Evaluation of expression CXCL8 chemokine and its relationship with oocyte maturation and embryo quality in the intracytoplasmic sperm injection method.

Background: The present study aimed to evaluate the expression of the chemokine CXCL8 in both mRNA and protein levels in the serum, follicular fluid (FF), and cumulus cells (CCs) and its relationship with oocyte maturation and embryo quality in women undergoing intracytoplasmic sperm injection (ICSI).

Methods: A total of 87 women who underwent an ICSI cycle were evaluated in two groups, including the case group (female factor infertility) and the control group (fertile). In the serum, FF, and CCs, the protein and mRNA expression of CXCL8 were measured using immunosorbent assay and Real-Time PCR, respectively. The quality and quantity of the oocytes and embryos were assessed, and the relationship of protein and mRNA CXCL8 was evaluated with oocyte maturation and embryo quality.

Results: The level of protein and mRNA of CXCL8 was significantly higher in the serum, FF, and CCs in the case group than in the control group. In the case group, the expression of mRNA and protein of CXCL8 had a significant increase in FF and CCs compared to serum; also, there was a CXCL8 protein significant increase in FF compared to CCs. The count of oocytes obtained, MII oocytes and the percentage of oocyte maturity significantly decreased in the case group. The expression of CXCL8 was inversely related to oocyte maturation, but no relationship was observed with embryo quality.

Conclusions: The elevated concentrations of CXCL8 in the serum and FF seem to be a predictor as a potential non-invasive biomarker for the oocyte maturation outcome in women with different causes of female factor infertility.