Pathogenetic significance of increased levels of interleukin-8 in the peritoneal fluid of patients with endometriosis

Objective: To investigate the role of interleukin-8 (IL-8) in peritoneal fluid of patients with endometriosis in the pathogenesis of endometriosis. Design: Peritoneal fluid was collected by laparoscopy. Endometrial and endometriotic stromal cells were obtained from normal endometrium and from chocolate cyst linings of the ovary. Setting: Department of Obstetrics and Gynecology of Tottori University Hospital, Yonago, Japan. Patient(s): Forty women who underwent either laparoscopy or laparoscopic surgery. Main Outcome Measure(s): The peritoneal fluid concentration of IL-8 was analyzed by enzyme-linked immunosorbent assay, and the correlation between the IL-8 concentration and the extent of active endometriosis was investigated. The effect of IL-8 on cell proliferation was examined by tetrazolium bromide and thymidine incorporation. The expression of IL-8 receptor was examined in stromal cells by reverse transcription polymerase chain reaction. Result(s): The level of IL-8 in peritoneal fluid was significantly higher in patients with endometriosis than in patients without endometriosis. A significant correlation was noted with the extent of active endometriosis. Interleukin-8 significantly increased the number of cells and DNA synthesis in the endometrial and endometriotic stromal cells in a dose-dependent manner. Transcripts of IL-g receptor type A were detected in stromal cells. Conclusion(s): The present study suggests that IL-8 found in the peritoneal fluid of patients with endometriosis contributes to the pathogenesis of endometriosis. (C) 1998 by American Society for Reproductive Medicine.