IL-17 and TNF-β: Predictive biomarkers for transition to psychosis in ultra-high risk individuals
Lijun Ouyang, David Li, Zongchang Li, Xiaoqian Ma, Yuan Liu, Lejia Fan, Zihao Yang, Zhenmei Zhang, Chunwang Li, Ying Hé, Xiaogang Chen
Abstract
Background Dysregulation of immunity, such as levels of inflammatory factors, has been regarded as a sign of schizophrenia. Changes in cytokine levels are not only described in the early onset of disease, but also observed in ultra-high risk (UHR) individuals. This study aimed to investigate the potential of cytokines as biomarkers for psychotic disorders and in individuals at UHR of developing a psychotic disorder in the future. Methods The Luminex liquid chip technology was used to detect the concentrations of Interferon-gamma (INF-γ), Interleukin (IL)-2, Interleukin (IL)-4, Interleukin (IL)-6, Interleukin (IL)-17, Interleukin-1beta (IL-1β), and Tumor Necrosis Factor-beta (TNF-β) in the plasma of all subjects. Meanwhile, the plasma level of Tumor Necrosis Factor-Alpha (TNF-α) was measured with the enzyme-linked immunosorbent assay (ELISA) kits. Then, the levels of these cytokines were compared among patients with Drug-naïve first-episode schizophrenia (FES; n = 40), UHR population (UHR; n = 49), and healthy controls (HCs; n = 30). Baseline cytokine levels were compared among UHR individuals who later transitioned (UHR-T; n = 14), those who did not transition (UHR-NT; n = 35), and HCs ( n = 30). Results Our analysis results showed that IL-1β levels were significantly higher in UHR group than HC group ( p = 0.015). Meanwhile, TNF-α concentration was significantly increased in FES group compared with HC group ( p = 0.027). IL-17 ( p = 0.04) and TNF-β ( p = 0.008) levels were significantly higher in UHR-T group compared with UHR-NT group. Conclusion In conclusion, our findings suggest that the immuno-inflammatory activation level is increased in the early stage of psychosis before psychotic conversion and the Drug-naïve FES. IL-1β and TNF-α are the representatives of the specific biomarkers for UHR and FES, respectively. IL-17 and TNF-β may be the potential selective predictive biomarkers for future transition in UHR individuals.