Higher frequency of circulating, but not tissue regulatory T cells in patients with endometriosis

BACKGROUND: Endometriosis is one of the most common chronic gynecological disorders affecting women at reproductive age. Dysregulation of immune cells, including regulatory T (Treg) cells has contributed to the growth of ectopic lesion in patients with endometriosis. OBJECTIVE: The present study investigated the frequency of Tregs in peripheral blood and the expression of Foxp3 in eutopic and ectopic endometriotic tissues in women with and without endometriosis. MATERIALS AND METHODS: Peripheral blood mononuclear cells (PBMCs) and eutopic and ectopic endometriotic tissues were obtained from 23 endometriotic and 20 non-endometriotic control women. The frequency of Treg cells in PBMCs was measured using flowcytometry and the expression of Foxp3 in eutopic and ectopic endometriotic tissues was determined by real-time PCR, western blotting and immunohistochemistry. RESULT: The frequency of circulating Tregs was significantly higher in endometriotic patients compared with non-endometriotic controls (P < 0.01). The mRNA and protein expression of Foxp3 in eutopic and ectopic endometriotic tissues had no significant differences between the two study groups. CONCLUSION: Higher frequency of circulating Tregs in patients with endometriosis compared with controls may be considered as a compensatory mechanism to regulate the inflammatory condition in this disease.