Activation of Th17 cells in drug naïve, first episode schizophrenia.

Objective: The present study was to examine the role of pro-inflammatory T helper 17 (Th17) cells in drug naïve, first episode schizophrenia.

Method: Patients with normal weight, drug naïve, first episode schizophrenia and healthy controls were enrolled in the study. Flow cytometric analysis was performed to analyze the proportion of Th17 cells among the CD4(+) T cells. Plasma levels of interleukin-17 (IL-17), interferon-γ (IFN-γ) and interleukin-6 (IL-6) were examined using enzyme-linked immunosorbent assay (ELISA). Psychopathology was assessed using the Positive and Negative Syndrome Scale (PANSS). All measures were repeated for the patient group after 4 weeks of risperidone treatment.

Results: Sixty-nine patients with normal weight, drug naïve, first episode schizophrenia and 60 healthy controls were enrolled. At baseline, the patient group hadz significantly higher proportions of Th17 cells and plasma levels of IFN-γ and IL-6 compared with the control group (p's<0.01). Within the patient group, there were significant positive relationships between the proportion of Th17 cells, plasma levels of IL-17, IFN-γ, IL-6 and the PANSS total score after controlling for potential confounding variables (p's<0.05). After 4weeks of risperidone treatment, the proportion of Th17 cells decreased significantly (p <0.001), and there was a significant positive relationship between the PANSS total score change rate and the change in proportion of Th17 cells (p = 0.039).

Conclusions: Patients with normal weight, drug naïve, first episode schizophrenia present activation of Th17 cells, which might be associated with therapeutic response after risperidone treatment.