Changes in serum TNF-α, IL-18, and IL-6 concentrations in patients with chronic schizophrenia at admission and at discharge.

Objective: Schizophrenia is correlated with aberrant cytokine concentrations. The goal of our study was to detect the serum concentrations of tumor necrosis factor (TNF)-α, interleukin (IL)-18, and IL-6 concentrations in patients with chronic schizophrenia in the acute relapse state at admission and at discharge and to analyze the correlations between the three cytokine concentrations with psychosis symptoms.

Methods: Enzyme-linked immunosorbent assay (ELISA) was used to analyze serum concentrations of TNF-α, IL-18, and IL-6 in 68 patients with chronic schizophrenia at admission and at discharge and in 80 controls. The Positive and Negative Syndrome Scale (PANSS) was used to analyze psychosis symptoms of the patients.

Results: Serum concentrations of TNF-α, IL-18, and IL-6 in patients at admission were significantly elevated compared to those in controls. After treatment, IL-6 concentrations in patients at discharge were significantly reduced compared to those in patients at admission, and IL-6 concentrations showed no significant difference between patients at discharge and controls. In contrast, TNF-α and IL-18 concentrations showed no significant difference between patients at discharge and patients at admission, and TNF-α and IL-18 concentrations in patients at discharge were still significantly elevated compared to those in controls. IL-6 concentrations in patients at admission showed a positive correlation with negative scores, and IL-6 concentrations in patients at discharge showed positive correlations with positive, negative, and total scores. Reduction in IL-6 concentrations showed positive correlations with reduction in positive, negative, and total scores in patients at discharge.

Conclusion: Serum concentrations of TNF-α, IL-18, and IL-6 were significantly elevated in patients with chronic schizophrenia in the acute relapse state. After treatment, IL-6 concentrations in patients at discharge were significantly reduced compared to these in patients at admission.