Increased activation of pelvic macrophages in infertile women with mild endometriosis

Pelvic fluid was collected from 66 women undergoing laparoscopic sterilization or diagnostic laparoscopy for evaluation of infertility. Cells consisting mainly of macrophages were separated, counted, and subjected to histochemical staining for acid phosphatase and myeloperoxidase as markers of cell irritation. Pelvic fluid was analyzed for acid phosphatase, neutral protease, and extractable prostaglandin E2 and F2 alpha. A higher proportion (46% versus 15%) of the macrophages in the group with mild endometriosis exhibited positive staining for acid phosphatase as compared with the fertile group. Pelvic fluid from patients with mild endometriosis had higher acid phosphatase and neutral protease activity than that from fertile patients (p less than 0.05, p less than 0.01). The content of either prostaglandin was not significantly higher in the endometriosis group as compared with the fertile group. The results suggest that mild endometriosis is associated with activation of macrophages and release of active substances into peritoneal fluid that may be responsible for the associated infertility.