Potential Significance of Serum Autoantibodies to Endometrial Antigens, α-Enolase and Hormones in Non-Invasive Diagnosis and Pathogenesis of Endometriosis

Abstract

The objective of the study was to evaluate the profile of serum autoantibodies and their diagnostic and pathogenetic significance in ovarian endometrioma (OEM) and deep infiltrative endometriosis (DIE). The study enrolled 74 patients with endometriosis (Group 1), including 53 patients with OEM (Subgroup 1a); 21 patients with DIE without ovarian lesions (Subgroup 1b); and 27 patients without endometriosis (Group 2). The diagnosis was confirmed by laparoscopic surgery and histologic examination of resected tissues. Antibodies (M, G) to tropomyosin 3 (TPM), tropomodulin 3 (TMOD), α-enolase (ENO), estradiol (E2), progesterone (PG), and human chorionic gonadotropin (hCG) were identified in blood serum using modified ELISA. In endometriosis, antibodies to endometrial antigens, hormones, and ENO were detected more often than antiphospholipid and antinuclear antibodies. Higher levels of IgM to TPM, hCG, E2, and PG and IgG to TMOD, ENO, E2, and hCG were found in Subgroup 1a compared to Group 2. IgM to TPM, hCG, E2, PG, and IgG to E2 and ENO had a high diagnostic value for OEM (AUC > 0.7), with antibodies to TPM having the highest sensitivity and specificity (73.6% and 81.5%). In Subgroup 1b, only the levels of IgM to TPM and hCG were higher than in Group 2. These antibodies had a high diagnostic value for DIE. Thus, endometriosis is associated with autoantibodies to endometrial antigens, α-enolase, steroid, and gonadotropic hormones. A wider spectrum of antibodies is detected in OEM than in DIE. These antibodies have a high diagnostic value for OEM and DIE and potential pathogenetic significance for endometriosis and associated infertility.