BackgroundThe ratio of soluble fms-like tyrosine kinase 1 (sFlt-1) to placental growth factor (PlGF) is elevated in pregnant women before the clinical onset of preeclampsia, but its predictive valu...

https://www.nejm.org/doi/pdf/10.1056/NEJMoa1414838

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

Preeclampsia is a clinical syndrome defined as the new onset of hypertension and proteinuria during the second half of pregnancy1 It afflicts 3% to 5% of pregnancies and is a leading cause of maternal mortality, especially in developing countries2,3 Because the only known remedy is delivery of the placenta, in developed countries preeclampsia is an important cause of premature delivery, usually medically indicated for the benefit of the mother This results in infant morbidity and substantial healthcare expenditure4 Despite the considerable morbidity and mortality, the cause of preeclampsia has remained enigmatic

Both hypertension and proteinuria implicate the endothelium as the target of the disease The hypertension of preeclampsia is characterized by peripheral vasoconstriction and decreased arterial compliance5,6 The proteinuria of preeclampsia is associated with a pathognomonic renal lesion known as glomerular endotheliosis, in which the endothelial cells of the glomerulus swell and endothelial fenestrations are lost7,8 Podocyturia has been recently associated with preeclampsia during clinical disease9; however, whether this is the cause or effect of proteinuria is unknown The glomerular filtration rate is decreased compared with normotensive pregnant women; in rare cases, acute renal failure may develop

Preeclampsia is a systemic vascular disorder that may also affect the liver and the brain in the mothers When the liver is involved, women may present with abdominal pain, nausea, vomiting, and elevated liver enzymes Pathological examination of the liver reveals periportal and sinusoidal fibrin deposition and, in more extreme cases, hemorrhage and necrosis10 The severe preeclampsia variant HELLP syndrome (hemolysis, elevated liver enzymes, low platelets) occurs in ≈20% of women with severe preeclampsia,11 and is named not only for the liver involvement, but also for the disorder of the coagulation system that develops12 Approximately 20% of …

Preeclampsia, a Disease of the Maternal Endothelium The Role of Antiangiogenic Factors and Implications for Later Cardiovascular Disease

Pre-eclampsia is characterized by new-onset hypertension and proteinuria at ≥20 weeks of gestation. In the absence of proteinuria, hypertension together with evidence of systemic disease (such as thrombocytopenia or elevated levels of liver transaminases) is required for diagnosis. This multisystemic disorder targets several organs, including the kidneys, liver and brain, and is a leading cause of maternal and perinatal morbidity and mortality. Glomeruloendotheliosis is considered to be a characteristic lesion of pre-eclampsia, but can also occur in healthy pregnant women. The placenta has an essential role in development of this disorder. Pathogenetic mechanisms implicated in pre-eclampsia include defective deep placentation, oxidative and endoplasmic reticulum stress, autoantibodies to type-1 angiotensin II receptor, platelet and thrombin activation, intravascular inflammation, endothelial dysfunction and the presence of an antiangiogenic state, among which an imbalance of angiogenesis has emerged as one of the most important factors. However, this imbalance is not specific to pre-eclampsia, as it also occurs in intrauterine growth restriction, fetal death, spontaneous preterm labour and maternal floor infarction (massive perivillous fibrin deposition). The severity and timing of the angiogenic imbalance, together with maternal susceptibility, might determine the clinical presentation of pre-eclampsia. This Review discusses the diagnosis, classification, clinical manifestations and putative pathogenetic mechanisms of pre-eclampsia.

Pre-eclampsia part 1: current understanding of its pathophysiology

Predictive Value of the sFlt-1 : PlGF Ratio in Women With Suspected Preeclampsia EDITORIAL COMMENT

Predictive Value of the sFlt-1: PlGF Ratio in Women With Suspected Preeclampsia EDITORIAL COMMENT

Objective  To develop a practical evidence based list of clinical risk factors that can be assessed by a clinician at ≤16 weeks’ gestation to estimate a woman’s risk of pre-eclampsia. Design  Systematic review and meta-analysis of cohort studies. Data sources  PubMed and Embase databases, 2000-15. Eligibility criteria for selecting studies  Cohort studies with ≥1000 participants that evaluated the risk of pre-eclampsia in relation to a common and generally accepted clinical risk factor assessed at ≤16 weeks’ gestation. Data extraction  Two independent reviewers extracted data from included studies. A pooled event rate and pooled relative risk for pre-eclampsia were calculated for each of 14 risk factors. Results  There were 25 356 688 pregnancies among 92 studies. The pooled relative risk for each risk factor significantly exceeded 1.0, except for prior intrauterine growth restriction. Women with antiphospholipid antibody syndrome had the highest pooled rate of pre-eclampsia (17.3%, 95% confidence interval 6.8% to 31.4%). Those with prior pre-eclampsia had the greatest pooled relative risk (8.4, 7.1 to 9.9). Chronic hypertension ranked second, both in terms of its pooled rate (16.0%, 12.6% to 19.7%) and pooled relative risk (5.1, 4.0 to 6.5) of pre-eclampsia. Pregestational diabetes (pooled rate 11.0%, 8.4% to 13.8%; pooled relative risk 3.7, 3.1 to 4.3), prepregnancy body mass index (BMI) >30 (7.1%, 6.1% to 8.2%; 2.8, 2.6 to 3.1), and use of assisted reproductive technology (6.2%, 4.7% to 7.9%; 1.8, 1.6 to 2.1) were other prominent risk factors. Conclusions  There are several practical clinical risk factors that, either alone or in combination, might identify women in early pregnancy who are at “high risk” of pre-eclampsia. These data can inform the generation of a clinical prediction model for pre-eclampsia and the use of aspirin prophylaxis in pregnancy.

https://www.bmj.com/content/bmj/353/bmj.i1753.full.pdf

Clinical risk factors for pre-eclampsia determined in early pregnancy: systematic review and meta-analysis of large cohort studies

An automated method for the determination of the sFlt-1/PIGF ratio in the assessment of preeclampsia

We showed earlier that activating autoantibodies against the angiotensin II type 1 (AT(1)) receptor (AT1-AA) circulate in preeclamptic women. They may be involved in the pathogenesis of preeclampsia. Protein alignment suggests that the binding site for AT1-AAs is highly homologous to the capsid protein VP2 of parvovirus B19. We performed a prospective, nested, case-control study of 30 gestational age-matched women with preeclampsia and 30 normotensive pregnant women. We measured AT1-AA, soluble fms-like tyrosine kinase 1 (sFlt-1), and serum immunoglobulin G against parvovirus B19 proteins. AT1-AAs were present in 70% of preeclamptic patients and absent in 80% of controls. Prediction by AT1-AA was improved in late-onset preeclampsia. The discrimination for sFlt-1 was 96%. We did not find an interaction between sFlt-1 and AT1-AA. A human monoclonal immunoglobulin G antibody against parvovirus B19 VP2-protein showed a positive reaction in the AT1-AA bioassay, which could be blocked by an AT(1) receptor blocker, as well as by the epitope amino acid sequence. Immunoglobulin G against parvovirus B19 proteins was similarly distributed between preeclamptic patients and controls and had no significant importance. We detected significantly more AT1-AA in women with an immune response corresponding with parvovirus B19 infection corresponding with a distant viral infection associated with virus elimination. We concluded that AT1-AAs were common in patients with preeclampsia in a prospective case-control study, although sFlt-1 was a superior biomarker. AT1-AA may represent a better marker for late disease, whereas sFlt1 is a better marker for early onset disease.

Prevalence of Agonistic Autoantibodies Against the Angiotensin II Type 1 Receptor and Soluble fms-Like Tyrosine Kinase 1 in a Gestational Age–Matched Case Study

AIMS The sFlt-1/PlGF ratio has been evaluated as a diagnostic marker for preeclampsia (PE). The aim of this study was to explore the use of the sFlt-1/PlGF ratio as an aid in prediction for PE. METHODS 150 patients with a high risk for PE were enrolled in this prospective study. Groups were compared according to the pregnancy outcome: controls (n=114), intrauterine growth restriction (IUGR) (n=14) and PE (n=22) with subclassification early PE<34 weeks (n=6). Measurements of sFlt-1 and PlGF were performed on the automated Elecsys system. Statistical comparison of the sFlt-1/PlGF ratio in different outcome groups and a mixed model analysis using random intercept models were performed. RESULTS The sFlt-1/PlGF ratio was significantly higher in pregnancies complicated by PE up to 4 weeks before clinical diagnosis compared to controls (106.7 ± 47.7 vs. 21.0 ± 4.1; P=0.02). Levels of the sFlt-1/PlGF ratio were higher throughout pregnancy in women with IUGR compared to PE/control patients (intercept 1.57 vs. 1.30/0.67; P<0.05). The slope for the sFlt-1/PlGF ratio was significantly higher in PE and IUGR pregnancies compared to controls, indicating that a steep increase of the sFlt-1/PlGF ratio correlates with pathologic pregnancy outcomes. CONCLUSION The sFlt-1/PlGF ratio can identify pathologic pregnancy outcomes such as IUGR and PE before clinical diagnosis. Repeated measurements are necessary to assess the dynamics in serum values. The time-dependent slope of the sFlt-1/PlGF ratio is predictive for future pregnancy outcome and risk of developing preeclampsia.

The importance of repeated measurements of the sFlt-1/PlGF ratio for the prediction of preeclampsia and intrauterine growth restriction.

Objectives: The utility of angiogenic and antiangiogenic biomarkers as diagnostic tools in preeclampsia (PE) has been shown in previous studies. Our study’s aim was to evaluate the use of automated measurement of sFlt1, PlGF and their ratio (sFlt1/PlGF) in differential diagnosis of hypertensive pregnancy disorders. Patients/Methods: Sixty-four patients with PE/HELLP, 18 with pregnancy-induced hypertension (PIH), 22 with gestational proteinuria (GP) and 232 controls were investigated. The PE/HELLP group was divided into mild PE (mPE, n = 31), severe PE (sevPE, n = 20), superimposed PE (supPE, n = 7) and HELLP syndrome (n = 6). sFlt1 and PlGF were measured in serum samples on an automated platform. Statistical analysis was performed using parametric and non-parametric methods, ROC analysis and logistic regression method. Results: PE patients showed higher sFlt1 and ratio and lower PlGF than controls (median ± SEM in pg/mL; 10 888 ± 878 versus 2456 ± 116; 268 ± 39 versus 16 ± 2 and 68 ± 6 versus 439 ± 37, ea...

J. Pape

Papers

An automated method for the determination of the sFlt-1/PIGF ratio in the assessment of preeclampsia

Prevalence of Agonistic Autoantibodies Against the Angiotensin II Type 1 Receptor and Soluble fms-Like Tyrosine Kinase 1 in a Gestational Age–Matched Case Study

The importance of repeated measurements of the sFlt-1/PlGF ratio for the prediction of preeclampsia and intrauterine growth restriction.

Automated measurement of sFlt1, PlGF and sFlt1/PlGF ratio in differential diagnosis of hypertensive pregnancy disorders

PP051. Prediction of preeclampsia with the sFlt-1/PLGF ratio: impact of the slope of repeated measurements