Association Between Serum G Protein–Coupled Estrogen Receptor and the Peripheral Blood Balance of T‐Helper/New Effector T‐Cells in Patients With Hashimoto’s Thyroiditis

Objective To investigate the effects of the G protein–coupled estrogen receptor (GPER) on the balance of regulatory T‐helper/new effector T‐cells (Treg/Th17) in the peripheral blood of patients with Hashimoto’s thyroiditis (HT) and healthy individuals. Methods A total of 230 participants were enrolled in this study, including 206 patients with new‐onset HT (HT group) and 24 healthy physical examinees (normal control [NC] group). Venous blood samples were obtained from the participants and tested for serum GPER levels using an enzyme‐linked immunosorbent assay. The peripheral blood proportion of Treg and Th17 cells and the Treg/Th17 ratio were determined using flow cytometry. Thyroid function, antibody levels, and biochemical and anthropometric tests were performed. Data management and statistical analyses were performed using SPSS Version 25.0. Results The serum GPER levels among the HT group participants were significantly higher than those among the NC group ( p < 0.001). Among the HT group participants with increasing serum GPER levels, the peripheral blood proportion of Treg cells and the Treg/Th17 ratio increased significantly ( p < 0.001), even after adjusting for relevant confounding factors. However, with increasing serum GPER levels, the peripheral blood proportion of Th17 cells decreased significantly ( p < 0.001), even after adjusting for confounding factors. Conclusion The results confirmed that the serum GPER expression level in the initial HT group was significantly higher than that in the NC group and was positively correlated with the Treg/Th17 ratio, peroxidase antibody, and thyroglobulin antibody. Our findings suggest that a compensatory increase in the proportion of Treg/Th17 cells may be related to increased serum GPER levels.