Pre-eclampsia is not associated with changes in the levels of regulatory T cells in peripheral blood

Problem The acceptance of the semi-allogeneic fetus within the maternal environment requires tolerance mechanisms not fully characterized yet. Normal pregnancy is known to be associated with a Th2 profile. Furthermore, regulatory T cells (Tregs) were proposed to regulate the Th2/Th1 balance at early stages of pregnancy. Treg may avoid the shift to a Th1 profile, thus preventing miscarriage. Accordingly, spontaneous abortion is characterized by a Th1 dominance and diminished levels of Treg. The major aim of the present work was to investigate if pre-eclampsia, a late immunological complication of pregnancy, is characterized by similar hallmarks. Method of study We measured the surface antigens CD4, CD25, CD8 and CTLA4 in peripheral blood from patients suffering from pre-eclampsia (n = 8) and age-matched patients undergoing normal pregnancies (n = 9) by four-color flow cytometry. Results We were not able to find any significant differences in the levels of CD4(+), CD25(+), CD8(+), CTLA4, CD4(+)/CD25(+), CD4(+)/CD25(bright), CD4(+)/CTLA4, CD25(+)/CTLA4, CD4(+)/CD25(+)/CTLA4, CD8(+)/CD25(+), CD8(+)/CTLA4 or CD8(+)/CD25(+)/CTLA4 cell subsets. Conclusions Our data confirm comparable number of Tregs during pre-eclampsia and normal pregnancy in peripheral blood. Other regulatory mechanisms might be involved during late pregnancy.