King's College London

Research portal

Real-world experience of assessing antibodies against the N-methyl-D-aspartate receptor (NMDAR-IgG) in psychiatric patients. A retrospective single-centre study

Research output: Contribution to journalArticlepeer-review

Original languageEnglish
Pages (from-to)330-336
Number of pages7
JournalBrain, Behavior, and Immunity
Volume98
DOIs
PublishedNov 2021

Bibliographical note

Funding Information: This paper represents independent research funded by the National Institute for Health Research (NIHR) Biomedical Research Centre at South London and Maudsley NHS Foundation Trust and King’s College London. The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR or the Department of Health and Social Care. The BITRECS project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 754550 and from “La Caixa” foundation. Funding Information: This paper represents independent research funded by the National Institute for Health Research (NIHR) Biomedical Research Centre at South London and Maudsley NHS Foundation Trust and King's College London. The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR or the Department of Health and Social Care. The BITRECS project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 754550 and from ?La Caixa? foundation. Publisher Copyright: © 2021 Copyright: Copyright 2021 Elsevier B.V., All rights reserved.

King's Authors

Abstract

Objective: To evaluate the frequency of anti-NMDAR encephalitis in a secondary mental health service and investigate the challenges of its diagnosis in routine clinical practice. Methods: Patients whose electronic health records registered an indication for NMDAR-IgG assessment were selected and seropositive patients were reviewed. Results: In 1661 patients assessed for NMDAR-IgG over 12 years, the positivity rate was 3.79% (95% confidence interval [CI]: 2.87–4.70%). The working diagnosis at assessment was new onset psychosis in 38.7% and a chronic psychotic syndrome in 34.0%. Among seropositive patients, 30 (47.6%, 95%CI: 35.8–59.7%) had a final alternative diagnosis different from encephalitis after a median period of 49 months from onset. Patients with a final diagnosis of encephalitis were more frequently female (27/35 vs 13/30, p = 0.011) than other seropositive patients and had more frequently an acute (34/35 vs 11/30, p < 0.001), fluctuating (21/23 vs 4/27, p < 0.001) or agitated (32/32 vs 10/26, p < 0.001) presentation. Nine encephalitic patients received specialized follow-up for chronic neuropsychiatric problems including learning disabilities, organic personality disorder, anxiety, fatigue, obsessive–compulsive and autism-like disorder. Conclusions: In a psychiatric setting, NMDAR-IgG seropositivity rates were low with a positive predictive value for encephalitis around 50% when screened patients had chronic presentations and absence of other diagnostic criteria for encephalitis or psychosis of autoimmune origin. Chronic neuropsychiatric problems in anti-NMDAR encephalitis are not uncommon, so better diagnostic and treatment strategies are still needed.

View graph of relations

© 2020 King's College London | Strand | London WC2R 2LS | England | United Kingdom | Tel +44 (0)20 7836 5454