Predictive Value of the sFlt-1:PlGF Ratio in Women with Suspected Preeclampsia

Villous explants from preeclamptic placentas induce sFlt1 in PBMCs: An ex vivo co-culture study

OBJECTIVES

Soluble Flt1 (sFlt1) is an anti-angiogenic protein linked to the pathology of preeclampsia (PE). While the placenta serves as the major organ producing sFlt1 during normal pregnancy, peripheral blood mononuclear cells (PBMCs), endothelial cells, and stromal cells also produce sFlt1. The key question is 'what drives the overexpression of sFlt1 observed during PE?' In the present work we show evidence for sFlt1 over-expression in PBMCs due to interaction with placental villi from PE patients.

STUDY DESIGN

sFlt1 production by PBMCs is estimated by using two blood collection methods with different coagulation chemistry. PBMCs were then cultured with homologous villous explants and heterologous villous explants to determine the effects of the interaction between the two tissues.

MAIN OUTCOME MEASURES

sFlt1 levels were estimated using real time PCR, ELISA, and gel electrophoresis.

RESULTS

Plasma samples obtained using CTAD as anti-coagulant showed 16-23% less sFlt1 compared to plasma collected in EDTA. Preeclamptic PBMCs showed higher basal level of sFlt1 mRNA. In addition, we show evidence of placental interaction as a cause of sFlt1 overexpression in PBMCs using homologous and heterologous co-culture system. However, during co-culture, we observed that while the sFlt1 expression in PE PBMCs is increased, PE villous explants show reduced sFlt1 RNA expression.

CONCLUSION

sFlt1 was produced in significant amounts by preeclamptic PBMCs, and ex vivo studies show that the placenta induces this over-expression. In contrast, exposure to PBMCs appears to decrease sFlt1 production by preeclamptic placenta.

What We Do and Do Not Know about Women and Kidney Diseases; Questions Unanswered and Answers Unquestioned: Reflection on World Kidney Day and International Women's Day

Chronic kidney disease affects approximately 10% of the world's adult population: it is within the top 20 causes of death worldwide, and its impact on patients and their families can be devastating. World Kidney Day and International Women's Day in 2018 coincide, thus offering an opportunity to reflect on the importance of women's health and specifically their kidney health, on the community and the next generations, as well as to strive to be more curious about the unique aspects of kidney disease in women so that we may apply those learnings more broadly. Girls and women, who make up approximately 50% of the world's population, are important contributors to society and their families. Gender differences continue to exist around the world in access to education, medical care, and participation in clinical studies. Pregnancy is a unique state for women, offering an opportunity for diagnosis of kidney disease, but also a state where acute and chronic kidney diseases may manifest, and which may impact future generations with respect to kidney health. There are various autoimmune and other conditions that are more likely to have an impact on women, with profound consequences for child bearing, and on the fetus. Women have different complications on dialysis than men, and are more likely to be donors than recipients of kidney transplants. In this editorial, we focus on what we do and do not know about women, kidney health, and kidney disease, and what we might learn in the future to improve outcomes worldwide.

What we do and do not know about women and kidney diseases; questions unanswered and answers unquestioned: reflection on World Kidney Day and International Women's Day

Chronic Kidney Disease affects approximately 10% of the world's adult population: it is within the top 20 causes of death worldwide, and its impact on patients and their families can be devastating. World Kidney Day and International Women's Day in 2018 coincide, thus offering an opportunity to reflect on the importance of women's health and specifically their kidney health, on the community, and the next generations, as well as to strive to be more curious about the unique aspects of kidney disease in women so that we may apply those learnings more broadly. Girls and women, who make up approximately 50% of the world's population, are important contributors to society and their families. Gender differences continue to exist around the world in access to education, medical care, and participation in clinical studies. Pregnancy is a unique state for women, offering an opportunity for diagnosis of kidney disease, but also a state where acute and chronic kidney diseases may manifest, and which may impact future generations with respect to kidney health. There are various autoimmune and other conditions that are more likely to impact women with profound consequences for child bearing, and on the fetus. Women have different complications on dialysis than men, and are more likely to be donors than recipients of kidney transplants. In this editorial, we focus on what we do and do not know about women, kidney health, and kidney disease, and what we might learn in the future to improve outcomes worldwide.

Thrombotic microangiopathies of pregnancy: Differential diagnosis

Thrombotic microangiopathy (TMA) disorders are characterized by microangiopathic hemolytic anemia, thrombocytopenia and end-organ injury. In pregnancy and postpartum, TMA is most commonly encountered with HELLP (hemolysis, elevated liver enzymes, low platelet count syndrome) or preeclampsia with severe features, but rarely TMA is due to thrombotic thrombocytopenic purpura (TTP) or atypical hemolytic uremic syndrome (aHUS). Due to overlapping clinical and laboratory features, TTP and aHUS are often mistaken for preeclampsia or HELLP. Unfortunately, delays in appropriate diagnosis and treatment may be life-threatening. Our objective is to alert obstetrician-gynecologists, certified nurse midwives, family medicine providers, and subspecialty consultants, to the range of TMA disorders that may occur in and around pregnancy. To do this, we have provided a review of individual disorders that comprise the differential diagnosis of pregnancy TMA, and we have proposed a systematic approach to make an accurate diagnosis with readily available clinical and laboratory data. In complex or critical cases, we recommend a multidisciplinary team approach (e.g., Critical Care, Hematology, Maternal Fetal Medicine, Nephrology) to expedite diagnosis and treatment, which may be life-saving.

What We Do and Do Not Know about Women and Kidney Diseases; Questions Unanswered and Answers Unquestioned: Reflection on World Kidney Day and International Woman's Day

Chronic kidney disease affects approximately 10% of the world's adult population: it is within the top 20 causes of death worldwide, and its impact on patients and their families can be devastating. World Kidney Day and International Women's Day in 2018 coincide, thus offering an opportunity to reflect on the importance of women's health and specifically their kidney health, on the community and the next generations, as well as to strive to be more curious about the unique aspects of kidney disease in women so that we may apply those learnings more broadly. Girls and women, who make up approximately 50% of the world's population, are important contributors to society and their families. Gender differences continue to exist around the world in access to education, medical care, and participation in clinical studies. Pregnancy is a unique state for women, offering an opportunity for diagnosis of kidney disease, but also a state where acute and chronic kidney diseases may manifest, and which may impact future generations with respect to kidney health. There are various autoimmune and other conditions that are more likely to have an impact on women, with profound consequences for child bearing, and on the fetus. Women have different complications on dialysis than men, and are more likely to be donors than recipients of kidney transplants. In this editorial, we focus on what we do and do not know about women, kidney health, and kidney disease, and what we might learn in the future to improve outcomes worldwide.

Prediction and prevention of pre-eclampsia in Asian subpopulation

The benefit of the early administration of aspirin to reduce preterm pre-eclampsia among screened positive European women from multivariate algorithmic approach (ASPRE trial) has opened an intense debate on the feasibility of universal screening. This review aims to assess the new perspectives in the combined screening of pre-eclampsia in the first trimester of pregnancy and the chances for prevention using low-dose aspirin with special emphasis on the particularities of the Asian population. PubMed, CENTRAL and Embase databases were searched from inception until 15 November 2017 using combinations of the search terms: preeclampsia, Asian, prenatal screening, early prediction, ultrasonography, pregnancy, biomarker, mean arterial pressure, soluble fms-like tyrosine kinase-1, placental growth factor, pregnancy-associated plasma protein-A and pulsatility index. This is not a systematic review or meta-analysis, so the risk of bias of the selected published articles and heterogeneity among the studies need to be considered. The prevalence of pre-eclampsia and serum levels of biochemical markers in Asian are different from Caucasian women; hence, Asian ethnicity needs to be corrected for in the algorithmic assessment of multiple variables to improve the screening performance. Aspirin prophylaxis may still be viable in Asian women, but resource implication needs to be considered. Asian ethnicity should be taken into account before implementing pre-eclampsia screening strategies in the region. The variables included can be mixed and matched to achieve an optimal performance that is appropriate for economical restriction in individual countries.

Placental growth factor (alone or in combination with soluble fms-like tyrosine kinase 1) as an aid to the assessment of women with suspected pre-eclampsia: systematic review and economic analysis

BACKGROUND

Pre-eclampsia (PE) prediction based on blood pressure, presence of protein in the urine, symptoms and laboratory test abnormalities can result in false-positive diagnoses. This may lead to unnecessary antenatal admissions and preterm delivery. Blood tests that measure placental growth factor (PlGF) or the ratio of soluble fms-like tyrosine kinase 1 (sFlt-1) to PlGF could aid prediction of PE if either were added to routine clinical assessment or used as a replacement for proteinuria testing.

OBJECTIVES

To evaluate the diagnostic accuracy and cost-effectiveness of PlGF-based tests for patients referred to secondary care with suspected PE in weeks 20-37 of pregnancy.

DESIGN

Systematic reviews and an economic analysis.

DATA SOURCES

Bibliographic databases including MEDLINE, EMBASE, Web of Science and The Cochrane Library and Database of Abstracts of Reviews of Effects were searched up to July 2015 for English-language references. Conferences, websites, systematic reviews and confidential company submissions were also accessed.

REVIEW METHODS

Systematic reviews of test accuracy and economic studies were conducted to inform an economic analysis. Test accuracy studies were required to include women with suspected PE and report quantitatively the accuracy of PlGF-based tests; their risk of bias was assessed using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS) criteria. The economic studies review had broad eligibility criteria to capture any types of economic analysis; critical appraisal employed standard checklists consistent with National Institute for Health and Care Excellence criteria. Study selection, critical appraisal and data extraction in both reviews were performed by two reviewers.

ECONOMIC ANALYSIS

An independent economic analysis was conducted based on a decision tree model, using the best evidence available. The model evaluates costs (2014, GBP) from a NHS and Personal Social Services perspective. Given the short analysis time horizon, no discounting was undertaken.

RESULTS

Four studies were included in the systematic review of test accuracy: two on Alere's Triage^® PlGF test (Alere, Inc., San Diego, CA, USA) for predicting PE requiring delivery within a specified time and two on Roche Diagnostics' Elecsys^® sFlt-1 to PlGF ratio test (Roche Diagnostics GmbH, Mannheim, Germany) for predicting PE within a specified time. Three studies were included in the systematic review of economic studies, and two confidential company economic analyses were assessed separately. Study heterogeneity precluded meta-analyses of test accuracy or cost-analysis outcomes, so narrative syntheses were conducted to inform the independent economic model. The model predicts that, when supplementing routine clinical assessment for rule-out and rule-in of PE, the two tests would be cost-saving in weeks 20-35 of gestation, and marginally cost-saving in weeks 35-37, but with minuscule impact on quality of life. Length of neonatal intensive care unit stay was the most influential parameter in sensitivity analyses. All other sensitivity analyses had negligible effects on results.

LIMITATIONS

No head-to-head comparisons of the tests were identified. No studies investigated accuracy of PlGF-based tests when used as a replacement for proteinuria testing. Test accuracy studies were found to be at high risk of clinical review bias.

CONCLUSIONS

The Triage and Elecsys tests would save money if added to routine clinical assessment for PE. The magnitude of savings is uncertain, but the tests remain cost-saving under worst-case assumptions. Further research is required to clarify how the test results would be interpreted and applied in clinical practice.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42015017670.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Placental-specific sFLT-1: role in pre-eclamptic pathophysiology and its translational possibilities for clinical prediction and diagnosis

Pre-eclampsia is a common obstetric complication globally responsible for a significant burden of maternal and perinatal morbidity and mortality. Central to its pathophysiology is the anti-angiogenic protein, soluble fms-like tyrosine kinase-1 (sFLT-1). sFLT-1 is released from a range of tissues into the circulation, where it antagonizes the activity of vascular endothelial growth factor and placental growth factor leading to endothelial dysfunction. It is this widespread endothelial dysfunction that produces the clinical features of pre-eclampsia including hypertension and proteinuria. There are multiple splice variants of sFLT-1. One, known as sFLT-1 e15a, evolved quite recently and is only present in humans and higher order primates. This sFLT-1 variant is also the main sFLT-1 secreted from the placenta. Recent work has shown that sFLT-1 e15a is significantly elevated in the placenta and circulation of women with pre-eclampsia. It is also biologically active, capable of causing endothelial dysfunction and the end-organ dysfunction seen in pre-eclampsia. Indeed, the over-expression of sFLT-1 e15a in mice recapitulates the pre-eclamptic phenotype in pregnancy. Therefore, here we propose that sFLT-1 e15a may be the sFLT-1 variant primarily responsible for pre-eclampsia, a uniquely human disease. Furthermore, this placental-specific sFLT-1 variant provides promise for use as an accurate biomarker in the prediction or diagnosis of pre-eclampsia.

Resting-state functional connectivity in children born from gestations complicated by preeclampsia: A pilot study cohort

BACKGROUND

Individuals (PE-F1s) born from preeclampsia (PE)-complicated pregnancies have elevated risks for cognitive impairment. Intervals of disturbed maternal plasma angiokines precede clinical signs of PE. We hypothesized pan-blastocyst dysregulation of angiokines underlies altered PE-F1 brain vascular and neurological development. This could alter brain functional connectivity (FC) patterns at rest.

MATERIALS AND METHODS

Resting-state functional MRI datasets of ten, matched child pairs (5 boys and 5 girls aged 7-10 years of age) from PE or control pregnancies were available for study. Seed-based analysis and independent component analysis (ICA) methodologies were used to assess whether differences in resting-state functional connectivity (rs-FC) were present between PE-F1s and controls. Bilateral amygdala, bilateral hippocampus, and medial prefrontal cortex (MPFC) were selected as regions of interest (ROI) for the seed-based analysis based on previous imaging differences that we reported in this set of children.

RESULTS

Compared to controls, PE-F1 children had increased rs-FC between the right amygdala and left frontal pole, the left amygdala and bilateral frontal pole, and the MPFC and precuneus. PE-F1 children additionally had decreased rs-FC between the MPFC and the left occipital fusiform gyrus compared to controls.

CONCLUSION

These are the first reported rs-FC data for PE-F1s of any age. Theysuggest that PE alters FC during human fetal brain development. Altered FC may contribute to the behavioural and neurological alterations reported in PE-F1s. Longitudinal MRI studies with larger sample sizes are required to confirm these novel findings.

The role of angiogenic biomarkers and uterine artery Doppler in pregnant women with systemic lupus erythematosus or antiphospholipid syndrome

OBJECTIVE

To evaluate the usefulness of the uterine artery mean pulsatility index (mPI-UtA) and the sFlt-1/PlGF ratio in women with systemic lupus erythematosus (SLE) or antiphospholipid syndrome (APS) for the prediction of placental dysfunction-related adverse outcomes (AO), namely pre-eclampsia (PE) and intrauterine growth restriction (IUGR), and for differential diagnosis between PE and SLE flares.

STUDY DESIGN

Observational prospective cohort study of 57 pregnant women with SLE or APS.

MAIN OUTCOME MEASURES

mPI-UtA and sFlt-1/PlGF ratio in maternal serum were obtained at four gestational age periods (11-14, 19-22, 24-29 and 32-34 weeks). Comparisons among pregnancies with normal outcome, SLE flare and AO were performed.

RESULTS

Overall, we had 44 ongoing pregnancies (36 with SLE and 8 with APS) of which most (n = 35, 80%) were uncomplicated. The overall rate of AO was 9% (n = 4), that was diagnosed at a mean (SD) gestational age of 34.1 (7.5) weeks. Five SLE patients (14%) suffered a SLE flare. No differences for these markers were found between normal pregnancies and those affected by SLE flare. mUtA-PI values were significantly higher in the AO group when compared with normal and SLE flare groups, at 19-22 weeks (1.52, 0.95 and 0.76) and 32-34 weeks (1.13, 0.68 and 0.65), respectively. The sFlt-1/PlGF ratio was significantly higher in the AO group at 24-29 weeks (191.1, 3.1 and 9.2), respectively.

CONCLUSION

Our preliminary results indicate that mPI-UtA and sFlt1/PlGF ratio may be useful to predict AO in women with SLE, and to make the differential diagnosis with a lupus flare.

Pregnancy in systemic sclerosis

This comprehensive review summarizes retrospective and prospective studies on pregnancy in systemic sclerosis in order to educate physicians on critical management issues. Fertility is normal in women with established systemic sclerosis. Their rates of spontaneous losses are comparable to the general population, except for patients with late diffuse systemic sclerosis and severe internal organ involvement who may have higher risks of abortion. Prematurity is clearly higher among systemic sclerosis women, similarly to other rheumatic diseases such as systemic lupus erythematosus and anti-phospholipid antibody syndrome. A placental vasculopathy has been observed in some women with systemic sclerosis. Overall, the disease generally remains stable in most pregnancies. Women with pulmonary hypertension should avoid pregnancy on account of the high maternal mortality risk. Management of systemic sclerosis patients before and during pregnancy includes evaluation of organ involvement and autoantibody analysis, preconceptional folic acid, and discontinuation of drugs with teratogenic potential (bosentan, mycophenolate mofetil, methotrexate, etc.). Management by high-risk pregnancy teams including neonatologists is very important to ensure the best outcomes.

Genetic predisposition to preeclampsia is conferred by fetal DNA variants near FLT1, a gene involved in the regulation of angiogenesis

Preeclampsia risk is influenced by both the mother's genetic background and the genetics of her fetus; however, the specific genes responsible for conferring preeclampsia risk have largely remained elusive. Evidence that preeclampsia has a genetic predisposition was first detailed in the early 1960s, and overall preeclampsia heritability is estimated at ∼55%. Many traditional gene discovery approaches have been used to investigate the specific genes that contribute to preeclampsia risk, but these have largely not been successful or reproducible. Over the past decade, genome-wide association studies have allowed for significant advances in the understanding of the genetic basis of many common diseases. Genome-wide association studies are predicated on the idea that the genetic basis of many common diseases are complex and polygenic with many variants, each with modest effects that contribute to disease risk. Using this approach in preeclampsia, a large genome-wide association study recently identified and replicated the first robust fetal genomic region associated with excess risk. A screen of >7 million genetic variants in 2658 offspring from preeclamptic women and 308,292 population controls identified a single association signal close to the Fms-like tyrosine kinase 1 gene, on chromosome 13. Fms-like tyrosine kinase 1 encodes soluble Fms-like tyrosine kinase 1, a splice variant of the vascular endothelial growth factor receptor that exerts antiangiogenic activity by inhibiting signaling of proangiogenic factors. The Fms-like tyrosine kinase 1 pathway is central in preeclampsia pathogenesis because excess circulating soluble Fms-like tyrosine kinase 1 in the maternal plasma leads to the hallmark clinical features of preeclampsia, including hypertension and proteinuria. The success of this landmark fetal preeclampsia genome-wide association study suggests that well-powered, larger maternal and fetal genome-wide association study will be fruitful in identifying additional common variants that implicate causal preeclampsia genes and pathways. Such efforts will rely on the continued development of large preeclampsia consortia focused on preeclampsia genetics to obtain adequate sample sizes, detailed clinical phenotyping, and matched maternal-fetal samples. In summary, the fetal preeclampsia genome-wide association study represents an exciting advance in preeclampsia biology, suggesting that dysregulation at the Fms-like tyrosine kinase 1 locus in the fetal genome (likely in the placenta) is a fundamental molecular defect in preeclampsia.

The Women's Health Diagnostic Gap

Pregnancy remains a significant health risk to women in both developed and underdeveloped countries. Worldwide, 10 to 20 million women have pregnancy complications including ectopic pregnancy, preterm birth, gestational diabetes mellitus, and hypertensive states, including preeclampsia. Despite advancements in women's health research, there is a large gap in the diagnostic tools available to screen, diagnose, and monitor these conditions. Herein, we examine existing diagnostic tools, such as the human chorionic gonadotropin discriminatory zone, cervicovaginal fetal fibronectin, sFlt-1:PlGF ratio, and glucose tolerance testing. We suggest specific objectives to improve diagnostic testing during pregnancy, including (1) developing high-quality biospecimen banks; (2) educating professionals on performance characteristics of screening tests for low prevalence diseases; (3) funding studies that address diseases unique to pregnancy; and (4) establishing trimester-specific reference intervals. Meeting these objectives could begin to narrow the diagnostic gap in women's health.

What We Do and Do Not Know about Women and Kidney Diseases; Questions Unanswered and Answers Unquestioned: Reflection on World Kidney Day and International Women's Day

Chronic kidney disease affects approximately 10$ of the world's adult population: it is within the top 20 causes of death worldwide, and its impact on patients and their families can be devastating. World Kidney Day and International Women's Day in 2018 coincide, thus offering an opportunity to reflect on the importance of women's health and specifically their kidney health, on the community and the next generations, as well as to strive to be more curious about the unique aspects of kidney disease in women so that we may apply those learnings more broadly. Girls and women, who make up approximately 50$ of the world's population, are important contributors to society and their families. Gender differences continue to exist around the world in access to education, medical care, and participation in clinical studies. Pregnancy is a unique state for women, offering an opportunity for diagnosis of kidney disease, but also a state where acute and chronic kidney diseases may manifest, and which may impact future generations with respect to kidney health. There are various autoimmune and other conditions that are more likely to have an impact on women, with profound consequences for child bearing, and on the fetus. Women have different complications on dialysis than men, and are more likely to be donors than recipients of kidney transplants. In this editorial, we focus on what we do and do not know about women, kidney health, and kidney disease, and what we might learn in the future to improve outcomes worldwide.

A placenta clinic approach to the diagnosis and management of fetal growth restriction

Effective detection and management of fetal growth restriction is relevant to all obstetric care providers. Models of best practice to care for these patients and their families continue to evolve. Since much of the disease burden in fetal growth restriction originates in the placenta, the concept of a multidisciplinary placenta clinic program, managed primarily within a maternal-fetal medicine division, has gained popularity. In this context, fetal growth restriction is merely one of many placenta-related disorders that can benefit from an interdisciplinary approach, incorporating expertise from specialist perinatal ultrasound and magnetic resonance imaging, reproductive genetics, neonatal pediatrics, internal medicine subspecialties, perinatal pathology, and nursing. The accurate diagnosis and prognosis for women with fetal growth restriction is established by comprehensive clinical review and detailed sonographic evaluation of the fetus, combined with uterine artery Doppler and morphologic assessment of the placenta. Diagnostic accuracy for placenta-mediated fetal growth restriction may be enhanced by quantification of maternal serum biomarkers including placenta growth factor alone or combined with soluble fms-like tyrosine kinase-1. Uterine artery Doppler is typically abnormal in most instances of early-onset fetal growth restriction and is associated with coexistent preeclampsia and underlying maternal vascular malperfusion pathology of the placenta. By contrast, rare but potentially more serious underlying placental diagnoses, such as massive perivillous fibrinoid deposition, chronic histiocytic intervillositis, or fetal thrombotic vasculopathy, may be associated with normal uterine artery Doppler waveforms. Despite minor variations in placental size, shape, and cord insertion, placental function remains, largely normal in the general population. Consequently, morphologic assessment of the placenta is not currently incorporated into current screening programs for placental complications. However, placental ultrasound can be diagnostic in the context of fetal growth restriction, for example in Breus' mole and triploidy, which in turn may enhance diagnosis and management. Several examples are illustrated in our figures and supplementary videos. Recent advances in the ability of multiparameter screening and intervention programs to reduce the risk of severe preeclampsia will likely increase efforts to deliver similar improvements for women at risk of fetal growth restriction. Placental pathology is important because the underlying pathologies associated with fetal growth restriction have a wide range of recurrence risks. Rare conditions such as massive perivillous fibrinoid deposition or chronic histolytic intervillositis may recur in >50% of subsequent pregnancies. Postpartum care in a placenta-focused program can provide effective counseling for modifiable maternal risk factors, and can assist in planning future pregnancy care based on the pathologic basis of fetal growth restriction.

Soluble FLT-1 rules placental destiny

INTRODUCTION

Placenta previa is an abnormality in which the placenta covers the internal uterine os, and it can cause serious morbidity and mortality in both mother and fetus due to catastrophic hemorrhage. Some pregnant women recover from placenta previa due to a phenomenon called "migration." However, the mechanism of "migration" of the placenta has not been elucidated.

METHODS

Human placentas were collected from patients with placenta previa and those with no abnormal placentation (control). A microarray analysis was performed to detect the genes up- or down-regulated only in the caudal part in the previa group. Specific mRNA expression was evaluated using real-time quantitative reverse transcription PCR (qRT-PCR). Unilateral uterine artery ablation of 8.5 dpc mice was performed to reproduce the reduction of placental blood supply, and weights of the placentas and fetuses were evaluated in 18.5 dpc. Specific mRNA expression was also evaluated in mice placentas.

RESULTS

According to the result of the microarray analysis, we focused on soluble fms-like tyrosine kinase-1 (sFLT-1) and hypoxia-inducible factor-1 (HIF-1) alpha. The sFLT-1 expression level is locally high in the caudal part of the human placenta in patients with placenta previa. In mice experiments, the weights of the placentas and fetuses were significantly smaller in the ablation side than those in the control side, and the sFlt-1 expression level was significantly higher in the ablation side than in the control side.

DISCUSSION

Our study suggests that "migration" of the placenta is derived from placental degeneration at the caudal part of the placenta, and sFlt-1 plays a role in this placental degeneration.

LIFR increases the release of soluble endoglin via the upregulation of MMP14 expression in preeclampsia

Preeclampsia (PE) is a pregnancy-specific disorder that is the main cause of maternal and perinatal morbidity and mortality worldwide. Inadequate trophoblastic invasion and endothelial dysfunction in the placenta are considered the foundation of the pathogenesis of preeclampsia in which soluble endoglin (sENG) plays an antiangiogenic role in the development of PE. The leukemia inhibitory factor receptor (LIFR) has been widely studied and is highly involved in arterial injury in vivo and in the migration of cancer cells in vitro Here, we tested the hypothesis that LIFR may be correlated with preeclampsia through its regulation of the release of sENG. Our data showed that LIFR protein, the expression of which significantly decreased with the progression of pregnancy, was located in the syncytiotrophoblast and cytotrophoblast. The LIFR protein level was increased in pregnancies with preeclampsia compared with normotensive full-term pregnancies. After the overexpression of LIFR in HTR8/SVneo cells, the release of sENG as well as the migration and invasion were significantly enhanced. Moreover, we also observed that LIFR induced the expression of matrix metalloproteinase14 (MMP14) and that the knockdown or inhibition of MMP14 decreased the release of sENG, as well as increased the LIFR-induced migration and invasion of HTR8/SVneo cells. These studies demonstrated that LIFR promoted the release of sENG through MMP14 in vitro, which indicates that LIFR may be involved in the development of preeclampsia.

Role of angiogenic factors in the pathogenesis and management of pre-eclampsia

The cause of pre-eclampsia is unknown. Different postulates have been developed to explain its pathogenesis. The two-stage theory and angiogenic imbalance are two notable postulates of the disease. Together, they propose that there is a lack of cytotrophoblastic invasion of the uterine spiral arteries in pre-eclampsia. The lumen of these arteries remains narrow instead of converting to the wide channels seen in normal pregnancy, and result in poor placental perfusion. Coupled with maternal susceptibility, this process leads to the release of mediators, including an excess of anti-angiogenic factors that result in the clinical manifestations of the disease. Circulating levels of anti-angiogenic factors such as soluble fms-like tyrosine kinase-1 increase, whereas pro-angiogenic factors such as placental growth factor decrease. Assessment of the circulating concentrations of these angiogenic factors, such as the soluble fms-like tyrosine kinase-1/placental growth factor ratio, has diverse clinical relevance in pre-eclampsia. The present review describes the role of angiogenic factors in the pathogenesis and management of pre-eclampsia.

Dynamics of serum C-type natriuretic peptide as predictor for preeclampsia

OBJECTIVE

To evaluate serum levels of the amino-terminal propeptide of C-type natriuretic peptide (NTproCNP) in uneventful pregnancies and pregnancies complicated by preeclampsia (PE) and NTproCNP's accuracy for prediction of PE.

STUDY DESIGN

Nested case control pilot study including women with uneventful pregnancy (Control, n = 100) and asymptomatic women who later developed PE (PE_long, n = 12). NTproCNP levels were measured in a maximum of ten sequential blood samples per patient (seven visits during pregnancy, three afterwards), which had been collected prospectively.

RESULTS

In controls, NTproCNP decreased from weeks 11-13 on, reaching a nadir at the end of the second trimester (weeks 23-27), and subsequently reached the highest levels at the end of pregnancy. In comparison, the PE_long group showed a significantly different NTproCNP course (p = .042), including significantly elevated levels in weeks 18-22 (p = .034) and 23-27 (p = .016). Significant predictive power of single time point measurements of NTproCNP for predicting short-term occurrence of preeclampsia in asymptomatic women was found in weeks 28-32 (p = .023) and 33-36 (p = .014). Furthermore, an increase > -0.038 pmol/l per week between weeks 11-13 and 14-17 was also predictive for PE (area under the curve, AUC: 0.75; p < .001; sensitivity: 90%; specificity: 60%), as was an increase of > 0.084 pmol/l per week between weeks 11-13 and 18-22 (AUC: 0.69, p = .048; sensitivity: 55%; specificity: 88%).

CONCLUSIONS

Measurement of NTproCNP in pregnancy might be useful to increase diagnostic awareness in women who will develop PE.

Biomarker Immunoassays in the Diagnosis of Preeclampsia: Calculating the sFlt1/PlGF Ratio Using the Cobas®e 411 Analyser

Preeclampsia is a relatively common pregnancy-related condition associated with serious maternal and fetal morbidity and mortality. It is now well established that anti-angiogenic sFlt1 is upregulated in preeclampsia and binds PlGF and VEGF, causing an imbalance in angiogenic factors with subsequent endothelial injury and dysfunction. Measurement of placental growth factor (PlGF) and the sFlt1/PlGF ratio have both been validated in other countries for screening and diagnosis of preeclampsia and the differentiation of preeclampsia from other hypertensive disorders of pregnancy. There are several automated, commercially available immunoassays capable of measuring PlGF and the sFlt1/PlGF ratio for preeclampsia diagnosis. Here we outline the methodology for using the Roche Cobas ^® e 411 immunoassay platform to determine the sFlt1/PlGF ratio.

A study of the association between the sFlt-1/PIGF ratio and preeclampsia in Xinjiang Uygur Autonomous Region of China

AIM

It was previously reported that the ratio of soluble fms-like tyrosine kinase-1 (sFlt-1) to placental growth factor (PlGF) can predict the clinical onset of preeclampsia. This study seeks to validate the association between ratios of sFlt-1/PlGF with preeclampsia and to identify the contribution of ethnicity across diverse populations of the Xinjiang Uygur Autonomous Region.

METHODS

Pregnant women were classified into those with preeclampsia (n = 136) and healthy controls (n = 350). Serum levels of sFlt-1 and PlGF were quantified using a Roche serum instrument in both patients and controls.

RESULTS

Compared to healthy controls, women with preeclampsia had significantly higher levels of sFlt-1 (7303.81 pg/ml vs. 2508.69 pg/ml, p < .001) and ratios of sFlt-1/PlGF (241.68 vs. 14.29, p < .001), whereas levels of PIGF were decreased (241.68 vs. 14.29, p < .001). These three values varied greatly across nationalities, and non-Han Chinese subjects (including Uygur, Kazak, Hui) were more likely to experience severe preeclampsia than Han Chinese subjects.

CONCLUSIONS

This is the first study to demonstrate that the ratio of sFlt-1/PlGF can both predict and serve as a diagnostic factor for preeclampsia in pregnant women from different populations within the Xinjiang region of China.

What we do and do not know about women and kidney diseases; questions unanswered and answers unquestioned: Reflection on World Kidney Day and International Woman's Day

Chronic kidney disease affects approximately 10% of the world's adult population: it is within the top 20 causes of death worldwide, and its impact on patients and their families can be devastating. World Kidney Day and International Women's Day in 2018 coincide, thus offering an opportunity to reflect on the importance of women's health and specifically their kidney health, on the community, and the next generations, as well as to strive to be more curious about the unique aspects of kidney disease in women so that we may apply those learnings more broadly. Girls and women, who make up approximately 50% of the world's population, are important contributors to society and their families. Gender differences continue to exist around the world in access to education, medical care, and participation in clinical studies. Pregnancy is a unique state for women, offering an opportunity for diagnosis of kidney disease, but also a state where acute and chronic kidney diseases may manifest, and which may impact future generations with respect to kidney health. There are various autoimmune and other conditions that are more likely to impact women with profound consequences for child bearing, and on the fetus. Women have different complications on dialysis than men, and are more likely to be donors than recipients of kidney transplants. In this editorial, we focus on what we do and do not know about women, kidney health, and kidney disease, and what we might learn in the future to improve outcomes worldwide.

[New perspectives on preeclampsia]

Preeclampsia is a major, frequent and potentially severe condition of pregnancy, characterized by severe hypertension and proteinuria. In this review, we describe recent advances in understanding the pathology, and discuss the long-term impacts on maternal vascular health. Next, we describe the genetic, epigenetic and immunological basis of preeclampsia. We describe the links between preeclampsia and oxidative stress in placental (trophoblast) and endothelial cells. We mention cellular and animal models commonly used to decipher modified pathophysiological pathways in a preeclamptic pregnancy compared to a normal pregnancy. Finally, we discuss the therapeutic options, readily available or in development, to improve the monitoring of pregnancies, the health of patients and that of children born from preeclamptic pregnancies.

Extracellular vesicles yield predictive pre-eclampsia biomarkers

Circulating extracellular vesicles (EVs) such as cholera toxin B chain (CTB)- or annexin V (AV)-binding EVs were previously shown to be rich sources of biomarkers. Here we test if previously identified pre-eclampsia (PE) candidate biomarkers, TIMP-1 in CTB-EVs (CTB-TIMP) and PAI-1 in AV-EVs (AV-PAI) complement plasma PlGF in predicting PE in a low-risk obstetric population. Eight hundred and forty-three prospectively banked plasma samples collected at 28 + 0 to 32 + 0 gestation weeks in the Neonatal and Obstetrics Risk Assessment (NORA) cohort study were assayed by sandwich ELISAs for plasma PlGF, CTB-TIMP1 and AV-PAI1. Nineteen patients subsequently developed PE 7.3 (±2.9) weeks later at a mean gestational age of 36.1 ± 3.5 weeks. The biomarkers were assessed for their predictive accuracy for PE using stepwise multivariate logistic regression analysis with Firth correction and Areas under the curve (AUC). To achieve 100% sensitivity in predicting PE, the cut-off for plasma PlGF, CTB-TIMP1 & AV-PAI1 were set at <1235, ≤300 or >1300 and <10,550 pg/mL plasma, respectively. The corresponding AUCs, specificity and PPV at a 95% confidence interval were 0.92, 52.1% and 4.7%; 0.72, 44.5% and 4.0%; and 0.69, 21.5% and 2.9%, respectively. At 100% sensitivity, the three biomarkers had a combined AUC of 0.96, specificity of 78.6%, and PPV of 9.9%.

This is the first large cohort validation of the utility of EV-associated analytes as disease biomarkers. Specifically, EV biomarkers enhanced the predictive robustness of an existing PE biomarker sufficiently to justify PE screening in a low-risk general obstetric population.

Angiogenic factors sFlt-1 and PlGF in preeclampsia: Prediction of risk and prognosis in a high-risk obstetric population

OBJECTIVES

Despite its simple definition, preeclampsia can have variable and atypical clinical presentations, an unpredictable course, and potential adverse maternal and fetal outcomes. No single test currently predicts risk or prognosis adequately. Scientific advances suggest that an angiogenic imbalance is involved in its pathophysiology. The objective of this study was to investigate the use of sFlt-1, PlGF, and their ratio in predicting preeclampsia.

MATERIALS AND METHODS

In a single-center prospective observational study, we measured the angiogenic markers sFlt-1 and PlGF and calculated the sFlt-1/PlGF ratio in patients at risk of preeclampsia at 20 to 37 weeks of gestation. The main outcomes were the occurrence of preeclampsia and the interval before its onset.

RESULTS

Of the 67 at risk patients included, 8 (12%) developed preeclampsia. For a sFlt-1/PlGF ratio ≥85, the specificity was 93%. The ratio was significantly higher (ratio=104±30) in women with an onset time less than 5 weeks than in those with later preeclampsia (ratio=10±2), P<0.001.

CONCLUSION

In a high-risk population, angiogenic markers appear to be an interesting aid in predicting the onset of preeclampsia with high specificity and in estimating time to onset. However, due to small number of cases of PE, more studies are needed before recommendations to use these markers in daily practice.

Efficacy of resveratrol to supplement oral nifedipine treatment in pregnancy-induced preeclampsia

OBJECTIVE

Preeclampsia (PE) is a complication affecting pregnant women worldwide, which usually manifests as severe maternal hypertension. Resveratrol (RESV), a naturally existing polyphenol, is known to exhibit beneficial effects in cardiovascular disease including hypertension. We evaluated the outcome of treatment combining oral nifedipine (NIFE) and RESV against PE.

DESIGN AND METHODS

Using a randomized group assignment, 400 PE patients were enrolled and received oral treatments of either NIFE + RESV or NIFE + placebo. Primary endpoints were defined as time to control blood pressure and time before a new hypertensive crisis. Secondary endpoints were defined as the number of doses needed to control blood pressure, maternal and neonatal adverse effects.

RESULTS

Compared with the NIFE + placebo group, the time needed to control blood pressure was significantly reduced in NIFE + RESV group, while time before a new hypertensive crisis was greatly delayed in NIFE + RESV group. The number of treatment doses needed to control blood pressure was also categorically lower in NIFE + RESV group. No differences in maternal or neonatal adverse effects were observed between the two treatment groups.

CONCLUSION

Our data support the potential of RESV as a safe and effective adjuvant of oral NIFE to attenuate hypertensive symptoms among PE patients.

The pregnancy outcome prediction (POP) study: Investigating the relationship between serial prenatal ultrasonography, biomarkers, placental phenotype and adverse pregnancy outcomes

Placental dysfunction is implicated in many major complications of pregnancy associated with adverse maternal and infant outcome, such as preeclampsia, fetal growth restriction and stillbirth. Yet, despite years of intensive research, screening for these complications is still largely based upon clinical grounds rather than ultrasonic and/or biochemical assessment of placental function. One of the few widely employed methods for assessment of risk, low first trimester levels of PAPP-A (Pregnancy Associated Plasma Protein A), was identified through secondary analysis of data collected to identify new methods of screening for Down's syndrome rather than as a purposeful search for screening tests for abnormal placentation. Development of improved methods for population screening requires better mechanistic understanding of the pathways leading to placentally-related complications of human pregnancy. This is in addition to a need for identification of biomarkers which reflect the underlying pathology, while predicting associated disease with high sensitivity and specificity. In this paper, we outline some of the challenges and opportunities in this area. Furthermore, we illustrate how some of these can be addressed in research studies using the example of the Pregnancy Outcome Prediction (POP) study, a prospective cohort study conducted in Cambridge, UK.

Angiogenic profile and smoking in the Finnish Genetics of Pre-Eclampsia Consortium (FINNPEC) cohort

OBJECTIVES

The biological mechanism by which smoking reduces the risk of pre-eclampsia (PE) is unresolved. We studied serum levels of soluble fms-like tyrosine kinase 1 (sFlt-1), placental growth factor (PlGF) and their ratio, in addition to soluble endoglin (sEng) in early and late pregnancy to ascertain whether these factors are altered in women who smoke.

SUBJECTS AND METHODS

First trimester serum samples were available from 217 women who later developed PE and 238 women who did not develop PE. Second/third trimester serum samples were available from 174 PE and 54 non-PE women.

RESULTS

PE women who smoked during pregnancy had elevated first trimester concentrations of serum PlGF [geometric mean (95% CI): 39.8 (32.6-48.5) pg/ml, p = .001] and reduced sEng concentration [5.0 (4.6-5.6) ng/ml, p = .047] compared to PE non-smokers [30.0 (28.1-32.1) pg/ml and 6.1 (5.9-6.4) ng/ml, respectively]. Non-smoking women in the PE group had the highest sFlt-1/PlGF ratio in early and late pregnancy.

CONCLUSIONS

The protective effect of smoking in reducing the risk of PE may be due to the early pregnancy change towards pro-angiogenic marker profile. Also, in late pregnancy, smoking exerted effect in sFlt-1/PlGF ratio in PE pregnancies, and may complicate its use as a prognostic and diagnostic marker. Key messages Smoking appears to have angiogenic effects in early pregnancy with reduced sEng concentrations and elevated PlGF concentrations in both normal and PE pregnancies. Throughout pregnancy, smoking exerted effect in PlGF concentration and sFlt-1/PlGF ratio in PE pregnancies, and thus may complicate its use as a prognostic and diagnostic marker.

Angiogenic and antiangiogenic factors in preeclampsia

BACKGROUND

Pre-eclampsia is a multifactorial hypertensive disorder that is triggered by placental insufficiency and that accounts for up to 15% of maternal deaths. In normal pregnancies, this process depends on the balance between the expression of angiogenic factors and antiangiogenic factors, which are responsible for remodeling the spiral arteries, as well as for neoangiogenesis and fetal development.

PURPOSE

The aim of this review is to discuss the main scientific findings regarding the role of angiogenic and antiangiogenic factors in the etiopathogenesis of preeclampsia.

METHODS

An extensive research was conducted in the Pubmed database in search of scientific manuscripts discussing potential associations between angiogenic and antiangiogenic factors and preeclampsia. Ninety-one papers were included in this review.

RESULTS

There is an increased expression of soluble fms-like tyrosine kinase receptor and soluble endoglin in pre-eclampsia, as well as reduced placental expression of vascular endothelial growth factor and placental growth factor. Systemic hypertension, proteinuria and kidney injury - such as enlargement and glomerular fibrin deposit, capillary occlusion due to edema, and hypertrophy of endocapillary cells - are some of these changes. The complex etiopathogenesis of preeclampsia instigates research of different biomarkers that allow for the early diagnosis of this entity, such as vascular endothelial growth factor, placental growth factor, soluble fms-like tyrosine kinase receptor, soluble endoglin, placental glycoprotein pregnancy-associated plasma protein-A and protein 13.

CONCLUSION

Even though it is possible to establish an efficient and effective diagnostic tool, three key principles must be observed in the management of preeclampsia: prevention, early screening and treatment.

Circulating soluble fms-like tyrosine kinase-1 and placental growth factor from 10 to 40 weeks' pregnancy in normotensive women

INTRODUCTION

Circulating soluble fms-like tyrosine kinase-1 (sFlt-1) and placental growth factor (PlGF) are potential markers for preeclampsia. The objective was to construct and analyse the reference ranges of serum levels of sFlt-1 and PlGF throughout the course of pregnancy in low-risk Thai pregnant women.

METHODS

We enrolled 110 low-risk, Thai women singleton pregnancy from 10 to 40 gestational weeks. Serum concentrations of sFlt-1 and PlGF were measured with an automated assay. The reference ranges of serum levels of sFlt-1, PlGF and sFlt-1/PlGF ratio were constructed and assessed for possible correlations with gestational age, maternal factors [age, parity, tobacco use, artificial reproductive technologies (ARTS) and body mass index (BMI)], and pregnancy outcomes (gestational age at delivery, development of preeclampsia, neonatal birth weight and placental weight).

RESULTS

None of the subjects developed preeclampsia. Serum sFlt-1 concentrations significantly elevated from 20 to 40 gestational weeks (P=0.003). Significant elevation and dropping of serum PlGF levels and sFlt-1/PlGF ratios were observed at 10 to 29 and 30 to 40 weeks of gestation, respectively (P<0.001). There was an inversed correlation between serum PlGF levels at 20 to 29 gestational weeks and neonatal birth weights (r=-0.48, P<0.05). There were no associations between serum levels of sFlt-1, PlGF, or sFlt-1/PlGF ratios and maternal BMI, gestational age at delivery, or placental weight (P>0.05). Effects from parity, smoking and ARTS were inconclusive.

CONCLUSION

Robust change of serum PlGF levels suggests for its broader clinical application compared to sFlt-1. Prediction of preeclampsia using serum analytes may be gestational period specific.

High first-trimester maternal blood cystatin C levels despite normal serum creatinine predict pre-eclampsia in singleton pregnancies

Early biochemical identification of women at high risk for the development of pre-eclampsia (PE) is still unsatisfactory. Renal markers measured during the first trimester were analysed to predict later occurrence of PE. A nested case-control study was conducted within the prospective predictive markers for the diagnosis of preeclampsia study. Pregnant women were included at the end of the first trimester and followed up until birth. Controls were matched to PE cases. Renal markers [i.e. creatinine, cystatin C (CysC), β₂ microglobulin (B2M), β-trace protein (BTP), glomerular filtration rate estimations (eGFR) of the aforementioned markers, uric acid (UA), urea, and serum uromodulin (sUMOD)] were compared to placental growth factor (PlGF), a marker known to predict PE later in pregnancy. Reference intervals were determined for the different markers. In the 183 women (PE, n = 39; controls, n = 144), CysC, the CysC/PlGF ratio (p < .01) and UA were higher, whereas the eGFR_CysC/eGFR_Crea ratio (a marker of glomerular endothelial integrity and shrunken pore syndrome) and PlGF were lower in women who developed PE (p < .05 for all). Compromised filtration of the larger molecule CysC together with a normal creatinine, in a subset of PE cases (15.3%) was a unique, strong and independent predictor of later PE if the baseline CysC concentration was >0.85 mg/l. In conclusion, CysC and its derivatives as well as UA, indicating volume expansion, measured at the end of the first trimester are predictive of PE. Thus, women can be easily identified and followed as an early reduction in glomerular filtration quality poses a high risk for a subsequent development of PE.

Detergent-Insoluble Proteome Analysis Revealed Aberrantly Aggregated Proteins in Human Preeclampsia Placentas

Preeclampsia (PE) is a placenta disease, featured by hypertension, proteinuria, and other multiorgan dysfunctions, and its etiology is unclear. We and others have shown that intensive endoplasmic reticulum (ER) stress and unfolded protein response (UPR) occur in the PE placenta. In this study, we isolated detergent-insoluble proteins (DIPs) from human placenta tissues, which were enriched with protein aggregates, to characterize the placenta UPR in PE. With data-independent acquisition (DIA) mass spectrometry, we identified 2066 DIPs across all normal (n = 10) and PE (n = 10) placenta samples, among which 110 and 108 DIPs were significantly up- and down-regulated in PE, respectively. Per clustering analysis, differential DIPs could generally distinguish PE from normal placentas. We verified the MS quantitation of endoglin and vimentin by immunoblotting. In addition, we observed that PE placenta tissues have remarkably more endoglin in the cytoplasm. Furthermore, we found that DIPs were evenly distributed across different chromosomes and could be enriched in diversified gene ontology terms, while differential DIPs avoided to distribute on X-chromosome. Significantly up-regulated DIPs in PE were focused on the top functions of lipid metabolism, while 23 of these DIPs could form the top network regulating cellular movement, development, growth, and proliferation. Our results implicate that human PE placentas have disease-relevant differential DIPs, which reflect aberrantly aggregated proteins of placental tissues. The mass spectrometry proteomics data have been deposited to ProteomeXchange consortium with the data set identifier PXD006654, and iProX database (accession number: IPX0000948000).

Hypertension in Pregnancy: Defining Blood Pressure Goals and the Value of Biomarkers for Preeclampsia

Hypertensive disorders in pregnancy have been the cause of much clinical dilemma, affecting up to 10 % of all pregnancies. The precise blood pressure to achieve in a pregnant woman is usually a battle between minimizing end organ damage to the mother and providing adequate perfusion to the placenta and the fetus. This predicament is becoming more, not less, frequent as maternal ages increase in high resource nations. Biomarkers to predict preeclampsia, a subcategory of hypertension in pregnancy, have always been elusive. The discovery of angiogenic factors relevant to preeclampsia in the last decade, however, has propelled much needed research, both in the basic science and clinical arenas. In this review, we summarize the latest clinical studies and international guidelines on blood pressure goals in pregnancy, and discuss the most promising of biomarkers to predict or diagnose preeclampsia.

Maternal vitamin D sufficiency and reduced placental gene expression in angiogenic biomarkers related to comorbidities of pregnancy

INTRODUCTION

Maternal circulating 25-hydroxyvitamin D [25(OH)D] has been shown to optimize production of 1,25-dihydroxyvitamin D [1,25(OH)₂D] during pregnancy at approximately 100nmoles/L, which has pronounced effects on fetal health outcomes. Additionally, associations are noted between low maternal 25(OH)D concentrations and vascular pregnancy complications, such as preeclampsia. To further elucidate the effects of vitamin D activity in pregnancy, we investigated the role of maternal 25(OH)D, the nutritional indicator of vitamin D status, in relation to placental maintenance and, specifically, expression of placental gene targets related to angiogenesis and vitamin D metabolism.

METHODS

A focused analysis of placental mRNA expression related to angiogenesis, pregnancy maintenance, and vitamin D metabolism was conducted in placentas from 43 subjects enrolled in a randomized controlled trial supplementing 400IU or 4400IU of vitamin D₃ per day during pregnancy. Placental mRNA was isolated from biopsies within one hour of delivery, followed by quantitative PCR. We classified pregnant women with circulating concentrations of <100nmoles/L as deficient and those with ≥100nmoles/L as sufficient. The value of each gene's change in the PCR cycle threshold (ΔCT), which is a relative measure of target concentration, was compared with maternal 25(OH)D concentrations <100nmoles/L and ≥100nmoles/L based on a two-sample Wilcoxon test.

RESULTS

Soluble FMS-like tyrosine kinase 1 (sFlt-1) and vascular endothelial growth factor (VEGF) gene expression was significantly downregulated in the maternal subgroup with circulating 25(OH)D ≥100ng/mL compared to the subgroup <100ng/mL.

DISCUSSION

Here, we report a significant association between maternal vitamin D status and the expression of sFlt-1 and VEGF at the mRNA level. Achieving maternal circulating 25(OH)D ≥100nmoles/L suggests the impact of maternal vitamin D₃ supplementation on gene transcription in the placenta, thereby potentially decreasing antiangiogenic factors that may contribute to vascular pregnancy complications.

The Association of Falling Insulin Requirements With Maternal Biomarkers and Placental Dysfunction: A Prospective Study of Women With Preexisting Diabetes in Pregnancy

OBJECTIVE

To investigate the association of falling insulin requirements (FIR) among women with preexisting diabetes with adverse obstetric outcomes and maternal biomarkers longitudinally in pregnancy.

RESEARCH DESIGN AND METHODS

A multicenter prospective cohort study of 158 women (41 with type 1 diabetes and 117 with type 2 diabetes) was conducted. Women with FIR of ≥15% from the peak total daily dose after 20 weeks' gestation were considered case subjects (n = 32). The primary outcome was a composite of clinical markers of placental dysfunction (preeclampsia, small for gestational age [≤5th centile], stillbirth, premature delivery [<30 weeks], and placental abruption). Maternal circulating angiogenic markers (placental growth factor [PlGF] and soluble fms-like tyrosine kinase 1 [sFlt-1]), placental hormones (human placental lactogen, progesterone, and tumor necrosis factor-α), HbA_1c, and creatinine were studied serially during pregnancy.

RESULTS

FIR ≥15% were associated with an increased risk of the composite primary outcome (odds ratio [OR] 4.38 [95% CI 1.9-10.3]; P < 0.001), preeclampsia (OR 6.76 [95% CI 2.7-16.7]; P < 0.001), and was more common among women with type 1 diabetes (36.6 vs. 14.5%; P = 0.002). Creatinine was modestly elevated among women with FIR ≥15%; however, there was no difference in HbA_1c. The ratio of sFlt-1 to PlGF was significantly higher among women with FIR at 25, 30, and 36 weeks, with differences maintained in the subgroup that developed preeclampsia. There was no difference in placental hormones between the groups.

CONCLUSIONS

This is the first prospective study to associate FIR with altered expression of placental antiangiogenic factors and preeclampsia. FIR are an important clinical sign, among women with preexisting diabetes, that should alert the clinician to investigate underlying placental dysfunction.

Performance of first trimester biochemical markers and mean arterial pressure in prediction of early-onset pre-eclampsia

OBJECTIVE

To develop a predictive risk model for early-onset pre-eclampsia (EO-PE) using maternal characteristics, combined screening markers, previously reported biomarkers for PE and mean arterial pressure (MAP).

METHODS

This retrospective study was conducted at Oulu University hospital between 2006 and 2010. Maternal serum from first trimester combined screening was further analyzed for alpha fetoprotein (AFP), placental growth factor (PlGF), soluble tumor necrosis factor receptor-1 (sTNFR1), retinol binding protein-4 (RBP4), a disintegrin and metalloprotease-12 (ADAM12), soluble P-selectin (sP-selectin), follistatin like-3 (FSTL3), adiponectin, angiopoietin-2 (Ang-2) and sex hormone binding globulin (SHBG). First, the training sample set with 29 cases of EO-PE and 652 controls was developed to study whether these biomarkers separately or in combination with prior risk (maternal characteristics, first trimester pregnancy associated plasma protein-A (PAPP-A) and free beta human chorionic gonadotrophin (fβ-hCG)) could be used to predict the development of EO-PE. Second, the developed risk models were validated with a test sample set of 42 EO-PE and 141 control subjects. For the test set MAP data was also available.

RESULTS

Single marker statistically significant (ANOVA p<0.05) changes between control and EO-PE pregnancies were observed with AFP, RBP4 and sTNFR1 with both training and test sample sets. Based on the test sample set performances, the best detection rate, 47% for a 10% false positive rate, was achieved with PlGF and sTNFR1 added with prior risk and MAP.

CONCLUSION

Based on our results, the best first trimester biomarkers to predict the subsequent EO-PE were AFP, PlGF, RBP4 and sTNFR1. The risk models that performed best for the prediction of EO-PE included prior risk, MAP, sTNFR1 and AFP or PlGF or RBP4.

Up-regulation of microRNA-202-3p in first trimester placenta of pregnancies destined to develop severe preeclampsia, a pilot study

MicroRNA (miRNA) expression has not been studied during placentation in pregnancies that develop preeclampsia, when it likely manifests. In this pilot study, miRNA expression in late first trimester placenta from four pregnancies that developed severe preeclampsia matched to controls using the Affymetrix GeneChip® miRNA 3.0 Array identified 9 miRNAs differentially expressed, with miR-202-3p the most significantly overexpressed in severe preeclampsia. Real-time reverse transcription polymerase chain reaction (qRT-PCR) confirmed overexpression of miR-202-3p in a validation cohort, with a 7-fold increase in pregnancies that developed severe preeclampsia (p≤0.05). Differential miRNA expression, specifically miR-202-3p, is seen in first trimester placenta in severe preeclampsia.