An endometrial antibody assay in the clinical diagnosis and management of endometriosis.

Coded serum samples from 11 normal fertile men and 17 fertile women without endometriosis (control groups) and 41 women with endometriosis were tested blindly for the presence of endometrial antibodies by use of a passive hemagglutination assay. Endometrial antibodies were either absent or present in low baseline titers in the serum samples from the control group. In contrast, 17 of the 23 (74%) patients with untreated endometriosis had elevated titers of endometrial antibodies in their serum. Of the 18 patients treated with danazol, endometrial antibodies were absent in 7 women who showed a good response at repeat laparoscopy, whereas 4 of 5 women with a poor response had significantly positive titers of antibodies. Six patients treated with danazol did not have repeat laparoscopy, but were found to have endometrial antibody titers in the baseline control range. Endometrial antibody titers in women with a good response to danazol were significantly lower than those in women with untreated endometriosis or with a poor response to danazol (P = 0.003). No correlation was observed between the antibody titers and the stage of endometriosis. The results suggest that the assay for serum endometrial antibodies may prove to be a clinically useful, noninvasive aid in the diagnosis of endometriosis. Sequential determination of endometrial antibody titers may be helpful in assessing the efficacy of pharmacologic therapy for endometriosis and evaluating the cases of patients with possible recurrence of the disease.