Regulatory T-cell Subpopulations in Severe or Early-onset Preeclampsia

Abstract

Problem: A deficiency in regulatory T (Treg) cells causing reduced immune regulatory capacity has been proposed in preeclampsia. Objective: Utilizing recent advances in flow cytometry phenotyping, we aimed to assess whether a deficiency of Treg subpopulations occurs in preeclampsia. Method of study: Six-color flow cytometry was used for Treg phenotyping in 18 preeclamptic women (one early-onset, one severe and 16 both), 20 women with normal pregnancy, and 20 non-pregnant controls. Results: No differences were found in major Treg populations including CD127lowCD25+/CD127owFOXP3+, resting (FOXP3dimCD45RA+), and activated (FOXP3brightCD45RA-) Treg cells, whereas preeclamptic women showed increased CTLA-4+ and CCR4+ proportions within resting/activated Treg populations. Corticosteroid treatment prior to blood sampling (n = 10) affected the distribution of Treg populations. Conclusions: Although we found no major alterations in circulating Treg frequencies, differences in CTLA-4+ and CCR4+ frequencies suggest a migratory defect of Treg cells in preeclampsia. Corticosteroid treatment should be taken into account when evaluating Treg cells.