The Frequency of Peripheral Blood CD4⁺FoxP3⁺ Regulatory T Cells in Women With Pre-eclampsia and Those With High-risk Factors for Pre-eclampsia

Abstract

Objective: We compared the frequency of peripheral blood Treg cells in women with pre-eclampsia (PE) and in those without, and investigated whether the frequency of Treg cells in women with high-risk factor for PE changed during pregnancy. Methods: We examined the frequency of CD4⁺FoxP3⁺ Treg cells in the peripheral blood using flow cytometry. Eleven women with PE and 10 women without PE (controls) were included. Every control had any risk factors for PE, such as high blood pressure, bilateral notching or a past history of PE or gestational hypertension. Blood sampling was conducted 1–3 times in the controls. Results: No significant differences were observed in the frequency of Treg cells between women with PE and the controls [mean ± SE (%): 5.74 ± 0.91 versus 5.48 ± 0.94, p = 0.843]. In five controls with serial sampling, the frequency of Treg cells significantly decreased from 5.83 ± 1.20 to 2.99 ± 0.54 (p = 0.046) (week of the first sampling to that of the last sampling [mean ± SD]: 21.5 ± 1.6 weeks to 31.2 ± 2.5 weeks). Conclusion: The frequency of Treg cells in women with PE was almost identical to that in the controls. The frequency of Treg cells in the controls was reduced by half from the second trimester to the third trimester. These results suggested that the levels of Treg cells in a high-risk pregnant cohort were decreased to those in women with PE in the third trimester irrespective of the occurrence of PE.

• Flow cytometry
• High risk
• Regulatory T cells
• Pre-eclampsia
• Pregnancy

DECLARATION OF INTEREST

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper. This study was supported by a Grant-in-Aid “Non-communicable Disease: NCD (MEXT-Supported Program for the Strategic Research Foundation at Private University, 2013-2017), Project Number: S1311029” from the Ministry of Education, Culture, Sports, Science and Technology, Japan.