Problem: Our aim was to investigate endometrial antigens involved in the autoimmunity of endometriosis.
Method: We detected endometrial antigens against which autoantibodies directed with Western blotting.
Results: Thirteen (72.2%), 14 (77.8%), and 15 (83.3%) of 18 serum samples from endometriosis patients had antibodies reactive against endometrial antigen wtih MW of 26 kd, 34 kd, and 42 kd, respectively, while 6 (33.3%), 8 (44.4%), and 8 (44.4%) of 18 samples from normal control women reacted against these antigens, respectively. The frequencies of antibodies to the endometrial antigens were significantly (P < 0.05) higher in the endometriosis patients than in the normal control women. Antibodies in peritoneal fluid (PF) reacted against antigens with MW of 26, 34, 38, 42, and 64 kd, while those from the normal control reacted against antigens with MW of 38, 42, and 64 kd. Serum samples from normal fertile males did not show any reactivity against these endometrial antigens.
Conclusions: Our results show that autoantibodies reactive against endometrial antigens are present in patients with endometriosis.