Biological profile of the follicular fluid. A pilot study

BACKGROUND: One of the most important research areas in the field of reproductive medicine is the search for biochemical and immunological parameters of oocyte quality and predicting the effectiveness of assisted reproductive technology protocols. AIM: The aim of this study was to evaluate the expression of follicular fluid soluble human leukocyte antigen-G, human leukocyte antigen-E, human leukocyte antigen-C, progesterone-inducing blocking factor, and relaxin levels in women with reproductive disorders. MATERIALS AND METHODS: This prospective cohort study included 22 patients undergoing infertility treatment in a superovulation stimulation protocol using gonadotropin-releasing hormone antagonists. The inclusion criteria were age from 25 to 39 years, tubal-peritoneal factor infertility, and voluntary participation informed consent. The levels of soluble human leukocyte antigen-G, human leukocyte antigen-E, human leukocyte antigen-C, progesterone-inducing blocking factor, and relaxin in follicular fluid samples were determined on the day of transvaginal follicle puncture by enzyme immunoassay. RESULTS: We established an inverse correlation between the expression levels of progesterone-inducing blocking factor and relaxin (r = 0.450) in the follicular fluid, antibodies to thyroperoxidase (r = 0.649), and thyroid-stimulating hormone (r = 0.519). We also found a direct correlation between human leukocyte antigen-E parameters in the follicular fluid, age (r = 0.813) and Body Mass Index (r = 0.866), as well as between human leukocyte antigen-C expression levels and total testosterone (r = 0.960). No data were obtained on any significant correlations between the studied biomarkers and the number of received oocytes. CONCLUSIONS: In this comprehensive study, we were the first who found the expression levels of five different follicular fluid components, namely, soluble human leukocyte antigen-G, human leukocyte antigen-E, human leukocyte antigen-C, progesterone-inducing blocking factor, and relaxin. Such a complex assessment of the follicular fluid can allow for establishing the quality of the oocyte to predict the onset of pregnancy in an in vitro fertilization protocol.