The vitamin E–binding protein afamin is altered significantly in the peritoneal fluid of women with endometriosis

The objective of this case-control study of 242 reproductive-age women was to determine the concentration of afamin in the serum and peritoneal fluid of women with and without endometriosis and to test afamin as a diagnostic marker of endometriosis. Afamin levels were altered significantly in the peritoneal fluid of women with endometriosis compared with disease-free controls, correlated with vitamin E levels, and are consistent with increased oxidative stress in the peritoneal cavity of women with endometriosis.