Tehran University of Medical Sciences Iranian Journal of Allergy, Asthma and Immunology 1735-1502 17 6 2018 12 02 540 547 EN Maryam Zare Department of Immunology, Shiraz University of Medical Sciences, Shiraz, Iran Mehrnoosh Doroudchi Department of Immunology, Shiraz University of Medical Sciences, Shiraz, Iran Behrouz Gharesi-Fard Department of Immunology, Shiraz University of Medical Sciences, Shiraz, Iran AND Infertility Research Center, Shiraz University of Medical Sciences, Shiraz, Iran 2017 12 05 2018 01 21 Regulatory T cells are of utmost importance for tolerating the fetus. In some pregnancy complications such as pre-eclampsia, the frequency of CD4+CD25+Foxp3+ regulatory T cells is altered, but there is no consistency regarding the results. Besides, little is known about the frequency of CD8+CD25+Foxp3+ Treg cells in pregnancy complications. Therefore, we aimed to investigate the frequency of both CD4+ and CD8+ regulatory T cells in the peripheral blood of women afflicted by preeclampsia. Ten non-pregnant, ten healthy pregnant, and ten preeclamptic women participated in this study. Four colors flow cytometry method was used to identify the frequency of the CD4+ and CD8+ regulatory T cells in the peripheral blood. Results indicated that the frequencies of CD4+CD25+Foxp3+ and CD8+CD25+Foxp3+ cells were significantly lower in preeclamptic women compared to healthy pregnant and non-pregnant ones (p<0.05). A positive correlation was also observed between CD4+ and CD8+ regulatory T cells (R= 0.532, p=0.002). Moreover, CD4+ regulatory T cells negatively correlated with systolic and diastolic blood pressures (R=-0.760 and -0.753, respectively; p<0.001). CD8+ regulatory T cells also had a negative correlation with systolic (R=-0.503, p=0.001) and diastolic (R=-0.590, p=0.005) blood pressures. In conclusion, a reduction in the frequencies of both CD4+ CD25+ Foxp3+ and CD8+CD25+Foxp3+ regulatory T cells might be important in the pathogenesis of pre-eclampsia. https://ijaai.tums.ac.ir/index.php/ijaai/article/view/1767 https://ijaai.tums.ac.ir/index.php/ijaai/article/download/1767/1376