Serum from patients with severe preeclampsia is not cytotoxic to endothelial cells

Vascular reactivity in preeclampsia

It has long been known that vascular reactivity is altered in preeclamptic patients compared with normal pregnant women. This change even occurs weeks earlier than any clinical manifestation of the disease. Many investigators believe that the conditions for the development of preeclampsia are set as early as the first trimester. These changes in vascular reactivity appear to be independent of the blood pressure because they also occur in chronic hypertensive women destined to have preeclampsia. This review focuses on these changes in vascular reactivity reported in preeclampsia. Increased reactivity of the blood vessels in preeclampsia has been described in most, but not all, studies. The cause for the differences in reactivity between vessels from preeclamptic and normal pregnant women is not known. However, it cannot be attributed solely and with certainty to abnormalities in endothelium-dependent relaxation or the nitric oxide system because the study results published to date remain contradictory. In addition to functional differences, vessels from normal pregnant and preeclamptic women show distinct mechanical properties.

Review: immunobiology of preeclampsia

Preeclampsia has been recognized clinically since the time of Hippocrates: however its etiology and pathophysiology remain enigmatic. This pregnancy-specific syndrome typically presents in late pregnancy as hypertension, edema, and proteinuria. Investigations over the past 15 years have revealed that preeclampsia is associated with abnormal placentation, reduced placental perfusion, endothelial cell dysfunction, and systemic vasospasm. Since it occurs more commonly in primigravidae and in women with underlying collagen-vascular diseases, an immunological component has long been suspected. Increased prevalence in high-order and molar pregnancies and those associated with increased placental mass suggests that trophoblastic volume and fetal antigen load are correlated with the syndrome. Epidemiological reports indicate that the prevalence of preeclampsia is decreased in women who received heterologous blood transfusions, practiced oral sex, or when a long period of cohabitation preceded an established pregnancy. Conversely, the use of condoms as a primary mode of contraception is associated with a higher risk of preeclampsia. These studies suggest that prior exposure to foreign or paternal antigens imparts a protection against the likelihood of developing preeclampsia. Clinical evidence of cellular and humoral immune dysfunction is associated with the syndrome. Fibrin and complement deposition and "foam" cells in atherosis lesions resemble the histopathology of renal allograft rejection. Relative T-cell, natural killer cell, and neutrophil activation have been reported in preeclampsia and circulating cytokines and antiphospholipid antibodies are more prevalent in preeclampsia than in normal pregnant women. These abnormalities are consistent with the systemic endothelial cell dysfunction that has been postulated as a pathophysiological feature of preeclampsia. While such associations do not prove causality, they suggest testable hypotheses for continued basic and clinical investigation of this major complication of human pregnancy.