Vascular endothelial growth factor and interleukin-6 in peritoneal fluid of women with endometriosis

Objective(s): To determine [1] vascular endothelial growth factor (VEGF) and interleukin-6 (IL-6) levels in peritoneal fluid from women with endometriosis and compare them with those from oral contraceptive (OC) users and normal cycling women and [2] any correlation between VEGF and IL-6 concentrations. Design: Controlled clinical study. Setting: University medical center. Patient(s): Patients undergoing laparoscopy for infertility or other benign gynecologic conditions. Intervention(s): Peritoneal fluid samples were collected. Main Outcome Measure(s): Levels of VEGF and IL-6 in peritoneal fluid were determined. Result(s): Compared with normal controls or women with less severe endometriosis (implant scores of 5 or less), women with more advanced endometriosis (implant scores of 6 or more) have elevated VEGF and IL-6 levels in peritoneal fluid. Compared with normal controls, markedly suppressed IL-6 but similar VEGF levels were found in peritoneal fluid from OC users. Neither VEGF nor IL-6 varied cyclically in normal women or those with endometriosis. There was no correlation between levels of VEGF and IL-6 in peritoneal fluid. There was no correlation between implant scores and VEGF or IL-6 levels. Conclusion: The inflammation associated with endometriosis, through increased levels of peritoneal fluid VEGF, may promote angiogenesis for the progressive growth of endometriosis. Effective treatment of endometriosis by combination estrogen–progestin pills may involve the suppression of such inflammatory responses.