Endometrial immunofluorescence associated with endometriosis and pelvic inflammatory disease

Anti-immunoglobulin G (anti-IgG) staining in the endometrium by immunofluorescence has been associated with endometriosis. To investigate this phenomenon further, we took endometrial samples from 42 patients who underwent laparoscopy or laparotomy, which were tested for immunofluorescence. Fluorescein-labeled anti-IgG was incubated with tissue samples. Of 18 patients with documented endometriosis, 16 had positive immunofluorescence (89% sensitivity). Of 24 patients with no evidence of endometriosis, 9 had false-positive immunofluorescence and 15 had negative immunofluorescence. Of the 9 false-positive samples, 8 had evidence of old pelvic inflammatory disease. In the absence of this condition, there was only one false-positive study for immunofluorescence. The implications of these findings in terms of the pathophysiology of endometriosis-associated infertility is that it may be an immune-mediated process. With regard to diagnosis, the high predictive value of endometrial immunofluorescent IgG may be a useful tool in indicating early laparoscopic examination of the infertile period.