Abstract
OBJECTIVE: Schizophrenia mainly begins in adolescence and leads to impairments of social functioning. Alterations in the immune system, as represented by cytokine levels, has been linked to the pathophysiology of schizophrenia. Among a variety of cytokines, transforming growth factor-β (TGF-β) plays a role in several neural events, e.g., neurogenesis and synapse formation. To date, few studies have evaluated the relationship between cytokine concentrations and social functioning in subjects with ultra-high-risk state for psychosis (UHR). In this study, we investigated the ability of serum levels of TGF-β to predict the change of social functioning in UHR subjects. METHODS: Fifty-two UHR subjects were recruited at 7 hospitals. We measured social function with the Specific Levels of Functioning scale (SLOF) at baseline, 4, 16, 28, 40, and 52 weeks after sampling blood to measure TGF-β levels. RESULTS: TGF-β1 concentration at baseline was correlated with changes from baseline in the SLOF scores at 4, 28, and 40 weeks. Mixed model for repeated measures analyses revealed that serum levels of TGF-β1 at baseline associated positively with changes from baseline in the SLOF scores, which was most evident at the 40-week time point. CONCLUSION: These results suggest that peripheral levels of TGF-β1 might be associated with longitudinal course of functional outcomes in UHR subjects.