Circulating Growth Differentiation Factor 15 Is Increased Preceding Preeclampsia Diagnosis: Implications as a Disease Biomarker

Evaluation of diagnostic potential of maternal serum ischemia modified albumin in cases of pre-eclampsia

OBJECTIVES

The underlying causes and mechanisms of pre-eclampsia (PE), its exact etiology remains unclear and poorly understood. Hypoxia, ischemia, and oxidative stress induced by free radicals have been associated with development of PE. Ischemia-modified albumin (IMA) is a chemically modified albumin due to oxidative stress. IMA, a serum biomarker of hypoxia, ischemia, and oxidative free radicals is a potential biomarker for PE. The aim of the current proposal was to study serum IMA as a diagnostic biomarker of pre-eclampsia (PE) in pregnant females and to evaluate the correlation between serum IMA and different markers of pre-eclampsia (BP, urinary protein, LFT, KFT, serum total protein & uric acid).

METHODS

A total of 60 pregnant women aged between 21 and 35 years were recruited (30 PE cases and 30 normal pregnancy). Serum IMA was measured by spectrophotometric method developed by Bar-Or D. BP and biochemical parameters (urinary protein, LFT, KFT, serum total protein & uric acid) were also assayed and compared between two groups. Correlation analysis was done for analyzing the relationship between serum IMA and biochemical parameters.

RESULTS

The mean serum IMA was significantly higher in normotensive pregnant females (0.93 ABSU) than PE cases (0.71 ABSU). Kidney function and liver function parameters were more deranged in PE cases than in controls. Serum IMA was positively correlated with serum creatinine (r=0.322), serum uric acid (r=0.54) and urinary protein (0.376) whereas negatively correlated with total serum bilirubin (r=-0.515) and serum albumin (r=-0.380).

CONCLUSIONS

Elevated serum IMA concentrations in normotensive pregnant controls as compared to PE cases suggest that apart from ongoing ischemia and oxidative stress in placenta IMA values are influenced by many other mechanisms in pregnancy.

NR2F1 overexpression alleviates trophoblast cell dysfunction by inhibiting GDF15/MAPK axis in preeclampsia

Abnormal functions of trophoblast cells are associated with the pathogenesis of preeclampsia (PE). Nuclear receptor subfamily 2 group F member 1 (NR2F1) acts as a transcriptionally regulator in many diseases, but its role in PE remains unknown. Hypoxia/reoxygenation (H/R)-stimulated HTR-8/SVneo cells were used to mimic PE injury in vitro. NR2F1 overexpression alleviated trophoblast apoptosis, as evidenced by the decreased number of TUNEL-positive cells and the downregulation of caspase 3 and caspase 9 expression in cells. NR2F1 overexpression increased the invasion and migration ability of HTR-8/SVneo cells, accompanied by increased protein levels of matrix metalloproteinase (MMP)-2 and MMP-9. mRNA-seq was applied to explore the underlying mechanism of NR2F1, identifying growth differentiation factor 15 (GDF15) as the possible downstream effector. Dual-luciferase reporter, ChIP-qPCR, and DNA pull-down assays confirmed that NR2F1 bound to the promoter of GDF15 and transcriptionally inhibited its expression. GDF15 overexpression increased apoptosis and decreased the ability of invasion and migration in HTR-8/SVneo cells expressing NR2F1. MAPK pathway was involved in the regulation of PE. Administration of p38 inhibitor, ERK inhibitor, and JNK inhibitor reversed the effect of simultaneous overexpression NR2F1 and GDF15 on trophoblast apoptosis, invasion, and migration. Our findings demonstrated that NR2F1 overexpression inhibited trophoblast apoptosis and promoted trophoblast invasion and migration. NR2F1 might negatively regulate GDF15 expression by binding to its promoter region, which further inhibited MAPK signaling pathway in PE. Our study highlights that NR2F1 might sever as a potential target in PE.

Association between plasma growth differentiation factor 15 levels and pre-eclampsia in China

Background

Growth differentiation factor-15 (GDF-15) is a stress response protein and is related to cardiovascular diseases (CVD). This study aimed to investigate the association between GDF-15 and pre-eclampsia (PE).

Method

The study involved 299 pregnant women, out of which 236 had normal pregnancies, while 63 participants had PE. Maternal serum levels of GDF-15 were measured by using enzyme-linked immunosorbent assay kits and then translated into multiple of median (MOM) to avoid the influence of gestational week at blood sampling. Logistic models were performed to estimate the association between GDF-15 MOM and PE, presenting as odd ratios (ORs) and 95% confidence intervals (CIs).

Results

MOM of GDF-15 in PE participants was higher compared with controls (1.588 vs. 1.000, p < 0.001). In the logistic model, pregnant women with higher MOM of GDF-15 (>1) had a 4.74-fold (95% CI = 2.23-10.08, p < 0.001) increased risk of PE, adjusted by age, preconceptional body mass index, gravidity, and parity.

Conclusions

These results demonstrated that higher levels of serum GDF-15 were associated with PE. GDF-15 may serve as a biomarker for diagnosing PE.

Biomarkers for Early Prediction and Management of Preeclampsia: A Comprehensive Review

Preeclampsia is a common complication of pregnancy. It is a multi-organ disorder that remains one of the main causes of maternal morbidity and mortality. Additionally, preeclampsia leads to many complications that can occur in the fetus or newborn. Preeclampsia occurs in about 1 in 20 pregnant women. This review focuses on the prediction of preeclampsia in women, using various biomarkers, in particular, a factor combining the use of soluble FMS-like tyrosinokinase-1 (sFlt-1) and placental growth factor (PlGF). A low value of the sFlt-1/PlGF ratio rules out the occurrence of preeclampsia within 4 weeks of the test result, and its high value predicts the occurrence of preeclampsia within even 1 week. The review also highlights other factors, such as pregnancy-associated plasma protein A, placental protein 13, disintegrin and metalloprotease 12, ß-human chorionic gonadotropin, inhibin-A, soluble endoglin, nitric oxide, and growth differentiation factor 15. Biomarker testing offers reliable and cost-effective screening methods for early detection, prognosis, and monitoring of preeclampsia. Early diagnosis in groups of women at high risk for preeclampsia allows for quick intervention, preventing the undesirable effects of preeclampsia. However, further research is needed to validate and optimize the use of biomarkers for more accurate prediction and diagnosis. This article aims to review the role of biomarkers, including the sFlt1/PlGF ratio, in the prognosis and management of preeclampsia.

Proteomic Analysis of Preeclampsia Amniotic Fluid Based on a Novel Solid-State Preservation Method

Objective: Amniotic fluid (AF) plays a crucial role in diagnosing and predicting perinatal diseases, specifically preeclampsia (PE). Adequate preservation of AF samples is essential for advancing the development of PE-related biomarkers and understanding the disease's mechanisms. Materials and Methods: This study presents a method for preserving proteins in AF on a solid medium, specifically a nitrocellulose membrane, which is referred to as an AF membrane. Samples were collected from normotensive subjects and PE patients and treated with direct freezing and the AF membrane methods, respectively. Protein quality was assessed through sodium dodecyl sulfate-page and capillary electrophoresis. Liquid chromatography tandem mass spectrometry (LC-MS/MS) with data-independent acquisition was employed for proteomic analysis. Bioinformatics analysis identified differentially expressed proteins and pathways distinguishing normotensive subjects from PE patients. Results: Comparison of the AF membrane method to the direct freezing method showed no significant impact on the protein content in the AF. The preservation methods employed did not result in evident protein differences or degradation in the AF obtained from both normotensive subjects and PE patients. Analysis based on Gene Ontology and HALLMARK gene sets revealed the upregulation of pathways associated with angiotensin, reactive oxygen species, and coagulation in PE patients. Furthermore, several biomarkers previously reported to be increased in PE serum, namely ENG, ERN1, FLT1, GDF15, HSPA5, LGALS3, PAPPA, PTX3, and SERPINE1, were significantly elevated in the AF. Conclusion: The AF membrane method proved to be highly effective, reliable, and durable for preserving proteins in AF samples. Preserving AF samples in a solid state holds significant value in discovering novel protein biomarkers and investigating the underlying mechanisms of PE.

Whole transcriptome profiling of placental pathobiology in SARS-CoV-2 pregnancies identifies placental dysfunction signatures

Objectives

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) virus infection in pregnancy is associated with higher incidence of placental dysfunction, referred to by a few studies as a 'preeclampsia-like syndrome'. However, the mechanisms underpinning SARS-CoV-2-induced placental malfunction are still unclear. Here, we investigated whether the transcriptional architecture of the placenta is altered in response to SARS-CoV-2 infection.

Methods

We utilised whole-transcriptome, digital spatial profiling, to examine gene expression patterns in placental tissues from participants who contracted SARS-CoV-2 in the third trimester of their pregnancy (n = 7) and those collected prior to the start of the coronavirus disease 2019 (COVID-19) pandemic (n = 9).

Results

Through comprehensive spatial transcriptomic analyses of the trophoblast and villous core stromal cell subpopulations in the placenta, we identified SARS-CoV-2 to promote signatures associated with hypoxia and placental dysfunction. Notably, genes associated with vasodilation (NOS3), oxidative stress (GDF15, CRH) and preeclampsia (FLT1, EGFR, KISS1, PAPPA2) were enriched with SARS-CoV-2. Pathways related to increased nutrient uptake, vascular tension, hypertension and inflammation were also enriched in SARS-CoV-2 samples compared to uninfected controls.

Conclusions

Our findings demonstrate the utility of spatially resolved transcriptomic analysis in defining the underlying pathogenic mechanisms of SARS-CoV-2 in pregnancy, particularly its role in placental dysfunction. Furthermore, this study highlights the significance of digital spatial profiling in mapping the intricate crosstalk between trophoblasts and villous core stromal cells, thus shedding light on pathways associated with placental dysfunction in pregnancies with SARS-CoV-2 infection.

High-Sensitivity Cardiac Troponin I Enhances Preeclampsia Prediction Beyond Maternal Factors and the sFlt-1/PlGF Ratio

BACKGROUND

Preeclampsia shares numerous risk factors with cardiovascular diseases. Here, we aimed to assess the potential utility of high-sensitivity cardiac troponin I (hs-cTnI) values during pregnancy in predicting preeclampsia occurrence.

METHODS

This study measured hs-cTnI levels in 3721 blood samples of 2245 pregnant women from 4 international, prospective cohorts. Three analytical approaches were used: (1) a cross-sectional analysis of all women using a single blood sample, (2) a longitudinal analysis of hs-cTnI trajectories in women with multiple samples, and (3) analyses of prediction models incorporating hs-cTnI, maternal factors, and the sFlt-1 (soluble fms-like tyrosine kinase 1)/PlGF (placental growth factor) ratio.

RESULTS

Women with hs-cTnI levels in the upper quarter had higher odds ratios for preeclampsia occurrence compared with women with levels in the lower quarter. Associations were driven by preterm preeclampsia (odds ratio, 5.78 [95% CI, 2.73-12.26]) and remained significant when using hs-cTnI as a continuous variable adjusted for confounders. Between-trimester hs-cTnI trajectories were independent of subsequent preeclampsia occurrence. A prediction model incorporating a practical hs-cTnI level of detection cutoff (≥1.9 pg/mL) alongside maternal factors provided comparable performance with the sFlt-1/PlGF ratio. A comprehensive model including sFlt-1/PlGF, maternal factors, and hs-cTnI provided added value (cross-validated area under the receiver operator characteristic, 0.78 [95% CI, 0.73-0.82]) above the sFlt-1/PlGF ratio alone (cross-validated area under the receiver operator characteristic, 0.70 [95% CI, 0.65-0.76]; P=0.027). As assessed by likelihood ratio tests, the addition of hs-cTnI to each prediction model significantly improved the respective prediction model not incorporating hs-cTnI, particularly for preterm preeclampsia. Net reclassification improvement analyses indicated that incorporating hs-cTnI improved risk prediction predominantly by correctly reclassifying women with subsequent preeclampsia occurrence.

CONCLUSIONS

These exploratory findings uncover a potential role for hs-cTnI as a complementary biomarker in the prediction of preeclampsia. After validation in prospective studies, hs-cTnI, alongside maternal factors, may either be considered as a substitute for angiogenic biomarkers in health care systems where they are sparce or unavailable, or as an enhancement to established prediction models using angiogenic markers.

Two distinct molecular faces of preeclampsia revealed by single-cell transcriptomics

INTRODUCTION

Preeclampsia is a multisystemic, pregnancy-specific disorder united by new-onset hypertension but with considerable variation in clinical manifestation, onset, and severity. For symptoms to regress, delivery of the placenta is required. For symptoms to regress, delivery of the placenta is required, making the placenta central to preeclampsia pathophysiology. To dissect which placental functions were impacted in two forms of preeclampsia, we studied molecular changes across the cell types of the placenta.

METHODS

We performed a transcriptomic survey of single-cells and single-nuclei on cases of early- and late-onset preeclampsia with gestation-matched controls.

FINDINGS

Our data revealed massive dysregulation of gene expression in all cell classes that was almost exclusive to early preeclampsia. For example, an important known receptor/ligand imbalance hallmarking angiogenic disfunction, sFLT1/placental growth factor (PGF), was reflected in striking, cell-autonomous dysregulation of FLT1 and PGF transcription in the syncytium in early preeclampsia only. Stromal cells and vasculature echoed an inflamed, stressed, anti-angiogenic environment. Finally, the placental immune niche set the tone for inflammation in early but not late preeclampsia. Here, fetal-origin Hofbauer and maternal-origin TREM2 macrophages were revealed as surprising main actors, while local cells of the adaptive immune system were largely unaffected. Late preeclampsia showed minimal cellular impact on the placenta.

CONCLUSIONS

Our survey provides systematic molecular evidence for two distinct diseases. We resolved systematic molecular dysregulation to individual cell types with strong implications for definition, early detection, diagnosis, and treatment.

FUNDING

Funded by the Preeclampsia Foundation through the Peter Joseph Pappas Research Grant.

Advances in preeclampsia testing

Preeclampsia is a multisystem hypertensive disorder and one of the leading causes of maternal and fetal morbidity and mortality. The clinical hallmarks such as hypertension and proteinuria, and additional laboratory tests currently available including liver enzyme testing, are neither specific nor sufficiently sensitive. Therefore, biomarkers for timely and accurate identification of patients at risk of developing preeclampsia are extremely valuable to improve patient outcomes and safety. In this chapter, we will first discuss the clinical characteristics of preeclampsia and current evidence of the role of angiogenic factors, such as placental growth factor (PlGF) and soluble FMS like tyrosine kinase 1 (sFlt-1) in the pathogenesis of preeclampsia. Second, we will review the clinical practice guidelines for preeclampsia diagnostic criteria and their recommendations on laboratory testing. Third, we will review the currently available PlGF and sFlt-1 assays in terms of their methodologies, analytical performance, and clinical diagnostic values. Finally, we will discuss the future research needs from both an analytical and clinical perspective.

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

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

Adipokines in Pregnancy: A Systematic Review of Clinical Data

Adipokines are signaling proteins involved in metabolic, endocrinological, vascular and immunogenic processes. Associations of various adipokines with not only insulin resistance but also with increased insulin sensitivity, increased systolic blood pressure, and atherosclerosis highlight the significance of adipokines in several components of metabolic syndrome and metabolic diseases in general. As pregnancy presents a unique metabolic state, the role of adipokines in pregnancy, and even in various pregnancy complications, appears to be key to elucidating these metabolic processes. Many studies in recent years have attempted to clarify the role of adipokines in pregnancy and gestational pathologies. In this review, we aim to investigate the changes in maternal adipokine levels in physiological gestation, as well as the association of adipokines with pregnancy pathologies, such as gestational diabetes mellitus (GDM) and preeclampsia (PE). Furthermore, we will analyze the association of adipokines in both maternal serum and cord blood with parameters of intrauterine growth and various pregnancy outcomes.

Potential biomarkers for late-onset and term preeclampsia: A scoping review

Preeclampsia is a progressive, multisystem pregnancy disorder. According to the time of onset or delivery, preeclampsia has been subclassified into early-onset (&lt;34 weeks) and late-onset (≥34 weeks), or preterm (&lt;37 weeks) and term (≥37 weeks). Preterm preeclampsia can be effectively predicted at 11–13 weeks well before onset, and its incidence can be reduced by preventively using low-dose aspirin. However, late-onset and term preeclampsia are more prevalent than early forms and still lack effective predictive and preventive measures. This scoping review aims to systematically identify the evidence of predictive biomarkers reported in late-onset and term preeclampsia. This study was conducted based on the guidance of the Joanna Briggs Institute (JBI) methodology for scoping reviews. The Preferred Reporting Items for Systematic Reviews and Meta-Analysis extension for scoping reviews (PRISMA-ScR) was used to guide the study. The following databases were searched for related studies: PubMed, Web of Science, Scopus, and ProQuest. Search terms contain “preeclampsia,” “late-onset,” “term,” “biomarker,” or “marker,” and other synonyms combined as appropriate using the Boolean operators “AND” and “OR.” The search was restricted to articles published in English from 2012 to August 2022. Publications were selected if study participants were pregnant women and biomarkers were detected in maternal blood or urine samples before late-onset or term preeclampsia diagnosis. The search retrieved 4,257 records, of which 125 studies were included in the final assessment. The results demonstrate that no single molecular biomarker presents sufficient clinical sensitivity and specificity for screening late-onset and term preeclampsia. Multivariable models combining maternal risk factors with biochemical and/or biophysical markers generate higher detection rates, but they need more effective biomarkers and validation data for clinical utility. This review proposes that further research into novel biomarkers for late-onset and term preeclampsia is warranted and important to find strategies to predict this complication. Other critical factors to help identify candidate markers should be considered, such as a consensus on defining preeclampsia subtypes, optimal testing time, and sample types.

Circulating Growth Differentiation Factor 15 and Preeclampsia: A Meta-Analysis

Growth differentiation factor 15 (GDF-15) has been suggested as a potential biomarker of preeclampsia. However, previous studies evaluating circulating GDF-15 in women with preeclampsia showed inconsistent results. A meta-analysis was performed accordingly in this study. Observational studies comparing circulating GDF-15 between women with preeclampsia normal pregnancy were identified by search of electronic databases including PubMed, Embase, Web of Science, Wanfang, and CNKI. The Newcastle-Ottawa Scale (NOS) was used for assessing the quality of the studies. A randomized-effect model incorporating the possible between-study heterogeneity was used to pool the results. Eleven observational studies including 498 women with preeclampsia and 2349 women with normal pregnancy contributed to the meta-analysis. Results showed that compared to controls of women with normal pregnancy at least matched for gestational ages, women with preeclampsia had significantly higher circulating GDF-15 at the diagnosis [standard mean difference (SMD): 0.66, 95% confidence interval (CI): 0.16 to 1.17, p=0.01, I2=93%]. Subgroup analysis showed consistent results in women with preterm and term preeclampsia in Asian and non-Asian women and in studies with different quality scores, which were not statistically significant between subgroups (p for subgroup difference>0.05). Moreover, a higher level of GDF-15 was also found before the diagnosis in women who subsequently developed preeclampsia than those who did not (SMD: 1.32, 95% CI: 0.45 to 2.18, p=0.003, I2=89%). In conclusion, a higher circulating GDF-15 is observed in women with preeclampsia even before the diagnosis of the disease.

Growth and differentiation factor 15 (GDF15) levels predict adverse respiratory outcomes in premature neonates

Growth and differentiation factor 15 (GDF15) is a stress-responsive cytokine, and its expression increases during inflammation, hyperoxia, and senescence. Significantly, GDF15 is secreted by the placenta, and maternal levels increase throughout pregnancy. Serum GDF15 level is a promising biomarker for many lung diseases like pulmonary hypertension and pulmonary fibrosis. However, circulating GDF15 levels in preterm infants and their role as a predictor of respiratory outcomes have not been studied. We hypothesized that GDF15 levels would increase with gestational age at birth, and that postnatal GDF15 will be correlated with adverse respiratory outcomes in preterm infants. Scavenged blood samples were retrieved from 57 preterm infants at five time points, from birth until 36-weeks postmenstrual age (PMA). GDF15 levels were measured using ELISA in 114 samples. We performed two-sample t-test, correlation and linear regression, logistic regression, and mixed-effects linear models for statistical analysis, and significance was identified when p < 0.05. Contrary to our hypothesis, for every 1-week increase in gestational age at birth, the predicted GDF15 level decreased by 475.0 pg/ml (p < 0.001). Greater PMA was significantly associated with lower serum GDF15 levels (p < 0.001). Interestingly, higher GDF15 levels were associated with a longer need for mechanical ventilation (p = 0.034), prolonged respiratory support need (p < 0.001), and length of hospital stay (p = 0.006). In conclusion, in preterm infants, GDF15 levels show an inverse correlation with gestational age at birth, with higher levels in more preterm babies, and levels trend down postnatally. Furthermore, longitudinal GDF15 levels through 36 weeks PMA predict adverse respiratory outcomes in preterm infants.

Circulating cardiovascular biomarkers during and after preeclampsia: Crosstalk with placental function?

Cardiovascular disease (CVD) is the leading cause of death in women, yet sex-specific risk factors remain understudied. Preeclampsia and other adverse pregnancy outcomes imply an increased maternal cardiovascular risk. We hypothesized that cardiac troponin T (cTnT), N-terminal pro-Brain Natriuretic Peptide (NT-proBNP) and growth differentiation factor 15 (GDF-15) are increased in such pregnancies and correlate with markers of placental dysfunction. We also investigated these cardiovascular biomarkers 1 or 3 years postpartum. Prior to delivery, we included serum from 417 pregnant women: 55 early-onset preeclampsia (EO-PE), 63 late-onset preeclampsia (LO-PE), 30 gestational hypertension (GH) and 269 healthy controls. Postpartum, we included 341 women 1 or 3 years after delivery: 26 EO-PE, 107 LO-PE, 61 GH, and 147 healthy pregnancies. Prior to delivery, median cTnT and NT-proBNP concentrations were higher in women with EO-PE, LO-PE, or GH than in controls. Median GDF-15 was higher in EO-PE and LO-PE compared to controls. Postpartum, GDF-15 was elevated in women with previous EO-PE. Markers of placental dysfunction correlated with CVD biomarkers in pregnancy, but not postpartum. Our findings underscore the cardiovascular burden of hypertensive disorders of pregnancy and the crosstalk with placental function. The upregulation of circulating GDF-15 following early-onset preeclampsia is in line with the epidemiological excessive risk of premature CVD in this group of women. GDF-15 may be explored for targeting postpartum women with most to gain from intensified preventive follow-up for CVD.

Reproductive biology research down under: highlights from the Australian and New Zealand Annual Meeting of the Society for Reproductive Biology, 2021

Against the backdrop of a global pandemic, the Society for Reproductive Biology (SRB) 2021 meeting reunited the Australian and New Zealand reproductive research community for the first time since 2019 and was the first virtual SRB meeting. Despite the recent global research disruptions, the conference revealed significant advancements in reproductive research, the importance of which span human health, agriculture, and conservation. A core theme was novel technologies, including the use of medical microrobots for therapeutic and sperm delivery, diagnostic hyperspectral imaging, and hydrogel condoms with potential beyond contraception. The importance of challenging the contraceptive status quo was further highlighted with innovations in gene therapies, non-hormonal female contraceptives, epigenetic semen analysis, and in applying evolutionary theory to suppress pest population reproduction. How best to support pregnancies, particularly in the context of global trends of increasing maternal age, was also discussed, with several promising therapies for improved outcomes in assisted reproductive technology, pre-eclampsia, and pre-term birth prevention. The unique insights gained via non-model species was another key focus and presented research emphasised the importance of studying diverse systems to understand fundamental aspects of reproductive biology and evolution. Finally, the meeting highlighted how to effectively translate reproductive research into policy and industry practice.

PSG7 and 9 (Pregnancy-Specific β-1 Glycoproteins 7 and 9): Novel Biomarkers for Preeclampsia

Background

Preeclampsia is pregnancy specific, involving significant maternal endothelial dysfunction. Predictive biomarkers are lacking. We evaluated the biomarker potential, expression, and function of PSG7 (pregnancy‐specific β‐1 glycoprotein 7) and PSG9 (pregnancy‐specific β‐1 glycoprotein 9) in preeclampsia.

Methods and Results

At 36 weeks gestation preceding term preeclampsia diagnosis, PSG7 and PSG9 (in Australian cohorts of n=918 and n=979, respectively) were significantly increased before the onset of term preeclampsia (PSG7, P=0.013; PSG9, P=0.0011). In samples collected at 28 to 32 weeks from those with preexisting cardiovascular disease and at high risk of preeclampsia (Manchester Antenatal Vascular Service, UK cohort, n=235), both PSG7 and PSG9 were also significantly increased preceding preeclampsia onset (PSG7, P<0.0001; PSG9, P=0.0003) relative to controls. These changes were validated in the plasma and placentas of patients with established preeclampsia who delivered at <34 weeks gestation (PSG7, P=0.0008; PSG9, P<0.0001). To examine whether PSG7 and PSG9 are associated with increasing disease severity, we measured them in a cohort from South Africa stratified for this outcome, the PROVE (Preeclampsia Obstetric Adverse Events) cohort (n=72). PSG7 (P=0.0027) and PSG9 (P=0.0028) were elevated among patients who were preeclamptic with severe features (PROVE cohort), but not significantly changed in those without severe features or with eclampsia. In syncytialized first trimester cytotrophoblast stem cells, exposure to TNFα (tumor necrosis factor α) or IL‐6 (interleukin 6) significantly increased the expression and secretion of PSG7 and PSG9. In contrast, when we treated primary endothelial cells with recombinant PSG7 and PSG9, we only observed modest changes in Flt‐1 (FMS‐like tyrosine kinase‐1) expression and Plgf (placental growth factor) expression, and no other effects on proangiogenic/antiangiogenic or endothelial dysfunction markers were observed.

Conclusions

Circulating PSG7 and PSG9 are increased before preeclampsia onset and among those with established disease with their production and release potentially driven by placental inflammation.

Clinical tools and biomarkers to predict preeclampsia

Preeclampsia is pregnancy-specific, and significantly contributes to maternal, and perinatal morbidity and mortality worldwide. An effective predictive test for preeclampsia would facilitate early diagnosis, targeted surveillance and timely delivery; however limited options currently exist. A first-trimester screening algorithm has been developed and validated to predict preterm preeclampsia, with poor utility for term disease, where the greatest burden lies. Biomarkers such as sFlt-1 and placental growth factor are also now being used clinically in cases of suspected preterm preeclampsia; their high negative predictive value enables confident exclusion of disease in women with normal results, but sensitivity is modest. There has been a concerted effort to identify potential novel biomarkers that might improve prediction. These largely originate from organs involved in preeclampsia's pathogenesis, including placental, cardiovascular and urinary biomarkers. This review outlines the clinical imperative for an effective test and those already in use and summarises current preeclampsia biomarker research.

A disintegrin and metalloproteinase 12 (ADAM12) is reduced at 36 weeks' gestation in pregnancies destined to deliver small for gestational age infants

First trimester circulating ADAM12 is reduced in fetal growth restriction (FGR) and preeclampsia. We measured plasma ADAM12 at 36 weeks' gestation preceding diagnosis of term preeclampsia or delivery of a small for gestational age (SGA; birthweight <10th centile) infant in two independent cohorts (Cohort 1 90 SGA, 41 preeclampsia, 862 controls; Cohort 2121 SGA 23 preeclampsia; 190 controls). ADAM12 was reduced with SGA in both cohorts (p = 0.0015 and 0.011 respectively), and further reduced with birthweight <5th centile (p = 0.0013 and 0.0058 respectively). This validates ADAM12 as an SGA biomarker near term. Circulating ADAM12 preceding preeclampsia was not consistently altered.