Increased Interleukin-6 Level in Taiwanese Schizophrenic Patients

Background: Schizophrenia is accompanied by an activation of the immune/inflammatorysystem. In the present study, the relationships between serum interleukin(IL)-6, tumor necrosis factor (TNF)-α, and transforming growth factor(TGF)-β1 levels and schizophrenia were explored in a group of Taiwaneseinpatients. Furthermore, the serum IL-6, TNF-α, and TGF-β1 levels ofpatients with schizophrenia were compared before and after 1 month ofantipsychotic treatment.Methods: The serum IL-6, TNF-α, and TGF-β1 levels of 34 acute stage schizophrenicpatients and 30 healthy control subjects were collected. These levels wereagain collected in the 34 patients after 1 month of antipsychotic treatment.An analysis of covariance (ANCOVA) adjusted for gender was performed toexamine the differences in cytokine levels between the schizophrenicpatients and the control group. Repeated measures ANCOVA adjusted forgender was performed to examine the differences in cytokine levels of theschizophrenic patients before and after 1 month of treatment.Results: Using ANCOVA adjusted for gender, significantly increased IL-6 levelswere found in schizophrenic patients compared with the control group (p =0.02), but there were no significant differences in TNF-α and TGF-β1 levels(p = 0.06 and 0.91, respectively). After 1 month of medical treatment, therewere no significant differences in IL-6 (p = 0.64), TNF-α (p = 0.48), andTGF-β1 (p = 0.23) levels in the schizophrenic patients, although IL-6appeared to be normalizing.Conclusion: An increase in the IL-6 level may play a role in the pathophysiology ofschizophrenia. A larger sample size and a longer period of follow-up areneeded to confirm this finding.