Th17 / Treg ratio: A prospective study in a group of pregnant women with preeclampsia and fetal growth restriction

Abstract

Introduction: During pregnancy, the maternal immune system is challenged to tolerate a semi-allogenic fetus. A proinflammatory profile has been linked to adverse pregnancy outcomes and poor placental development. In this study, the authors evaluated the number of circulating Tregs and Th17 cells in a group of patients diagnosed with preeclampsia(PE) and fetal growth restriction(FGR).

Methods: Prospective longitudinal observational study where peripheral blood lymphocyte subsets were analyzed in a cohort of pregnant patients with PE, FGR, and a control group of healthy pregnant women.

Results: The diagnosis of PE was associated with a significative higher number of circulating Th17 cells and a significative relative reduction in the Treg cell count. This proinflammatory profile was also expressed in the evolution of the Th17/ CD4⁺CD25^highFOXP3⁺ Treg ratio. In the FGR group, the Th17 cell count was significantly higher during the third trimester of pregnancy. This proinflammatory profile was also expressed in the evolution of the Th17/ CD4⁺CD25^highFOXP3⁺ Treg ratio. When we compare the immunological profiles of patients with PE and FGR we observed a higher number of proinflammatory Th17 cells and a significative lower number of Treg cells in PE patients. This is particularly expressed in the differences found between the Th17/ CD4⁺CD25^highFOXP3⁺ Treg ratios of these two groups. Discussion/Conclusion Our data showed a that a proinflammatory profile and a relative excess of Th17 cells was associated with the diagnosis of PE and FGR. A more exuberant systemic proinflammatory profile present in the PE patients is absent in patients with FGR without preeclampsia.

Keywords: Fetal growth restriction; Preeclampsia; Th17 cells; Treg cells.