Decreased levels of peritoneal interleukin-1 receptor antagonist in patients with endometriosis and disease-related dysmenorrhea

ObjectiveTo determine the level of interleukin-1 receptor antagonist (IL-1ra) in peritoneal fluid (PF) and serum in patients with endometriosis.DesignA prospective analytical study.SettingUniversity-affiliated obstetrics and gynecology academic training hospital.Patient(s)One hundred eighteen patients underwent laparoscopy for benign gynecologic diseases.Intervention(s)Peripheral blood and PF were obtained before and during surgical procedures, and the levels of IL-1ra were measured.Main Outcome Measure(s)The concentrations of IL-1ra in PF and serum were correlated with the presence of endometriosis, disease stage, and the phase of menstrual cycle.Result(s)Peritoneal fluid IL-1ra concentrations were significantly lower in patients with endometriosis than in patients without endometriosis. Peritoneal fluid IL-1ra concentrations decreased with the increased severity of endometriosis and also decreased in disease-related dysmenorrhea; serum IL-1ra levels showed no significant difference between the patients with and without endometriosis. The concentrations of IL-1ra in PF and serum were not correlated with the phase of menstrual cycle.Conclusion(s)Our results suggested that decreased levels of PF IL-1ra in patients with endometriosis and disease-related dysmenorrhea may play an important role in the pathogenesis of this disease.