Th1/Th2 cytokines in Type 1 diabetes: Relation to duration of disease and gender

BACKGROUND: T-cells are important in the pathogenesis of Type 1 diabetes (T1D). However, the exact role of T-cell subpopulations in this pathway remains unknown. The purpose of this study was to assess the expression pattern of T helper 1 (Th1) interferon-gamma (IFN-γ) and Th2 interleukin-4 (IL-4) cytokines and their relationship with sex and disease duration in T1D patients. MATERIALS AND METHODS: This study was conducted on 21 T1D patients and 22 healthy subjects. Gene expression analysis of peripheral blood mononuclear cells (PBMCs) was performed using real-time reverse transcriptase polymerase chain reaction. RESULTS: IFN-γ gene expression was significantly lower in T1D patients compared with controls (P < 0.05). Conversely, IL-4 mRNAs were significantly increased in the PBMCs from patients as compared to controls (P < 0.05). There was no significant difference in the expression of IL-4 and IFN-γ between men and women with T1D (P > 0.05) while IL-4 mRNA expression in male patients was about 1.9 folds higher than female patients. Moreover, IFN-γ mRNA expression in female patients was about 1.8 folds lower than male patients. Patients were divided into two groups regarding their disease duration: <10 years and >10 years. A significant increase in the IL-4 expression was observed between two groups of patients compared to controls (P < 0.0001). Conversely, there was a significant difference in the expression of IFN-γ only between patients with more than 10 years of disease duration (P = 0.02). CONCLUSION: These data propose supplementary implications for the role of Th1/Th2 imbalance in T1D immunopathogenesis. Moreover, factors such as sex and disease duration may have some influence on cytokine mRNA expression.