Detection of immunoreactive interleukin-11 in human follicular fluid: correlations with ovarian steroid, insulin-like growth factor I levels, and follicular maturity

To prove the presence of interleukin-11 (IL-11) in the follicular fluid (FF), to determine its source and the correlation between IL-11 and fertilization outcome, follicular size, number of follicles per patient, steroids, and insulin-like growth factor-1 (IGF-I) levels.Interleukin-11 levels were measured in FFs, aspirated during oocyte pickup for IVF.Academic hospital and research environment.Follicular fluid and serum were obtained with informed consent from 44 patients undergoing IVF-ET. Granulosa cells were isolated from 17 patients.We hypothesized that IL-11 might play a role in follicular development, as do other related cytokines present in FF. Interleukin-11 was measured with ELISA.Interleukin-11 was absent in the serum but present in FF and in conditioned medium from granulosa cells. Atretic follicles had higher concentrations of IL-11. No correlation was found between IL-11 and fertilization outcome, follicular size, steroid, IGF-I, and total protein concentrations.We conclude that IL-11 is present in FF. The role of IL-11 in follicular development should be the object of further investigations.