Transforming growth factor-beta activity is increased in peritoneal fluid from women with endometriosis

OBJECTIVE: To investigate the presence of transforming growth factor-beta in peritoneal fluid of women with and without endometriosis. METHODS: Fifty-two peritoneal fluid samples, obtained during laparoscopies performed for tubal ligation (n = 10), infertility (n = 38), or pain (n = 4), were examined for the presence of transforming growth factor-beta using the Mv1Lu cell growth inhibition assay. At laparoscopy, 26 women had endometriosis. The other 26 women had no endometriosis; 16 of them had infertility, and ten who had no pelvic pathology at tubal sterilization served as fertile controls. RESULTS: The concentration of transforming growth factor-beta was increased in the peritoneal fluid from women with endometriosis (11.4 +/- 3.3 ng/mL) compared to both the fertile control group without endometriosis (1.1 +/- 0.29 ng/mL) and the infertile control group without endometriosis (3.6 +/- 1.4 ng/mL). Twenty-five of the 52 women (48%) demonstrated levels of transforming growth factor-beta higher than 2 ng/mL. Patients with endometriosis were significantly more likely to have elevated concentrations of transforming growth factor-beta than were women without endometriosis (16 of 26, 61.5%, versus nine of 26, 34.6%). CONCLUSIONS: These findings demonstrate the presence of transforming growth factor-beta in peritoneal fluid. Elevated levels in women with endometriosis could be important in the pathophysiology of this disease.