Serum inhibin A and activin A are elevated prior to the onset of pre-eclampsia

Identification and validation of feature genes associated with M1 macrophages in preeclampsia

Preeclampsia (PE) is a pregnancy-specific cardiovascular complication that is the leading cause of maternal and neonatal morbidity and mortality. Previous studies have indicated the importance of immune cells, such as M1 and M2 macrophages, in the pathogenesis of PE. However, the mechanisms leading to immune dysregulation are unclear. Data-independent acquisition proteomic analysis was performed on placental tissues collected from patients with PE and healthy controls. Transcriptome data for placenta samples from patients with PE and their corresponding controls were obtained from the Gene Expression Omnibus database. Differential analysis of transcriptome and proteome data between PE and control groups was performed using R software. Immunocytic infiltration scoring was performed using the quantiseq algorithm. Weighted gene co-expression network analysis (WGCNA) screened for feature genes associated with M1 cell infiltration. Protein-protein interaction (PPI) analysis identified hub genes. We confirm that the infiltration score of M1 macrophages was significantly increased in the placental tissues of patients with PE. Differential analysis, WGCNA, and PPI analysis identified four hub molecules associated with M1 cell infiltration (HTRA4, POGK, MFAP5, and INHBA). The hub molecules displayed dysregulated expression in PE tissues. The qPCR, Western blots, and immunohistochemistry analyses confirmed that Inhibin, beta A (INHBA) was highly expressed in placental tissues of patients with PE. Immunofluorescence revealed the extensive infiltration of M1 macrophages in the placental tissues of patients with PE and their co-localization with INHBA. The collective results identified hub genes associated with M1 macrophage infiltration, providing potential targets for the pathogenesis and treatment of PE.

From Biomarkers to the Molecular Mechanism of Preeclampsia-A Comprehensive Literature Review

Preeclampsia (PE) is a prevalent obstetric illness affecting pregnant women worldwide. This comprehensive literature review aims to examine the role of biomarkers and understand the molecular mechanisms underlying PE. The review encompasses studies on biomarkers for predicting, diagnosing, and monitoring PE, focusing on their molecular mechanisms in maternal blood or urine samples. Past research has advanced our understanding of PE pathogenesis, but the etiology remains unclear. Biomarkers such as PlGF, sFlt-1, PP-13, and PAPP-A have shown promise in risk classification and preventive measures, although challenges exist, including low detection rates and discrepancies in predicting different PE subtypes. Future perspectives highlight the importance of larger prospective studies to explore predictive biomarkers and their molecular mechanisms, improving screening efficacy and distinguishing between early-onset and late-onset PE. Biomarker assessments offer reliable and cost-effective screening methods for early detection, prognosis, and monitoring of PE. Early identification of high-risk women enables timely intervention, preventing adverse outcomes. Further research is needed to validate and optimize biomarker models for accurate prediction and diagnosis, ultimately improving maternal and fetal health outcomes.

Evaluation of first trimester maternal serum inhibin-A for preeclampsia screening

BACKGROUND

International professional organizations recommend aspirin prophylaxis to women screened high risk for preterm preeclampsia (PE) in the first trimester. The UK Fetal Medicine Foundation (FMF) screening test for preterm PE using mean arterial pressure (MAP), uterine artery pulsatility index (UTPI) and placental growth factor (PlGF) was demonstrated to have lower detection rate (DR) in Asian population studies. Additional biomarkers are therefore needed in Asian women to improve screening DRs as a significant proportion of women with preterm and term PE are currently not identified.

OBJECTIVES

To evaluate maternal serum inhibin-A at 11-13 weeks as an alternative to PlGF or as an additional biomarker within the FMF screening test for preterm PE.

STUDY DESIGN

This is a nested case-control study using pregnancies initially screened at 11-13 weeks for preterm PE using the FMF triple test in a non-intervention study conducted between December 2016 and June 2018. Inhibin-A levels were retrospectively measured in 1,792 singleton pregnancies, 112 (1.7%) with PE matched for time of initial screening with 1,680 unaffected pregnancies. Inhibin-A levels were transformed to multiple of the expected median (MoM). The distribution of log10 inhibin-A MoM in PE and unaffected pregnancies and the association between log10 inhibin-A MoM and gestational age (GA) at delivery in PE were assessed. The screening performance determined by area under receiver operating characteristic curves (AUC) and detection rates (DRs) at a 10% fixed false positive rate (FPR), for preterm and term PE was determined. All risks for preterm and term PE were based on the FMF competing risk model and Bayes theorem. Differences in AUC (ΔAUC) between different biomarker combinations were compared using the Delong test. McNemar's test was used to assess the off-diagonal change in screening performance at a fixed 10% FPR after adding inhibin-A or replacing PlGF in the preterm PE adjusted risk estimation model.

RESULTS

Inhibin-A levels in unaffected pregnancies were significantly dependent on GA, maternal age and weight and were lower in parous women with no previous history of PE. Mean log10 inhibin-A MoM in any-onset PE (p<0.001), preterm (p<0.001) and term PE (p = 0.015) pregnancies were all significantly higher than that of unaffected pregnancies. Log10 inhibin-A MoM was inversely but not significantly correlated (p = 0.165) with GA at delivery in PE pregnancies. Replacing PlGF with inhibin-A in the FMF triple test reduced AUC and DR from 0.859 and 64.86% to 0.837 and 54.05%, the ΔAUC was not statistically significant. AUC and DR when adding inhibin-A to the FMF triple test were 0.814, 54.05% and the -0.045 reduction in AUC was statistically significant (p = 0.001). At a fixed 10% FPR, replacing PlGF with inhibin-A identified 1 (2.7%) additional pregnancy but missed 5 (13.5%) pregnancies which subsequently developed preterm PE identified by the FMF triple test. Adding inhibin-A missed 4 (10.8%) pregnancies and did not identify any additional pregnancies with preterm PE.

CONCLUSION

Replacing PlGF by inhibin-A or adding inhibin-A as an additional biomarker in and to the FMF triple screening test for preterm PE does not improve screening performance and will fail to identify pregnancies that are currently identified by the FMF triple test.

Blood Plasma Calorimetric Profiles of Women with Preeclampsia: Effect of Oxidative Stress

Preeclampsia is a pregnancy-related disease with poor placentation and presents itself through hypertension and proteinuria. The disease is also associated with the oxidative modification of proteins in maternal blood plasma. In this work, we combine differential scanning calorimetry (DSC), capillary electrophoresis, and atomic force microscopy (AFM) to evaluate the changes in the plasma denaturation profiles of patients with preeclampsia (PE) as compared with those of pregnant controls. Our results demonstrate that the last trimester of pregnancy substantially affects the main calorimetric characteristics of blood plasma from pregnant controls relative to nonpregnant women. These variations correlate well with the changes in protein levels determined by electrophoresis. DSC analysis revealed significant deviations in the plasma heat capacity profiles of preeclamptic patients from those of pregnant controls. These alterations are expressed mainly in a substantial reduction in albumin-assigned transitions and an upward shift in its denaturation temperature, lower calorimetric enthalpy changes, and a reduced ratio of heat capacity in the albumin/globulin-assigned thermal transitions, which are more pronounced in severe PE cases. The in vitro oxidation model shows that the alteration of PE thermograms is partly related to protein oxidation. AFM data detected numerous aggregate formations in the plasma of PE samples and fewer small ones in the pregnant controls, which are not found in healthy nonpregnant samples. These findings could serve as a basis for further investigations to reveal the possible relationship between albumin thermal stabilization, the increased inflammatory state and oxidative stress, and protein misfolding in preeclampsia.

Activin A and pathologies of pregnancy: a review

Activin A is a two-subunit protein belonging to the transforming growth factor β superfamily. First discovered almost three decades ago, it has since been implicated in diverse physiological roles, ranging from wound repair to reproduction. After 30 years of research, altered activin A levels are now understood to be associated with the development of various diseases, making activin A a potential therapeutic target. In pregnancy, the placenta and fetal membranes are major producers of activin A, with significantly enhanced serum concentrations now recognised as a contributor to numerous gestational disorders. Evidence now suggests that circulating levels of activin A may be clinically relevant in the early detection of pregnancy complications, including miscarriage and preeclampsia. This review aims to summarise our current understanding of activin A as a potential diagnostic marker in common pregnancy pathologies.

Inflammation in Preeclampsia: Genetic Biomarkers, Mechanisms, and Therapeutic Strategies

Objective

Preeclampsia is a common and serious complication of pregnancy, posing a threat to maternal and fetal safety due to the lack of effective biomarkers and treatment strategies. This study aimed to identify potential biomarkers that can be used to predict preeclampsia and identify the molecular mechanisms of preeclampsia pathogenesis and drug prediction at the transcriptome level.

Methods

We analyzed differential expression genes (DEGs) in preeclampsia and non-preeclampsia groups in the GSE75010 dataset, cross-linking with extracted inflammatory response-related genes to obtain differentially expressed inflammation-related genes (DINRGs). Enrichment analysis and protein-protein interaction (PPI) networks were constructed to understand the functions and enrichment pathways. Machine learning models were used to identify key genes associated with preeclampsia and build a nomogram in the training set, which was validated in the validation set. The R package RcisTarget was used to predict transcription factors, and Cytoscape was used to construct miRNA-mRNA pathways, which could identify the molecular mechanisms. Then, we conducted molecular docking of the obtained key genes INHBA (inhibin subunit beta A), OPRK1 (opioid receptor kappa 1), and TPBG (trophoblast glycoprotein), as well as predicted transcription factors with drug molecules. Additionally, the CIBERSORT method explored the differences in immune cell infiltration between preeclampsia and non-preeclampsia samples based on the GSE75010 dataset.

Results

A total of 69 DINRGs associated with preeclampsia patients were screened. INHBA, OPRK1, and TPBG were the key genes based on machine learning models. A nomogram for prediction was further constructed, and the receiver operating curves (ROCs) showed good performance. Based on the transcriptome level of key genes, we proposed that RELA-miR-548K/miR-1206-TPBG may be a potential RNA regulatory pathway regulating the progression of early preeclampsia. Molecular docking suggested the effectiveness of curcumin in the treatment of preeclampsia. Additionally, regulatory T cells (Tregs) and resting mast cells were significantly different between the two groups.

Conclusion

In summary, we identified three key inflammation-associated genes, namely INHBA, OPRK1, and TPBG, which can be used as potential genetic biomarkers for preeclampsia prediction and treatment, and established a nomogram as a predictive model. Additionally, we provided insights into the mechanisms of preeclampsia development at the transcriptome level and performed corresponding drug predictions.

Sustained Elevated Circulating Activin A Impairs Global Longitudinal Strain in Pregnant Rats: A Potential Mechanism for Preeclampsia-Related Cardiac Dysfunction

Mediators of cardiac injury in preeclampsia are not well understood. Preeclamptic women have decreased cardiac global longitudinal strain (GLS), a sensitive measure of systolic function that indicates fibrosis and tissue injury. GLS is worse in preeclampsia compared to gestational hypertension, despite comparable blood pressure, suggesting that placental factors may be involved. We previously showed that Activin A, a pro-fibrotic factor produced in excess by the placenta in preeclampsia, predicts impaired GLS postpartum. Here, we hypothesized that chronic excess levels of Activin A during pregnancy induces cardiac dysfunction. Rats were assigned to sham or activin A infusion (1.25–6 µg/day) on a gestational day (GD) 14 (n = 6–10/group). All animals underwent blood pressure measurement and comprehensive echocardiography followed by euthanasia and the collection of tissue samples on GD 19. Increased circulating activin A (sham: 0.59 ± 0.05 ng/mL, 6 µg/day: 2.8 ± 0.41 ng/mL, p < 0.01) was associated with impaired GLS (Sham: −22.1 ± 0.8%, 6 µg/day: −14.7 ± 1.14%, p < 0.01). Activin A infusion (6 µg/day) increased beta-myosin heavy chain expression in heart tissue, indicating cardiac injury. In summary, our findings indicate that increasing levels of activin A during pregnancy induces cardiac dysfunction and supports the concept that activin A may serve as a possible mediator of PE-induced cardiac dysfunction.

Endocrine and metabolic interactions in healthy pregnancies and hyperinsulinemic pregnancies affected by polycystic ovary syndrome, diabetes and obesity

During pregnancy, the fetoplacental unit is key in the pronounced physiological endocrine changes which support pregnancy, fetal development and survival, birth and lactation. In healthy women, pregnancy is characterized by changes in insulin sensitivity and increased maternal androgen levels. These are accompanied by a suite of mechanisms that support fetal growth, maintain glucose homeostasis and protect both mother and fetus from adverse effects of pregnancy induced insulin and androgen excess. In pregnancies affected by endocrine, metabolic disorders such as polycystic ovary syndrome (PCOS), diabetes and obesity, there is an imbalance of beneficial and adverse impacts of pregnancy induced endocrine changes. These inter-related conditions are characterized by an interplay of hyperinsulinemia and hyperandrogenism which influence fetoplacental function and are associated with adverse pregnancy outcomes including hypertensive disorders of pregnancy, macrosomia, preterm delivery and caesarean section. However, the exact underlying mechanisms and relationships of the endocrine and metabolic milieu in these disorders and the impact they have on the prenatal endocrine environment and developing fetus remain poorly understood. Here we aim to review the complex endocrine and metabolic interactions in healthy women during normal pregnancies and those in pregnancies complicated by hyperinsulinemic disorders (PCOS, diabetes and obesity). We also explore the relationships between these endocrine and metabolic differences and the fetoplacental unit, pregnancy outcomes and the developing fetus.

Circulating Activin A is elevated at 36 weeks' gestation preceding a diagnosis of preeclampsia

Activin A is aberrantly expressed by the preeclamptic placenta and circulating levels have been investigated as a potential biomarker for the disease. In a nested case-control study we measured Activin A levels in maternal plasma at 28- and 36-weeks' gestation preceding term preeclampsia diagnosis. At 28 weeks Activin A was not significantly altered (n = 73 destined to develop preeclampsia vs n = 191 controls). At 36 weeks' gestation Activin A was significantly increased in 40 women destined to develop preeclampsia relative to 201 controls (p < 0.0001). These findings provide further validation of Activin A as a potential biomarker for subsequent term preeclampsia.

Defective Uteroplacental Vascular Remodeling in Preeclampsia: Key Molecular Factors Leading to Long Term Cardiovascular Disease

Preeclampsia is a complex hypertensive disorder in pregnancy which can be lethal and is responsible for more than 70,000 maternal deaths worldwide every year. Besides the higher risk of unfavorable obstetric outcomes in women with preeclampsia, another crucial aspect that needs to be considered is the association between preeclampsia and the postpartum cardiovascular health of the mother. Currently, preeclampsia is classified as one of the major risk factors of cardiovascular disease (CVD) in women, which doubles the risk of venous thromboembolic events, stroke, and ischemic heart disease. In order to comprehend the pathophysiology behind the linkage between preeclampsia and the development of postpartum CVD, a thorough understanding of the abnormal uteroplacental vascular remodeling in preeclampsia is essential. Therefore, this review aims to summarize the current knowledge of the defective process of spiral artery remodeling in preeclampsia and how the resulting placental damage leads to excessive angiogenic imbalance and systemic inflammation in long term CVD. Key molecular factors in the pathway-including novel findings of microRNAs-will be discussed with suggestions of future management strategies of preventing CVD in women with a history of preeclampsia.

Melatonin for the Management of Preeclampsia: A Review

Preeclampsia is a disease specific to pregnancy characterised by new-onset hypertension with maternal organ dysfunction and/or fetal growth restriction. It remains a major cause of maternal and perinatal morbidity and mortality. For sixty years, antihypertensives have been the mainstay of treating preeclampsia and only recently have insights into the pathogenesis of the disease opened new avenues for novel therapies. Melatonin is one such option, an endogenous and safe antioxidant, that may improve the maternal condition in preeclampsia while protecting the fetus from a hostile intrauterine environment. Here we review the evidence for melatonin as a possible adjuvant therapy for preeclampsia, including in vitro evidence supporting a role for melatonin in protecting the human placenta, preclinical models, vascular studies, and clinical studies in hypertension and pregnancy.

Maternal Serum Inhibin-A Augments the Value of Maternal Serum PlGF and of sFlt-1/PlGF Ratio in the Prediction of Preeclampsia and/or FGR Near Delivery—A Secondary Analysis

Objective: We previously provided evidence to confirm that maternal serum levels of soluble Fms-like tyrosine kinase-1 (sFlt-1), placental growth factor (PlGF), and their ratio are useful tools to direct the management of preeclampsia (PE), fetal growth restriction (FGR), and PE+FGR near delivery. In this secondary analysis, we further examine the potential additive value of maternal serum Inhibin-A, which is a hormone marker of the transforming growth factor family, to the accuracy provided by maternal serum PlGF and sFlt-1. Methods: We conducted a secondary analysis where we extracted the data of a cohort of 125 pregnant women enrolled near delivery at the clinics of the University Medical Center of Ljubljana, Slovenia. The dataset included 31 cases of PE, 16 of FGR, 42 of PE+FGR, 15 preterm delivery (PTD), and 21 unaffected controls with delivery of a healthy baby at term. Cases delivered before 34 weeks’ gestation included 10 of PE, 12 of FGR, 28 of PE+FGR, and 6 of PTD. In addition to the recorded demographic characteristics and medical history and the maternal serum levels of PlGF and sFlt-1/PlGF ratio, which were previously published, we evaluated the added value of maternal serum Inhibin-A. The predictive accuracy of each biomarker, their ratios, and combinations were estimated from areas under the curve (AUC) of receiver operating characteristics (ROC) curves, Box and Whisker plots, and by multiple regression. We estimated accuracy by the continuous marker model and a cutoff model. Results: In this study, we combined Inhibin-A with PlGF or with the sFlt-1/PlGF ratio and showed a 10–20% increase in AUCs and 15–45% increase in the detection rate, at 10% false positive rate, of PE, and a lower, but significant, increase for PE+FGR and FGR in all cases but not for FGR in early cases delivered < 34 weeks. The use of a cutoff model was adequate, although a bit higher accuracy was obtained from the continuous model. The highest correlation was found for PlGF with all three complications. Conclusion: In this secondary analysis, we have found that maternal serum Inhibin-A improves the accuracy of predicting PE and PE+FGR provided by maternal serum angiogenic markers alone, bringing the results to a diagnostic level; thus, it could be considered for directing clinical management. Inhibin-A had smaller or no added value for the accuracy of predicting FGR alone, mainly of early cases delivered <34 weeks.

PAPP-A2 and Inhibin A as Novel Predictors for Pregnancy Complications in Women With Suspected or Confirmed Preeclampsia

Background We aimed to evaluate the value of inhibin A and PAPP-A2 (pregnancy-associated plasma protein-A2) as novel biomarkers in the prediction of preeclampsia-related complications and how they compare with angiogenic biomarkers. Methods and Results Making use of a secondary analysis of a prospective, multicenter, observational study, intended to evaluate the usefulness of sFlt-1 (soluble Fms-like tyrosine kinase-1)/PlGF (placental growth factor) ratio, we measured inhibin A and PAPP-A2 levels in 524 women with suspected/confirmed preeclampsia. Women had a median gestational age of 35 weeks (range, 20-41 weeks) while preeclampsia occurred in 170 (32%) women. Levels of inhibin A and PAPP-A2 were significantly increased in women with preeclampsia and in maternal perfusate of preeclamptic placentas. Inhibin A and PAPP-A2 (C-index = 0.73 and 0.75) significantly improved the prediction of maternal complications when added on top of the traditional criteria; gestational age, parity, proteinuria, and diastolic blood pressure (C-index = 0.60). PAPP-A2 was able to improve the C-index from 0.75 to 0.77 when added on top of the sFlt-1/PlGF ratio for the prediction of maternal complications. To discriminate fetal/neonatal complications on top of traditional criteria, inhibin A and PAPP-A2 showed additive value (C-index = 0.79 to 0.80 and 0.82, respectively) but their discriminative ability remained inferior to that of sFlt-1/PlGF ratio or PlGF. Interestingly, the PAPP-A2/PlGF ratio alone showed remarkable value to predict pregnancy complications, being superior to sFlt-1/PlGF ratio in the case of maternal complications. Conclusions Inhibin A and PAPP-A2 show significant potential to predict preeclampsia-related pregnancy complications and might prove beneficial on top of the angiogenic markers.

Preeclampsia Is a Syndrome with a Cascade of Pathophysiologic Events

This review integrates the currently available information on the molecular, cellular, and systemic mechanisms involved in the pathophysiology of preeclampsia. It highlights that the growth, protection, and promotion of the conceptus requires the modulation of an intact maternal immune system, communication between the mother and fetus, and adaptation of the maternal organic functions. A malfunction in any of these factors, on either side, will result in a failure of the cascade of events required for the normal course of pregnancy. Maladaptive processes, initially aiming to protect the conceptus, fail to anticipate the gradually increasing cardiovascular volume load during the course of pregnancy. As a result, multiple organ dysfunctions install progressively and eventually reach a state where mother and/or fetus are at risk of severe morbidity or even mortality, and where the termination of pregnancy becomes the least harmful solution. The helicopter view on pathophysiologic processes associated with preeclampsia, as presented in this paper, illustrates that the etiology of preeclampsia cannot be reduced to one single mechanism, but is to be considered a cascade of consecutive events, fundamentally not unique to pregnancy.

Changes in pregnancy-related serum biomarkers early in gestation are associated with later development of preeclampsia

Background

Placental protein expression plays a crucial role during pregnancy. We hypothesized that: (1) circulating levels of pregnancy-associated, placenta-related proteins throughout gestation reflect the temporal progression of the uncomplicated, full-term pregnancy, and can effectively estimate gestational ages (GAs); and (2) preeclampsia (PE) is associated with disruptions in these protein levels early in gestation; and can identify impending PE. We also compared gestational profiles of proteins in the human and mouse, using pregnant heme oxygenase-1 (HO-1) heterozygote (Het) mice, a mouse model reflecting PE-like symptoms.

Methods

Serum levels of placenta-related proteins–leptin (LEP), chorionic somatomammotropin hormone like 1 (CSHL1), elabela (ELA), activin A, soluble fms-like tyrosine kinase 1 (sFlt-1), and placental growth factor (PlGF)–were quantified by ELISA in blood serially collected throughout human pregnancies (20 normal subjects with 66 samples, and 20 subjects who developed PE with 61 samples). Multivariate analysis was performed to estimate the GA in normal pregnancy. Mean-squared errors of GA estimations were used to identify impending PE. The human protein profiles were then compared with those in the pregnant HO-1 Het mice.

Results

An elastic net-based gestational dating model was developed (R² = 0.76) and validated (R² = 0.61) using serum levels of the 6 proteins measured at various GAs from women with normal uncomplicated pregnancies. In women who developed PE, the model was not (R² = -0.17) associated with GA. Deviations from the model estimations were observed in women who developed PE (P = 0.01). The model developed with 5 proteins (ELA excluded) performed similarly from sera from normal human (R² = 0.68) and WT mouse (R² = 0.85) pregnancies. Disruptions of this model were observed in both human PE-associated (R² = 0.27) and mouse HO-1 Het (R² = 0.30) pregnancies. LEP outperformed sFlt-1 and PlGF in differentiating impending PE at early human and late mouse GAs.

Conclusions

Serum placenta-related protein profiles are temporally regulated throughout normal pregnancies and significantly disrupted in women who develop PE. LEP changes earlier than the well-established biomarkers (sFlt-1 and PlGF). There may be evidence of a causative action of HO-1 deficiency in LEP upregulation in a PE-like murine model.

The transforming growth factor β superfamily as possible biomarkers of preeclampsia: a comprehensive review

The etiology of preeclampsia - an abnormal placentation-mediated disease - is not fully understood; and there are very few biomarkers with which to predict and diagnose it. Early prediction and diagnosis of this pathology can lead to a significant improvement in maternal and perinatal outcomes. Since members of the transforming growth factor β superfamily influence placentation, and are released from the placenta into the maternal circulatory system, several studies have investigated the involvement of these cytokines in preeclampsia and the possibility of using their serum levels as biomarkers of the disease. In this review, we have summarized the reported relationships between the levels of this superfamily of cytokines and preeclampsia. The available information indicates that altered levels of some of these cytokines are involved in the pathogenesis and pathophysiology of preeclampsia, suggesting their likelihood of serving as predictive and diagnostic biomarkers of the disease.

Targeting the vascular dysfunction: Potential treatments for preeclampsia

Preeclampsia is a pregnancy-specific disorder, primarily characterized by new-onset hypertension in combination with a variety of other maternal or fetal signs. The pathophysiological mechanisms underlying the disease are still not entirely clear. Systemic maternal vascular dysfunction underlies the clinical features of preeclampsia. It is a result of oxidative stress and the actions of excessive anti-angiogenic factors, such as soluble fms-like tyrosine kinase, soluble endoglin, and activin A, released by a dysfunctional placenta. The vascular dysfunction then leads to impaired regulation and secretion of relaxation factors and an increase in sensitivity/production of constrictors. This results in a more constricted vasculature rather than the relaxed vasodilated state associated with normal pregnancy. Currently, the only effective "treatment" for preeclampsia is delivery of the placenta and therefore the baby. Often, this means a preterm delivery to save the life of the mother, with all the attendant risks and burdens associated with fetal prematurity. To lessen this burden, there is a pressing need for more effective treatments that target the maternal vascular dysfunction that underlies the hypertension. This review details the vascular effects of key drugs undergoing clinical assessment as potential treatments for women with preeclampsia.

Preeclampsia and the challenge of early prediction: reality or utopia? State of art and critical review of literature

Purpose: The challenge to obtain improved predictive tools, able to identify women destined to develop preeclampsia (PE), is raising the interest of researchers for the attractive chance to allow for timely initiation of prophylactic therapy, appropriate antenatal surveillance, and better-targeted research into preventive interventions. We aimed to gather all the evidence reported up to now in scientific literature relating to all prediction tests for PE.Materials and methods: We searched articles on conventional literature platforms from January 1952 to August 2016, using the terms "preeclampsia," "gestational preeclampsia," and "gestational hypertensive disorders" combined with "predictive test" and "risk assessment." Abstracts/titles identified by the search were screened by three investigators.Results: The search identified 203 citations, of which 154 potentially relevant after the initial evaluation. Among these studies, 20 full articles were excluded, therefore, 134 primary studies met the criteria for inclusion and were analyzed.Conclusions: Current evidence suggests that a combination of several features may provide the best predictive accuracy for the identification of PE. Large-scale, multicenter, multiethnic, prospective trials are required to propose an ideal combination of markers for routine screening.

A study of the diagnostic value of Inhibin A Tests for occurrence of preeclampsia in pregnant women

Background

Hypertensive disorders are common during pregnancy, and are among 3 important causes of maternal death. Preeclampsia occurs in 3 to 5% of pregnancies. Early diagnosis of this disorder can lead to better pregnancy outcomes.

Objective

The aim of this study was to determine the relationship between inhibin A serum levels during second stage pregnancy screening tests, and incidence and severity of preeclampsia.

Methods

In this study, 300 pregnant women who referred to Kowsar Hospital and carried out second stage pregnancy screening tests from September 2014 to March 2015 in Urmia city, Iran, were enrolled. Five ml venous blood samples were obtained from each participant, and inhibin A serum levels were evaluated in all cases. Finally, all the necessary information was obtained from the pregnancy files of participants after delivery, and gathered in a questionnaire. The data were analyzed using SPSS software version 18 and independent t-test, ANOVA and descriptive statistics were used. P-values less than 0.05 were considered significant.

Results

Among the 300 pregnant women who were studied, the gestational age at the time of acquiring blood samples was as follows: 169 cases (56.3%) at 16-17 weeks, 77 cases (25.7%) at 18-19 weeks and 14 cases at 20 weeks (4.7%). In this study, MOM of inhibin A was more than 1.25 in 12 cases that finally, preeclampsia occurred in them. This relationship was statistically significant (p=0.001). The relationship between MOM of inhibin A and severe preeclampsia was evaluated, and the relationship was significant (p=0.004). The relationship between MOM of inhibin A and pregnancy hypertension was not significant (p=0.643).

Conclusion

Considering the results of this study, we can conclude that MOM of inhibin A levels in maternal serum during second stage pregnancy screening tests can predict incidence and severity of developing preeclampsia in pregnant women. This is not true in cases of pregnancy hypertension.

Role of Activin A in the Pathogenesis of Endothelial Cell Dysfunction in Preeclampsia

This chapter describes the methodologies which may be used in evaluating in vitro endothelial cell dysfunction in preeclampsia.

Blood laboratory testing for early prediction of preeclampsia: chasing the finish line or at the starting blocks?

Preeclampsia (PE) affects 2-8% of pregnancies worldwide, thus representing an important cause of maternal and neonatal morbidity, up to death. Many studies have been designed to identify putative biomarkers for accurate and timely diagnosing PE, but only some of them were focused on specific and sensitive biomarkers for early prediction of this life-threatening condition. In particular, some prospective studies aimed to investigate the predictive role of circulating biomarkers before 20 weeks of gestation in the general pregnant population yielded conflicting results. This article is hence centered on results obtained in studies investigating the predictive performances of angiogenic, anti-angiogenic, inflammatory, endocrine, and epigenetic biomarkers. The available evidence suggests that angiogenic and anti-angiogenic molecules, in particular the sFlt1:PlGF ratio, may be considered the biomarkers with the best diagnostic performance in the second trimester. However, doubts remain about their use in clinical settings before the 20th gestational week. Even lower evidence is available for other biomarkers, due to the fact that some positive results have not been confirmed in ensuing investigations, whereas unresolved analytical issues still contribute to make their clinical reliability rather questionable. Differential expression of microRNAs seems also a promising evidence for early prediction of PE, but additional research and well-designed prospective studies are needed to identify and validate routine predictive tests. KEY MESSAGES Preeclampsia affects 2-8% of pregnant women worldwide, thus remaining one of the leading causes of maternal and neonatal morbidity and mortality. Several studies have investigated the predictive role of circulating biomarkers before 20th week of gestation with conflicting results. Additional research and well-designed prospective studies are needed to identify and validate predictive tests in clinical practice.

Maternal circulating levels of transforming growth factor-β superfamily and its soluble receptors in hypertensive disorders of pregnancy

OBJECTIVE

To assess circulating levels of transforming growth factor (TGF)-β superfamily members and their soluble receptors in hypertensive disorders of pregnancy, and to investigate associations with clinical manifestations.

METHODS

A retrospective study was conducted using data for women admitted to a center in China for delivery between May 2011 and April 2013. Women with severe pre-eclampsia, mild pre-eclampsia, and gestational hypertension were included, along with a control group. Serum levels of activin A, inhibin A, TGF-β1, soluble endoglin (sEng), and soluble betaglycan (sBG) were measured.

RESULTS

Women with severe pre-eclampsia (n = 17) had higher mean levels of activin A (23.5±2.1 μg/L), inhibin A (1.7±0.2 μg/L), sEng (32.1±3.2 μg/L), and sBG (84.1±9.4 μg/L) than did normotensive controls (n = 18), women with gestational hypertension (n = 15), and those with mild pre-eclampsia (n = 14; all P<0.05). Women with early-onset pre-eclampsia (n = 13) had higher levels of these serum markers than did preterm normotensive controls (n = 8; all P<0.001). Women with severe or early-onset pre-eclampsia had the lowest TGF-β1 levels. Activin A, inhibin A, sEng, and sBG levels were positively correlated with mean arterial pressure and proteinuria (all P<0.01).

CONCLUSION

Pre-eclampsia is associated with an imbalance of members of the TGF-β superfamily and their soluble receptors, which might contribute to the development of pre-eclampsia and help to predict onset and severity.

Activins in reproductive biology and beyond

BACKGROUND

Activins are members of the pleiotrophic family of the transforming growth factor-beta (TGF-β) superfamily of cytokines, initially isolated for their capacity to induce the release of FSH from pituitary extracts. Subsequent research has demonstrated that activins are involved in multiple biological functions including the control of inflammation, fibrosis, developmental biology and tumourigenesis. This review summarizes the current knowledge on the roles of activin in reproductive and developmental biology. It also discusses interesting advances in the field of modulating the bioactivity of activins as a therapeutic target, which would undoubtedly be beneficial for patients with reproductive pathology.

METHODS

A comprehensive literature search was carried out using PUBMED and Google Scholar databases to identify studies in the English language which have contributed to the advancement of the field of activin biology, since its initial isolation in 1987 until July 2015. 'Activin', 'testis', 'ovary', 'embryonic development' and 'therapeutic targets' were used as the keywords in combination with other search phrases relevant to the topic of activin biology.

RESULTS

Activins, which are dimers of inhibin β subunits, act via a classical TGF-β signalling pathway. The bioactivity of activin is regulated by two endogenous inhibitors, inhibin and follistatin. Activin is a major regulator of testicular and ovarian development. In the ovary, activin A promotes oocyte maturation and regulates granulosa cell steroidogenesis. It is also essential in endometrial repair following menstruation, decidualization and maintaining pregnancy. Dysregulation of the activin-follistatin-inhibin system leads to disorders of female reproduction and pregnancy, including polycystic ovary syndrome, ectopic pregnancy, miscarriage, fetal growth restriction, gestational diabetes, pre-eclampsia and pre-term birth. Moreover, a rise in serum activin A, accompanied by elevated FSH, is characteristic of female reproductive aging. In the male, activin A is an autocrine and paracrine modulator of germ cell development and Sertoli cell proliferation. Disruption of normal activin signalling is characteristic of many tumours affecting reproductive organs, including endometrial carcinoma, cervical cancer, testicular and ovarian cancer as well as prostate cancer. While activin A and B aid the progression of many tumours of the reproductive organs, activin C acts as a tumour suppressor. Activins are important in embryonic induction, morphogenesis of branched glandular organs, development of limbs and nervous system, craniofacial and dental development and morphogenesis of the Wolffian duct.

CONCLUSIONS

The field of activin biology has advanced considerably since its initial discovery as an FSH stimulating agent. Now, activin is well known as a growth factor and cytokine that regulates many aspects of reproductive biology, developmental biology and also inflammation and immunological mechanisms. Current research provides evidence for novel roles of activins in maintaining the structure and function of reproductive and other organ systems. The fact that activin A is elevated both locally as well as systemically in major disorders of the reproductive system makes it an important biomarker. Given the established role of activin A as a pro-inflammatory and pro-fibrotic agent, studies of its involvement in disorders of reproduction resulting from these processes should be examined. Follistatin, as a key regulator of the biological actions of activin, should be evaluated as a therapeutic agent in conditions where activin A overexpression is established as a contributing factor.

Evidence-Based Revised View of the Pathophysiology of Preeclampsia

Preeclampsia is a life-threatening vascular disorder of pregnancy due to a failing stressed placenta. Millions of women risk death to give birth each year and globally each year, almost 300,000 lose their life in this process and over 500,000 babies die as a consequence of preeclampsia. Despite decades of research, we lack pharmacological agents to treat it. Maternal endothelial oxidative stress is a central phenomenon responsible for the preeclampsia phenotype of high maternal blood pressure and proteinuria. In 1997, it was proposed that preeclampsia arises due to the loss of VEGF activity, possibly due to elevation in anti-angiogenic factor, soluble Flt-1 (sFlt-1). Researchers showed that high sFlt-1 and soluble endoglin (sEng) elicit the severe preeclampsia phenotype in pregnant rodents. We demonstrated that heme oxygenase-1 (HO-1)/carbon monoxide (CO) pathway prevents placental stress and suppresses sFlt-1 and sEng release. Likewise, hydrogen sulphide (H₂S)/cystathionine-γ-lyase (Cth) systems limit sFlt-1 and sEng and protect against the preeclampsia phenotype in mice. Importantly, H₂S restores placental vasculature, and in doing so improves lagging fetal growth. These molecules act as the inhibitor systems in pregnancy and when they fail, preeclampsia is triggered. In this review, we discuss what are the hypotheses and models for the pathophysiology of preeclampsia on the basis of Bradford Hill causation criteria for disease causation and how further in vivo experimentation is needed to establish 'proof of principle'. Hypotheses that fail to meet the Bradford Hill causation criteria include abnormal spiral artery remodelling and inflammation and should be considered associated or consequential to the disorder. In contrast, the protection against cellular stress hypothesis that states that the protective pathways mitigate cellular stress by limiting elevation of anti-angiogenic factors or oxidative stress and the subsequent clinical signs of preeclampsia appear to fulfil most of Bradford Hill causation criteria. Identifying the candidates on the roadmap to this pathway is essential in developing diagnostics and therapeutics to target the pathogenesis of preeclampsia.

The endocrine function of human placenta: an overview

During pregnancy, several tightly coordinated and regulated processes take place to enable proper fetal development and gestational success. The formation and development of the placenta is one of these critical pregnancy events. This organ plays essential roles during gestation, including fetal nourishment, support and protection, gas exchange and production of several hormones and other mediators. Placental hormones are mainly secreted by the syncytiotrophoblast, in a highly and tightly regulated way. These hormones are important for pregnancy establishment and maintenance, exerting autocrine and paracrine effects that regulate decidualization, placental development, angiogenesis, endometrial receptivity, embryo implantation, immunotolerance and fetal development. In addition, because they are released into maternal circulation, the profile of their blood levels throughout pregnancy has been the target of intense research towards finding potential robust and reliable biomarkers to predict and diagnose pregnancy-associated complications. In fact, altered levels of these hormones have been associated with some pathologies, such as chromosomal anomalies or pre-eclampsia. This review proposes to revise and update the main pregnancy-related hormones, addressing their major characteristics, molecular targets, function throughout pregnancy, regulators of their expression and their potential clinical interest.

Combined Screening for Early Detection of Pre-Eclampsia

Although the precise pathophysiology of pre-eclampsia remains unknown, this condition continues to be a major cause of maternal and fetal mortality. Early prediction of pre-eclampsia would allow for timely initiation of preventive therapy. A combination of biophysical and biochemical markers are superior to other tests for early prediction of the development of pre-eclampsia. Apart from the use of parameters in first-trimester aneuploidy screening, cell-free fetal DNA quantification is emerging as a promising marker for prediction of pre-eclampsia. This article reviews the current research of the most important strategies for prediction of pre-eclampsia, including the use of maternal risk factors, mean maternal arterial pressure, ultrasound parameters, and biomarkers.

Longitudinal analysis of maternal serum Follistatin concentration in normal pregnancy and preeclampsia

OBJECTIVE

Follistatin (FST) is a regulator of the biological activity of activin A (Act A), binding and blocking it, which could contribute to the modulation of its pro-inflammatory activity during pregnancy. We sought to investigate, in this nested case-control study, FST serum levels during normal pregnancy and correlate it with the FST profile in preeclamptic pregnant women, normal pregnant women followed 3 months postpartum and eumenorrheic nonpregnant women throughout the menstrual cycle.

SUBJECTS AND METHODS

Follistatin serum levels determined by ELISA, biochemical and anthropometric variables were measured in normal pregnant (n = 28) and preeclamptic (n = 20) women during three periods of gestation. In addition, FST serum levels were measured in a subset of normal pregnant women (n = 13) followed 3 months postpartum and in eumenorrheic nonpregnant women (n = 20) during the follicular and luteal phases of the menstrual cycle.

RESULTS

Follistatin serum levels in the eumenorrheic nonpregnant and postpartum group were significantly lower when compared to levels throughout gestation (P < 0·01). Serum FST levels increased in each period of pregnancy analysed, being significantly higher towards the end of gestation (P < 0·01). FST levels were lower in late pregnancy in preeclamptic women compared to normal pregnant women (P < 0·05). Finally, FST levels were higher in the luteal phase when compared with the follicular phase of the menstrual cycle (P < 0·05).

CONCLUSIONS

These analyses would permit the consideration that changes in FST levels during pregnancy contribute to the control of the Act A system.

Changes in antimüllerian hormone levels in early pregnancy are associated with preterm birth

OBJECTIVE

To determine the association of preterm birth with antimüllerian hormone (AMH) levels both in isolation and in combination with other markers of fetoplacental health commonly measured during integrated prenatal screening (IPS) for aneuploidy.

DESIGN

Retrospective case-control study.

SETTING

Not applicable.

PATIENT(S)

Pregnant women in Iowa who elected to undergo IPS and who subsequently delivered in Iowa, including women giving birth at <37 weeks' gestation and controls who delivered at ≥37 weeks' gestation.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Probability of a preterm birth.

RESULT(S)

Second trimester AMH levels were not associated with preterm birth, either independently or after controlling for other markers of fetoplacental health. The AMH difference was not associated with preterm birth when modeled alone, but a statistically significant association was found after adjusting for maternal serum α-fetoprotein (MSAFP) and maternal weight change between the first and second trimesters. After stratifying the model by MSAFP level, most of the risk for preterm birth was identified in women with an MSAFP >1 multiple of the median and who had a stable or rising AMH level in early pregnancy.

CONCLUSION(S)

A lack of decline in the AMH level in early pregnancy can be used to identify women with a high probability for preterm birth, especially when MSAFP levels are >1 multiple of the median. Monitoring changes in the AMH level between the first and second trimesters of pregnancy may help identify women who would benefit from interventional therapies such as supplemental progesterone.

Urine proteomic studies in preeclampsia

Preeclampsia (PE) is a multisystem disorder of pregnancy that develops after 20 wk of gestation in previously normotensive women and complicates 5-8% of pregnancies. This rapidly progressive syndrome is usually diagnosed when the mother develops hypertension and proteinuria. The only effective treatment is delivery of the baby although early low-dose aspirin has been shown to significantly reduce the risk for PE. Recent advances in proteomic methods of protein separation, identification, and quantitation may allow for the identification of proteins and peptides that could facilitate early detection of disease, improve assessment of prognosis, and allow closer monitoring of women at risk for PE. This review summarizes all currently available markers for prediction and diagnosis of PE and presents urine proteomic studies performed for the identification of novel biomarkers.

Activin and NADPH-oxidase in preeclampsia: insights from in vitro and murine studies

OBJECTIVE

Clinical management of preeclampsia has remained unchanged for almost 5 decades. We now understand that maternal endothelial dysfunction likely arises because of placenta-derived vasoactive factors. Activin A is one such antiangiogenic factor that is released by the placenta and that is elevated in maternal serum in women with preeclampsia. Whether activin has a role in the pathogenesis of preeclampsia is not known.

STUDY DESIGN

To assess the effects of activin on endothelial cell function, we cultured human umbilical vein endothelial cells in the presence of activin or serum from normal pregnant women or pregnant women with preeclampsia, with or without follistatin, a functional activin antagonist or apocynin, a NADPH oxidase (Nox2) inhibitor. We also administered activin to pregnant C57Bl6 mice, with or without apocynin, and studied maternal and fetal outcomes. Last, we assessed endothelial cell Nox2 and nitric oxide synthase expression in normal pregnant women and pregnant women with preeclampsia.

RESULTS

Activin and preeclamptic serum induced endothelial cell oxidative stress by Nox2 up-regulation and endothelial cell dysfunction, which are effects that are mitigated by either follistatin or apocynin. The administration of activin to pregnant mice induced endothelial oxidative stress, hypertension, proteinuria, fetal growth restriction, and preterm littering. Apocynin prevented all of these effects. Compared with normal pregnant women, women with preeclampsia had increased endothelial Nox2 expression.

CONCLUSION

An activin-Nox2 pathway is a likely link between an injured placenta, endothelial dysfunction, and preeclampsia. This offers opportunities that are not novel therapeutic approaches to preeclampsia.

Preeclampsia from a renal point of view: Insides into disease models, biomarkers and therapy

Proteinuria is a frequently detected symptom, found in 20% of pregnancies. A common reason for proteinuria in pregnancy is preeclampsia. To diagnose preeclampsia clinically and to get new insights into the pathophysiology of the disease it is at first essential to be familiar with conditions in normal pregnancy. Animal models and biomarkers can help to learn more about disease conditions and to find new treatment strategies. In this article we review the changes in kidney function during normal pregnancy and the differential diagnosis of proteinuria in pregnancy. We summarize different pathophysiological theories of preeclampsia with a special focus on the renal facets of the disease. We describe the current animal models and give a broad overview of different biomarkers that were reported to predict preeclampsia or have a prognostic value in preeclampsia cases. We end with a summary of treatment options for preeclampsia related symptoms including the use of plasmapheresis as a rescue therapy for so far refractory preeclampsia. Most of these novel biomarkers for preeclampsia are not yet implemented in clinical use. Therefore, we recommend using proteinuria (measured by UPC ratio) as a screening parameter for preeclampsia. Delivery is the only curative treatment for preeclampsia. In early preeclampsia the primary therapy goal is to prolong pregnancy until a state were the child has an acceptable chance of survival after delivery.

Inhibin at 90: from discovery to clinical application, a historical review

When it was initially discovered in 1923, inhibin was characterized as a hypophysiotropic hormone that acts on pituitary cells to regulate pituitary hormone secretion. Ninety years later, what we know about inhibin stretches far beyond its well-established capacity to inhibit activin signaling and suppress pituitary FSH production. Inhibin is one of the major reproductive hormones involved in the regulation of folliculogenesis and steroidogenesis. Although the physiological role of inhibin as an activin antagonist in other organ systems is not as well defined as it is in the pituitary-gonadal axis, inhibin also modulates biological processes in other organs through paracrine, autocrine, and/or endocrine mechanisms. Inhibin and components of its signaling pathway are expressed in many organs. Diagnostically, inhibin is used for prenatal screening of Down syndrome as part of the quadruple test and as a biochemical marker in the assessment of ovarian reserve. In this review, we provide a comprehensive summary of our current understanding of the biological role of inhibin, its relationship with activin, its signaling mechanisms, and its potential value as a diagnostic marker for reproductive function and pregnancy-associated conditions.

Maternal genotype and severe preeclampsia: a HuGE review

Severe preeclampsia is a common cause of maternal and perinatal morbidity worldwide. The disease clusters in families; however, individual genetic studies have produced inconsistent results. We conducted a review to examine relationships between maternal genotype and severe preeclampsia. We searched the MEDLINE and Embase databases for prospective and retrospective cohort and case-control studies reporting associations between genes and severe preeclampsia. Four reviewers independently undertook study selection, quality assessment, and data extraction. We performed random-effects meta-analyses by genotype and predefined functional gene group (thrombophilic, vasoactive, metabolic, immune, and cell signalling). Fifty-seven studies evaluated 50 genotypes in 5,049 cases and 16,989 controls. Meta-analysis showed a higher risk of severe preeclampsia with coagulation factor V gene (proaccelerin, labile factor) (F5) polymorphism rs6025 (odds ratio = 1.90, 95% confidence interval: 1.42, 2.54; 23 studies, I(2) = 29%), coagulation factor II (thrombin) gene (F2) mutation G20210A (rs1799963) (odds ratio = 2.01, 95% confidence interval: 1.14, 3.55, 9 studies, I(2) = 0%), leptin receptor gene (LEPR) polymorphism rs1137100 (odds ratio = 1.75, 95% confidence interval: 1.15, 2.65; 2 studies, I(2) = 0%), and the thrombophilic gene group (odds ratio = 1.87, 95% confidence interval: 1.43, 2.45, I(2) = 27%). There were no associations with other gene groups. There was moderate heterogeneity between studies and potential for bias from poor-quality genotyping and inconsistent definition of phenotype. Further studies with robust methods should investigate genetic factors that might potentially be used to stratify pregnancies according to risk of complications.

Role of biomarkers in early detection of preeclampsia

Preeclampsia (PE) is a pregnancy-related, potentially life threatening condition. The incidence of PE has increased in the past decade, which has been attributed to various predisposing factors. Abnormal placentation is central to the evolution of this disease process. However, the triggering factor for this is still unknown. Interestingly, intense research done in this arena has unveiled the names of some important biomolecules which play important role in the vasculognesis of the early placenta, namely, vascular endothelial growth factor (VEGF) and placental growth factor (PlGF) and their antagonists, namely, soluble fms-like tyrosine kinase 1 (sFlt-1, also known as sVEGFR1), and soluble endoglin (sEng). Besides these, Renin Angiotensin System (RAS) was also implicated in this disease process. The roles of immune factors, genetic factors have been stressed from time to time. More novel approaches made, have shed light on the upcoming biomolecules. All these endeavours are directed to diagnose PE as early as possible, which is a real challenge. Question remains whether a single set parameters could diagnose a disease entity which is as complex as PE. Therefore, it is imperative to design feasible, predictive test-set utilizing multiple biomarkers.

Effect of selenium on markers of risk of pre-eclampsia in UK pregnant women: a randomised, controlled pilot trial

Pre-eclampsia is a serious hypertensive condition of pregnancy associated with high maternal and fetal morbidity and mortality. Se intake or status has been linked to the occurrence of pre-eclampsia by our own work and that of others. We hypothesised that a small increase in the Se intake of UK pregnant women of inadequate Se status would protect against the risk of pre-eclampsia, as assessed by biomarkers of pre-eclampsia. In a double-blind, placebo-controlled, pilot trial, we randomised 230 primiparous pregnant women to Se (60 μg/d, as Se-enriched yeast) or placebo treatment from 12 to 14 weeks of gestation until delivery. Whole-blood Se concentration was measured at baseline and 35 weeks, and plasma selenoprotein P (SEPP1) concentration at 35 weeks. The primary outcome measure of the present study was serum soluble vascular endothelial growth factor receptor-1 (sFlt-1), an anti-angiogenic factor linked with the risk of pre-eclampsia. Other serum/plasma components related to the risk of pre-eclampsia were also measured. Between 12 and 35 weeks, whole-blood Se concentration increased significantly in the Se-treated group but decreased significantly in the placebo group. At 35 weeks, significantly higher concentrations of whole-blood Se and plasma SEPP1 were observed in the Se-treated group than in the placebo group. In line with our hypothesis, the concentration of sFlt-1 was significantly lower at 35 weeks in the Se-treated group than in the placebo group in participants in the lowest quartile of Se status at baseline (P= 0·039). None of the secondary outcome measures was significantly affected by treatment. The present finding that Se supplementation has the potential to reduce the risk of pre-eclampsia in pregnant women of low Se status needs to be validated in an adequately powered trial.

Screening models using multiple markers for early detection of late-onset preeclampsia in low-risk pregnancy

BACKGROUND

Our primary objective was to establish a cutoff value for the soluble fms-like tyrosine kinase 1(sFlt-1)/placental growth factor (PlGF) ratio measured using the Elecsys assay to predict late-onset preeclampsia in low-risk pregnancies. Our secondary objective was to evaluate the ability of combination models using Elecsys data, second trimester uterine artery (UtA) Doppler ultrasonography measurements, and the serum fetoplacental protein levels used for Down's syndrome screening, to predict preeclampsia.

METHODS

This prospective cohort study included 262 pregnant women with a low risk of preeclampsia. Plasma levels of pregnancy-associated plasma protein-A (PAPP-A) and serum levels of alpha-fetoprotein, unconjugated estriol, human chorionic gonadotropin, and inhibin-A were measured, and sFlt-1/PlGF ratios were calculated. All women underwent UtA Doppler ultrasonography at 20 to 24 weeks of gestation.

RESULTS

Eight of the 262 women (3.0%) developed late-onset preeclampsia. Receiver operating characteristic curve analysis showed that the third trimester sFlt-1/PlGF ratio yielded the best detection rate (DR) for preeclampsia at a fixed false-positive rate (FPR) of 10%, followed by the second trimester sFlt-1/PlGF ratio, sFlt-1 level, and PlGF level. Binary logistic regression analysis was used to determine the five best combination models for early detection of late-onset preeclampsia. The combination of the PAPP-A level and the second trimester sFlt-1/PlGF ratio yielded a DR of 87.5% at a fixed FPR of 5%, the combination of second and third trimester sFlt-1/PlGF ratios yielded a DR of 87.5% at a fixed FPR of 10%, the combination of body mass index and the second trimester sFlt-1 level yielded a DR of 87.5% at a fixed FPR of 10%, the combination of the PAPP-A and inhibin-A levels yielded a DR of 50% at a fixed FPR of 10%, and the combination of the PAPP-A level and the third trimester sFlt-1/PlGF ratio yielded a DR of 62.5% at a fixed FPR of 10%.

CONCLUSIONS

The combination of the PAPP-A level and the second trimester sFlt-1/PlGF ratio, and the combination of the second trimester sFlt-1 level with body mass index, were better predictors of late-onset preeclampsia than any individual marker.

Cytokines as key players in the pathophysiology of preeclampsia

Preeclampsia (PE) is an important, common, and dangerous complication of pregnancy; it causes maternal and perinatal illness and is responsible for a high proportion of maternal and infant deaths. PE is associated with increased blood pressure and proteinuria, with a whole host of other potentially serious complications in the mother and fetus. The maternal syndrome in PE is primarily that of generalized dysfunction of the maternal endothelium, and this generalized endothelial dysfunction appears to be part of an exaggerated systemic inflammatory response that involves maternal leukocytes and proinflammatory cytokines. This review examines evidence that points to a significant role for the maternal immune system; inadequate trophoblast invasion of spiral arteries initiates ischemia and hypoxia in the placenta, resulting in an increased release of proinflammatory cytokines in the placenta. Placental ischemia and hypoxia also cause the enhanced release of trophoblast microparticles into the maternal circulation which stimulates increased induction of proinflammatory cytokines and the activation of maternal endothelial cells. This activation results in a systemic, diffuse endothelial cell dysfunction which is the fundamental pathophysiological feature of this syndrome. Recent evidence also supports important roles for proinflammatory cytokines in hypertension, proteinuria, and edema which are characteristic features of PE.

The obstetric syndromes: clinical relevance of placental hormones

Preterm delivery, preeclampsia and intrauterine growth restriction are the major diseases of pregnancy. A key role in their pathogenesis is played by the placenta, which is the source of hormones and other important regulatory molecules providing the metabolic and endocrine homeostasis of the fetal-placental unit. Since obstetric syndromes are characterized by important maternal and neonatal morbidity and mortality worldwide, numerous efforts have been made over the years to prevent and treat them. Due to their complex pathogenesis, however, the therapy is poor and not very effective. Therefore, great emphasis is currently given to the prevention of these diseases through the identification of biochemical and biophysical markers, among which placental factors play a crucial role. The increasing knowledge of the role of placental molecules can indeed lead to the development of new therapeutic and diagnostic tools.