Antigenic differences between the endometrium of women with and without endometriosis

Serum and peritoneal fluid from 12 women with endometriosis, 4 women with uterine leiomyomata and 6 fertile women without endometriosis (controls) and serum from 4 women with adenomyosis were tested with a passive hemagglutination assay for antibodies against endometrium from all the controls, 8 patients with endometriosis and all patients with uterine leiomyomata and from implants from 8 patients with endometriosis. Serum antibody titers in patients with endometriosis or leiomyomata were significantly higher against endometrial or implant antigens from patients with endometriosis and 2 patients with leiomyomata than those against the controls' endometrium. Peritoneal fluid endometrial antibody titers failed to reflect these antigenic differences. Controls and patients with adenomyosis had low titers of endometrial antibodies in their serum or peritoneal fluid. Antigenic differences appear to exist between the endometrium of patients with endometriosis and that of controls.