Leukocyte activation and circulating leukocyte-derived microparticles in preeclampsia

Preeclampsia shows characteristics of an inflammatory disease including leukocyte activation. Analyses of leukocyte-derived microparticles (MP) and mRNA expression of inflammation-related genes in leukocytes may establish which subgroups of leukocytes contribute to the development of preeclampsia.

Blood samples were obtained from preeclamptic patients, normotensive pregnant and non-pregnant controls. sL-selectin and elastase were measured by ELISA. mRNA was isolated from leukocytes and gene expression was determined by multiplex ligation-dependent probe amplification (MLPA). MP were characterized by flow cytometry.

Altered concentrations of sL-selectin and elastase confirmed leukocyte activation in preeclampsia. These leukocytes showed up-regulation of Nuclear Factor of Kappa light chain gene enhancer in B cells inhibitor (NFkappaB-1A) and cyclin-dependent kinase inhibitor (CDKN)-1A compared with normotensive pregnant women. Interleukin-1 Receptor Antagonist (IL-1RA) and tumor necrosis factor (TNF)-R1 were increased compared with those in non-pregnant controls. Monocyte-derived MP were elevated in preeclamptic patients compared with pregnant women. The numbers of cytotoxic T-cell-derived and granulocyte-derived MP were elevated compared with those of non-pregnant women.

Leukocytes are activated in preeclampsia. A pro-inflammatory gene expression profile is not prominent, although differences in mRNA expression can be detected. Increased levels of particular subsets of leukocyte-derived MP reflect activation of their parental cells in preeclampsia.