Expression of tumor necrosis factor-α (TNF-α) on peritoneal fluid mononuclear cells in women with endometriosis

Objectives: Tumor necrosis factor-alpha (TNF-alpha) plays a key role in the processes underlying the development of pelvic endometriosis, TNF-alpha acts on target cells via two receptors: TNFR1(p55) and TNFR2(p75). Depending on cell type and its activation state, ligand binding to TNF-alpha may induce activation and proliferation of the cells or promote apoptosis. The aim of our study has been to evaluate the expression of TNFR I and TNFR2 on peritoneal fluid macrophages and T lymphocytes derived from women with endometriosis. Material and methods: The study group consisted of 22 patients with endometriosis (stage I and II rAFS). 74 patients with benign, non-inflammatory ovarian tumors composed the reference group. Mononuclear cells have been isolated from peritoneal fluid, obtained during laparoscopy. The expression of TNFR I and TNFR2 proteins has been evaluated by means of flow cytometry, using monoclonal antibodies against CD120a, CD120b, CD3 and CD14. Results: The percentage of peritoneal fluid macrophages revealing the expression of TNFR1 and TNFR2 proteins has been higher in patients with endometriosis, in comparison with control group (22.6 +/- 5.3% vs. 6.8 +/- 1.8%; p=0.03 and 29.3 +/- 2.3% vs. 8.8 +/- 1.8%; p=0.01, respectively). The percentage of T lymphocytes with the expression of TNFR1 and TNFR2 has been similar in endometriosis and control group. Conclusion: Higher percentage of peritoneal fluid macrophages expressing TNFR1 and TNFR2 proteins in endometriosis suggests dependence of these cells on TNF-alpha. stimulation. Changes in TNF receptors distribution on PF macrophages, but not lymphocyte, may play its role in the pathogenesis of endometriosis.