Differential interleukin-6 messenger ribonucleic acid expression and its distribution pattern in eutopic and ectopic endometrium

ObjectiveTo evaluate the concentration and distribution pattern of interleukin-6–producing cells in ectopic and eutopic endometrium.DesignCollection of both tissues at the proliferative cycle phase.SettingA university endocrinology and laparoscopy program.Patient(s)Twelve samples from six women were obtained at operative laparoscopy in the proliferative phase of each woman's cycle.Intervention(s)Paired sampling of ectopic (n = 6) and eutopic endometrium (n = 6).Main Outcome Measure(s)Concentration of IL-6 messenger RNA (mRNA) was measured by real-time RT-PCR, and its distribution was determined by in situ RT-PCR.Result(s)In vitro RT-PCR analysis showed distinct bands at 234 bp and 115 bp for IL-6 mRNA in eutopic and ectopic endometrium and in placenta as positive control. Real-time RT-PCR indicated significantly higher expression of IL-6 in tissue with endometriosis than in tissue without. In all 12 samples subjected to in situ RT-PCR, positive signals of IL-6 mRNA were observed in cytoplasm of epithelial and stroma cells of ectopic and eutopic endometrium tissue.Conclusion(s)The significant IL-6 mRNA increase in endometriosis compared with in eutopic endometrium may play a role in the development of endometriosis and may provide new directions for endometriosis research.