The promise of angiogenic markers for the early diagnosis and prediction of preeclampsia

sFlt-1/PlGF ratio predicts serious outcomes in confirmed early-onset preeclampsia

OBJECTIVES

We aimed to determine whether a high ratio of soluble fms-like tyrosine kinase-1 (sFlt-1) to placental growth factor (PlGF) would be associated with serious negative consequences and shorter pregnancy duration in cases of early-onset preeclampsia (PE).

STUDY DESIGN

This retrospective cohort study included women (n = 65) diagnosed with PE at <34.0 weeks of gestation and recruited from a single primary and tertiary medical centre in Japan. The sFlt-1/PlGF ratio in the study participants was measured. To determine the optimal threshold for the sFlt-1/PlGF ratio, a receiver operating characteristic curve was employed, with the aim of predicting serious adverse outcomes within 1 week after serum angiogenic marker measurements. We performed Kaplan-Meier analysis and the log-rank test to assess delivery probability based on the sFlt-1/PlGF ratio.

RESULTS

Thirty-seven women (56.9 %) delivered within 1 week of serum angiogenic marker measurements due to the aggravation of early-onset preeclampsia. Women who developed serious adverse outcomes within 1 week had a significantly higher sFlt-1/PlGF ratio than that of women who did not develop serious complications (408.5 vs. 166.6, P < 0.001). A cut-off value of 224.6 for the sFlt-1/PlGF ratio predicted serious adverse outcomes, with a sensitivity of 81.1 % and a specificity of 71.4 % (area under the curve: 0.77). Moreover, 78.9 % of women with an sFlt-1/PlGF ratio ≥ 224.6 compared to 25.9 % of those with an sFlt-1/PlGF ratio < 224.6 delivered within 1 week of presentation (P < 0.001).

CONCLUSIONS

Women with confirmed early-onset preeclampsia and high sFlt-1/PlGF ratio are more likely to develop serious adverse outcomes within 1 week after serum angiogenic marker measurements.

Real-world evidence for the utility of serum soluble fms-like tyrosine kinase 1/placental growth factor test for routine clinical evaluation of hospitalized women with hypertensive disorders of pregnancy

BACKGROUND

An imbalance of the antiangiogenic factor, soluble fms-like tyrosine kinase-1, and proangiogenic factor, placental growth factor, in the circulation is a reliable predictor for the development of preeclampsia with severe features and related adverse outcomes. In 2023, the US Food and Drug Administration approved a serum soluble fms-like tyrosine kinase-1/placental growth factor test at a cutoff of 40 to aid in the risk assessment of women hospitalized for hypertensive disorders of pregnancy for the progression to preeclampsia with severe features between 23 and 35 weeks.

OBJECTIVE

This study aimed to generate real-world evidence for clinical utility for serum soluble fms-like tyrosine kinase-1/placental growth factor test when made available to clinicians in a timely fashion as an aid in risk stratification of development of preeclampsia with severe features within 2 weeks of testing among hospitalized patients with hypertensive disorders of pregnancy.

STUDY DESIGN

Hospitalized patients with hypertensive disorders of pregnancy between 23 weeks to 34 weeks and 6 days of gestation were prospectively studied from June 2023 to January 2024 after the implementation of serum soluble fms-like tyrosine kinase-1/placental growth factor testing into routine clinical practice. Serum samples were obtained from patients via venipuncture and analyzed on an automated immunoassay platform (placental growth factor and soluble fms-like tyrosine kinase-1 assays; Thermo Fisher Scientific). Before implementation, physicians were educated on appropriate use and management guidelines on the basis of biomarkers but made pragmatic management decisions independently. Results of soluble fms-like tyrosine kinase-1/placental growth factor tests were available to clinicians within 24 hours of venipuncture. The association between soluble fms-like tyrosine kinase-1/placental growth factor ≥40 and progression to preeclampsia with severe features and adverse maternal/perinatal outcomes were assessed.

RESULTS

Of the 65 patient encounters, 36 had a soluble fms-like tyrosine kinase-1/placental growth factor <40 (55.4%). The rate of delivery for indications related to hypertensive disorders of pregnancy within 2 weeks was significantly lower among encounters with a low ratio vs high ratio (2/36 [5.6%] vs 21/29 [72.4%]) even after controlling for relevant confounders (adjusted hazard ratio, 7.52; 95% confidence interval, 3.05-18.54; P<.001). A diagnosis of preeclampsia with severe features within 2 weeks of testing was also less likely among the encounters with soluble fms-like tyrosine kinase-1/placental growth factor ratio <40 when compared with soluble fms-like tyrosine kinase-1/placental growth factor ratio ≥40 (2/36 [5.6%] vs 23/29 [79.3%], P<.001; positive predictive value of 79% [95% confidence interval, 0.65-0.94] and negative predictive value of 0.94 [95% confidence interval, 0.87-1.00]). The positive and negative likelihood ratios for the development of preeclampsia with severe features within 2 weeks of testing were 6.13 and 0.09, respectively. Encounters with a soluble fms-like tyrosine kinase-1/placental growth factor ratio <40 were less likely to experience a maternal or fetal adverse event as compared with encounters with soluble fms-like tyrosine kinase-1/placental growth factor ratio ≥40 (3/36 [8.3%] vs 10/29 [34.5%], P=.01). Among 36 encounters involving low soluble fms-like tyrosine kinase-1/placental growth factor values, 22 had had equivocal clinical or laboratory criteria resembling preeclampsia at presentation but were expectantly managed on the basis of biomarkers, and none developed preeclampsia with severe features or adverse outcomes at 2 weeks. The median latency defined as days between biomarker measurement and delivery in patients with a low biomarker ratio was 33 (interquartile ratio, 23-47) vs 7 (interquartile ratio, 4-14) days among patients with a high ratio (P<.001). Corticosteroid use within 2 weeks was also significantly reduced in the low biomarker group when compared with the high biomarker group (8/35 [22.9%] vs 24/29 [82.8%], P<.001).

CONCLUSION

In this study, the incorporation of soluble fms-like tyrosine kinase-1/placental growth factor ratio into clinical practice serves as a dependable supplement in assessing risk for progression to preeclampsia with severe features and adverse outcomes in patients with hypertensive disorders of pregnancy in the United States. Among patients with a low ratio, pregnancy may be prolonged, which results in better neonatal outcomes without harm to the mother.

Association of angiogenic factors (placental growth factor and soluble FMS-like tyrosine kinase-1) in preeclamptic women of African ancestry comorbid with HIV infection

BACKGROUND

Preeclampsia is a significant cause of maternal and fetal morbidity and mortality, particularly in low- and middle-income countries like South Africa.

AIM

The aim of our study was to investigate the association between placental growth factor (PlGF) and soluble FMS-like tyrosine kinase-1 (sFlt-1) in South African preeclamptic women of African ancestry, comorbid with HIV infection.

METHODS

The study population consisted of women attending a regional hospital in Durban, South Africa, stratified by pregnancy type (normotensive pregnant and preeclampsia) and HIV status. Preeclampsia was defined as new-onset hypertension and proteinuria. DNA was obtained from whole blood. The SNPs of interest were rs722503 in sFlt-1 and rs4903273 in PlGF.

RESULTS

Our findings suggest that single nucleotide polymorphisms of rs722503 analysis show no significant associations between the genotypic frequencies of rs722503 variants and preeclampsia risk in either HIV-negative or HIV-positive groups of women of African ancestry. Similarly, the rs493273 polymorphism showed no significant association with preeclampsia risk in either HIV-negative or HIV-positive pregnant women. Additionally, comparisons of dominant, recessive, and over-dominant allele models did not reveal significant associations. These findings suggest that these genetic variants may not significantly contribute to preeclampsia development in this African ancestry population. However, significant differences were observed in the rs4903273 genotype frequencies between normotensive and preeclamptic women, regardless of HIV status, over dominant alleles AA + GG vs AG showed a significant difference [OR = 2.706; 95% Cl (1.199-5.979); adjusted p = 0.0234*], also in normotensive compared to EOPE (OR = 2.804; 95% Cl (1.151-6.89) p = 0.0326* and LOPE (OR = 2.601; 95% Cl (1.0310-6.539) p = 0.0492*), suggesting that they may be the potential role of this variant in preeclampsia susceptibility.

CONCLUSION

The findings suggest that the rs722503 and rs493273 polymorphisms do not significantly contribute to preeclampsia susceptibility in HIV-negative or HIV-positive pregnant women. However, the rs4903273 genotype frequencies showed notable differences between normotensive and preeclamptic women, indicating a potential association with preeclampsia development in the African ancestry population irrespective of HIV status.

The addition of the sFlt-1/PlGF ratio to the protein/creatinine ratio in multiple pregnancy: Post-hoc analysis of the PREPARE cohort study

OBJECTIVE

To assess the predictive accuracy of the sFlt-1/PlGF ratio cut-off 38 in addition to the standard-of-care spot urine protein/creatinine ratio (PCr) for multiple pregnancies in women with suspected pre-eclampsia.

STUDY DESIGN

Post-hoc analysis of a prospective cohort study.

MAIN OUTCOME MEASURES

Primary outcome was the occurrence of pre-eclampsia in one and four weeks after presentation with suspected pre-eclampsia. Test characteristics with 95% confidence intervals (CI) were calculated on pre-eclampsia development in one and four weeks.

RESULTS

Twenty-three multiple pregnancies with suspected pre-eclampsia between 20 and 37 weeks gestation were included for analysis. Women who eventually developed pre-eclampsia had a significantly higher PCr (34.0 vs. 16.5, p = 0.015), sFlt-1 (17033 vs. 5270 pg/ml, p = 0.047) and sFlt-1/PlGF ratio (99 vs. 25, p = 0.033) at baseline. Furthermore, PCr ≥ 30 and sFlt-1/PlGF ratio > 38 was respectively seen in 1/16 (6.3 %) and 3/16 (18.8 %) of the women who did not develop pre-eclampsia. For predicting pre-eclampsia within one week the sFlt-1/PlGF ratio sensitivity was 75.0 % [95 % CI 19.4-99.4] and the negative predictive value 93.8 % [73.0-98.8], while no pre-eclampsia developed when PCr was < 30. Consequently, the combination of these tests did not lead to an improvement in test characteristics, with non-significant differences in positive predictive value (50.0 % [29.5-70.5] versus 80.0 % [37.3-96.4]) compared to PCr alone for pre-eclampsia development in one week.

CONCLUSIONS

In addition to standard-of-care spot urine PCr measurements, this study has not been able to demonstrate that the sFlt-1/PlGF ratio cut-off 38 is of added value in the prediction of pre-eclampsia in multiple pregnancy.

TRIAL REGISTRATION

Netherlands Trial Register (NL8308).

Correlation of sFlt/PlGF ratio with severity of preeclampsia in an Indian population

Background

Preeclampsia affects 2% to 8% of pregnant women and significantly increases the risk for maternal and perinatal morbidity, especially in low- and middle-income countries. There is increasing evidence to support the use of biochemical markers such as placental growth factor and soluble fms-like tyrosine kinase-1 in predicting the severity of preeclampsia and to rule out severe disease in clinical conditions masquerading as severe preeclampsia.

OBJECTIVE

This study aimed to assess the role of the sFlt-1/PlGF ratio in predicting adverse perinatal and maternal outcomes in women with preeclampsia in a South Asian population with a higher rate of the disease and its associated complications.

STUDY DESIGN

This was a prospective cohort study of women diagnosed with preeclampsia or suspected to have preeclampsia who underwent biophysical and biochemical investigations to measure the severity, including determining maternal hemodynamic indices, mean arterial pressure, fetal biometric and Doppler parameters, and soluble fms-like tyrosine kinase-1 and placental growth factor levels. The performance of these markers, individually or in combination, in predicting adverse perinatal and maternal outcomes was then assessed using receiver operating characteristic curve analysis. An adverse maternal outcome was defined as 1 or more of severe hypertension; admission to the intensive care unit; eclampsia; placental abruption; hemolysis, elevated liver enzymes, low-platelet count syndrome; disseminated intravascular coagulation; platelets <100×10⁹/L; creatinine >1.1 mg/dL; and alanine aminotransferase >100 U/L. An adverse perinatal outcome was defined as 1 or more of preterm birth ≤34+0 weeks' gestation, neonatal intensive care unit admission for >48 hours, respiratory distress syndrome, intraventricular hemorrhage, hypoxic ischemic encephalopathy, necrotizing enterocolitis, retinopathy of prematurity, and confirmed fetal infection.

RESULTS

We recruited 91 women with preeclampsia with a mean gestational age of 30.63±2.86 weeks. Women who had adverse maternal events had higher median maternal concentrations of soluble fms-like tyrosine kinase (11,500.0 pg/mL vs 3051.0 pg/mL; P<.001), lower concentrations of placental growth factor (44.88 pg/mL vs 148.50 pg/mL; P<.001), and a higher sFlt-1/PlGF ratio (306.22 vs 30.63; P<.001) than women who did not. Pregnancies with an adverse perinatal outcome also had a higher soluble fms-like tyrosine kinase concentration (12,100.0 pg/mL vs 3051.0 pg/mL; P<.001), lower placental growth factor concentration (27.2 pg/mL vs 148.50 pg/mL; P<.001), and higher sFlt-1/PlGF ratio (378.45.4 vs 30.63; P<.001). The area under the receiver operating characteristic curve showed that soluble fms-like tyrosine kinase and placental growth factor were the best biomarkers when compared with other biochemical markers to predict adverse maternal (area under the curve, 0.81; 95% confidence interval, 0.72-0.90) and fetal (area under the curve, 0.88; 95% confidence interval, 0.80-0.96) outcomes in preeclampsia.

CONCLUSION

The sFlt-1/PlGF ratio correlates better with adverse maternal and perinatal outcomes than any other biochemical marker in an Indian population. The incorporation of the sFlt-1/PlGF ratio in women with preeclampsia can help in predicting the severity of the condition and the timings of the delivery.

Cardiovascular and renal health: Preeclampsia as a risk marker

BACKGROUND

Cardiovascular (CVD) and chronic kidney disease (CKD) in women have unique risk factors related to hormonal status and obstetric history that must be taken into account. Pregnancy complications, such as preeclampsia (PE), can reveal a subclinical predisposition for the development of future disease that may help identify women who could benefit from early CVD and CKD prevention strategies.

MATERIALS AND METHODS

Review of PE and its association with future development of CVD and CKD.

RESULTS

Multiple studies have established an association between PE and the development of ischemic heart disease, chronic hypertension, peripheral vascular disease, stroke and CKD. It has not been sufficiently clarified if this relation is a causal one or if it is mediated by common risk factors. Nevertheless, the presence of endothelial dysfunction and thrombotic microangiopathy during pregnancies complicated with PE makes us believe that PE may leave a long-term imprint. Early identification of women who have had a pregnancy complicated by PE becomes a window of opportunity to improve women's health through adequate follow-up and targeted preventive actions. Oxidative stress biomarkers and vascular ultrasound may play a key role in the early detection of this arterial damage.

CONCLUSIONS

The implementation of preventive multidisciplinary targeted strategies can help slow down CVD and CKD's natural history in women at risk through lifestyle modifications and adequate blood pressure control. Therefore, we propose a series of recommendations to guide the prediction and prevention of CVD and CKD throughout life of women with a history of PE.

Associations Among Biomarkers of Inflammation, Tubular Injury and Lipid Metabolism With Gestational Diabetes Mellitus Status, Microalbuminuria and Retinopathy in the Microalbuminuria and Retinopathy in Gestational Diabetes Study

OBJECTIVES

Pregnancy may be complicated by gestational diabetes mellitus (GDM) and/or microvascular complications like albuminuria, retinopathy and pre-eclampsia. In this study we aimed to identify whether mechanistic pathways associated with microvascular complications are active in pregnant women with GDM or microvascular disease.

METHODS

Urinary albumin excretion and biomarkers of inflammation, lipoprotein metabolism and tubular injury were quantified in 355 pregnant women with and without GDM. Participants underwent fundus photography graded for retinopathy. Adjusted associations between individual biomarkers and each outcome variable of interest, including GDM status, albuminuria and retinopathy, were performed using logistic regression.

RESULTS

After adjusting for age, systolic blood pressure, body mass index and ethnicity, significant associations between GDM status and apolipoprotein A1, interleukin (IL)-6, IL-8, soluble tumour necrosis factor receptor-I and -II (sTNFR-I and -II), vascular endothelial growth factor and von Willebrand factor were observed. Increased high-sensitivity C-reactive protein (hsCRP) and sTNFR-II were associated with higher levels of albuminuria. hsCRP and previous GDM were associated with retinopathy.

CONCLUSION

Mechanistic pathways associated with microvascular complications appear to be active in pregnant women with GDM or microvascular disease.

Utility of sFtl-1 and Placental Growth Factor Ratio for Adequate Preeclampsia Management

Introduction: The pathophysiology of preeclampsia is represented by placental ischemia and the release of angiogenic factors. Recent research suggests that using the value of the sFtl-1/PIGF ratio is more accurate for monitoring angiogenic activity. The aim of this study consists in assessing the clinical utility of the sFtl-1/PIGF ratio in determining the diagnosis and severity of preeclampsia. Material and Methods: In our study a descriptive and prospective plan was used for analyzing the specific value of the sFtl-1/PIGF ratio in women with preeclampsia and in women with gestational hypertension, depending on the gestational age and severity. Results: The study included 59 women with preeclampsia and 25 women with gestational hypertension. The mean value of the sFtl-1/PIGF ratio of pregnant women with preeclampsia was 209.2 pg/mL, while in the gestational hypertension group, the mean value of the sFtl-1/PIGF ratio was 46.08 pg/mL. The difference between the value of the sFtl-1/PIGF ratio of the group with preeclampsia and the gestational hypertension group was > 67 (pg/mL), with a sensitivity of 86.44% and a specificity of 92.00%. Significant differences were found between the median values of the sFtl-1/PIGF ratio in pregnant women with severe preeclampsia in the early-onset subgroup compared to those in the late-onset subgroup (307 pg/mL, and 98 pg/mL, respectively, p = 0.009 < α = 0.05). Conclusions: The sFtl-1/PIGF ratio may be an alternative method for diagnosing preeclampsia and it can provide data about this condition's severity.

Clinical value and cost analysis of the sFlt-1/PlGF ratio in addition to the spot urine protein/creatinine ratio in women with suspected pre-eclampsia: PREPARE cohort study

BACKGROUND

This study investigated the clinical value of adding the sFlt-1/PlGF ratio to the spot urine protein/creatinine ratio (PCr) in women with suspected pre-eclampsia.

METHODS

This was a prospective cohort study performed in a tertiary referral centre. Based on the combination of PCr (< 30) and sFlt-1/PlGF (≤38) results, four groups were described: a double negative result, group A-/-; a negative PCr and positive sFlt-1/PlGF, group B-/+; a positive PCr and negative sFlt-1/PlGF, group C+/-; and a double positive result, group D+/+. The primary outcome was the proportion of false negatives of the combined tests in comparison with PCr alone in the first week after baseline. Secondary, a cost analysis comparing the costs and savings of adding the sFlt-1/PlGF ratio was performed for different follow-up scenarios.

RESULTS

A total of 199 women were included. Pre-eclampsia in the first week was observed in 2 women (2%) in group A-/-, 12 (26%) in group B-/+, 4 (27%) in group C+/-, and 12 (92%) in group D+/+. The proportion of false negatives of 8.2% [95% CI 4.9-13.3] with the PCr alone was significantly reduced to 1.6% [0.4-5.7] by adding a negative sFlt-1/PlGF ratio. Furthermore, the addition of the sFlt-1/PlGF ratio to the spot urine PCr, with telemonitoring of women at risk, could result in a reduction of 41% admissions and 36% outpatient visits, leading to a cost reduction of €46,- per patient.

CONCLUSIONS

Implementation of the sFlt-1/PlGF ratio in addition to the spot urine PCr, may lead to improved selection of women at low risk and a reduction of hospital care for women with suspected pre-eclampsia.

TRIAL REGISTRATION

Netherlands Trial Register (NL8308).

Prediction of Delivery Within 7 Days After Diagnosis of Early Onset Preeclampsia Using Machine-Learning Models

Background

Early onset preeclampsia (eoPE) is a hypertensive disorder of pregnancy with endothelial dysfunction manifested before 34 weeks where expectant management is usually attempted. However, the timing of hospitalization, corticosteroids, and delivery remain a challenge. We aim to develop a prediction model using machine-learning tools for the need for delivery within 7 days of diagnosis (model D) and the risk of developing hemolysis, elevated liver enzymes, and low platelets (HELLP) syndrome or abruptio placentae (model HA).

Materials and Methods

A retrospective cohort of singleton pregnancies with eoPE and attempted expectant management between 2014 and 2020. A Mono-objective Genetic Algorithm based on supervised classification models was implemented to develop D and HA models. Maternal basal characteristics and data gathered during eoPE diagnosis: gestational age, blood pressure, platelets, creatinine, transaminases, angiogenesis biomarkers (soluble fms-like tyrosine kinase-1, placental growth factor), and ultrasound data were pooled for analysis. The most relevant variables were selected by bio-inspired algorithms. We developed basal models that solely included demographic characteristics of the patient (D1, HA1), and advanced models adding information available at diagnosis of eoPE (D2, HA2).

Results

We evaluated 215 eoPE cases and 47.9% required delivery within 7 days. The median time-to-delivery was 8 days. Basal models were better predicted by K-nearest-neighbor in D1, which had a diagnostic precision of 0.68 ± 0.09, with 63.6% sensitivity (Sn), 71.4% specificity (Sp), 70% positive predictive value (PPV), and 65.2% negative predictive value (NPV) using 13 variables and HA1 of 0.77 ± 0.09, 60.4% Sn, 80% Sp, 50% PPV, and 87.9% NPV. Models at diagnosis were better developed by support vector machine (SVM) using 18 variables, where D2's precision improved to 0.79 ± 0.05 with 77.3% Sn, 80.1% Sp, 81.5% PPV, and 76.2% NPV, and HA2 had a precision of 0.79 ± 0.08 with 66.7% Sn, 82.8% Sp, 51.6% PPV, and 90.3% NPV.

Conclusion

At the time of diagnosis of eoPE, SVM with evolutionary feature selection process provides good predictive information of the need for delivery within 7 days and development of HELLP/abruptio placentae, using maternal characteristics and markers that can be obtained routinely. This information could be of value when assessing hospitalization and timing of antenatal corticosteroid administration.

Rule-in and rule-out of pre-eclampsia using DELFIA Xpress PlGF 1-2-3 and sFlt-1: PlGF ratio

OBJECTIVES

The objective of this study was to explore and validate thresholds for Placental growth factor (PlGF) and soluble fms-like tyrosine-kinase 1 (s-Flt-1) (as s-Flt-1: PlGF ratio), to rule-in and rule-out disease in women with suspected pre-eclampsia, using DELFIA® Xpress PlGF1-2-3 and sFlt-1 assays.

STUDY DESIGN

369 samples from women with suspected or confirmed pre-eclampsia were analysed from a prospective cohort study.

MAIN OUTCOME MEASURES

Serum PlGF and sFlt-1: PlGF were quantified using DELFIA® Xpress PlGF1-2-3 and DELFIA® Xpress sFlt-1 tests. Performances were evaluated at established and exploratory thresholds. Low PlGF concentration and sFlt-1: PlGF AUROC were compared.

RESULTS

PlGF 1-2-3 concentration thresholds were confirmed to have high performance for rule-in (<50 pg/ml) and rule-out (≥150 pg/ml) pre-eclampsia within seven days (20-33⁺⁶ Weeks <50 pg/ml: Negative predictive value (NPV) 90.7% (95% CI 83.9, 95.3); ≥150 pg/ml: NPV 94.8% (95% CI 88.4, 98.3)) and 28 days (20-33⁺⁶ Weeks <50 pg/ml: Negative predictive value (NPV) 83.9% (95% CI 76.0, 90.0); ≥150 pg/ml: NPV 92.8% (95% CI 85.7, 97.0)). Optimal sFlt-1: PlGF thresholds for rule-in were ≥ 70 before 34 weeks and ≥ 90 after 34 weeks, and <50 to rule-out pre-eclampsia. Low PlGF alone had comparable performance to sFlt-1: PlGF, but test performance for both was reduced in women with Kidney Disease.

CONCLUSIONS

DELFIA® Xpress PlGF1-2-3 and sFlt-1 assays for pre-eclampsia rule-in and rule-out have comparable performance to other established assays, and could be an alternative for clinical use. Performance was not enhanced by use of sFlt-1: PlGF ratio, suggesting that PlGF alone could provide a cheaper alternative to dual biomarker testing.

Imbalances in circulating angiogenic factors in the pathophysiology of preeclampsia and related disorders

Preeclampsia is a devastating medical complication of pregnancy that can lead to significant maternal and fetal morbidity and mortality. It is currently believed that there is abnormal placentation in as early as the first trimester in women destined to develop preeclampsia. Although the etiology of the abnormal placentation is being debated, numerous epidemiologic and experimental studies suggest that imbalances in circulating angiogenic factors released from the placenta are responsible for the maternal signs and symptoms of preeclampsia. In particular, circulating levels of soluble fms-like tyrosine kinase 1, an antiangiogenic factor, are markedly increased in women with preeclampsia, whereas free levels of its ligand, placental, growth factor are markedly diminished. Alterations in these angiogenic factors precede the onset of clinical signs of preeclampsia and correlate with disease severity. Recently, the availability of automated assays for the measurement of angiogenic biomarkers in the plasma, serum, and urine has helped investigators worldwide to demonstrate a key role for these factors in the clinical diagnosis and prediction of preeclampsia. Numerous studies have reported that circulating angiogenic biomarkers have a very high negative predictive value to rule out clinical disease among women with suspected preeclampsia. These blood-based biomarkers have provided a valuable tool to clinicians to accelerate the time to clinical diagnosis and minimize maternal adverse outcomes in women with preeclampsia. Angiogenic biomarkers have also been useful to elucidate the pathogenesis of related disorders of abnormal placentation such as intrauterine growth restriction, intrauterine fetal death, twin-to-twin transfusion syndrome, and fetal hydrops. In summary, the discovery and characterization of angiogenic proteins of placental origin have provided clinicians a noninvasive blood-based tool to monitor placental function and health and for early detection of disorders of placentation. Uncovering the mechanisms of altered angiogenic factors in preeclampsia and related disorders of placentation may provide insights into novel preventive and therapeutic options.

Predictive value of the sFlt-1/PlGF ratio for preeclampsia in twin pregnancies: a retrospective study

Objective: This study aimed to investigate the efficiency of the soluble Fms-like tyrosine kinase 1 (sFlt-1)/placental growth factor (PlGF) ratio in predicting preeclampsia (PE) within 4 weeks in twin pregnancies.Methods: Seventy-eight women with serum angiogenic markers measured at 28 + 0 to 30 + 6 weeks of gestation were enrolled. A receiver-operating characteristic curve was used to determine the sFlt-1/PlGF ratio threshold to predict PE.Results: A cutoff value for the sFlt-1/PlGF ratio of 22.2 predicted PE presence within 4 weeks.Conclusion: An sFlt-1/PlGF ratio of ≤22.2 is potentially indicative of PE absence within 4 weeks in twin pregnancies.

Prenatal serum sFlt-1/PlGF ratio predicts the adverse neonatal outcomes among small-for-gestational-age fetuses in normotensive pregnant women: A prospective cohort study

We investigated the predictive value of the soluble fms-like tyrosine kinase-1 (sFlt-1)-to-placental growth factor (PlGF) ratio for poor neonatal outcomes of SGA neonates in the absence of preeclampsia.This prospective cohort study included 530 singleton pregnant women who attended a prenatal screening program at a single institution. The sFlt-1/PlGF values at 24 to 28+6 weeks and 29 to 36+6 weeks of gestation were analyzed and compared between control and SGA group (subdivided as with normal neonatal outcomes and with poor neonatal outcomes).After 22 preeclampsia cases were excluded, 47 SGA neonates and 461 control neonates were included. In the SGA group, 17 neonates had adverse neonatal outcomes (36.1%, 17/47). The mean (±D) sFlt-1/PlGF ratio of early third trimester was significantly higher in SGA with averse neonatal outcome group than in the control group (14.42 ± 23.8 vs 109.12 3.96, P = .041) and the ratio retained an independent and significant association with SGA with adverse neonatal outcomes (odds ratio = 1.017, P = .01). A sFlt-1/PlGF ratio cut-off of 28.15 at 29 to 36+6 weeks significantly predicted adverse outcomes among SGA neonates (sensitivity = 76.9%, specificity = 88%).In this study, sFlt-1/PlGF ratio at 29 to 36 + 6wks of SGA with adverse neonatal outcome group was significantly higher than control group. This study suggests the feasibility of the sFlt-1/PlGF ratio as helpful objective measurement for predicting the adverse SGA neonatal outcome by providing sFlt-1/PlGF cut-off value.

Correlation between Apelin and Some Angiogenic Factors in the Pathogenesis of Preeclampsia: Apelin-13 as Novel Drug for Treating Preeclampsia and Its Physiological Effects on Placenta

Preeclampsia (PE) is one of the commonest causes for maternal and fetal morbidity and mortality. Imbalances of angiogenic factors, oxidative stress, and inflammatory response have a role in the pathogenesis of PE. Data regarding the circulating apelin level and its role in PE remains controversial. This study was formulated to assess the serum apelin level in PE, investigate its correlation with some inflammatory, oxidative stress, and angiogenic proteins in a nitric oxide synthase inhibitor; the N (gamma)-nitro-L-arginine methyl ester (L-NAME)-induced rat model of PE and determine whether apelin administration could protect against development of PE. 40 healthy adult female albino rats and 10 adult male albino rats were used in this study. The pregnant female rats were randomly divided into three groups: group 1 (normal pregnant group), group 2 (PE-induced group), injected subcutaneously with 75 mg L-NAME/kg bodyweight/day starting from day 9 to 20 of gestation, and group 3 (PE-induced group supplemented with apelin (PE + apelin)); PE induced as before and simultaneously subcutaneously injected with apelin-13 (6 × 10^-8 mol/kg bodyweight/twice daily) beginning from day 6 to 20 of gestation. In all groups, blood pressure and urine protein were determined at gestation days (GD) 0, 10, and 18. Moreover, serum apelin, placental growth factor (PLGF), vascular endothelial growth factor (VEGF), soluble fms-like tyrosine kinase-1 (sFlt-1), soluble endoglin (sEng), interferon-gamma (IFN-γ), and interleukin-10 (IL-10) levels and serum superoxide dismutase enzyme (SOD) and catalase (CAT) activities of all groups were estimated at the end of experiment. Placental histopathological examination was also performed. PE-induced rats showed significantly decreased serum apelin levels. Moreover, they showed significantly increased blood pressures, urine proteins, sFlt-1, sEng, and IFN-γ (mean arterial blood pressure, urine proteins, sFlt-1, sEng, and IFN-γ showed significant negative correlations with serum apelin level), but it showed significantly decreased VEGF, PLGF, IL-10, SOD, and CAT (VEGF, PLGF, IL-10, and SOD showed significant positive correlations with serum apelin level). In contrast, exogenous apelin administration significantly ameliorated these parameters together with improvement in the placental histoarchitecture in the apelin-supplemented PE group. This study demonstrated the protective effects of apelin administration on the pathogenesis of PE.

Real life outpatient biomarker use in management of hypertensive pregnancies in third trimester in a low resource SeTting: ROBUST study

OBJECTIVES

The utility of angiogenic biomarkers in a low resource outpatient setting is not well known. This study evaluates the clinical utility of angiogenic biomarkers, soluble fms-like tyrosine kinase 1 (sFlt1) and placental growth factor (PlGF) among patients at risk for preeclampsia in a low resource outpatient setting.

STUDY DESIGN

This was a prospective pilot study among high risk third trimester outpatients conducted in Bengaluru, India. Serum sFlt1/PlGF was measured between 28 and 37 weeks. Patients with high risk ratio were managed with close observation, intermediate risk had serum redrawn in one week, and those with low risk ratio received routine care. Delivery decisions were made based on local protocols.

MAIN OUTCOME MEASURES

Maternal complication rate, development of preeclampsia with severe features, and latency to delivery was examined by sFlt1/PlGF ratio.

RESULTS

The study included 50 patients. Compared to women with a low risk ratio, women with a high-risk ratio were more likely to have preeclampsia with severe features (90.91% vs 8.00%, p < 0.0001), a higher composite maternal complication rate (18.18% vs 0%, p = 0.04) and deliver at earlier gestational ages (32.57 [30.43, 34.71] vs 37.43 [36.86, 38.14] weeks, p = 0.0001).

CONCLUSION

Angiogenic factors may have utility in the low resource outpatient setting for women with a hypertensive disease. Low sFlt1/PlGF levels were associated with a longer latency to delivery and no maternal complications. This study confirms the broad clinical utility of biomarkers in the real world.

Evaluation of Angiogenic Factors (PlGF and sFlt-1) in Pre-eclampsia Diagnosis

OBJECTIVE

 Recent observations support the hypothesis that an imbalance between angiogenic factors has a fundamental role in the pathogenesis of pre-eclampsia and is responsible for the clinical manifestations of the disease. The goal of the present study was to evaluate the sensitivity, specificity, and the best accuracy level of Soluble fms-like tyrosine kinase-1 (sFlt-1), placental growth factor (PlGF), and sFlt-1/PlGF ratio in maternal serum and protein/creatinine ratio in urine sample to define the best cutoff point of these tests to discriminate between the patients with gestational hypertension and the patients with pre-eclampsia, to evaluate the possibility of using them as diagnostic methods.

METHODS

 A prospective longitudinal study was performed, and blood samples were collected from 95 pregnant patients with hypertension to measure serum concentrations of biomarkers sFlt-1 and PlGF. Urine samples were collected for protein screening. Significance was set as p < 0.05.

RESULTS

 The sFlt-1/PlGF ratio demonstrated a sensitivity of 57.5% and a specificity of 60% using 50.4 as a cutoff point. The test that showed the best accuracy in the diagnosis of pre-eclampsia was protein/creatinine ratio, with a sensitivity of 78.9% and a specificity of 70% using 0.4 as a cutoff point and showing an area under the receiver operating characteristic curve of 0.80 (p < 0.001).

CONCLUSION

 No studied laboratory test proved to be fairly accurate for the diagnosis of pre-eclampsia, except for the protein/creatinine ratio. The evidence is insufficient to recommend biomarkers sFlt-1 and PlGF to be used for the diagnosis of pre-eclampsia.

Affinity-Enhanced Multimeric VEGF (Vascular Endothelial Growth Factor) and PlGF (Placental Growth Factor) Variants for Specific Adsorption of sFlt-1 to Restore Angiogenic Balance in Preeclampsia

Preeclampsia is a potentially life-threatening multisystem disease affecting 4% to 8% of pregnant women after the 20th week of gestation. An excess of placental expressed antiangiogenic soluble VEGF (vascular endothelial growth factor)-receptor 1 (soluble FMS-like tyrosine kinase 1) scavenges VEGF and PlGF (placental growth factor), causing generalized endothelial dysfunction. Interventions to restore the angiogenic balance in preeclamptic pregnancies are intensively studied and improve maternal and neonatal outcomes. Especially extracorporeal strategies to remove sFlt-1 are promising in human pregnancy. However, available apheresis systems adsorb sFlt-1 unspecifically and with low efficiency. Affinity-enhanced ligands are needed to improve performance and compatibility of apheresis treatments. Using computerized molecular modeling, we developed multimeric VEGF molecules comprised of single-chain VEGF¹⁶⁵ dimers (scVEGF¹⁶⁵). A short peptide linker hampers intrachain dimerization to induce assembly preferably as tetrameric molecules as visualized in negative staining electron microscopy. scVEGF¹⁶⁵ multimers possess 1.2-fold higher affinity for sFlt-1 as compared to the available antibodies or monomeric VEGF. Consequently, scVEGF multimers have the ability to competitively release sFlt-1 bound PlGF and, in particular, VEGF. In ex vivo adsorption experiments using serum samples from patients with preeclampsia, scVEGF multimers reduce sFlt-1 levels by 85% and increase PlGF and VEGF levels by 20- and 9-fold, respectively. Finally, performance and stability of sFlt-1 capturing scVEGF¹⁶⁵ multimers were scrutinized on different matrices of which biocompatible agarose matrix yielded optimal results. We introduce the first VEGF-based highly efficient sFlt-1 apheresis system that is directly applicable in vivo due to utilization of inert agarose matrix, using a homomultimeric form of VEGF¹⁶⁵ to restore the angiogenic balance in preeclampsia.

Increased NDRG1 expression suppresses angiogenesis via PI3K/AKT pathway in human placental cells

OBJECTIVE

To observe whether and how N-myc downstream-regulated gene 1 (NDRG1) regulates placental angiogenesis via JEG-3 placental-derived cells.

METHODS

Expression of NDRG1 in stably transfected JEG-3 cells was detected using western blot and real-time quantitative polymerase chain reaction. Angiogenesis was examined by tube formation assay. The levels of placental growth factor (PLGF) and soluble fms-like tyrosine kinase-1 (sFlt-1) were examined using enzyme-linked immunosorbent assay. The expression of vascular endothelial growth factor (VEGF), PI3K, and AKT was examined by western blot. The relationship between PI3K and NDRG1 was detected by co-immunoprecipitation.

RESULTS

NDRG1 was significantly down-regulated at both the mRNA and protein level by lentivirus (Lv)-NDRG1-shRNA (P < 0.001), whereas it was significantly up-regulated by Lv-NDRG1 (P < 0.001). NDRG1 knockdown significantly increase the expression of PLGF and VEGF in JEG-3 cells (P < 0.001), while NDRG1 knockdown significantly reduced the secretion of sFlt-1 (P < 0.001). NDRG1 was specific bound to PI3K, and NDRG1 knockdown significantly up-regulated the expressions of PI3K and AKT in JEG-3 cells (P < 0.001).

CONCLUSION

NDRG1 suppresses angiogenesis in preeclampsia, and the PI3K/AKT signaling pathway may be involved in the regulation of angiogenesis by NDRG1.

Verification of placental growth factor and soluble-fms-like tyrosine kinase 1 assay performance in late pregnancy and their diagnostic test accuracy in women with reduced fetal movement

BACKGROUND

Placental growth factor (PlGF) and soluble-fms-like tyrosine kinase 1 (sFlt-1) are biomarkers of placental function used to aid the diagnosis and prediction of pregnancy complications. This work verified the analytical performance of both biomarkers and provides preliminary diagnostic accuracy data to identify adverse pregnancy outcome in women with reduced fetal movement.

METHODS

Verification of sFlt-1 and PlGF assays included a comparative accuracy assessment of 24 serum samples analysed at six different sites and laboratory-specific precision estimates. The sFlt-1/PlGF ratio was assessed in serum samples obtained prospectively from 295 women with reduced fetal movement ≥36 weeks' gestation; diagnostic accuracy was evaluated using 2 × 2 tables and area under the receiver operator characteristic (AUROC) curve.

RESULTS

Regression analysis showed that performance between sites was good with Passing-Bablok slopes ranging from 0.96 to 1.05 (sFlt-1) and 0.93 to 1.08 (PlGF). All sites had a mean bias <15%, although there was poorer agreement at the lowest PlGF concentrations. All within- and between-batch coefficients of variation were <10%. In 289 women with an appropriately grown fetus, an sFlt-1/PlGF ratio ≥38 had a sensitivity of 0.20 (95% confidence interval [CI] 0.07, 0.41), specificity of 0.88 (95% CI 0.83, 0.92) and AUROC curve of 0.58 (95% CI 0.47, 0.68) to identify adverse pregnancy outcome.

CONCLUSIONS

Analytical performance of the sFlt-1 and PlGF assays was comparable across different sites. The sensitivity of sFlt-1/PlGF to identify adverse pregnancy outcome in women with reduced fetal movement was considered acceptable, in the absence of other tests, to progress to a pilot randomized controlled trial.

Getting an Early Start in Understanding Perinatal Asphyxia Impact on the Cardiovascular System

Perinatal asphyxia (PA) is a burdening pathology with high short-term mortality and severe long-term consequences. Its incidence, reaching as high as 10 cases per 1000 live births in the less developed countries, prompts the need for better awareness and prevention of cases at risk, together with management by easily applicable protocols. PA acts first and foremost on the nervous tissue, but also on the heart, by hypoxia and subsequent ischemia-reperfusion injury. Myocardial development at birth is still incomplete and cannot adequately respond to this aggression. Cardiac dysfunction, including low ventricular output, bradycardia, and pulmonary hypertension, complicates the already compromised circulatory status of the newborn with PA. Multiorgan and especially cardiovascular failure seem to play a crucial role in the secondary phase of hypoxic-ischemic encephalopathy (HIE) and its high mortality rate. Hypothermia is an acceptable solution for HIE, but there is a fragile equilibrium between therapeutic gain and cardiovascular instability. A profound understanding of the underlying mechanisms of the nervous and cardiovascular systems and a close collaboration between the bench and bedside specialists in these domains is compulsory. More resources need to be directed toward the prevention of PA and the consecutive decrease of cardiovascular dysfunction. Not much can be done in case of an unexpected acute event that produces PA, where recognition and prompt delivery are the key factors for a positive clinical result. However, the situation is different for high-risk pregnancies or circumstances that make the fetus more vulnerable to asphyxia. Improving the outcome in these cases is possible through careful monitoring, identifying the high-risk pregnancies, and the implementation of novel prenatal strategies. Also, apart from adequately supporting the heart through the acute episode, there is a need for protocols for long-term cardiovascular follow-up. This will increase our recognition of any lasting myocardial damage and will enhance our perspective on the real impact of PA. The goal of this article is to review data on the cardiovascular consequences of PA, in the context of an immature cardiovascular system, discuss the potential contribution of cardiovascular impairment on short and long-term outcomes, and propose further directions of research in this field.

Altered level of salivary placental growth factor is associated with preeclampsia

A pilot, case-control study was conducted to compare the concentrations of placental growth factor (PlGF) and placental alkaline phosphatase (PLAP) in saliva of preeclampsia (PE) patients with normotensive controls in the second and third trimesters. Measured by ELISA assays, levels of salivary PlGF were significantly lower in PE patients (n = 13) compared to controls (n = 15) (two-way ANOVA, p = 0.0208) independent of gestational age at time of collection (p = 0.49). Salivary PLAP differences between PE and controls were not statistically significant. Placenta-specific proteins are detectable in maternal saliva and may serve as noninvasive biomarkers to monitor placenta health and disease during pregnancy.

Changes in VEGF-related factors are associated with presence of inflammatory factors in carbohydrate metabolism disorders during pregnancy

The aim of this study was to determine the action of molecules in carbohydrate metabolism disorders during pregnancy. The concentration of different types of cytokines and vascular endothelial growth factor (VEGF) in the plasma were measured in 4 groups of women: Group I, normal pregnancy (n = 10); Group II, patients with gestational DM (n = 12); Group III, pregnant patients with preexisting DM (n = 16); and Group IV, diabetic non-pregnant women (n = 22). The plasma VEGF concentration was significantly higher in the women in Group IV than in other groups (P <0.01). The concentration of the soluble form of the VEGF receptor-1 (sVEGFR-1) was significantly higher in Group I than in other groups (P <0.01). The concentration of soluble form of the VEGF receptor-2 (sVEGFR-2) was significantly lower in Groups I than in other groups (P <0.05). The concentrations of monocyte chemotactic protein-1 (MCP-1) and eotaxin were significantly lower in Group I than in Groups III and IV. The levels of interleukin (IL)-8, IL-6, and tumor necrosis factor-α (TNF-α) were significantly higher in Group I than in Group IV. Both the VEGF-related molecules and the Inflammatory cytokines are altered in pregnant women with the carbohydrate metabolism disorders.

Stability of placental growth factor, soluble fms-like tyrosine kinase 1, and soluble fms-like tyrosine kinase 1 e15a in human serum and plasma

Placental growth factor (PlGF), total soluble fms-like tyrosine-kinase 1 (sFlt-1) and its placental-specific variant, sFlt-1 e15a, show promise as biomarkers for the prediction and diagnosis of preeclampsia. This study describes the degradation of PlGF, sFlt-1 and sFlt-1 e15a within maternal serum and plasma to assist clinical implementation. Whole blood was refrigerated at 4 °C for up to 48 h prior to centrifugation for isolation of plasma and serum. PlGF and sFlt-1 were quantified using the B.R.A.H.M.S Kryptor Compact PLUS; sFlt-1 e15a via a custom ELISA. All three analytes are stable for at least 48 h at 4 °C. Serum and plasma performed comparably.

Profiles of circular RNAs in human placenta and their potential roles related to preeclampsia

To identify the profiles of circular RNAs (circRNAs) in human placental tissues and to explore the potential roles of dysregulated circRNAs in the pathological genesis of preeclampsia, expression profiles of circRNAs in human placentas were performed in this study. Utilizing high-throughput technology, based on fold changes and P values, 300 circRNAs that are differentially expressed between preeclampsia and normal placental tissues were identified. Among them, hg38_circ_0014736 and hsa_circ_0015382 were validated as significantly upregulated by real-time quantitative PCR with divergent primers. At the same time, hsa_circ_0007121 was significantly downregulated. GO analysis revealed that the three altered circRNAs had a relationship with transcription regulation, proliferation, protein binding, and response to hypoxia. KEGG analysis yielded that apoptosis, Wnt signaling, and HIF-1 pathways were significantly enriched. Interestingly, hsa_circ_0007121 was found to be expressed differently in plasma between preeclampsia and normal pregnancy and this difference could be detected before 20 gestational weeks. Besides, addition receiver operating characteristic (ROC) curve analysis showed that the area under the ROC curve of hsa_circ_0007121 reached 0.72 ([0.59-0.85], P = 0.004) with a sensitivity of 0.77 and specificity of 0.70. Collectively, this study demonstrates the existence of dysregulated circRNAs in the placenta of preeclampsia patients and annotates their potential roles in the pathogenesis of the disease. Encouragingly, hsa_circ_0007121 was found to be a potential noninvasive biomarker for the prediction of preeclampsia.

Maternal Serum Angiogenic Factor sFlt-1 to PlGF Ratio in Preeclampsia: A Useful Marker for Differential Diagnosis and Prognosis Evaluation in Chinese Women

The ratio of soluble fms-like tyrosine kinase-1 to placental growth factor (sFlt-1/PlGF) is elevated and proved to be useful in preeclampsia (PE) diagnosis. Its value in differential diagnosis with other pregnancy complications and prediction of pregnancy duration has yet to be clarified in Chinese population. We retrospectively analyzed 118 singleton pregnancies with suspected or diagnosed PE at the Peking Union Medical College Hospital (PUMCH) in China. Among these, 62 pregnancies were diagnosed as PE (48 early onsets and 14 late onsets, with 39 and 5 severe PE, respectively), 12 gestational hypertension (GH), 15 chronic hypertension (chrHTN), 16 autoimmune diseases, and 13 pregnancies with uncomplicated proteinuria. And 76 normal pregnancies were included as control. The results showed (1) the sFlt-1/PlGF ratio in early onset PE subgroup was significantly higher than that in GH, chrHTN, and control groups; the sFlt-1/PlGF ratio in late onset PE subgroup was significantly higher than that in chrHTN and control groups, but similar as GH group; the sFlt-1/PlGF ratio was similar among GH, chrHTN, and control groups. (2) The sFlt-1/PlGF ratio was significantly increased in the PE group compared with autoimmune disease and uncomplicated proteinuria pregnancies. (3) By ROC curve analysis, the cutoff value of the sFlt-1/PlGF ratio was less than 21.5 to rule out PE and higher than 97.2 to confirm the diagnosis of PE. (4) The sFlt-1/PlGF ratio was higher in PE pregnancies delivering within 7 days than those more than 7 days, either in early onset PE or severe PE. In conclusion, we show that maternal sFlt-1/PlGF ratio is an efficient biomarker in the diagnosis and differential diagnosis of PE. This ratio can be used to predict the timing of delivery for PE pregnancies.

Elevated soluble-St2 concentrations in preeclampsia correlate with echocardiographic parameters of diastolic dysfunction and return to normal values one year after delivery

Objectives: To compare soluble-ST2 (sST2) concentrations in patients with severe features of preeclampsia and healthy pregnant controls before as well as 1 year after delivery. Another objective was to assess potential correlation between sST2 concentrations and myocardial function.Methods: Patients with singleton pregnancy complicated by severe features of preeclampsia and healthy controls were included in a prospective observational study. Plasma sST2 concentrations were measured within 24 h before delivery and 1 year after delivery. Standard two-dimensional and Doppler echocardiography was performed at the time of first sST2 measurement before delivery. Mann-Whitney U test was used to compare sST2 values in preeclamptic patients versus controls. Kendall's tau was used to assess correlation between sST2 values and echocardiographic measures of left ventricular systolic and diastolic function (p < .05 significant).Results: We included 24 patients with severe preeclampsia and 29 controls. One year after delivery, sST2 concentrations were available for 24 (45%) participants (13 in preeclampsia group and 11 controls). Concentrations of sST2 were markedly elevated in patients with severe preeclampsia compared to healthy controls before delivery (p = .04), but not 1 year after delivery (p = .80). There was no significant correlation between sST2 and parameters of systolic function. In preeclamptic patients, we found a significant inverse correlation between sST2 and markers of diastolic function: peak early mitral inflow velocity E (Kendall's tau = -0.40; p = .02), peak early diastolic myocardial velocities at septal and lateral mitral annulus (e') (Kendall's tau = -0.354, p = .04) and ratio between e' and peak systolic myocardial velocities at the septal and lateral mitral annulus (e'/s') (Kendall's tau = -0.362, p = .04).Conclusions: Preeclampsia with severe features is associated with increased maternal plasma concentrations of sST2, which return to normal values in the first year after delivery. Higher sST2 levels in preeclamptic patients correlate with impaired parameters of left ventricular diastolic function.

Increased circulating levels of Epidermal Growth Factor-like Domain 7 in pregnant women affected by preeclampsia

Proper placental development is crucial to establish a successful pregnancy. Defective placentation is the major cause of several pregnancy complications, including preeclampsia (PE). We have previously demonstrated that the secreted factor Epidermal Growth Factor-like Domain 7 (EGFL7) is expressed in trophoblast cells of the human placenta and that it regulates trophoblast migration and invasion, suggesting a role in placental development. In the present study, we demonstrate that circulating levels of EGFL7 are undetectable in nonpregnant women, increase during pregnancy and decline toward term. Close to term, circulating levels of EGFL7 are significantly higher in patients affected by PE when compared to normal pregnancies. Consistent with these results, villus explant cultures obtained from placentas affected by PE display increased release of EGFL7 in the culture medium when compared to those from normal placentas. Our results suggest that increased release of placenta-derived EGFL7 and increased circulating levels of EGFL7 are associated with the clinical manifestation of PE.

Pre-eclampsia: pathogenesis, novel diagnostics and therapies

Pre-eclampsia is a complication of pregnancy that is associated with substantial maternal and fetal morbidity and mortality. The disease presents with new-onset hypertension and often proteinuria in the mother, which can progress to multi-organ dysfunction, including hepatic, renal and cerebral disease, if the fetus and placenta are not delivered. Maternal endothelial dysfunction due to circulating factors of fetal origin from the placenta is a hallmark of pre-eclampsia. Risk factors for the disease include maternal comorbidities, such as chronic kidney disease, hypertension and obesity; a family history of pre-eclampsia, nulliparity or multiple pregnancies; and previous pre-eclampsia or intrauterine fetal growth restriction. In the past decade, the discovery and characterization of novel antiangiogenic pathways have been particularly impactful both in increasing understanding of the disease pathophysiology and in directing predictive and therapeutic efforts. In this Review, we discuss the pathogenic role of antiangiogenic proteins released by the placenta in the development of pre-eclampsia and review novel therapeutic strategies directed at restoring the angiogenic imbalance observed during pre-eclampsia. We also highlight other notable advances in the field, including the identification of long-term maternal and fetal risks conferred by pre-eclampsia.

Low Serum Levels of HtrA3 at 15 Weeks of Gestation Are Associated with Late-Onset Preeclampsia Development and Small for Gestational Age Birth

OBJECTIVE

The aim of this study was to investigate the potential utility of serum HtrA1 and HtrA3, serine proteases that are highly expressed in the developing placenta, at 15 and 20 weeks of gestation for predicting later development of adverse pregnancy outcomes of preeclampsia (PE), gestational hypertension (GHT), preterm birth (PTB), and small for gestational age (SGA) birth.

METHODS

This is a nested case control study of 665 samples (330 controls, 335 cases) from the Adelaide SCOPE cohort. The cases included were 92 PE, 71 GHT, 56 PTB, and 116 SGA. Samples were assessed by ELISA and data adjusted for maternal age, BMI, socioeconomic index, hCG, and smoking status. Multivariate logistic regression was performed with other biochemical and biophysical parameters available for these samples.

RESULTS

HtrA1 did not differ between the controls and cases. In contrast, HtrA3 was significantly lower at 15 weeks in pregnancies that later developed late-onset PE (LPE) or resulted in SGA birth, with an area under the ROC curve (AUC) of 0.716 and 0.790, respectively. The combination of HtrA3 with PAPP-A, uterine, and umbilical Doppler improved the AUC to 0.755 for LPE and 0.844 for SGA.

CONCLUSION

HtrA3 at 15 weeks is associated with, and may be useful for, the early detection of LPE development and SGA birth.

Role of plasma PlGF, PDGF-AA, ANG-1, ANG-2, and the ANG-1/ANG-2 ratio as predictors of preeclampsia in a cohort of pregnant women

INTRODUCTION

Preeclampsia affects 3-5% of pregnancies worldwide and is the primary cause of maternal-fetal and neonatal mortality. Previous studies show that alterations in maternal concentrations of angiogenic factors, such as PlGF, PDGF AA, ANG-1, and ANG-2, may play fundamental roles in the pathophysiology of the disease.

OBJECTIVE

Determine whether the PlGF, PDGF AA, ANG-1, and ANG-2 are predictors of preeclampsia occurrence in a prenatal cohort study.

PATIENTS AND METHODS

This is a case-control study associated with a prospective cohort of pregnant women, with gestational ages between 20 and 25 weeks, composed of 30 pregnant women with preeclampsia (PE) and 90 healthy pregnant women (HP). The plasma concentrations of the markers were determined using the ELISA method. The comparison between the case and control groups was performed using the t test on the SAS® 9.4 software. Also, ROC curves were constructed to evaluate the predictive potential of the biomarkers.

RESULTS

Differences in the concentrations of PlGF, PDGF AA, ANG-1 and ANG-2, and the ANG-1/ANG-2 ratio were not observed between the PE and the HP groups. The predictive capacity of the biomarkers was assessed using ROC curves, in which the area under the curve for PlGF AUC = 0.55; PDGF AA AUC = 0.55; ANG-1 AUC = 0.47; ANG-2 AUC = 0.51, and the ANG-1/ANG-2 ratio AUC = 0.57.

CONCLUSION

In pregnant women, with gestational ages between 20 and 25 weeks significant differences in biomarker concentrations between groups PE and HP were not observed. The ROC curves showed that the biomarkers were ineffective as preeclampsia predictors in the analyzed cohort.

Hypertension and Pregnancy: Management and Future Risks

Pregnancy-induced hypertension is a major cause of maternal and fetal morbidity and mortality. The overall strategies of defining and managing these conditions are aimed at preventing cardiovascular and cerebrovascular complications in the mother without jeopardizing fetal well-being. Our understanding of the origin of these disorders is evolving. Women with chronic hypertension should undergo a prepregnancy evaluation and close monitoring during and after pregnancy to ensure medication safety and to prevent end-organ damage. Based on available data, the current recommendation is that antihypertensive therapy should be initiated only in women with severe hypertension (defined as systolic blood pressure ≥160 mm Hg and/or diastolic blood pressure ≥105 mm Hg). It is now becoming more and more clear that hypertensive complications during pregnancy are potentially linked to cardiovascular, kidney, and metabolic diseases later in life. This review discusses the spectrum of hypertensive disorders of pregnancy, general management principles, and the need to monitor for long-term cardiovascular sequelae for decades afterward.

Maternal Serum sEndoglin and Cell-Free Fetal DNA as Probable Markers of Preeclampsia: A Study in Single Center, Egypt

Background: This study was conducted to compare the levels of maternal serum soluble endoglin (sEng) and cell-free fetal DNA (cffDNA) in pregnant females with PE to normotensive pregnant ones, together with relating these levels to preeclampsia (PE) severity and onset. Method of the study: It was a comparative study in Mansoura University Hospital, Egypt, to detect the levels of serum sEng by ELISA besides the levels of cffDNA by quantitative real-time polymerase chain reaction in 80 pregnant females suffering from PE in addition to 80 normotensive pregnant ones that were included as control. Results: Levels of serum sEng and cffDNA were higher in PE cases than control (p < 0.0001٭ both) and were significantly related to the severity of the disease. Levels were also higher in early than late onset PE (p < 0.003٭ and <0.002٭, respectively). Sensitivities, specificities, positive, and negative predictive values in addition to accuracy of serum sEng and cffDNA were 97.5%, 98.8%, 98.7%, 97.5%, and 98.1% and 97.5%, 93.8%, 94.0%, 97.4%, and 95.6%, respectively. Conclusion: Maternal serum sEng and cffDNA can be good markers for diagnosis of PE in Egyptian patients. They are positively related to the disease severity. Abbreviations: cffDNA; Cell-Free Fetal DNA, sEng; soluble Endoglin, PE; preeclampsia, qRT PCR; Quantitative real-time polymerase chain reaction.

Contribution of angiotensinogen M235T and T174M gene variants and haplotypes to preeclampsia and its severity in (North African) Tunisians

BACKGROUND

Preeclampsia (PE) is a pregnancy-associated hypertensive disorder and a leading cause of maternal and neonatal morbidity and mortality. While its pathogenesis remains ill defined, several candidate genes for PE have been identified, but results remain inconclusive. We investigated the association of the angiotensinogen ( AGT) gene variants M235T and T174M with PE, and we analyzed the contribution of both variants to the severity of PE.

METHODS

This case-control study enrolled 550 Tunisian pregnant women: 272 with PE, of whom 147 presented with mild, and 125 with severe PE, along with 278 unrelated age- and ethnically matched control women. AGT genotyping was performed by polymerase chain reaction-restriction fragment length polymorphism.

RESULTS

Significantly higher M235T minor allele frequency (MAF) was associated with increased risk of PE ( p < 0.001). Decreased frequency of heterozygous T174M genotype carriers were found in control women ( p = 0.015), suggesting a protective effect of this genotype (odds ratio (95% confidence interval) = 0.51 (0.29-0.89)). Two-locus haplotype analysis demonstrated MM and TT haplotypes to be negatively and positively associated with PE, respectively. MAF of M253T, but not T174M, was higher in the severe PE group, and carrying M235T or T174M minor allele was associated with increased body mass index ( p < 0.001) among unselected PE women.

CONCLUSIONS

AGT M235T and T174M variants contribute to an increased risk of developing PE, and for M235T to PE severity.

Angiogenic factors: potential to change clinical practice in pre-eclampsia?

Pre‐eclampsia is a complex disease with significant maternal and fetal morbidity and mortality. Its syndromic nature makes diagnosis and management difficult. The field is rapidly evolving with the definition of pre‐eclampsia being challenged by some organisations, with proteinuria no longer being essential in the presence of other features. In the last decade, angiogenic factors, in particular soluble fms‐like tyrosine kinase 1 (sFlt‐1), have emerged as important molecules in the pathogenesis of pre‐eclampsia. Here we review the most recent evidence regarding the potential of these factors as biomarkers and therapeutic targets for pre‐eclampsia.

Tweetable abstract

A review of angiogenic factors, sFlt‐1 and PlGF, in the diagnosis, prediction and management of pre‐eclampsia.

A review of angiogenic factors, sFlt‐1 and PlGF, in the diagnosis, prediction and management of pre‐eclampsia.

Metformin, the aspirin of the 21st century: its role in gestational diabetes mellitus, prevention of preeclampsia and cancer, and the promotion of longevity

Metformin is everywhere. Originally introduced in clinical practice as an antidiabetic agent, its role as a therapeutic agent is expanding to include treatment of prediabetes mellitus, gestational diabetes mellitus, and polycystic ovarian disease; more recently, experimental studies and observations in randomized clinical trials suggest that metformin could have a place in the treatment or prevention of preeclampsia. This article provides a brief overview of the history of metformin in the treatment of diabetes mellitus and reviews the results of metaanalyses of metformin in gestational diabetes mellitus as well as the treatment of obese, non-diabetic, pregnant women to prevent macrosomia. We highlight the results of a randomized clinical trial in which metformin administration in early pregnancy did not reduce the frequency of large-for-gestational-age infants (the primary endpoint) but did decrease the frequency of preeclampsia (a secondary endpoint). The mechanisms by which metformin may prevent preeclampsia include a reduction in the production of antiangiogenic factors (soluble vascular endothelial growth factor receptor-1 and soluble endoglin) and the improvement of endothelial dysfunction, probably through an effect on the mitochondria. Another potential mechanism whereby metformin may play a role in the prevention of preeclampsia is its ability to modify cellular homeostasis and energy disposition, mediated by rapamycin, a mechanistic target. Metformin has a molecular weight of 129 Daltons and therefore readily crosses the placenta. There is considerable evidence to suggest that this agent is safe during pregnancy. New literature on the role of metformin as a chemotherapeutic adjuvant in the prevention of cancer and in prolonging life and protecting against aging is reviewed briefly. Herein, we discuss the mechanisms of action and potential benefits of metformin.

Recombinant vascular endothelial growth factor 121 injection for the prevention of fetal growth restriction in a preeclampsia mouse model

AIM

To discover the potential role of recombinant VEGF121 (rVEGF121) injection for the prevention of fetal growth restriction in a preeclampsia (PE) mouse model (Mus musculus).

SUBJECTS AND METHODS

This is an experimental study of 30 pregnant mice that were randomly divided into three groups: normal, PE, and PE with rVEGF121 injection. The PE mouse model was created by injecting anti Qa-2 10 ng iv, which is deleterious to Qa-2 expression (homologous to HLA-G), from the first to the fourth day of gestation. PE was validated by measuring serum levels of soluble fms-like tyrosine kinase-1 (sFlt-1) and placental growth factor(PIGF) and also by kidney histopathology. Recombinant VEGF121 was given on the ninth day until the 11th day of pregnancy; mice were terminated on the 16th day. Fetal weights were acquired with a Denver analytical balance. Serum levels of sFlt-1 and PlGF were measured using enzyme-linked immunosorbent assay (ELISA). The data were statistically analyzed via analysis of variance (ANOVA).

RESULTS

On average, fetal birth weight was 0.7150 g in the normal group, 0.4936 g in the PE group, and 0.6768 g in the PE with rVEGF121 injection group. ANOVA showed significant growth restriction in the PE group (P=0.006), confirming the use of anti Qa-2 as a suitable PE model. Kidney histopathology results, sFlt-1 levels, and PlGF levels also demonstrated that anti Qa-2 consistently conferred hallmarks of PE in mice. Vascular endothelial growth factor (VEGF) injection prevented fetal growth restriction; comparable fetal weights were observed between the PE model with VEGF treatment and the normal group (P=0.610) but differed from the untreated PE group (P=0.021).

CONCLUSIONS

Injection of rVEGF121 has the potential to prevent fetal growth restriction in a newly proposed PE mouse model.

The use of angiogenic biomarkers in maternal blood to identify which SGA fetuses will require a preterm delivery and mothers who will develop pre-eclampsia

OBJECTIVE

To determine (1) whether maternal plasma concentrations of angiogenic and anti-angiogenic factors can predict which mothers diagnosed with "suspected small for gestational age fetuses (sSGA)" will develop pre-eclampsia (PE) or require an indicated early preterm delivery (≤ 34 weeks of gestation); and (2) whether risk assessment performance is improved using these proteins in addition to clinical factors and Doppler parameters.

METHODS

This prospective cohort study included women with singleton pregnancies diagnosed with sSGA (estimated fetal weight <10th percentile) between 24 and 34 weeks of gestation (n = 314). Plasma concentrations of soluble vascular endothelial growth factor receptor-1 (sVEGFR-1), soluble endoglin (sEng) and placental growth factor (PlGF) were determined in maternal blood obtained at the time of diagnosis. Doppler velocimetry of the umbilical (Umb) and uterine (UT) arteries was performed. The outcomes were (1) subsequent development of PE; and (2) indicated preterm delivery at ≤ 34 weeks of gestation (excluding deliveries as a result of spontaneous preterm labor, preterm pre-labor rupture of membranes or chorioamnionitis).

RESULTS

(1) The prevalence of PE and indicated preterm delivery was 9.2% (n = 29/314) and 7.3% (n = 23/314), respectively; (2) the area under the receiver operating characteristic curve (AUC) for the identification of patients who developed PE and/or required indicated preterm delivery was greater than 80% for the UT artery pulsatility index (PI) z-score and each biochemical marker (including their ratios) except sVEGFR-1 MoM; (3) using cutoffs at a false positive rate of 15%, women with abnormal plasma concentrations of angiogenic/anti-angiogenic factors were 7-13 times more likely to develop PE, and 12-22 times more likely to require preterm delivery than those with normal plasma MoM concentrations of these factors; (4) sEng, PlGF, PIGF/sEng and PIGF/sVEGFR-1 ratios MoM, each contributed significant information about the risk of PE beyond that provided by clinical factors and/or Doppler parameters: women who had low MoM values for these biomarkers were at 5-9 times greater risk of developing PE than women who had normal values, adjusting for clinical factors and Doppler parameters (adjusted odds ratio for PlGF: 9.1, PlGF/sEng: 5.6); (5) the concentrations of sVEGFR-1 and PlGF/sVEGFR-1 ratio MoM, each contributed significant information about the risk of indicated preterm delivery beyond that provided by clinical factors and/or Doppler parameters: women who had abnormal values were at 8-9 times greater risk for indicated preterm delivery, adjusting for clinical factors and Doppler parameters; and (6) for a two-stage risk assessment (Umb artery Doppler followed by Ut artery Doppler plus biochemical markers), among women who had normal Umb artery Doppler velocimetry (n = 279), 21 (7.5%) developed PE and 11 (52%) of these women were identified by an abnormal UT artery Doppler mean PI z-score (>2SD): a combination of PlGF/sEng ratio MoM concentration and abnormal UT artery Doppler velocimetry increased the sensitivity of abnormal UT artery Doppler velocimetry to 76% (16/21) at a fixed false-positive rate of 10% (p = 0.06).

CONCLUSION

Angiogenic and anti-angiogenic factors measured in maternal blood between 24 and 34 weeks of gestation can identify the majority of mothers diagnosed with "suspected SGA" who subsequently developed PE or those who later required preterm delivery ≤ 34 weeks of gestation. Moreover, incorporation of these biochemical markers significantly improves risk assessment performance for these outcomes beyond that of clinical factors and uterine and umbilical artery Doppler velocimetry.

Influence of the sFlt-1/PlGF ratio on clinical decision-making in women with suspected preeclampsia--the PreOS study protocol

OBJECTIVE

To assess how routine clinical use of the Roche fully automated Elecsys® sFlt-1/PlGF test changes decision-making of physicians to hospitalize pregnant women with suspected preeclampsia.

METHODS

The Preeclampsia Open Study (PreOS) study is a multicenter, prospective, open-label, non-interventional study in 150 women showing signs and symptoms of preeclampsia (suspected preeclampsia). Physicians record their intended procedures before and after knowledge of participants' sFlt-1/PlGF ratio. The study is conducted at five investigational sites in Germany and Austria.

CONCLUSION

The PreOS study will provide evidence on how sFlt-1/PlGF ratio testing influences clinical decision-making in women with suspected preeclampsia in real-world clinical practice.

Altered Biomarkers in Trophoblast Cells Obtained Noninvasively Prior to Clinical Manifestation of Perinatal Disease

A contributing factor to poor placental perfusion, leading to intrauterine growth restriction and preeclampsia, is the failure of invading extravillous trophoblast (EVT) cells to remodel the maternal uterine arteries during the first and second trimesters of pregnancy. Noninvasive assessment of EVT cells in ongoing pregnancies is possible beginning three weeks after conception, using trophoblast retrieval and isolation from the cervix (TRIC). Seven proteins were semi-quantified by immunofluorescence microscopy in EVT cells obtained between gestational weeks 6 and 20 from pregnancies with normal outcomes (N = 29) and those with intrauterine growth restriction or preeclampsia (N = 12). Significant differences were measured in expression of PAPPA, FLT1, ENG, AFP, PGF, and LGALS14, but not LGALS13 or the lineage marker KRT7. These findings provide for the first time direct evidence of pathology-associated protein dysregulation in EVT cells during early placentation. The TRIC platform provides a novel approach to acquire molecular signatures of EVT cells that can be correlated with pregnancy outcome.

Diagnostic and prognostic significance of serum soluble endoglin levels in preeclampsia and eclampsia

Background:

Preeclampsia is a multisystem disorder of unknown etiology that affects 4–5% of all pregnancies. The aim of the study was to evaluate the diagnostic accuracy of serum soluble endoglin (sEng) in preeclampsia and eclampsia and also to evaluate its prognostic significance.

Materials and Methods:

This prospective case–control study carried out over a period of 1 year in the Department of Obstetrics and Gynaecology, King George Medical University, Lucknow. After written informed consent and ethical clearance, total 90 subjects were enrolled. Among them, 30 subjects of eclampsia, 15 of nonsevere preeclampsia, 15 of severe preeclampsia served as cases, and 30 healthy pregnant normotensive women served as controls. Levels were estimated by enzyme-linked immunosorbent assay technique in both cases and controls.

Results:

Mean level was highest in eclampsia group (14.96 ± 1.96 ng/mL) and lowest in controls (2.08 ± 0.56 ng/mL). At cut-off value of sEng levels of ≥6.26 ng/mL, it was found to be 100% sensitive and 100% specific for the diagnosis of preeclampsia (area under curve =1) at 95% confidence interval. sEng levels were strongly correlated with systolic (r = 0.928) and diastolic blood pressure (r = 0.916), serum lactate dehydrogenase (r = 0.791) and serum uric acid (r = 0.722). All four maternal deaths were reported within eclampsia group, in whom the mean sEng level was significantly higher (17.84 ± 0.22) as compared to other subjects (9.50 ± 5.80).

Conclusion:

sEng is a novel marker for diagnosis of preeclampsia, and it can also be used as a prognostic marker to predict the severity of preeclampsia.