The safety and efficacy of intravenous immunoglobulin in autoimmune encephalitis

Abstract

Objective Although intravenous immunoglobulin (IVIG) is the first‐line immunotherapy in autoimmune encephalitis, all supporting evidence comes from retrospective case series. Here, we performed a prospective clinical trial of IVIG for functional recovery in autoimmune encephalitis. Methods This single‐arm, open‐label study assessed the efficacy and safety of 10% intravenous IVIG treatment in newly diagnosed patients with possible autoimmune encephalitis. Patients received IVIG (0.4 g/kg/day) for 5 days. Rescue immunotherapy was permitted when the patient deteriorated before day 8 or showed no improvement at day 8. The primary outcome was the change in the modified Rankin Scale (mRS) score at day 8 and 29. The secondary outcomes were the mRS score improvement and the score changes and improvements on four other clinical scales. Results Overall, 23 patients received IVIG (intension‐to‐treat, ITT), and 18 patients completed the study according to the protocol (per‐protocol, PP). mRS improved significantly at days 8 and 29 compared to baseline in both the ITT and PP populations. Other secondary outcomes also improved significantly at day 8, 15, and 29 versus baseline. In the PP population, 6/18 patients achieved favorable outcomes with IVIG alone (mRS = 0~2 at day 8), and 12/18 patients received rescue immunotherapy. Five adverse events were reported in relation to IVIG, all of which were mild. Interpretation IVIG improved neurological functional outcomes, and the improvement was evident by day 8. Adverse effects were tolerable. These data provide the prospective evidence regarding the efficacy of IVIG in improving the functional outcomes of autoimmune encephalitis.

Postvaccinal GABA‐B receptor antibody encephalitis after ChAdOx1 nCoV‐19 vaccination

“… 14 In our institution, a prospective clinical trial of IVIg for functional recovery in autoimmune encephalitis was conducted. 15 The study revealed favorable efficacy of IVIg regarding functional outcomes of autoimmune encephalitis. As supported by this case, when it is difficult to administer high‐dose corticosteroids, the use of IVIg alone seems to be sufficiently effective as a first‐line therapy for autoimmune encephalitis treatment.…”

“…If antibody‐mediated autoimmune encephalitis, such as N‐methyl‐D‐aspartate receptor (NMDAR) antibody encephalitis, was suspected, 40% of responders chose the use of IVIg alone or in combination therapy 14 . In our institution, a prospective clinical trial of IVIg for functional recovery in autoimmune encephalitis was conducted 15 . The study revealed favorable efficacy of IVIg regarding functional outcomes of autoimmune encephalitis.…”

Autoimmune Encephalitis With Autoimmune Diabetes: A Case of Horror Autotoxicus

“…Therapeutic plasma exchanges in refractory autoimmune encephalitis had been successful in around 50% of patients (predominantly anti-NMDAR encephalitis) [ 30 ]. Response of seronegative autoimmune encephalitis to IVIg has been recently reported to be favorable in most cases and one-third of patients as monotherapy, yet few may require other lines of treatment [ 31 ]. Second-line agents include alkylating agents, such as cyclophosphamide, often avoided due to toxicity, and B-cell depleting agents, such as anti-CD20 rituximab.…”

Catatonia in adult anti-NMDAR encephalitis: an observational cohort study

“…Poor outcomes were defined as an mRS score ≥ 3 at follow-up. Unfavourable clinical outcomes were also defined by a CASE score ≥ 4 [ 34 ]. Relapse was identified as the presence of any new symptoms or a worsening of previous symptoms after being stable for 2 months.…”