Review/Advances in Neurological Therapeutics (2023). Autoimmune encephalitis

Abstract

We reviewed autoimmune encephalitis (AE) articles published in 2023. A meta–analysis was conducted to determine the effect of ovarian teratoma resection on patients with N–methyl–D–aspartate receptor (NMDAR) antibody encephalitis. However, the data were insufficient to provide a recommendation regarding teratoma resection. Recently, a fusion protein containing the Fc part of immunoglobulin G and NMDAR subunits was developed. This construct can neutralize NMDAR antibodies and inhibit the binding of NMDAR antibodies to receptors. Chimeric autoantibody receptor (CAAR)–T cells were also developed as a potential treatment for NMDAR encephalitis. CAAR–T cells express an extracellular NMDAR antigen and an intracellular signaling domain, which is cytotoxic only to B cells producing NMDAR antibodies. A retrospective study of anti–leucine–rich glioma–inactivated 1 (LGI1) encephalitis showed that a minority of patients experienced poor functional outcomes and relapse. Advanced age, cognitive impairment, and LGI1 antibody positivity in the cerebrospinal fluid were associated with poor outcomes. Another retrospective analysis of patients with anti–immunoglobulin–like cell adhesion molecule 5 disease showed that 41% had clinical improvement after short–term immunotherapy. Low pre–treatment serum neurofilament light chain levels and long–term immunotherapy initiation within the first year of disease onset were significant predictors of treatment response. A recent study analyzed the effect of long–term immunotherapy using rituximab and found that it was associated with a reduced hazard for time to first relapse and recurring relapses. Another study showed that immunotherapy was effective for most patients with seronegative as well as seropositive AE. In a study of patients with immunotherapy–refractory AE, escalation therapy with bortezomib and/or daratumumab improved functional outcomes, despite high disease severity at maximum disease. A study of AE patients treated with mycophenolate mofetil as a long–term immunotherapy reported that the beneficial effects of oral corticosteroid treatment do not persist beyond 12 months and the risk of adverse effects may be increased.