Macrophage Scavenger Receptor(s) and Oxidatively Modified Proteins in Endometriosis

Objective: To determine whether cultured human peritoneal macrophages have functional scavenger receptor(s) and whether activation of macrophages in endometriosis may involve an increase in scavenger receptor activity.

Design: A controlled clinical study comparing peritoneal fluid (PF) macrophages of women with endometriosis and controls without endometriosis.

Setting: Women undergoing laparoscopic evaluation and treatment in a tertiary medical center.

Patient(s): Twenty-one women undergoing evaluation for pelvic pain or infertility and 10 women undergoing elective laparoscopic tubal ligation.

Intervention(s): None.

Main Outcome Measure(s): Evidence for functional macrophage scavenger receptor and evidence of ligands for the scavenger receptor in PF.

Result(s): Peritoneal macrophages of women with endometriosis degrade significantly more endothelial cell-low density lipoprotein (EC-LDL) and copper-oxidized LDL (Cu-LDL) than native LDL. Macrophages of women with endometriosis also incorporate more labeled oleic acid into cholesteryl ester in the presence of oxidized LDL (Ox-LDL) than in the presence of native LDL. Western blot analysis demonstrates the presence of adducts between lipid peroxidation products and proteins in PF of patients with and without endometriosis. The PF of women with endometriosis competes with labeled Ox-LDL for uptake by mouse peritoneal macrophages in a dose-dependent manner.

Conclusion(s): We demonstrate for the first time that human macrophages have functional scavenger receptor(s) and that activation of macrophages in endometriosis involves an increase in scavenger receptor activity. Two lines of evidence indicate the presence of ligands for the scavenger receptor in PF.