Serum IL-6 and IL-8 levels in schizophrenia and changes with antipsychotic treatment

Abstract

Objective: The immunological hypothesis of schizophrenia is one of the important in that it may lead to the identification of biological markers and the development of diagnostic laboratory tests. To date these studies have found no definite evidence about the immune system dysfunction in the pathogenesis of schizophrenia. In this study, it is aimed to compare the serum levels of proinflammatory cytokines IL-8 and IL-6 of patients with schizophreni who were free of antipsychotic medication for at least two weeks with the healthy controls and to determine the relationship between the serum levels of cytokines and changes with treatment. Method: Thirty three patients (27 males, 6 females) who met the diagnostic criteria for schizophrenia according to the evaluation with SCID-I and 20 (16 males, 4 females) matched healthy controls were recruited in the study. Blood samples were obtained in the first week from both groups; and four weeks after antipsychotic treatment from the patient group. The patients with schizophreni were evaluated by SAPS and SANS during their first evaluation and again at the fourth week after antipsychotic treatment. Data were evaluated with SPSS 11.0 software. Results: After the four weeks of antipsychotic treatment, the serum levels of IL-8 were lower and the levels of IL-6 were higher compared with the levels which were measured before antipsychotic treatment. There was no statistical difference in the decrease of IL-8 levels whereas post treatment elevated IL-6 levels were statistically significant compared with pretreatment values. Conclusion: Our data indicates that antipsychotic medication may have effects on proinflammatory cytokine IL-6 and new studies can be performed to determine the effects of antiinflammatory agents in the treatment and to obtain new data about the etiopathogenesis of schizophrenia.