PP13 and PAPP-A in the First and Second Trimesters: Predictive Factors for Preeclampsia?

Pregnancy-Associated Plasma Protein-A and Free β-Human Chorionic Gonadotrophin in Relation with Oxidative Stress in Obese Pregnant Women: A Clinical Cross-Sectional Study

Background: The pathophysiological mechanism underlying pregnancy complications is not entirely known. Although it is currently impossible to predict the occurrence of redox imbalance, it is possible to identify women with a high or medium risk of developing this disease prior to a negative outcome by non-invasive diagnostic methods. The Aim: This study aimed to examine the possible role of the parameter of oxidative stress (OS) measured in early pregnancy in the screening/treatment of obesity and its complications during pregnancy. Methods: This research was designed as a prospective observational cross-sectional clinical study which included 40 non-obese and 31 obese pregnant women between 11 and 13 g.w. who were managed in the Department of Obstetrics, University Clinical Center Kragujevac in Serbia. We collected anthropometric and clinical indicators, maternal and pregnancy factors, and measured prooxidative parameters from blood samples. Results: We observed significantly increased levels of the superoxide anion radical, hydrogen peroxide and the index of lipid peroxidation in the Obese group in comparison with the Non-Obese group and significantly decreased bioavailability of nitrites in the Obese group in comparison with the Non-Obese group. Conclusions: The determination of systemic parameters of OS in early pregnancy could be a good methodological approach in the screening/treatment of obesity during pregnancy and this approach should be followed for the screening of endothelial dysfunction in pregnancy which needs further monitoring and/or treatment.

PLACENTAL BIOMARKERS: PP13, VEGF IN DIAGNOSTICS OF EARLY AND LATE PREECLAMPSIA

OBJECTIVE

The aim: To investigate role of CD23, VEGF and PP13 in diagnostics of early and late preeclampsia, and their benefit for prediction of preeclampsia.

PATIENTS AND METHODS

Materials and methods: Investigation included 40 placentas from deliveries in women with preeclampsia (main group) and 40 placentas from physiological delivery in somatically healthy women, who had no complications during pregnancy (control group). Placentas in the main group were devided into two sub-groups (20 in each) - with early and late preeclampsia. Each group underwent both hystomorphometrical and immunohystochemical investigation with biomarkers CD23, VEGF and PP13.

RESULTS

Results: Positive immunohystochemical reaction to PP13 was determined in all samples of syncitiotrophoblast of villi of chorion. Investigations showed that expression of PP13 in sub-groups with early and late preeclampsia was a lot lower comparing to control group (normal pregnancies). Positive immunohystochemical reaction to VEGF was determined in all samples of endothelia of the capillaries of the villi of chorion. Our investigation showed that expression of VEGF in sub-groups with early and late PE was a lot lower comparing to a control group. Immunohystochemical reaction to CD23 was comperatively lower in all samples in endothelia of the capillariesof the villi of chorion and cyncithiotrophoblast.

CONCLUSION

Conclusions: Determined specialties of the expression of angiogenic factors ( PlGF, VEGF, endoglin) and production of PP13, by altered expression of VEGF, PlGF in first trimester of pregnancy, which is associated with lowest production of PP13, accompanied by placental dysfunction and preeclampsia.

Factors Associated with the Severity of Pregnancy-Related Hypertensive Disorder: Significance of Clinical, Laboratory, and Histopathological Features

The purpose of this paper is to evaluate the association of maternal clinical and laboratory features and placental histopathological changes with disease severity in pregnancy-related hypertensive disorders. From January 2021 to December 2021, clinical and laboratory data at the time of delivery and histopathological features of the placenta were collected from pregnant women with pregnancy-related hypertensive disorders at a single institution. The women were classified according to the pregnancy-related hypertensive disorder clinical severity, and each variable was compared accordingly. Gestational age-matched normotensive groups were also compared. Univariate and multivariate regression analyses were used to identify factors influencing pregnancy-related hypertensive disorder severity. Fifty-eight pregnancies were analyzed. Maternal albumin levels before delivery (beta coefficient −0.83, p = 0.043) and increased placental syncytial knots (beta coefficient 0.71, p = 0.026) are important parameters that are closely related to disease severity in women with pregnancy-related hypertensive disorders. The combination of albumin, PAPP-A, total bilirubin, and eGFR levels appears to be optimal for predicting pregnancy-related hypertensive disorder severity.

Diagnostic biomolecules and combination therapy for pre-eclampsia

Pre-eclampsia (PE), associated with placental malperfusion, is the primary reason for maternal and perinatal mortality and morbidity that can cause vascular endothelial injury and multi-organ injury. Despite considerable research efforts, no pharmaceutical has been shown to stop disease progression. If women precisely diagnosed with PE can achieve treatment at early gestation, the maternal and fetal outcomes can be maximally optimized by expectant management. Current diagnostic approaches applying maternal characteristics or biophysical markers, including blood test, urine analysis and biophysical profile, possess limitations in the precise diagnosis of PE. Biochemical factor research associated with PE development has generated ambitious diagnostic targets based on PE pathogenesis and dissecting molecular phenotypes. This review focuses on current developments in biochemical prediction of PE and the corresponding interventions to ameliorate disease progression, aiming to provide references for clinical diagnoses and treatments.

Predictive Performance of Placental Protein 13 for Screening Preeclampsia in the First Trimester: A Systematic Review and Meta-Analysis

Preeclampsia is a pregnancy-specific syndrome that affects maternal and neonatal mortality. Several serum biomarkers can be used to predict preeclampsia. Among these proteins, placental protein 13 (PP13) has received progressively more interest in recent studies. The decrease in PP13 expression is one of the earliest signs for the development of preeclampsia and has shown its predictive performance for preeclampsia. In this meta-analysis, we collected 17 observational studies with 40,474 pregnant women. The overall sensitivity of PP13 to predict preeclampsia was 0.62 [95% confidence interval (CI) = 0.49–0.74], the specificity was 0.84 (95%CI = 0.81–0.86), and the diagnostic odds ratio was nine (95%CI = 5–15). The area under the curve for summary receiver operating characteristic was 0.84. We then chose the early-onset preeclampsia as a subgroup. The sensitivity of early-onset subgroup was 0.63 (95%CI = 0.58–0.76), the specificity was 0.85 (95%CI = 0.82–0.88), and the diagnostic odds ratio was 10 (95%CI = 6–18). The findings of our meta-analysis indicate that PP13 may be an effective serum biomarker for the predictive screening of preeclampsia. Nonetheless, large prospective cohort studies and randomized controlled trials are expected to uncover its application in clinical practice. The heterogeneity of the original trials may limit the clinical application of PP13.

Systematic Review Registration:https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=188948 The meta-analysis was registered in PROSPERO (CRD42020188948).

Screening of serum biomarkers of preeclampsia by proteomics combination with bioinformatics

Objective: To screen for novel predictive serum markers of preeclampsia (PE). Method: Blood samples were collected from seven women with PE and five with healthy pregnancies. Serum proteins were identified using isobaric tags for relative and absolute quantitation (iTRAQ) technology combined with liquid chromatography mass spectrometry analysis. The differentially expressed proteins in the PE samples were identified using the SwissProt database, and functionally annotated by gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. The upregulated proteins from iTRAQ result were verified by ELISA. Results: We identified 121 differentially expressed proteins, of which 76 were upregulated and 45 were downregulated, and 14 were differentially expressed by more than two-folds. The top GO terms for Cellular Components (CC) were high-density lipoprotein particles and plasma lipoprotein particles, defense response for Biological Processes (BP), and glycosaminoglycan binding, heparin binding and sulfur compound for Molecular functions (MF). The pathway hsa04979 for Cholesterol metabolism was significantly enriched among the upregulated proteins, while the structural domain was enriched in immunoglobulin subtype 2. The dysregulation of pregnancy-specific beta-1-glycoprotein 2 (PSG2) was confirmed by ELISA. Conclusion: PE pathogenesis is related to lipid metabolism and inflammation, and proteins related to these pathways are potential early diagnostic markers for PE.PSG2 may be a marker of PE.

The Relationship of Pregnancy-Associated Plasma Protein A and Human Chorionic Gonadotropin with Adverse Pregnancy Outcomes: A Prospective Study

Purpose

This prospective study investigated the relationship between pregnancy-associated plasma protein A (PAPP-A) and human chorionic gonadotropin (hCG) and adverse pregnancy outcomes in the Iranian population.

Materials

Overall, 994 singleton pregnant mothers of 18-35-year old were referred for first-trimester screening tests, including PAPP-A and β-hCG, at the age of 6 days and 11-13 weeks, and were followed until the end of their pregnancy. The adverse pregnancy outcomes, PAPP-A, and β-hCG serum levels were recorded and analyzed. The sensitivity and specificity of the test were measured by calculating the area under the curve of receiver operating characteristic curve (ROC).

Results

The mean serum level of PAPP-A and β-hCG was 1.10 ± 0.69 and 1.09 ± 0.8 MoM, respectively. Pregnancy-associated plasma protein A, regardless of its percentile, showed a significant relationship with the incidence of preeclampsia, preterm birth, and fetal low birth weight (p < 0.001 for each). However, the relationship between PAPP-A and abortion was not significant (p > 0.05). According to ROC, the results indicated that PAPP-A had a significant relationship with the incidence of preeclampsia, preterm birth, and fetal low birth weight (p < 0.001). However, β-hCG levels showed no significant relationship with adverse pregnancy outcomes.

Conclusions

The result of this study revealed that lower level of PAPP-A and β-hCG could be a predictive factor in preterm labor. Also, this study indicated that PAPP-A measurements could be a screening test for adverse pregnancy outcomes, such as preeclampsia, low birth weight and preterm labor.

Placental protein 13: An important biological protein in preeclampsia

Placental protein 13 (PP13), a glycan binding protein predominantly expressed in syncytiotrophoblast, dimeric in nature, lacks N-terminal signal peptide, bypasses the endoplasmic reticulum, and secretes into maternal circulation as exosomes or microvesicles. PP13 has jelly roll fold conformation with conserved carbohydrate recognition domain which specifically binds to β-galactosides of the glycan receptors during placentation. PP13 binds to glycosylated receptors on human erythrocytes and brings about hemagglutination by the property of lectin activity; other functions are immunoregulation and vasodilation during placentation and vascularization. The gene LGALS13 located on 19q13.2 comprising four exons expresses a 32-kDa protein with 139 amino acid residues, PP13. Impaired expression due to mutation in the gene leads to a nonfunctional truncated PP13. The low serum levels predict high risk for the onset of preeclampsia or obstetric complications. Hence, PP13 turned to be an early marker for risk assessment of preeclampsia. The recombinant PP13 and monoclonal antibodies availability help for replenishing PP13 in conditions with low serum levels and for detection and prevention of preeclampsia, respectively.

Serum screening in first trimester to predict pre-eclampsia, small for gestational age and preterm delivery: systematic review and meta-analysis

Background

Early assessment before the establishment of placental dysfunction has the potential to improve treatment and prognosis for clinical practice.The objective of the study is to investigate the accuracy of serum biochemical markers(Pregnancy- Associated Plasma Protein-A (PAPP-A), human Chorionic Gonadotropin (hCG), Placental Growth Factor (PlGF), Placental Protein 13 (PP13) used in first trimester serum screening in predicting preelampsia, small for gestational age (SGA) and preterm delivery.

Methods

The data sources included Medline, Embase, Cochrane library, Medion, hand searching of relevant journals, reference list checking of included articles and contact with experts. Two reviewers independently selected the articles. Two authors independently extracted data on study characteristics, quality and results.

Results

The results showed low predictive accuracy overall. For preeclampsia, the best predictor was PlGF; LR + 4.01 (3.74, 4.28), LR-(0.67, 0.64, 0.69). The predictive value of serum markers for early preeclampsia was better than that of late preeclampsia. For SGA the best predictor was PP13; LR+ 3.70 (3.39, 4.03), LR- 0.70 (0.67, 0.73). For preterm delivery, the best predictor was PP13; LR+ 4.16 (2.72, 5.61), LR- 0.56 (0.45, 0.67).

Conclusion

First trimester screening analytes have low predictive accuracy for pre-eclampsia, small for gestational age and preterm delivery. However, the predict value of first trimester analytes is not worse than that of the second trimester markers.

Galectins: Double-edged Swords in the Cross-roads of Pregnancy Complications and Female Reproductive Tract Inflammation and Neoplasia

Galectins are an evolutionarily ancient and widely expressed family of lectins that have unique glycan-binding characteristics. They are pleiotropic regulators of key biological processes, such as cell growth, proliferation, differentiation, apoptosis, signal transduction, and pre-mRNA splicing, as well as homo- and heterotypic cell-cell and cell-extracellular matrix interactions. Galectins are also pivotal in immune responses since they regulate host-pathogen interactions, innate and adaptive immune responses, acute and chronic inflammation, and immune tolerance. Some galectins are also central to the regulation of angiogenesis, cell migration and invasion. Expression and functional data provide convincing evidence that, due to these functions, galectins play key roles in shared and unique pathways of normal embryonic and placental development as well as oncodevelopmental processes in tumorigenesis. Therefore, galectins may sometimes act as double-edged swords since they have beneficial but also harmful effects for the organism. Recent advances facilitate the use of galectins as biomarkers in obstetrical syndromes and in various malignancies, and their therapeutic applications are also under investigation. This review provides a general overview of galectins and a focused review of this lectin subfamily in the context of inflammation, infection and tumors of the female reproductive tract as well as in normal pregnancies and those complicated by the great obstetrical syndromes.

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

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

Placental Protein 13 (PP13) - A Placental Immunoregulatory Galectin Protecting Pregnancy

Galectins are glycan-binding proteins that regulate innate and adaptive immune responses, and some confer maternal-fetal immune tolerance in eutherian mammals. A chromosome 19 cluster of galectins has emerged in anthropoid primates, species with deep placentation and long gestation. Three of the five human cluster galectins are solely expressed in the placenta, where they may confer additional immunoregulatory functions to enable deep placentation. One of these is galectin-13, also known as Placental Protein 13 (PP13). It has a "jelly-roll" fold, carbohydrate-recognition domain and sugar-binding preference resembling other mammalian galectins. PP13 is predominantly expressed by the syncytiotrophoblast and released from the placenta into the maternal circulation. Its ability to induce apoptosis of activated T cells in vitro, and to divert and kill T cells as well as macrophages in the maternal decidua in situ, suggests important immune functions. Indeed, mutations in the promoter and an exon of LGALS13 presumably leading to altered or non-functional protein expression are associated with a higher frequency of preeclampsia and other obstetrical syndromes, which involve immune dysregulation. Moreover, decreased placental expression of PP13 and its low concentrations in first trimester maternal sera are associated with elevated risk of preeclampsia. Indeed, PP13 turned to be a good early biomarker to assess maternal risk for the subsequent development of pregnancy complications caused by impaired placentation. Due to the ischemic placental stress in preterm preeclampsia, there is increased trophoblastic shedding of PP13 immunopositive microvesicles starting in the second trimester, which leads to high maternal blood PP13 concentrations. Our meta-analysis suggests that this phenomenon may enable the potential use of PP13 in directing patient management near to or at the time of delivery. Recent findings on the beneficial effects of PP13 on decreasing blood pressure due to vasodilatation in pregnant animals suggest its therapeutic potential in preeclampsia.

Second- and third-trimester biochemical and ultrasound markers predictive of ischemic placental disease

Ischemic placental disease is a recently coined term that describes the vascular insufficiency now believed to be an important etiologic factor in preeclampsia, intrauterine fetal growth restriction, and placental abruption. Given the increased risk for poor maternal and fetal outcomes, early prediction and prevention of this disorder is of significant clinical interest for many. In this article, we review the second- and third-trimester serum and ultrasound markers predictive of ischemic placental disease. Limited first-trimester data is also presented. While current studies report a statistical association between marker levels and various adverse perinatal outcomes, the observed diagnostic accuracy is below the threshold required for clinical utility. An exception to this generalization is uterine artery Doppler for the prediction of early-onset preeclampsia. Metabolomics is a relatively new analytic platform that holds promise as a first-trimester marker for the prediction of both early- and late-onset preeclampsia.

Investigating the Relationship between Serum Level of s-Met (Soluble Hepatic Growth Factor Receptor) and Preeclampsia in the First and Second Trimesters of Pregnancy

Introduction. Preeclampsia (PE) is an important cause of mortality and morbidity for mothers, fetuses, and the newborns. Placenta plays a pivotal role in pathogenesis of PE. Hepatic growth factor (HGF) is a cytokine expressed by the mesenchymal stalk of placental villi during pregnancy and assumes a paracrine role in trophoblasts which express its receptor (c-MET). In the present study, we investigate the diagnostic value of s-Met (the soluble form of the receptor) in the first and second trimesters of pregnancy for early diagnosis of preeclampsia. Method and Materials. This is a case-control study conducted on 95 pregnant women. The serum level of s-Met was measured in the first and second trimesters, and the participants were followed until delivery. 44 individuals with preeclampsia (the case group) and 51 individuals without preeclampsia (the control group) were evaluated. Results. Serum level of s-Met in preeclamptic participants was lower than that of the control group in both the first and the second trimesters (P < 0.0001). In addition, serum levels of s-Met were significantly lower during the first and second trimesters in patients with early, severe preeclampsia compared to those with late, mild preeclampsia (P < 0.0001). The sensitivity and specificity of s-Met in the first and second trimesters were, respectively, (83%, 94%) and (77%, 94%) for early preeclampsia and (88%, 92%) and (86%, 98%) for severe preeclampsia. Conclusion. Considering our findings, serum level of s-Met may be used as a predictive factor for early detection of preeclampsia. Further research is required to corroborate the functional and therapeutic value of s-Met in preeclampsia.

Association between first-trimester maternal serum pregnancy-associated plasma protein-A and obstetric complications

OBJECTIVE

This study aimed to investigate the relationship between maternal serum pregnancy-associated plasma protein-A (PAPP-A) in the first trimester of pregnancy and the development of preeclampsia (PE), early PE, small-for-gestational age (SGA) fetus and preterm delivery (PD).

METHOD

This is a retrospective study of 12,355 pregnant women that delivered between 2008 and 2011. We define the first, third and fifth percentiles of maternal serum PAPP-A multiples of the median (MoM). The primary outcome measures were the occurrence of PE, early PE (PE requiring delivery before 34 weeks), SGA fetus (birth weight < 5th centile) and PD. The Mann-Whitney U-test and chi-squared test were used to analyze continuous and dichotomous variables, respectively.

RESULTS

Maternal serum PAPP-A was significantly lower in women with PE, early PE, SGA fetus and PD (0.91, 0.74, 0.80 and 0.84 MoM, respectively) than in the study population (0.99 MoM) (p < 0.05). The lower the MoM percentile of PAPP-A, the higher are the odds ratio (OR) to develop PE, early PE, SGA fetus and PD.

CONCLUSIONS

Maternal serum PAPP-A levels are lower in women who develop preeclampsia, those with SGA fetus and those who deliver preterm. However, on its own, maternal serum PAPP-A performs poorly (OR for PE between 1.76 and 2.41 with the lower percentile of PAPP-A) as a screening test for these conditions.

Placental protein 13 (PP13): a new biological target shifting individualized risk assessment to personalized drug design combating pre-eclampsia

BACKGROUND

Pre-eclampsia affects 2-7% of all pregnant women and is a major cause of maternal and fetal morbidity and mortality. The etiology of pre-eclampsia is still unknown but it is well documented that impaired placentation is a major contributor to its development. One of the placenta-specific proteins is placental protein 13 (PP13). Lower first trimester levels of maternal serum PP13 and its encoding placental mRNA are associated with the development of both early and late-onset severe pre-eclampsia. In cases where this protein is mutated, the frequency of pre-eclampsia is higher.

METHODS

19 out of 68 studies on PP13, published between January 2006 and September 2012, were used to evaluate the value of maternal blood PP13 as a marker of pre-eclampsia.

RESULTS

A meta-analysis presented in this review shows that low serum levels of PP13 in the first trimester of pregnancy can predict the development of pre-eclampsia later in pregnancy. Although some functions of this protein have been assessed in in vitro experiments, the in vivo functions of PP13 are still unknown, especially when circulating in the maternal bloodstream. A recent pilot study has shown that in gravid rats PP13 causes significant vasodilatation, reduced blood pressure and increased maternal uterine artery remodeling.

CONCLUSION

Reviewing these effects of PP13, the authors propose the use of PP13 as a new drug candidate. Replenishing PP13 in those women with low serum levels early in pregnancy may help prepare their vasculature for pregnancy. This novel pharmacological approach to combat pre-eclampsia is presented as a new direction to transfer from individualized risk to personalized prevention.

Evaluation of serum β-hCG and PAPP-A levels in pregnant women at risk of developing preeclampsia

BACKGROUND AND AIM

Preeclampsia remains a major problem of modern obstetrics with insufficiently elucidated etiology; early detection would diminish maternal and fetal mortality and morbidity. The aim of this study was to determine the serum values of β-hCG in the first and second trimesters of pregnancy and PAPP-A values in the first trimester of pregnancy in pregnant women with risk factors for preeclampsia, in order to evaluate their relevance in the prediction of this disorder.

MATERIAL AND METHODS

We performed a prospective longitudinal study on 120 pregnant women divided into two groups according to the evolution of pregnancy: group I - 26 pregnant women who developed preeclampsia and group II - 94 pregnant women who did not develop preeclampsia and had a physiological evolution of pregnancy.

RESULTS

Our results indicate the association between high β-hCG levels in the first and second trimesters of pregnancy and the development of PE, β-hCG having the highest predictive power in the second trimester. We also obtained a positive association between low serum levels in PAPP-A in the first trimester and onset of PE. The predictive power of conjugated β-hCG and PAPP-A values in the first trimester of pregnancy was better that any other marker analyzed separately.

CONCLUSIONS

Increased β-hCG levels in the first and second trimesters of pregnancy and low PAPP-A levels in the second trimester of pregnancy are associated with a higher risk for PE, the study providing only a modest efficiency of the prediction capacity.