The human ovarian follicular fluid level of interleukin-8 is associated with follicular size and patient age

Objective: To investigate the relationship between interleukin-8 (IL-8) in the human ovarian follicle and follicular size, patient age, and fertility factors in IVF cycles. Design: Prospective study. Setting: University hospital research laboratory and infertility clinic. Patient(s): Women undergoing IVF with oocyte retrieval. Intervention(s): Follicular fluid (FF) aspiration, oocyte isolation, FF storage, and experimental studies. Main Outcome Measure(s): Quantization of IL-8 by ELISAs and protein microarray; high-performance liquid chromatography (HPLC) followed by ELISA and Western blotting to evaluate a-macroglobulin (alpha M-2) bound IL-8; association of IL-8 to follicular size, patient age, and IVF outcomes. Result(s): Samples of FF from 63 patients contained an average of 629.59 pg/mL of IL-8 with 50%-70% bound to alpha M-2. Large follicles contained higher levels of IL-8 than small follicles (937.34 vs. 86.97 pg/mL). The IL-8 concentration in the large follicles of women of young age was higher than that of older reproductive age women (1,373.61 vs. 673.29 pg/mL). There were no statistically significant associations found between IL-8 concentration and other IVF cycle factors or pregnancy outcome. Conclusion(s): Our findings indicate that IL-8 is present in FF, both in its free and alpha M-2-bound state, and its concentration is correlated with follicular size and patient age. (Fertil Steril(R) 2010 93:537-43. (C)2010 by American Society for Reproductive Medicine.)