Eutopic endometrial interleukin-18 system mRNA and protein expression at the level of endometrial-myometrial interface in adenomyosis patients

ObjectiveTo investigate the eutopic endometrial interleukin-18 (IL-18) system including interleukin-18 (IL-18), IL-18 receptor (IL-18R), and IL-18 binding protein (IL-18BP), mRNA, and protein expression in patients with adenomyosis.DesignA clinical and molecular study.SettingClinical and academic research setting in a university medical center.Patient(s)Twenty-eight samples of human eutopic endometria were obtained from surgical specimens of normal cycling women undergoing hysterectomy for uterine adenomyosis (n = 19); the control group (n = 9) was women undergoing hysterectomy for benign reason including uterine fibroids.Intervention(s)Quantitative competitive polymerase chain reaction (QC PCR) and immunohistochemistry studies were performed.Main Outcome Measurement(s)The differences of the IL-18 system mRNA and the ratio of IL-18BP to IL-18 in the eutopic endometrium of uterine adenomyosis and control group were analyzed.Result(s)IL-18 system mRNA and protein expression was demonstrated in the eutopic endometrium of both adenomyosis and control women. Quantitative competitive PCR demonstrated that endometrial IL-18R mRNA and the ratio of IL-18BP to IL-18 were significantly increased in adenomyosis patients in comparison to the control group. Pearson's correlation showed a significant correlation between IL-18 and IL-18R in the eutopic endometrium of women with uterine adenomyosis, but not the control group.Conclusion(s)The expression of the eutopic endometrial IL-18 system and the ratio of antagonist to agonist at the level of the endometrial-myometrial interface (EMI) may possibly be responsible for the pathologic process of adenomyosis.