Angiotensin Receptor Agonistic Autoantibody Is Highly Prevalent in Preeclampsia

Abstract

Preeclampsia (PE), a syndrome affecting 5% of pregnancies, characterized by hypertension and proteinuria, is a leading cause of maternal and fetal morbidity and mortality. The condition is often accompanied by the presence of a circulating maternal autoantibody, the angiotensin II type I receptor agonistic autoantibody (AT 1 -AA). However, the prevalence of AT 1 -AA in PE remains unknown, and the correlation of AT 1 -AA titers with the severity of the disease remains undetermined. We used a sensitive and high-throughput luciferase bioassay to detect AT 1 -AA levels in the serum of 30 normal, 37 preeclamptic (10 mild and 27 severe), and 23 gestational hypertensive individuals. Here we report that AT 1 -AA is highly prevalent in PE (≈95%). Next, by comparing the levels of AT 1 -AA among women with mild and severe PE, we found that the titer of AT 1 -AA is proportional to the severity of the disease. Intriguingly, among severe preeclamptic patients, we discovered that the titer of AT 1 -AA is significantly correlated with the clinical features of PE: systolic blood pressure ( r =0.56), proteinuria ( r =0.70), and soluble fms-like tyrosine kinase-1 level ( r =0.71), respectively. Notably, only AT 1 -AA, and not soluble fms-like tyrosine kinase-1, levels are elevated in gestational hypertensive patients. These data serve as compelling clinical evidence that AT 1 -AA is highly prevalent in PE, and its titer is strongly correlated to the severity of the disease.