Study On The Role Of Th17 Cells And Related Cytokines In The Pathogenesis Of AITD

ObjectiveTo detect the levels of Th17 cells in the peripherial blood of AITD incipient patients and normal people and those of their five related cytokines, namely IFN-γ, IL-6,IL-17,IL-23 and TGF-β1 in the course of differentiation and maturity of the cells, and to explore the correlation between Th17 cells and their related cytokines, thyroid function parameters and thyroid related autoimmune antibodies. In doing so, the author of this paper intends to identify the role of the cells and their related cytokins in the pathogenesis of AITD and provide valuable references for immunological diagnosis and treatment on AITD.MethodsAltogether 46 AITD incipient patients were enrolled, among whom 23 were afflicted with Graves disease(GD group), and another 23 with Hashimoto’s thyroiditis(HT group)while 23 gender and age matched normal controls(NC group) were also examined. The concentration of IFN-γ,IL-6,IL-17 and TGF-β1 in the serums were measured by ELISA;the levels of FT3, FT4, TSH, TPOAb and TgAb were determined by ECLIA; and the levels of TrAb were tested by RRA. The frequency of CD4+IL-17+T cells in CD4+T cells were tested by FCM.Result⑴ The frequency of Th17 cells in PMBC in GD group and HT group was significantly higher than that of NC group(P<0.01) and the frequency of HT group was apparently higher than that of GD group. The concentration of Th17/CD4+ T cells in the peripheral blood in GD group showed apparent positive correlation with that of FT3 and FT4 in the serums(rs>0.4771;P<0.05,for all parameters). The frequency of Th17/CD4+T cells in the peripheral blood in the patients of HT group showed apparent positive correlation with the levels of TgAb and TPOAb in the serums(rs>0.5083;P<0.05,for all parameters).⑵The concentrations of IFN-γ、IL-6、IL-17、IL-23 and TGF-β1 in GD group were all apparently higher than those of NC group(P<0.05, for all cytokines). The concentrations of all the five cytokines were all positively correlated with the levels of FT3, FT4, TPOAb, TrAb and TgAb in GD group and NC group(rs>0.3019,P<0.05,for all cytokines),and the concentrations of all the five cytokines were negatively correlatedwith the level of TSH in GD group and NC group(rs<-0.4451,P<0.05,for all cytokines).⑶ The concentrations of IFN- γ, IL-6, IL-17 and IL-23 in HT group were all apparently higher than those of NC group(P<0.05, for all cytokines) and the concentration of IL-23 in HT group was also apparently higher than that of GD group(P<0.01). The difference in the concentration of TGF-β1 had no statistical significance between HT group and NC group(P>0.05). Correlation analysis revealed that the IL-17 was highly negatively correlated to FT4(r=- 0.4135,P<0.01) and apparently positively correlated to TSH, TPOAb, TgAb and TrAb(rs >0.3808;P<0.01,for all parameters);the IFN-γand IL-6 in HT group were positively correlated to TPOAb(rs>0.3399,P<0.05,for all cytokines);the IL-23 in HT group was negatively correlated with FT3 and FT4(r<-0.4157; p<0.05, for all parameters) and positively correlated with TSH, TgAb,TPOAb(r>0.4325;p<0.05,for all parameters).ConclusionTh17 cells and their related cytokines IFN-γ,IL-6,IL-17 and IL-23 are highly expressed in the serums of patients with GD or HT,and TGF-β1 is only highly expressed in the peripheral blood of GD patients. Th17 cells and their relative cytokines have certain relevance with thyroid function parameters and the levels of the antibodies of the patients with AITD,which are important molecular mechanisms for the pathogenesis of AITD disease and are related to the severity of AITD disease..