Comprehensive analysis of cytokines in the follicular fluid and serum during in vitro fertilization and embryo transfer
Pregnancy rate for in vitro fertilization (IVF) remains low, for which the quality of ovum may be a contributing factor. Hence, comprehensive analysis of cytokines in follicular fluid was performed to identify potential markers of ovum quality. Ova from women undergoing IVF for male factors or unknown etiology, excluding those undergoing treatment for female factors, were selected for cytokine analysis. Comprehensive cytokine/chemokine analysis of follicular fluid was performed. Next, enzyme-linked immunosorbent assay (ELISA) for quantifying interleukin (IL)-4, IL-17A, and IL-1ra levels in the serum and follicular fluid of 142 randomly selected patients was conducted. The comprehensive analysis revealed significant differences in the levels of IL-4, IL-17A, and IL-1ra in the follicular fluid from all ovum grades. The cytokine levels in serum revealed a significant difference in IL-17A levels between women whose ova developed into blastocysts and women whose ova did not. However, no significant differences were found in the cytokine levels of follicular fluid. No significant difference were found between the follicular fluid of women whose ova developed into blastocysts and those whose ova did not; however, serum IL-17A levels significantly differed. Therefore, serum IL-17A levels may be the marker of ovum quality.