Preeclampsia is a pregnancy-specific disorder that affects 2 to 8% of all pregnancies and remains a leading cause of maternal and perinatal morbidity and mortality worldwide. Diagnosis is based on new onset of hypertension and proteinuria. Multiple organ systems can be affected with severe disease. The wide range of risk factors reflects the heterogeneity of preeclampsia. Obesity, which is increasing at an alarming rate, is also a risk factor for preeclampsia as well as for later life cardiovascular disease. Exploring common features may provide insight into the pathophysiologic mechanisms underlying preeclampsia among obese and overweight women.
Background Preeclampsia is a pregnancy-specific disorder that remains a leading cause of maternal, fetal and neonatal morbidity and mortality, and is associated with risk for future cardiovascular disease. There are no reliable predictors, specific preventative measures or treatments other than delivery. A widely-held view is that the antecedents of preeclampsia lie with impaired placentation in early pregnancy. Accordingly, we hypothesized dysregulation of global gene expression in first trimester placentas of women who later manifested preeclampsia. Methods Surplus chorionic villus sampling (CVS) tissues were collected at 10–12 weeks gestation in 160 patients with singleton fetuses. Four patients developed preeclampsia, and their banked CVS specimens were matched to 8 control samples from patients with unaffected pregnancies. Affymetrix HG-U133 Plus 2.0 GeneChips were utilized for microarray analysis. Naïve Bayes prediction modeling and pathway analysis were conducted. qRT-PCR examined three of the dysregulated genes. Results Thirty-six differentially expressed genes were identified in the preeclampsia placentas. qRT-PCR verified the microarray analysis. Thirty-one genes were down-regulated. Many were related to inflammation/immunoregulation and cell motility. Decidual gene dysregulation was prominent. No evidence was found for alterations in hypoxia and oxidative stress regulated genes. Conclusions To our knowledge, this is the first study to show dysregulation of gene expression in the early placentas of women ~6 months before developing preeclampsia, thereby reinforcing a placental origin of the disorder. We hypothesize that placentation in preeclampsia is compromised in the first trimester by maternal and fetal immune dysregulation, abnormal decidualization, or both, thereby impairing trophoblast invasion. Several of the genes provide potential targets for the development of clinical biomarkers in maternal blood during the first trimester. Supplementary materials are available for this article via the publisher’s online edition.
Abstract. Preeclampsia, the de novo occurrence of hypertension and proteinuria after the 20th week of gestation, continues to exert an inordinate toll on mothers and children alike. Recent clinical trials, new physiologic insights, and novel observations on pathogenesis have altered the thinking about preeclampsia. The mechanisms surrounding relaxin and its effects on the circulation and on matrix metalloproteinases have been elucidated. The growth factor's receptor, fms-like tyrosine kinase 1, has been shown to exist in a soluble form that is able to inactivate vascular endothelial-derived growth factor and human placental growth factor. Compelling evidence has been brought forth suggesting that fms-like tyrosine kinase 1 is a circulating factor that can cause preeclampsia. Preeclamptic women have high circulating levels of asymmetric dimethyl arginine that could account for the generalized endothelial dysfunction observed in preeclampsia. Preeclamptic women also produce novel autoantibodies that may serve to activate angiotensin receptors. These new observations raise the possibility that the treatment of preeclamptic women will soon be improved.The term preeclampsia refers to the new onset of hypertension (Ͼ140/90 mmHg) and proteinuria after 20 wk of gestation in previously normotensive, nonproteinuric women (1). The condition is common and occurs in~5% of pregnancies in the United States and Europe. Eclampsia is a life-threatening complication and is characterized by grand mal seizures. The term comes from the Greek word for lightning. A severe variant of preeclampsia also features hemolysis, elevated liver enzymes, and low platelets (HELLP syndrome). This condition occurs iñ 1 per 1000 pregnancies. Predisposing factors are a positive family history, hypertension, diabetes, preexisting renal disease, multiple pregnancies, and a poor obstetric history. Nephrologists are often called on to see preeclamptic women because of the severe BP elevation and renal disease. Thus, new clinical or experimental information on this condition is important information for nephrologists. Preeclampsia and Subsequent Cardiovascular RiskThe relevance of preeclampsia to the offspring is well recognized. Children who are born to preeclamptic mothers commonly have low birth weight, and their subsequent cardiovascular risk has been a vast investigational field. The mother's outcome has attracted less interest. Chesley, the father of modern preeclampsia research, was of the opinion that once the condition was over, the mothers had no greater risk of adverse long-term outcomes than women without preeclampsia from the general population (2). This issue may prove to be the only matter in which Chesley's opinion was erroneous. Several recent studies suggest that the converse is the case. Smith et al. (3) studied the pregnancy complications and the maternal risk of ischemic cardiac death in 129,290 births. They found that delivering an infant with low birth weight for gestational age increased the hazard ratio for ischemic heart disease o...
BackgroundDifferences in circulating concentrations of antiangiogenic factors sFlt1 and soluble endoglin (sEng) and the pro-angiogenic growth factor PlGF are reported to precede the onset of preeclampsia weeks to months in low-risk pregnant women. The objective of this study was to investigate whether similar changes can be detected in pregnant women at high-risk to develop the syndrome.MethodsThis study is a secondary analysis of the NICHD MFMU trial of aspirin to prevent preeclampsia in high-risk pregnancies. Serum samples were available from 194 women with pre-existing diabetes, 313 with chronic hypertension, 234 with multifetal gestation, and 252 with a history of preeclampsia in a previous pregnancy. Samples collected across pregnancy were analyzed in a blinded fashion for sFlt1, sEng and PlGF.ResultsThe odds of developing preeclampsia were significantly increased among women with multiple fetuses for each 2-fold elevation in sFlt1, sEng and the ratio of angiogenic factors (e.g. OR 2.18, 95% CI 1.46-3.32), and significantly decreased for each 2-fold elevation in circulating PlGF (OR 0.50, 95% CI 0.30-0.82) between 7 and 26 weeks' gestation. Cross-sectional analysis of the angiogenic factors across gestation showed significant differences during the third trimester in women who develop preeclampsia compared with appropriate controls in all high-risk groups. However, when data were examined in relation to the gestational week when preeclampsia was diagnosed only sFlt1 was significantly higher 2 to 5 weeks before the clinical onset of preeclampsia and only in women with previous preeclampsia.ConclusionsThe pattern of elevated concentrations of sFlt1 and sEng, and low PlGF in high-risk pregnant subjects who develop preeclampsia is similar to that reported in low-risk pregnant women. However, differences in these factors among high-risk women who do and do not develop preeclampsia are modest, and do not appear to be clinically useful predictors in these high-risk pregnant women.
Preeclampsia is a heterogeneous syndrome affecting 3–5% of all pregnancies. An imbalance of the anti and pro-angiogenic factors, soluble receptor fms-like tyrosine kinase 1 (sFLT1) and placental growth factor (PGF), are thought to contribute to the pathophysiology of preeclampsia. Maternal plasma PGF and sFLT1 were quantified by specific immunoassays in cross-sectional samples from 130 preeclamptic subjects and 342 normotensive controls at delivery, and longitudinally in samples from 50 women who developed preeclampsia and 250 normotensive controls. Among women who developed preeclampsia, 46% (n=23) evidenced a pattern of consistently low maternal PGF across pregnancy below the lower 95%CI of controls from 15 weeks gestation to term. In contrast, the remaining 54% (n=27) women who developed preeclampsia had maternal PGF concentrations similar to or above (n=7) those of normotensive controls. Subjects with low PGF across pregnancy who developed preeclampsia evidenced significantly higher blood pressure in early pregnancy (p<0.05), and after diagnosis, earlier gestational age at delivery (p<0.05), and more preterm birth (p<0.05) compared to preeclamptic patients with high PGF. A significant subset of women who develop preeclampsia evidence consistently low PGF across pregnancy. Low PGF with preeclampsia was associated with preterm delivery compared to preeclamptic patients with high PGF. Identifying women with consistently low plasma PGF during pregnancy may provide a greater understanding of preeclampsia pathophysiology, and may provide more focused research and clinical activities.
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