Detection of T lymphocyte subsets and related functional molecules in follicular fluid of patients with polycystic ovary syndrome

Immune responses play an important role in the pathogenesis of polycystic ovary syndrome (PCOS). However, the characteristics of T lymphocyte subsets in PCOS remain insufficiently understood. In this study, lymphocytes of follicular fluid (FF) were obtained from oocyte retrieval before in-vitro fertilization (IVF) in infertile women with or without PCOS. The levels of cluster of differentiation 25 (CD25), CD69, programmed death 1 (PD-1), interferon-γ (IFN-γ), interleukin 17A (IL-17A) and IL-10 in T lymphocytes were determined by flow cytometry. Our results showed that the percentage of FF CD8(+) T cells was significantly decreased in infertile patients with PCOS (P < 0.05). Furthermore, the levels of CD69 and IFN-γ were significantly decreased and the level of PD-1 was increased in both CD4(+) and CD8(+) T cells from infertile patients with PCOS (P < 0.05). Moreover, the expression of PD-1 on CD4(+) or CD8(+) T cells was positively correlated with the estradiol (E2) levels in the serum and reversely correlated with the expression of IFN-γ in CD4(+) or CD8(+) T cells in infertile patients with PCOS. These results suggested that T cell dysfunction may be involved in the pathogenesis of PCOS.