Elevated concentration and biologic activity of monocyte chemotactic protein-1 in the peritoneal fluid of patients with endometriosis

OBJECTIVE: To estimate the concentration and the biologic activity of monocyte chemotactic protein-1 (MCP-1) in the peritoneal fluid (PF) of women with and without endometriosis. DESIGN: A case control study was conducted. SETTING: Gynecology clinic and Laboratories of endocrinology of reproduction and immunology. PATIENTS: Women presenting for infertility, pelvic pain, or tubal ligation in which endometriosis was diagnosed at laparoscopy (n = 36) and normal fertile controls presenting for tubal ligation (n = 21). INTERVENTIONS: Collection of PF via laparoscopy. MAIN OUTCOME MEASURES: Determination of PF concentrations of MCP-1 by an ELISA and evaluation of its monocyte chemotactic activity using a human hystiocytic cell line (U937). RESULTS. The concentration of MCP-1 (median, range of values) was increased in the PF of endometriosis patients (283, 0 to 1,930 pg/mL; conversion factor to SI unit, 0.155) compared with the control group (140, 0 to 435 pg/mL). The most significant elevation of MCP-1 levels was found in the stage II of the disease (371, 200 to 1,930 pg/mL). An increased chemotactic activity for monocytes (mean number of migrating cells/mm2 +/- SD) also was found in stages I (1,460 +/- 312) and II (1,541 +/- 336) of the disease when compared with fertile controls (393 +/- 56). Forty percent to 53% of this activity was inhibited in the presence of an antibody specific to MCP-1. CONCLUSIONS: These observations are consistent with previous data indicating increased leukocyte chemotaxis in the PF of patients with endometriosis and suggest that MCP-1 may play a relevant role in the peritoneal inflammatory reaction associated with the disease.