Serum From Patients With Severe Preeclampsia Is Not Cytotoxic to Endothelial Cells

Abstract

Objective: We evaluated the hypothesis that circulating factors in preeclampsia promote direct endothelial cell injury using an in vitro index of cytotoxicity.

Methods: Subconfluent umbilical vein endothelial cell monolayers were established and radiolabeled with chromium (⁵¹Cr), then randomly exposed for 24 hours in triplicate to 20% sera from nonlaboring patients with severe preeclampsia (n = 5) or mild preeclampsia (n = 5), and normotensive controls (n = 5). Additional experiments were performed by exposing endothelial monolayers to sera for 3 and 48 hours, and under hypoxic conditions (1% oxygen). Cytotoxicity was defined by the percentage of ⁵¹Cr release, expressed as the ratio of radioactivity in the supernatant to the maximum cell-associated radioactivity.

Results: Mean ⁵¹Cr release was similar in all experiments comparing preeclamptic and normal sera. Although consistently greater ⁵¹Cr release was noted in hypoxic as compared with normoxic incubations, no differences in cytotoxicity were identified among severe preeclampsia, mild preeclampsia, and normal sera in hypoxia.

Conclusion: Sera from patients with preeclampsia do not appear to be cytotoxic to vascular endothelium in this in vitro model.