OBJECTIVE: The objective of the study was to test the hypothesis that factors circulating in the plasma of pregnant women and women with preeclampsia activate monocytes.STUDY DESIGN: Blood samples were taken from patients with early-onset severe preeclampsia (n = 9), healthy pregnant women (n = 9), and healthy nonpregnant women (n = 9). A monocytic cell line was incubated with the plasma for 4, 16, and 24 hours. After the incubation, reactive oxygen species (ROS) production and intercellular adhesion molecule (ICAM)-1 expression (protein and messenger ribonucleic acid) were measured.RESULTS: Plasma of both pregnant women and women with preeclampsia, as compared with plasma from nonpregnant women, increased the mean channel brightness (MCB) ...