Transferrin Receptor (CD71) Expression in Peritoneal Macrophages from Fertile and Infertile Women With and Without Endometriosis

PROBLEM: Hyperactivated macrophages are implicated in the pathophysiology of endometriosis-associated infertility. This study investigates transferrin receptor expression (CD71) as a marker of hyperactivity in peritoneal macrophages of infertile patients with minimal to mild endometriosis (group 1, n = 25). METHOD OF STUDY: Expression of the activation antigen CD71 on peritoneal fluid macrophages was determined by a specific monoclonal anti-CD71 antibody using indirect immunofluorescence technique and was analyzed by flow cytometry. Three different control groups of women were used: women with unexplained infertility (group 2, n = 25), fertile women with endometriosis (group 3, n = 10), and fertile women without endometriosis (group 4, n = 25). RESULTS: The percentage of CD71 positive cells was significantly increased in infertile women with endometriosis as compared with the three control groups. There were no differences among groups 2, 3, and 4 with respect to the percentage of CD71 positive macrophages. CONCLUSIONS: Our results favor the concept that hyperactivated macrophages play a role in the pathophysiology of endometriosis-associated subfertility, a feature which is lacking in patients with unexplained infertility.