Improving the Prediction of Preeclampsia

The preventive effect of low-dose aspirin in a PPAR-γ antagonist treated mouse model of preeclampsia

Background

Preeclampsia (PE) is one of the leading causes of maternal and perinatal mortality and morbidity. Low-dose aspirin (LDA) is the most widely used drug to prevent PE, but the recommended dose of LDA varies according to different guidelines. Peroxisome proliferator-activated receptor (PPAR)-γ is involved in the formation of the placenta during pregnancy and is expressed in women with severe PE. In the present study, Our purpose was to investigate whether aspirin intervention in preeclampsia was related to PPAR-γ.

Methods

We administered pregnant mice with PPAR-γ-specific antagonist(T0070907) 2 mg/kg/d at 8.5–12.5 days of pregnancy. Mice treated with T0070907 developed key features of preeclampsia. Two doses of LDA (10 mg/kg/d and 20 mg/kg/d) were administered to the mice with a PE phenotype for intervention.

Results

LDA effectively decreased the increase in blood pressure in mice caused by T0070907 and decreased urinary protein levels and the urinary protein/creatinine ratio. LDA also inhibited the overexpression of endoglin and IL-β treated by T0070907. In addition, LDA evidently increased the placental weight and alleviates the degree of placental lesions of placenta and kidney. LDA alleviated the inhibition of PPAR-γ mRNA expression. The beneficial effect of 20 mg LDA was significantly better than that of 10 mg.

Conclusions

(1) LDA has a preventive effect against PE treated by PPAR-γ antagonist. (2) The preventive effect of LDA against PE is dose-dependent.

Short-Term Prediction of Preeclampsia in Chinese Women Using the Soluble fms-Like Tyrosine Kinase 1/Placental Growth Factor Ratio: A Sub-Analysis of the PROGNOSIS Asia Study

The diagnosis of preeclampsia in China currently relies on limited clinical signs and unspecific laboratory findings. These are inadequate predictors of preeclampsia development, limiting early diagnosis and appropriate management. Previously, the Prediction of Short-Term Outcome in Pregnant Women with Suspected Preeclampsia Study (PROGNOSIS) and PROGNOSIS Asia demonstrated that a soluble fms-like tyrosine kinase 1 (sFlt-1)/placental growth factor (PlGF) ratio of ≤38 can be used to rule out preeclampsia within 1 week, with negative predictive values of 99.3 and 98.6%, respectively. This is an exploratory sub-analysis of the Chinese cohort (n = 225) of the PROGNOSIS Asia study. The primary objectives were to assess the predictive performance of using the sFlt-1/PlGF ratio to rule out preeclampsia within 1 week and to rule in preeclampsia within 4 weeks. The sFlt-1/PlGF ratio was also examined for short-term prediction of fetal adverse outcomes, maternal adverse outcomes, and time to delivery. The overall prevalence of preeclampsia was 17.3%. With the use of an sFlt-1/PlGF ratio of ≤38, the negative predictive value for ruling out preeclampsia within 1 week was 97.3% [95% confidence interval (CI), 93.8-99.1], with a sensitivity of 64.3% and specificity of 85.3%. With the use of an sFlt-1/PlGF ratio of >38, the positive predictive value for ruling in preeclampsia within 4 weeks was 35.0% (95% CI, 20.6-51.7), with a sensitivity of 50.0% and specificity of 86.8%. In the analyses of the sFlt-1/PlGF ratio and fetal adverse outcomes, the area under the receiver operating characteristic curve was 92.8% (95% CI, 83.5-98.7) for ruling out fetal adverse outcomes within 1 week and 79.9% (95% CI, 68.1-90.3) for ruling in fetal adverse outcomes within 4 weeks. An sFlt-1/PlGF ratio of >38 increased the likelihood of imminent delivery 3.3-fold compared with a ratio of ≤38 [hazard ratio, 3.3 (95% CI, 2.1-5.1)]. This sub-analysis confirms the high predictive performance of the sFlt-1/PlGF ratio cutoff of 38 for short-term prediction of preeclampsia in Chinese women, which may help prevent unnecessary hospitalization of women with low risk of developing preeclampsia.

Let-7a inhibits Bcl-xl and YAP1 expression to induce apoptosis of trophoblast cells in early-onset severe preeclampsia

Dysregulation of the MicroRNA (miR) Let-7 family has been implicated in preeclampsia (PE). Abnormal trophoblast cell proliferation and apoptosis associate with the pathogenesis of PE. The present study was designed to test the hypothesis whether let-7a could regulate the biological functions of trophoblasts and explore the mechanism how it works in the development of early-onset severe PE. The putative target genes Bcl-xl and YAP1 of let-7a were verified by luciferase assay. The roles of let-7a, Bcl-xl and YAP1 in regulating JEG-3 cell functions were examined by altering their expression with mimic, overexpression plasmids or siRNAs. The methylation status of let-7a-3 in PE was assessed by methylation-specific and bisulfite sequencing PCR assays. JEG-3 cells were treated with DNA methyltransferase inhibitor to analyze whether let-7a-3 demethylation functioned in PE. Tumor growth and cell apoptosis were measured from nude mice inoculated with JEG-3 cells overexpressing let-7a. The results revealed let-7a was highly expressed in early-onset severe PE and let-7a-3 presented a low methylation level. Functionally, let-7a upregulation could inhibit the viability and cell cycle progression but induce the apoptosis of JEG-3 cells. Bcl-xl and YAP1, target genes of let-7a, could rescue cell apoptosis induced by let-7a. The demethylation of let-7a-3 was also observed to elevate the expression of let-7a and enhance JEG-3 cell apoptosis. Let-7a inhibited tumorigenic ability of JEG-3 cells and enhanced cell apoptosis in vivo. Altogether, let-7a could enhance cell apoptosis in trophoblasts through downregulation of Bcl-xl and YAP1, which suggests that let-7a might be a key regulator in the progression of PE.

Potential Protein Biomarkers for Preeclampsia

To date, the etiology of preeclampsia (PE) has not been clarified and the specific treatment is lacking; hence, early prediction and prevention are very important. Thus, a large number of biomarkers that may be associated with PE have been identified based on proteomics to provide a reference for the prediction of PE and for the understanding of the pathological mechanisms of this disease. This article briefly summarizes the application of proteomics in PE and the potential protein biomarkers to provide a reference for other researchers.

Placental growth factor predicts time to delivery in women with signs or symptoms of early preterm preeclampsia: a prospective multicenter study

BACKGROUND

There is a robust association between altered angiogenic factor concentrations, which includes placental growth factor and clinically recognized preeclampsia. Alterations in concentrations of angiogenic factors precede the clinical onset of preeclampsia by several weeks. The temporal relationship between the measured angiogenic factors and the time to delivery in women with suspected preeclampsia at <35 weeks gestation, however, remains to be clarified.

OBJECTIVE

The purposes of this study were to examine the relationship between placental growth factor and time to delivery in women at <35 weeks gestation with signs or symptoms of preeclampsia and to compare the performance of placental growth factor to other clinical markers for prediction of time to delivery in preeclampsia.

STUDY DESIGN

Women with signs or symptoms of preeclampsia between 20.0 and 35.0 weeks gestation were enrolled in a prospective, observational study at 24 centers. Blood was collected at presentation for placental growth factor, and subjects were evaluated and treated according to local protocols. Clinical outcomes were obtained, and all final diagnoses were adjudicated by an independent expert panel according to 2013 American College of Obstetricians and Gynecologists' Hypertension in Pregnancy criteria. Placental growth factor was measured retrospectively on the Alere, Inc, triage platform. A normal placental growth factor was defined as >100 pg/mL; the assay's limit of detection is 12 pg/mL. Two-by-2 tables were constructed for comparison of test outcomes that included negative predictive value; time-to-delivery was analyzed by survival curves and Cox regression.

RESULTS

Seven hundred fifty-three subjects were enrolled; 538 (71%) had a final diagnosis of preeclampsia; 542 (72%) delivered at <37 weeks gestation, and 358 (47%) delivered at <34 weeks gestation. Among the 279 women (37%) with a normal placental growth factor at presentation, the negative predictive value for preeclampsia delivered within 14 days or within 7 days was 90% and 93%, respectively. Compared with women with normal placental growth factor, women with placental growth factor ≤100 pg/mL have a hazard ratio of 7.17 (confidence interval, 5.08-10.13) in Cox regression for time to delivery after adjustment for both gestational age at enrollment and the final diagnosis of preeclampsia. The placental growth factor levels of normal (>100 pg/mL), low (12-100 pg/mL), and very low (<12 pg/mL) have well-separated distributions of time to delivery, with median values of 45, 10, and 2 days, respectively. Subjects with placental growth factor ≤100 pg/mL have a perinatal death rate of 5.7% and a small-for-gestational-age rate of 51.7%; subjects with placental growth factor >100 pg/mL have a perinatal death rate of 0% (no observations in this cohort) and an a small-for-gestational-age rate of 16.8%.

CONCLUSION

In women with suspected preeclampsia at <35.0 weeks gestation, a low placental growth factor was correlated strongly with preterm delivery independent of a diagnosis of preeclampsia or gestational age at presentation, whereas a normal placental growth factor was associated with pregnancy prolongation, even in patients who ultimately had a final diagnosis of preeclampsia. This suggests that placental growth factor levels are superior to clinical markers in the prediction of adverse pregnancy in women with suspected preeclampsia.

Metabolomics Identifies Placental Dysfunction and Confirms Flt-1 (FMS-Like Tyrosine Kinase Receptor 1) Biomarker Specificity

Clinical end-stage parameters define the pregnancy disorders preeclampsia and fetal growth restriction while classification of the underlying placental dysfunction is missing and urgently needed. Flt-1 (FMS-like tyrosine kinase receptor 1) is the most promising placenta-derived predictive biomarker for preeclampsia. We aimed to classify placental dysfunction in preeclampsia and fetal growth restriction at delivery by metabolic profiling and authenticate the biomarker Flt-1 for placental dysfunction. We studied 143 pregnancies with or without preeclampsia and/or fetal growth restriction delivered by cesarean section. Metabolic placenta profiles were created by high-resolution magic angle spinning nuclear magnetic resonance spectroscopy and the resulting placental phenotypes obtained by hierarchical clustering. Placental Flt-1 expression (membrane-bound and soluble isoforms combined) and maternal serum Flt-1 expression (soluble isoforms) were analyzed by immunohistochemistry and ELISA, respectively. We identified 3 distinct placenta groups by 21 metabolites and diagnostic outcome parameters; normal placentas, moderate placental dysfunction, and severe placental dysfunction. Increased placental Flt-1 was associated with severe placental dysfunction, and increased serum Flt-1 was associated with moderate and severe placental dysfunction. The preeclamptic pregnancies with and without placental dysfunction could be distinguished by 5 metabolites and placental Flt-1. Placental Flt-1 alone could separate normal pregnancies with and without placental dysfunction. In conclusion, metabolomics could classify placental dysfunction and provide information not identified by traditional diagnostics and metabolites with biomarker potential were identified. Flt-1 was confirmed as precision biomarker for placental dysfunction, substantiating its usefulness for identification of high-risk pregnancies for preeclampsia and fetal growth restriction with placental involvement.

Angiogenic Dysregulation in Pregnancy-Related Hypertension-A Role for Metformin

In the face of escalating maternal and fetal health threats, hypertensive pregnancy disorders (HPDs) is one of the leading cause of maternal and fetal morbidity and mortality. The range of HPDs include white-coat hypertension, chronic hypertension, gestational hypertension, mild-to-moderate and severe preeclampsia and eclampsia. Current evidence implicates an imbalance of circulating anti- and angiogenic factors in HPDs emanating from the placental vasculature, impacting on angiogenesis. Delivery of the fetus is thus far the only curative measure, albeit with increased risk. Resultant endothelial dysfunction caused by the excessive production of placental soluble fms-like tyrosine kinase-1 has been the basis of many studies to find a safer treatment strategy. Metformin, used historically in the treatment of diabetes mellitus has also found its therapeutic reach in many other disease states. These include, but are not limited to, improving blood flow in certain cancer types, treatment of polycystic ovarian disease, improving vasodilation, and reducing inflammation. Metformin is used to treat hyperglycemic endothelial dysfunction through the enhancement of the nitric oxide system, endothelin-derived hyperpolarizing factor and sirtuin 1. Similarly, endothelial dysfunction in preeclampsia and other HPDs leads to a hypoxic state and elevated blood pressures. Dubbed as the new "aspirin" of current times, the retardation of the antiangiogenic status by metformin provides an exciting and promising alternate strategy in treating these pregnancy disorders.

Angiogenic and Antiangiogenic Markers for Prediction and Risk Classification of Preeclampsia

Preeclampsia is a pregnancy-specific hypertensive disorder with multisystem involvement and is a significant cause of obstetric morbidity and mortality worldwide. A major issue in the treatment of preeclampsia stems from its still significant rates of misclassification and misdiagnosis. Angiogenic factors have been speculated as a possible diagnostic modality due to a perceived imbalance in angiogenesis in preeclampsia. Factors currently studied include soluble fms-like protein kinase 1 and placental growth factor. Because of significant mortality associated with preeclampsia it is felt that both early and accurate diagnosis of preeclampsia is imperative if this disease process is to be treated.

Cytokine-Ion Channel Interactions in Pulmonary Inflammation

The lungs conceptually represent a sponge that is interposed in series in the bodies’ systemic circulation to take up oxygen and eliminate carbon dioxide. As such, it matches the huge surface areas of the alveolar epithelium to the pulmonary blood capillaries. The lung’s constant exposure to the exterior necessitates a competent immune system, as evidenced by the association of clinical immunodeficiencies with pulmonary infections. From the in utero to the postnatal and adult situation, there is an inherent vital need to manage alveolar fluid reabsorption, be it postnatally, or in case of hydrostatic or permeability edema. Whereas a wealth of literature exists on the physiological basis of fluid and solute reabsorption by ion channels and water pores, only sparse knowledge is available so far on pathological situations, such as in microbial infection, acute lung injury or acute respiratory distress syndrome, and in the pulmonary reimplantation response in transplanted lungs. The aim of this review is to discuss alveolar liquid clearance in a selection of lung injury models, thereby especially focusing on cytokines and mediators that modulate ion channels. Inflammation is characterized by complex and probably time-dependent co-signaling, interactions between the involved cell types, as well as by cell demise and barrier dysfunction, which may not uniquely determine a clinical picture. This review, therefore, aims to give integrative thoughts and wants to foster the unraveling of unmet needs in future research.

Maternal and fetal outcomes of pregnant women with type 1 diabetes, a national population study

Pregnancy in women with type 1 diabetes is associated with poor maternal and neonatal outcomes. However, the risk of these outcomes has never been evaluated in an Asian national population. In this work, we report the maternal and fetal outcomes of pregnant women with type 1 diabetes in Taiwan. A total of 2,350,339 pregnancy records created between 2001 and 2012 were obtained from the National Health Insurance database and analyzed. Here, 630 pregnancy records were identified in women having type 1 diabetes. Compared with pregnant women without type 1 diabetes, pregnant women with the disease showed increased risk of multiple adverse outcomes, including preeclampsia, eclampsia, cesarean delivery, adult respiratory distress syndrome, pulmonary edema, sepsis, chorioamnionitis, pregnancy-related hypertension, puerperal cerebrovascular disorders, acute renal failure, and shock. Fetuses of type 1 diabetic mothers were at increased risk of stillbirth, premature birth, large for gestational age, low birth weight, and low Apgar score. Of the studied endpoints, only preeclampsia showed an improvement in the late period (2011-2012) when compared with the early period (2001-2010). These findings reveal that pregnant women with type 1 diabetes are at significantly increased risk of developing many adverse maternal and fetal outcomes. Therefore, pregnancy outcomes in women with type 1 diabetes should be improved.

Hypertension in CKD Pregnancy: a Question of Cause and Effect (Cause or Effect? This Is the Question)

Chronic kidney disease (CKD) is increasingly encountered in pregnancy, and hypertension is frequently concomitant. In pregnancy, the prevalence of CKD is estimated to be about 3%, while the prevalence of chronic hypertension is about 5-8%. The prevalence of hypertension and CKD in pregnancy is unknown. Both are independently related to adverse pregnancy outcomes, and the clinical picture merges with pregnancy-induced hypertension and preeclampsia. Precise risk quantification is not available, but risks linked to CKD stage, hypertension, and proteinuria are probably multiplicative, each at least doubling the rates of preterm and early preterm delivery, small for gestational age babies, and related outcomes. Differential diagnosis (based upon utero-placental flows, fetal growth, and supported by serum biomarkers) is important for clinical management. In the absence of guidelines for hypertension in CKD pregnancies, the ideal blood pressure goal has not been established; we support a tailored approach, depending on compliance, baseline control, and CKD stages, with strict blood pressure monitoring. The choice of antihypertensive drugs and the use of diuretics and of erythropoiesis-stimulating agents (ESAs) are still open questions which only future studies may clarify.