Immunotherapy in Autoantibody-Associated Psychiatric Syndromes in Adults

Background: Autoantibody-associated psychiatric syndromes are often distinct from, but might also be part of autoimmune encephalitis. Our article focuses on potential immunotherapy in these patients with a probable autoimmune origin of their psychiatric syndrome. Methods: We searched through PubMed for appropriate articles on immunotherapy in autoantibody-associated psychiatric syndromes between 2010 and 2020 for this narrative review. Results: In line with prior recommendations for autoimmune encephalitis and autoimmune psychosis, we suggest that in patients with a probable autoimmune-based psychiatric syndrome should be given early corticosteroids, intravenous immunoglobulins, or plasmapheresis as first line immunotherapy. If these therapeutic options fail, second-line immunotherapy should be applied within 1 month consisting of rituximab or cyclophosphamide. Maintenance therapy is best for those patients responding to steroids including mycofenolate mofetil or azathioprine. So far, there is evidence from a few retrospective cohort studies supporting the usage of first- and second-line, and maintenance immunotherapies for autoantibody-associated psychiatric syndromes. Some immunological agents are discussed that might exert an effect in autoimmune-based psychiatric syndromes, but the latest evidence is low and derived from case reports or series with autoimmune encephalitis patients. Conclusions: Taken together, the immunotherapeutic landscape for patients with autoantibody-associated psychiatric syndromes is delineated. Our suggestions rely on observational studies in autoantibody-associated psychiatric syndromes and a few placebo-controlled, randomized trials for patients with autoimmune encephalitis and psychosis. Thus, adequate powered, prospective as well as placebo-controlled clinical trials in patients with autoantibody-associated psychiatric syndromes are warranted in order to enlighten efficacy and safety aspects of current and novel therapy strategies.