Macrophage-derived cytokines in the follicular fluids of women with infertility due to immunological causes. Elevated levels of interleukin 6 and low levels of granulocyte macrophage colony stimulating factor

The cytokines are (glyco)proteins secreted by lymphoid and non-lymphoid cells which modulate several biological responses including the ovarian function. Interleukin (IL)-1 and tumour necrosis factor (TNF)-alpha suppress 17beta-estradiol (E2) and progesterone release from granulosa and luteal cells in vitro. TNF-alpha affects negatively folliculogenesis and ovarian maturation. Additional in vivo evidence for a role of this macrophage-derived cytokine came from our recent observation that women with infertility due to immunological causes have elevated intrafollicular fluid levels of TNF-alpha and decreased levels of E2 compared to women with a tubal factor of infertility. Because the macrophages are a primary component of the intrafollicular compartment, the present study was undertaken to evaluate whether other macrophage-derived cytokines are also released in the human follicular fluid. To accomplish this, we measured the levels of IL-1beta, IL-6, IL-10 and granulocyte-macrophage colony-stimulating factor (GM-CSF) in the follicular fluids of two groups of infertile women undergoing to an in vitro fertilization program. The first group of women had a significant titre of anti-spermatozoon antibodies in the serum and/or the mucus as the only cause of infertility, whilst the second group of women was infertile because of non patent fallopian tubes. Intrafollicular cytokines levels were measured by solid-phase ELISA and steroid concentrations by radioimmunoassay. Whilst IL-1beta, IL-6, IL-10, and GLM-CSF were all measurable in the follicular fluid of both groups of women, the levels of IL-6 were found to be significantly more elevated and those of GM-CSF lower in patients with infertility due to immunological causes as compared to those with tubal infertility. The former had also decreased intrafollicular E2 levels and increased progesterone concentrations. No difference was seen in the follicular fluid levels of testosterone and androstenedione. In conclusion, several macrophage-derived cytokines are present in the follicular fluids of infertile women. Patients with infertility due to immunological causes had higher levels of IL-6 and lower concentrations of GM-CSF as compared to patient with a tubal factor of infertility. We speculate that this abnormal cytokine profile may contribute to the altered intrafollicular steroid milieu.