Antineuronal antibodies in cerebrospinal fluid and serum of 104 patients with psychotic disorders compared to 104 individually matched healthy controls

Replacing universal anti-neuronal antibody screening with clinical assessment and testing of high probability cases in psychotic disorders

“…Initial studies that estimated 8% of individuals with psychosis had NMDA antibodies, primarily reported on serum assessment and included immunoglobulin A and immunoglobulin M antibodies, which have unknown clinical relevance (Jeppesen et al, 2023). More recent meta-analysis of psychosis cohort studies where only serum IgG NMDA antibodies were examined demonstrates a reduced positivity rate to 1.46% (Jeppesen et al, 2023). When examining studies that assess CSF NMDA antibodies in psychosis cohorts, prevalence of positivity is between 0% and 0.6% (Jeppesen et al, 2023).…”

“…More recent meta-analysis of psychosis cohort studies where only serum IgG NMDA antibodies were examined demonstrates a reduced positivity rate to 1.46% (Jeppesen et al, 2023). When examining studies that assess CSF NMDA antibodies in psychosis cohorts, prevalence of positivity is between 0% and 0.6% (Jeppesen et al, 2023).…”

“…Psychiatric presentations of VGKC encephalitis are the minority and psychotic symptoms are less commonly reported than mood or anxiety disturbance (Chan et al, 2021; Dalmau et al, 2019). Serum studies demonstrate prevalence in psychosis cohorts between 0% and 2.5%; however, samples were small, testing methodology varied and titre was not consistently reported (Jeppesen et al, 2023).…”

“…In addition, it is now understood that the classical syndromes associated with VGKC testing actually result from pathogenic antibodies directed to specific parts of the VGKC complex – either leucine-rich glioma-inactivated protein 1 (LGI1) or contactin-associated protein 2 (CASPR2; Dalmau et al, 2019). Only a handful of studies have assessed prevalence of LGI1 and CASPR2 antibodies in psychosis cohorts, and in the four CSF-based studies, with around 700 individuals with psychosis, no positive antibody results have been reported (Jeppesen et al, 2023). When psychosis has been noted in individuals with LGI1 and CASPR2 encephalitis, it almost always occurs in conjunction with neurological features and/or abnormal paraclinical (neuroimaging or electroencephalogram [EEG]) investigations (Chan et al, 2021).…”

Long-Term Course of Neural Autoantibody-Associated Psychiatric Disorders: Retrospective Data from a Specifically Immunopsychiatric Outpatient Clinic

“…Neural autoantibody-associated psychiatric disease is an increasing phenomenon in psychiatry affecting different psychiatric patient groups [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 ]. It is a significant phenomenon associated with approximately 23% of affective disorders [ 16 ], 17% of schizophrenic disorders [ 16 ], and 27% of disorders with cognitive dysfunction [ 13 ].…”