Detection of extracellular vesicles in urine for diagnosis of preeclampsia

ABSTRACT Preeclampsia (PE) is a pregnancy-specific disorder commonly characterized by hypertension and the appear- ance of proteins such as albumin in patient urine. This disorder occurs in ~5% of pregnancies worldwide and is the second leading cause of maternal/fetal morbidity and mortality worldwide. The etiology of this disease is poorly understood. This confounds therapeutic intervention and makes delivery the only recourse for saving the mother. Prognostic and diagnostic tests for PE are highly desirable but currently are not unavailable. Our team (Garovic) identified the presence of specialized kidney epithelial cells, podocytes, as well as podocyte- derived extracellular vesicles (EVs) in the urine of patients with PE as novel biomarkers for this disease. Spe- cifically, we demonstrated that the ratio of podocin to nephrin expressed on urinary EVs correlated with PE. However, the technique used by us previously for quantifying podocin-to-nephrin ratios (nanoflow cytometry) is too complex and labor intensive to be used widely for screening of pregnant women. Our project will fill this technological gap and provide a simple-to-use diagnostic test for PE. This Phase II STTR project will leverage an electrochemical immunoassay for detection of EV surface markers developed by our team during Phase I. The immunoassay will be implemented in a novel electrochemical microtiter plate to enable simple and sensi- tive screening patient urine for EV expression of podocin and nephrin. Activities outlined in this project will represent an important step toward developing a clinical diagnostic test for PE that could be performed for all pregnant women during their prenatal checkups. Overall impact: Our vision is to develop a technology that will enable testing for PE at the point of point-of- use, in the hospitals or OBGYN clinics. Detection of EV-based biomarkers in urine will allow a physician to di- agnose preeclampsia before the clinical syndrome (hypertension and proteinuria) develops and will be specific to all subtypes of the disease. If a test result is positive, a pregnancy will be deemed at risk for PE and will be monitored more closely for symptoms and signs of this disease. This test will represent a paradigm shift in the care for patients with preeclampsia.