DETECTION OF A UNIQUE 32-KD PROTEIN IN THE PERITONEAL-FLUID OF WOMEN WITH ENDOMETRIOSIS

Objective: To test the hypothesis that endometriotic tissue secretes e ndometriotic-specific proteins into the peritoneal fluid (PF) of women with endometriosis. Design: A prospective design was utilized in this study. Setting: Tertiary care, university-based center and reproducti ve endocrinology laboratory. Participants: Women of reproductive age w ho were infertile with endometriosis (n = 19), as well as without endo metriosis (n = 7), and fertile women undergoing tubal ligation (n = 6) . Interventions: Collection of PF fluid via laparoscopy. Main Outcome Measures: Peritoneal fluid proteins were isolated and assessed by two- dimensional polyacrylamide gel electrophoresis. Results: Two-dimension al electrophoresis of PF proteins isolated a group of proteins (M(r) = 32 to 40 kd, I-p = 4.5 to 5.2) in all PF samples that was similar to the rat endometriotic implant-specific protein, Endo-1. This group of proteins consisted of 5 to 12 individual proteins with endometriosis P F containing a significantly higher number of proteins (median = 11) c ompared with either PF from infertile women without endometriosis (med ian = 8) or from women undergoing tubal ligation (median = 7). In addi tion, one protein (M(r) = 32 kd, I-p = 5.8), termed EPF-32, was detect ed predominantly (18 of 19 samples analyzed) in PF from women with end ometriosis. This protein was also detected in PF from infertile women without endometriosis (2 of 7 samples) but not in the PF of fertile wo men undergoing tubal ligation (0 of 6 samples). The appearance of this protein was not associated with the severity of endometriosis. Conclu sion: It is concluded from this study that PF from women with endometr iosis predominantly contains a 32-kd protein (EPF-32) compared with th e PF of women without the disease. The role of EPF-32 in the pathophys iology of endometriosis is not established but this protein may functi on as a diagnostic marker for endometriosis.