Locomotion of human neutrophils in response to plasma and serum of women with preeclampsia

To examine whether the previously reported neutrophil activation which occurs in the maternal circulation of women with preeclampsia is due to a factor(s) in plasma/serum which increases neutrophil locomotion. Methods: The locomotory responses of human neutrophils to plasma/ serum of women with preeclampsia were compared with normal, pregnant women matched for maternal age and gestational age at blood sampling. Twelve patients from each group were studied. Preeclampsia was defined as persistent diastolic blood pressure > 90 mm Hg, with proteinuria > 0.3 g/24 h, in patients who were normotensive before 20 weeks gestation. A simple microcomputer-based system for real-time analysis of neutrophil behavior in vitro was used to measure the dynamic parameters of locomotion. Locomotion of human neutrophils in response to plasma, serum (20%), and heat-inactivated serum from both groups of patients was measured. Serum was heat inactivated to destroy complement-derived chemotactic activity. Main Outcome Measures: Speed, persistence, and diffusion coefficient to describe the behavior of randomly moving cells. Results: A significant stimulation of neutrophil locomotion in response to plasma, serum (20%), and heat-inactivated serum occurred in both groups compared with control cells incubated with phosphate-buffered saline; however, no significant differences were found in response to these three stimuli between the two groups of patients. Conclusions: These studies found no evidence of a humoral factor in the plasma/serum of women with preeclampsia which alters the locomotion of human neutrophils. The existence of such a potential factor may be revealed, however, upon examination of subsequent stages of neutrophil activation, namely adhesion to endothelial cells and/or neutrophil metabolic activation.