Evaluation of sFlt-1/PlGF Ratio, Osteoprotegerin (OPG) and Soluble Endoglin (sEng) as Predictive Biomarkers in the Diagnosis and Treatment Evaluation of Preeclampsia

Preeclampsia is a pregnancy-specific hypertensive disorder characterized by newonset hypertension and proteinuria or other maternal organ dysfunction after 20 weeks of gestation. It affects 2-8% of pregnancies globally and remains a major contributor to maternal and perinatal morbidity and mortality The etiology is multifactorial, but placental dysfunction and abnormal angiogenesis are central to its pathogenesis. Given the limitations of current clinical indicators (e.g., blood pressure, proteinuria), there is growing interest in identifying predictive and diagnostic biomarkers to improve early detection, prognosis, and monitoring of therapeutic response. This study proposes to investigate three biomarkers: the sFlt-1/PlGF ratio, soluble endoglin (sEng), and osteoprotegerin (OPG), based on their roles in angiogenesis and endothelial dysfunction, which are hallmarks of preeclampsia

sFlt-1/PlGF Ratio Soluble fms-like tyrosine kinase-1 (sFlt-1) is an anti-angiogenic protein that binds to vascular endothelial growth factor (VEGF) and placental growth factor (PlGF), preventing their interaction with endothelial receptors. The imbalance, especially elevated sFlt-1 and decreased PlGF, is characteristic of preeclampsia. Numerous studies, including the multicenter PROGNOSIS trial, have validated the sFlt-1/PlGF ratio as a strong predictor of preeclampsia. A ratio ≥85 is associated with a high risk of developing preeclampsia within two weeks, while ≤38 effectively rules it out .

Soluble Endoglin (sEng) Endoglin is a co-receptor for transforming growth factor-beta (TGF-β), involved in vascular development. Its soluble form (sEng) acts as a decoy receptor, inhibiting TGF-β signaling, contributing to endothelial dysfunction, a key feature of preeclampsia. sEng levels are elevated in the maternal circulation prior to clinical onset and correlate with disease severity.

Osteoprotegerin (OPG) OPG, a member of the TNF receptor superfamily, is primarily involved in bone metabolism but also plays a role in vascular biology. Some studies have reported altered OPG levels in preeclampsia, potentially reflecting vascular damage or endothelial activation . Its role remains less defined, but it may complement other angiogenic markers in profiling disease status.