Accentuated cyclic activation of peritoneal macrophages in patients with endometriosis

Peritoneal fluid was collected from 107 women undergoing laparoscopic sterilization or diagnostic laparoscopy for evaluation of infertility. Cells consisting mainly of macrophages were separated and subjected to sophisticated flow fluorocytometric analysis. In this way more detailed information was obtained about activational characteristics of the pelvic macrophage population during the menstrual cycle. In normal women the macrophages, as compared to peripheral monocytes, showed evidence of elevated baseline activation, and a gradual increase in several markers occurred during the menstrual cycle. Cells increased in size, lost their ability to stain for myeloperoxidase, and increased in activity of both endoenzymes and ectoenzymes. These results suggest that female peritoneal macrophages are continuously responding to stimuli. The macrophage irritation was much more pronounced in women with mild endometriosis. This accentuated cyclic activation may represent an inflammatory response to bleeding from ectopic implants or retrograde menstruation or may be a consequence of some defect in the cell-mediated immune response in endometriosis.