Detection and significance of free endometrial antigens and their immune complex in serum

Enzyme linked immunosorbent assay (ELISA) was used to detect free endometrial antigens (EMAg) and their immune complex (EMAg-ICs) in the serum of pregnancy, endometriosis (EMT), abortive and infertile women. EMAg levels were 16.4+-11.5 (U/ml, x+-s) in pregnant women (n=63), 56.0+-31.7, 53.9+-44.6 and 44.3+-26.0 in EMT (n=30), abortive (n=37) and infertile (n=48) patients, respectively. EMT was considered as positive when the level was 40 U/ml or higher. The positive rates of EMAg in three patient groups were 56.7%, 32.4% and 31.3%. respectively; they were all significantly higher than pregnant women group (0. P<0.01). The EMAg-ICs level (x+-s) and its positive rate were 0.33+-0.09 and 0% in pregnant women, 0.71+-0.08 and 73.3% in EMT group, 0.53+-0.24 and 29.71%in abortive group, and 0.50+-0.17 and 27.1%in infertile group, respectively. It suggests that EMAg-ICs may play a role in immune injury of the endometrium, which may contribute to abortion and infertility.