Angiogenic proteins as aid in the diagnosis and prediction of preeclampsia

Increased Levels of sENG and sVCAM-1 and Decreased Levels of VEGF in Severe Preeclampsia

BACKGROUND

Preeclampsia (PE) is characterized by hypertension and proteinuria after the 20th week in pregnant women who have had no previous symptoms. Clinically, it is important to diagnose the severe form of the disease, in which blood pressure is much higher. Imbalance between angiogenic and antiangiogenic factors, as well as changes in adhesion molecules seem to contribute to the endothelial dysfunction and PE clinical manifestations. The aim of this study was to assess plasma levels of the angiogenic factors (free vascular endothelial growth factor (VEGF) and soluble endoglin (sEng)) and adhesion molecules (soluble forms of intercellular adhesion molecule-1 (sICAM-1) and soluble forms of vascular cell adhesion molecule-1 (sVCAM-1)) in severe PE (sPE), in order to clarify the circulating profile of these factors.

METHODS

Sixty women with sPE (34 with early sPE and 26 with late sPE), and 60 normotensive pregnant were enrolled in this study. Free VEGF, sICAM-1, sVCAM-1, and sEng plasma levels were determined by ELISA.

RESULTS

Increased sEng and sVCAM-1 and decreased free VEGF plasma levels were found in women with sPE, compared with normotensive pregnant group. However, no significant difference was observed comparing early and late sPE.

CONCLUSION

Our data confirm the imbalance in changes in angiogenic and antiangiogenic factors, as well changes in adhesion molecule (sVCAM-1) in PE. These findings give support to the hypothesis that circulating angiogenic proteins and endothelial dysfunction may have an important biologic role in PE. Data from prospective, longitudinal studies producing serial determinations of these molecules throughout pregnancy are needed to better understanding the relevance of these markers in PE diagnosis and prognosis.

Is the imbalance between pro-angiogenic and anti-angiogenic factors associated with preeclampsia?

BACKGROUND

Preeclampsia (PE) is a multisystem disease characterized by the development of hypertension and proteinuria. Although PE etiology is not fully known, the placenta seems to play a central role in the development of disease. The inadequate placentation process results in a change in angiogenic factors levels, such as vascular endothelial growth factor (VEGF), placental growth factor (PlGF), soluble form of endoglin (s-Eng) and soluble form of vascular endothelial growth factor receptor type 1 (sFlt-1).

OBJECTIVE

The aim of this review was to clarify if the imbalance between pro-angiogenic and anti-angiogenic factors is associated with PE.

CONCLUSION

It is known that inadequate placentation process is the primary mechanism suggested for PE occurrence and angiogenic factors are involved in this process. The state-of-the-art suggests that progress in grasp the imbalance of pro-angiogenic and anti-angiogenic factors is essential for the improvement of knowledge about PE. The development of prospective, longitudinal studies with serial determinations of these factors throughout pregnancy is needed to better assess the relevance of these markers for understanding the etiology, prevention, diagnosis, prognosis and treatment of this challenging disease.

Modeling risk for severe adverse outcomes using angiogenic factor measurements in women with suspected preterm preeclampsia

INTRODUCTION

Preeclampsia (PE) is a pregnancy-specific syndrome associated with adverse maternal and fetal outcomes. Patient-specific risks based on angiogenic factors might better categorize those who might have a severe adverse outcome.

METHODS

Women evaluated for suspected PE at a tertiary hospital (2009-2012) had pregnancy outcomes categorized as 'referent' or 'severe', based solely on maternal/fetal findings. Outcomes that may have been influenced by a PE diagnosis were considered 'unclassified'. Soluble fms-like tyrosine kinase (sFlt1) and placental growth factor (PlGF) were subjected to bivariate discriminant modeling, allowing patient-specific risks to be assigned for severe outcomes.

RESULTS

Three hundred twenty-eight singleton pregnancies presented at ≤34.0 weeks' gestation. sFlt1 and PlGF levels were adjusted for gestational age. Risks above 5 : 1 (10-fold over background) occurred in 77% of severe (95% CI 66 to 87%) and 0.7% of referent (95% CI <0.1 to 3.8%) outcomes. Positive likelihood ratios for the modeling and validation datasets were 19 (95% CI 6.2-58) and 15 (95% CI 5.8-40) fold, respectively.

CONCLUSIONS

This validated model assigns patient-specific risks of any severe outcome among women attending PE triage. In practice, women with high risks would receive close surveillance with the added potential for reducing unnecessary preterm deliveries among remaining women. © 2015 The Authors. Prenatal Diagnosis published by John Wiley & Sons Ltd.

Angiogenic factors in preeclampsia and related disorders

During fetal development, the human placenta undergoes high levels of both angiogenesis and vasculogenesis. Additionally, the developing placenta undergoes a process of vascular mimicry (referred to as pseudovasculogenesis) as cytotrophoblasts convert from an epithelial to an endothelial phenotype. The initiation, maturation, and maintenance of the placental vasculature are of critical importance. Failure to do so can lead to adverse obstetric outcomes such as preeclampsia and/or intrauterine growth restriction (IUGR). Furthermore, the foundation of many aspects of adult health is laid in utero. In this context, normal placental function is not only critical for normal fetal development but can also permanently influence long-term health and disease. Understanding the mechanisms that regulate placental vasculogenesis and angiogenesis is therefore of critical importance. This chapter will focus on placental vascular development with a particular emphasis on the role of angiogenic factors in the pathogenesis of the maternal syndrome of preeclampsia and related disorders.