Aim
An imbalance between T‐helper type 1 (Th1) and type 2 (Th2) cytokines has been implicated in schizophrenia, although empirical evidence is rare. The aim of this study was to examine if a Th1/Th2 imbalance occurs in schizophrenia and schizophrenia‐related disorder.
Methods
Twenty‐six subjects with schizophrenia, 26 subjects with schizophrenia‐related disorders, and 26 healthy controls were recruited. The Human Th1/Th2 Cytokine Cytometric Bead Array Kit‐II was utilized to assess serum Th1/Th2 cytokines and ratios simultaneously. MANOVA was used to detect differences among the three diagnostic groups in distinct Th1/Th2 cytokines/ratios. Pearson/Spearman correlations were used to examine the relationships between distinct Th1/Th2 cytokines/ratios and clinical/psychopathological data in schizophrenia.
Results
Interferon (IFN)‐γ/interleukin (IL)‐4, IFN‐γ/IL‐10, IL‐2/IL‐4, and tumor necrosis factor (TNF)‐α/IL‐4 ratios were significantly decreased in schizophrenia, but not in schizophrenia‐related disorders compared to healthy controls. IFN‐γ/IL‐4 and IFN‐γ/IL‐10 in schizophrenia subjects positively correlated with age, but not in schizophrenia‐related disorder subjects or in healthy controls.
Conclusion
A clear Th2 shift was observed in schizophrenia, but not in schizophrenia‐related disorders. The Th2 shift in schizophrenia appeared to be an aberrant developmental phenomenon.