Threshold values of antibodies to estrogen, progesteron and benzo [a] pyrene as a risk factor for the development of endometriosis

Objectives The objective of the study was to determine the level of antibodies (AB) of Ig classes A and G to estradiol (E2), progesterone (P) and benzo [a] pyrene (Bp) in patients with endometriosis of various severity and estimate their threshold values as a risk factor for the development of endometriosis. Methods A retrospective case–control study was performed. The study involved 200 women. Group I: women with endometriosis (n=100), Group II: patients with tubal-peritoneal infertility (n=100). All patients underwent immunological studies of blood serum; and the levels of steroid hormones (P, E2), antibodies to them and Bp were determined. A ROC analysis was carried out to identify threshold values of antibodies levels. Results Women with endometriosis were found to have statistically significantly higher levels of antibodies IgA and IgG to E2, P and benzo [a] pyrene compared to women of Group II. The threshold levels of IgA-Bp, IgA-E2 and IgA-P are >5 CU (conventional unit), IgG-Bp, IgG-E2>9 CU and IgG-P>8 CU. The level of IgG-P in patients with severe forms of endometriosis is statistically significantly higher than in minor forms of the disease. In case of severe forms, there is a tendency to increasing other classes of antibodies. Conclusions Patients with endometriosis usually have a higher level of IgA and IgG to Bp, E2, P. Their threshold values, which are risk factors for the development of the disease, are estimated.