The relationship between serum cytokine levels and degree of psychosis in patients with schizophrenia

Several observations indicate that cytokine concentrations might also relate to the severity of the psychosis. In this study we assessed whether inflammatory and anti-inflammatory cytokine concentrations are associated with the degree of the psychotic manifestations. A group of 41 patients with schizophrenia suffering from an acute psychosis leading to hospitalization in a psychiatric ward were assessed for the intensity of their psychotic manifestations by the PANSS score. Serum IL-2R, IL-6, IL-8, IL-10 were analyzed by commercial ELISA kits. These patients were compared to controls without schizophrenia. At the univariate analysis, statistically significant elevated levels of the cytokines IL-6, IL-2R and IL-8 were detected in the sera of the patients with schizophrenia compared to controls. At the multivariate analysis, statistically significance held only for IL-2R concentration. Furthermore, positive correlation was found between symptom severity as measured by the PANSS and IL-6 levels as well as IL-2R levels. In Conclusion, our data indicate that elevated serum concentrations of IL-6, IL-8 and IL-2R are associated with severe clinical symptoms measured by the total, general, negative and positive scores of the PANSS scale.