The expression of cytokines IFN-γ, IL-4, IL-17A, and TGF-β1 in peripheral blood and follicular fluid of patients testing positive for anti-thyroid autoantibodies and its influence on in vitro fertilization and embryo transfer pregnancy outcomes

Abstract

The aim of this work was to study the expression of the cytokines IFN-γ, IL-4, IL-17 A, and TGF-β1 in peripheral blood and follicular fluid (FF) of patients positive for antithyroid autoantibodies (ATA⁺) with normal thyroid gland function and the influence of these autoantibodies on in vitro fertilization and embryo transfer (IVF-ET) pregnancy outcomes. Nineteen patients were in the ATA⁺ group, and 27 patients tested negative for anti-thyroid autoantibody (ATA^-). Blood samples were drawn from the two groups of patients on the oocyte retrieval day and the 5th and 14th days of transplantation; in addition, FF was extracted on the oocyte retrieval day from both groups of patients and tested through enzyme-linked immunosorbent assay (ELISA) for IFN-γ, IL-4, IL-17 A, and TGF-β1. For the ATA⁺ group, the concentration of IFN-γ increased whereas the concentration of TGF-β1 decreased in peripheral blood on the oocyte retrieval day (p < .05); the concentration of IL-4 decreased in peripheral blood on the 5th and 14th days of transplantation for the ATA⁺ group (p < .05); further, the concentration of IL-17 A increased whereas that of TGF-β1 decreased in FF (p < .05). The ratio of IL-17 A/TGF-β1 in the ATA⁺ group significantly increased in FF and peripheral blood on the oocyte retrieval day and the 14th day of transplantation (p < .05). The ratio of IL-17 A/TGF-β1 in FF of the pregnant patients was significantly lower than in the non-pregnant patients (p < .05). The findings suggested that the ratio between pro-inflammatory and anti-inflammatory cytokines was adversely affected; therefore, adverse pregnancy outcomes of patients with ATA⁺ undergoing IVF-ET treatment may be attributed to immunological mechanisms.

Keywords: Follicular fluid; IFN-γ; IL-17A; IL-4; TGF-β1.