Endometriosis is a chronic benign hormone-dependent condition when the endometrial tissue, identical with the endometrium by its morphological and functional properties, grows outside the borders of the uterine mucous membrane. Recent studies have pointed to the possible role of matrix metalloproteinases (MMPs) in the pathogenesis of endometriosis. We suggested a hypothesis that increased expression of MMPs activity in eutopic and ectopic endometrium of patients with endometriosis might correlate with the presence of endometriotic lesions.

The aim of the study was to evaluate the level of MMP-2 and MMP-9 expression in the ectopic endometrium of women with visible endometriotic lesions and eutopic endometrium in patients with no signs of endometriosis.

The study was conducted on 43 patients. They were divided into two groups. Group 1 included 31 patients with peritoneal/ovarian endometriosis who had undergone laparoscopy and hysteroscopy. Group 2 consisted of 12 patients with leiomyoma, endometrial polyps or relatively healthy patients who had undergone hysterectomy or polypectomy and endometrial curettage.

This study showed statistically higher expression of MMP-2 (1.7783 ± 0.22 immunohistochemistry (IHC) optical density score compared to the control group – 1.41± 0.34, p = 0.0017) and MMP-9 (1.352 ± 0.067 versus 1.85 ± 0.26 in the control group, p = 0.001) in ectopic and eutopic endometrium samples from patients with endometriosis compared to samples taken from patients without endometriosis. A strong correlation between expression of the above-mentioned MMPs (r=0.74 for MMP-2 and r=0.88 for MMP-9) in ectopic and eutopic endometrium might be of promising diagnostic value.