Preeclampsia (PE) is a pregnancy disorder with a high mortality rate. Patients with PE exhibit systemic high oxidative stress status and inflammatory immune activation. This study aims to define the role of H2O2 in the activation of neutrophils and T lymphocytes in PE patients. CD3+/HLA-DR+ cells in blood from PE patients are remarkably increased compared with those of normal non-pregnancies or normal pregnancies, while the percentage of CD3+/CD62L+ cells is significantly reduced in PE patients compared to normal pregnancies. Furthermore, CD62L levels in granulocytes of periphery blood of PE patients are significantly higher than non-pregnancies, but significantly lower than normal pregnancies. To characterize the effects of intracellular reactive oxygen species (ROS) on T lymphocyte activation in PE patients, PBMCs from normal pregnancies were challenged with H2O2, and intracellular ROS levels in neutrophil granulocytes, as well as T cell surface marker levels, have been determined. We confirm that H2O2 exposure increases intracellular ROS levels in neutrophil granulocytes, and increases the proportion of CD3+/HLA-DR+ cells, but does not alter the percentage of CD3+/CD62L+ cells in PBMCs. Our study has confirmed dysregulated CD3+/HLA-DR+ and CD3+/CD62L+ T lymphocytes in PE patient peripheral blood, and the dysregulative effects of H2O2 on T lymphocyte activation, suggesting a novel mechanism of immune activation in PE.
Keywords: CD62L; HLA-DR; T lymphocyte; hydrogen peroxide; neutrophil; preeclampsia.