Macrophages and infertility: oviductal macrophages as potential mediators of infertility

Human peritoneal macrophages have previously been shown to phagocytize normal sperm. We had hypothesized that if macrophages were present in the distal oviducts, they could interfere with fertilization by phagocytizing sperm in vivo. The present study was designed to determine whether functional macrophages are present in the human oviducts, and to determine the relationship between oviductal and peritoneal macrophages. Forty patients undergoing laparotomy for sterilization or evaluation of infertility or other gynecologic factors were studied. Infertile patients with endometriosis had more peritoneal macrophages than did fertile normal women or infertile women with distal or proximal tubal obstruction. Oviductal macrophages were observed in all patients. The oviductal macrophages were indistinguishable from the peritoneal macrophages, as judged by similar morphologic features, adherence to plastic, phagocytosis of polystyrene spheres and IgG-coated erythrocytes, and presence of peroxidase and alpha-naphthylbutyrate esterase. Patients with endometriosis had the highest numbers of oviductal macrophages, while those patients with distal tubal obstruction had extremely few oviductal macrophages. The results suggest that oviductal macrophages may arise from peritoneal macrophages that migrate into the oviducts.