Cytolysis of Eutopic and Ectopic Endometrial Cells by Peripheral Blood Monocytes and Peritoneal Macrophages in Women with Endometriosis

Objective: To compare the ability of peripheral blood monocytes (PBM) and peritoneal macrophages (PM) to mediate the in vitro cytolysis of endometrial cells from eutopic and ectopic endometrium in women with endometriosis.

Design: Prospective study of immune function.

Setting: Institute for the Study and Treatment of Endometriosis and university-based research laboratories.

Patient(s): Twenty-four women with endometriosis (15 in stage I/II, 9 in stage III/IV) and 4 patients treated with GnRH agonists.

Intervention(s): Peritoneal fluid and peripheral blood were sampled and eutopic and ectopic endometrium were biopsied during diagnostic laparoscopy.

Main Outcome Measure(s): Lysis of autologous endometrial cells.

Result(s): Peripheral blood monocytes were significantly more cytolytic than peritoneal macrophages against autologous uterine endometrial cells. However, PBM and PM displayed a similar degree of cytolysis against a hepatoma cell line. Ectopic endometrial cells were significantly more resistant to cytolysis by autologous PBMC than were matched eutopic endometrial cells, and were completely resistant to cytolysis by autologous PM.

Conclusion(s): The reduced capacity of PM from women with endometriosis to mediate the destruction of endometrial cells coupled with the increased resistance of ectopic endometrial cells to macrophage-mediated cytolysis may facilitate the survival of these cells within the peritoneal cavity of women with endometriosis.