Frequency of Regulatory T Cells in Peripheral Blood Mononuclear Cells (PBMCs) of Endometriosis Patients

Background: Endometriosis is a chronic inflammatory condition characterized by the growth of stromal cells outside the uterine cavity. Regulatory T cells (Tregs), as part of the immune system, might play a role in the pathogenesis of endometriosis via abrogating local cellular immune responses. Thus, here we evaluated Treg frequency in PBMCs of non-endometriosis and endometriosis patients. Methods: PBMCs were obtained from peripheral blood of endometriosis and non-endometriosis women and Tregs subpopulations were analyzed by flow cytometry using CD4+, CD25+, and FoxP3+ markers. Furthermore, FoxP3 mRNA expression was analyzed by quantitative real-time RT-PCR. Results: There was no significant difference in the percentage of CD4+CD25+FoxP3+ Tregs cells between endometriosis and nonendometriosis samples. In addition, we observed no marked differences between the groups with respect to FoxP3 expression. However, the percentage of Tregs and FoxP3 expression increased in peripheral blood in the secretory phase when compared to proliferative phase in both endometriosis and non-endometriosis groups. Conclusion: The results of several pioneer studies have well proved the existence of Tregs in ectopic lesions obtained in secretory phase from endometriosis patients. However, with respect to the circulating Tregs, the reports in the literature are controversial. To our results, there was no difference with respect to Treg number in the secretory phase between non-endometriosis andendometriosis patients. Hence, the tissue change in the percentage of Tregs during endometriosis does not necessarily show itself at the peripheral blood level.

Keywords:

Endometriosis , Regulatory T Cells , Foxp3 , Secretory Phase