*4.1. Patients*

The study included 16 women (mean age 35.8 years, range 25–46) with laparoscopically and histopathologically confirmed endometriosis. All patients had ovarian endometriotic cysts and the disease was classified as moderate/severe (III/IV) stage according to the revised criteria of the American Society for Reproductive Medicine [57]. The control group comprised 14 women (mean age 31.8 years, range 19–46) without visible endometriosis foci, pelvic inflammation or related pathology who underwent laparoscopic excision of ovarian dermoid cysts. All women had regular menses and none of them had a history of previous pelvic surgery or chronic systemic disease. The patients were not subjected to any hormonal or immunomodulatory therapy for at least six months prior to the study.

All participants gave a written informed consent to the study. The procedures were approved by the Institutional Bioethical Review Board of the Medical University of Warsaw, Poland and were conducted according to the Helsinki Declaration ethical principles.
