The correlation between interleukin 2 and soluble interleukin 2 receptors to oestradiol, progesterone and testosterone levels in periovulatory follicles of in-vitro fertilization patients.

The present study was performed to evaluate the correlation between follicular fluid levels of interleukin 2 (IL-2) and IL-2 soluble receptor (sIL-2R), oestradiol, progesterone and testosterone levels, oocyte fertilization, embryo quality and pregnancy rates. Twenty-eight patients with a pure tubal factor and undergoing in-vitro fertilization and embryo transfer were randomly chosen and treated with gonadotrophin releasing hormone agonist (GnRHa) in the midluteal phase (long protocol) coupled with follicular phase administration of human menopausal gonadotrophin. Transvaginal follicular aspiration was performed 36 h after human chorionic gonadotrophin administration, followed 48 h later by embryo transfer. One hundred and twenty-three follicular fluids were sampled. The mean follicular fluid levels (+/- SD) were 2.30 +/- 0.80 fmol for IL-2, 458.2 +/- 236.0 units/ml for sIL-2R, 28.5 +/- 58.1 ng/ml for oestradiol, 2360.5 +/- 2846 ng/ml for progesterone and 7.22 +/- 7.08 ng/ml for testosterone. There was a significant (P less than 0.01) correlation between IL-2 and testosterone levels. No correlation was found between the lymphokines and serum oestradiol, follicular fluid progesterone, oocyte fertilization, embryo quality and pregnancy. It may be concluded that significant concentrations of IL-2 and sIL-2R exist in follicular fluid. Wide variations in follicular IL-2 and sIL-2R concentrations of different follicles were found in the same patients.