Immunotherapies on autoimmune encephalitis

Autoimmune encephalitis (AE) is a heterogeneous inflammatory syndrome caused by autoantibodies targeted at either neuronal cell surface proteins and synaptic receptors, or at intracellular epitopes. Clinical presentation is dependent on the underlying neuronal antigen, typically involving subacute progressive cognitive deficits, psychiatric and behavioral disturbances, seizures, hyperkinesia, and autonomic dysfunction. Prompt diagnosis and treatment of AE can result in clinical remission and favorable long-term prognosis, diminishing risk of relapse, morbidity, and mortality. Current treatment regimens are primarily based on retrospective case studies and expert opinion, as robust randomized-controlled trials are lacking. First-line immunotherapy involves high-dose intravenous glucocorticoids, intravenous immunoglobulins (IVIg) and plasmapheresis, or a combination of these agents. In severe cases or relapsing disease, sequential treatment with second-line therapy with rituximab or cyclophosphamide is indicated. Novel drugs options have been introduced to the field in recent years, although data regarding clinical efficacy is sparse. Maintenance therapy is only indicated for specific antibodies, or in patients with multiple relapses.