Detecting mild neuroinflammation in the cerebrospinal fluid of patients with psychosis

Background: Neuroinflammatory mechanisms have been increasingly implicated in the development of schizophreniform psychosis and can be identified by the examination of cerebrospinal fluid (CSF). Besides the basic CSF diagnostic, there are other parameters that can provide information about acute or past neuroinflammation. For instance cytokines as mediators of inflammatory processes or neurodegeneration markers as indirect indicators. Furthermore, elevated pathogen-specific antibody indices (AI) indicate intrathecal antibody synthesis even many years after infection and may also provide evidence for a polyspecific immune response. Methods: Basic CSF parameters (white blood cell count, protein concentrations, albumin quotient, IgG index, and oligoclonal bands) were analysed in a cohort of 992 patients with schizophreniform and affective psychosis.1 In smaller subgroups, analyses of cytokines (N = 40)2, AI of EBV, CMV, HSV and Toxoplasmosis (N = 100)3, and neurodegeneration markers like tau, amyloid beta, and neurofilaments (N= 100 )4 were performed in CSF (and also blood for AI calculation) using ELISAs and compared to a mentally healthy control group of 39 patients with idiopathic intracranial hypertension. Results: In basic CSF diagnostics, 8% of patients were identified with neuroinflammatory signs. Further advanced analyses of cytokines revealed significantly higher IL-8 levels in patients with schizophreniform psychosis compared to controls (p