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-8 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.