Cytokine Profile in the Endometrium of Normal Fertile and Women with Repeated Implantation Failure

Background: Repeated Implantation Failure (RIF) is one of the most intricate obstacles in assisted reproduction. The cytokine and chemokine composition of uterine cavity seem to play important roles in the implantation process. Objective: To compare the cytokine profile in the endometrium of normal fertile women and those with repeated implantation failure. Methods: After enzymatic digestion of endometrial tissues, whole endometrial cells and endometrial stromal cells from RIF and normal fertile women were cultivated and stimulated for cytokine secretion. The levels of IL-10, TGF-β, IFN-γ, IL-6, IL-8 and IL-17 in culture supernatants of the two groups were assayed by ELISA and compared together. Results: Endometrial stromal cells and whole endometrial cells of normal fertile women produced higher levels of IL-6, IL-8 and TGF-β compared to RIF group, although this difference was statistically significant only in endometrial stromal cells (p=0.005, 0.002 and 0.001, respectively). In addition, endometrial stromal cells of normal fertile women produced lower levels of IL-10 in comparison with RIF group (p=0.005). Conclusion: Disturbances in cytokine production at the feto-maternal interface could be a cause of implantation failure. A pro-inflammatory cytokine milieu seems to be pivotal for successful implantation.