Association between Th1/Th2 immune imbalance and obesity in women with or without polycystic ovary syndrome

Objectives: This study aimed to investigate the Th1/Th2 cells in peripheral blood of PCOS patients, and assess the potential correlation between Th1/Th2 imbalance and obesity.Methods: Thirty-nine PCOS patients and 23 age-matched controls were enrolled. The PBMCs were obtained before pharmacological intervention in women with or without PCOS. The profiles of Th1 (IFN-γ) and Th2 (IL-4) cytokines of CD3+CD− T lymphocyte subsets were analyzed by flow cytometry. Plasma sex hormones including E2, T, FSH, LH, and FINS, FPG were measured, together with BMI, WC, LH/FSH, E2/T and HOMA-IR index being calculated. Association between Th1/Th2 imbalance and BMI, WC were evaluated.Results: The proportion of Th1 cells and Th1/Th2 ratio were significantly higher in PCOS patients than those in controls, accompanied by elevated T, LH, LH/FSH, FINS, HOMA-IR index and reduced E2/T. The Th1/Th2 ratio was increased when BMI and WC were enhanced in PCOS. Moreover, the significant difference of Th1/Th2 ratio was observed between WC subgroups of PCOS.Conclusions: It is concluded that Th1 type immunity is predominant in systemic immunization of PCOS patients. Th1/Th2 immune imbalance is connected with obesity, especially abdominal obesity, and may be one of the underlying mechanism for the pathogenesis of PCOS.