespecified candidate variables were the prescriptions of IVIg, IVMP or IPI. Propensity score matching was also performed to control potential confounders.A total of 347 NMDAR encephalitis patients were finally analyzed in this study. After TriMatch for NMDAR encephalitis, 37 triplets were generated. Compared to IVIg or IVMP, the administration of IPI exhibited a significant benefit of a higher response rate (86.5% vs. 55.6% vs. 68.7%, pcorr < 0.01), improved modified Rankin Scale score at 3, 6 and 12 months (pcorr < 0.05), and reduced further recurrence rate (10 of 37 [27.0%] vs. 9 of 37 [24.3%] vs. 2 of 37 [5.4%]; p log rank = 0.01). There was no association between treatment superiority and patient sex or the presence of tumors (p ≥ 0.05). Patients treated with IVMP had a significantly higher number of adverse events, but 99% of adverse events were mild to moderate and did not lead to a change in treatment.In patients with NMDAR encephalitis, adequate response, favorable outcome and less recurrence were each more likely to occur in individuals treated with a combined immunotherapy than in monotherapy individuals.