Introduction
Preeclampsia (PE) is identified in approximately 4–5% of pregnancies
and is the second most common cause of pregnancy-related maternal death.
More than 90% of maternal deaths occur in low-and lower-middle-income
countries1,2. PE leads not only to maternal death and
short-term maternal morbidities but also to long-term cardiovascular
sequelae3. By terminating pregnancy through early
diagnosis, more than half of all hypertension-related mortality can be
prevented4. The diagnosis of PE is established when
women have high blood pressure and evidence of multi-organ involvement,
such as proteinuria, thrombocytopenia, liver involvement, or cerebral
symptoms5,6. However, this method requires
considerable time and specialized facilities to obtain laboratory
findings and evidence of abnormal protein excretion in urine. In
countries where this method cannot be easily performed, the diagnosis
and treatment of PE may be delayed. To date, efforts have been made to
develop easy and simple methods for the diagnosis of PE. However, they
are still in the developmental stage and have not been fully validated.
Nephrin is a transmembrane protein of the slit diaphragm in podocytes
and consists of a renal filtration barrier7. In kidney
injuries, damaged podocytes lead to alterations of the slit diaphragm
and foot process structure, resulting in nephrinuria. Thus, urine
nephrin is well known as an early biomarker for glomerular injury in
glomerulonephritis and diabetic nephropathy8-11. In
addition, some studies have revealed that women with PE have
nephrinuria, which is considered a marker for possible renal damage and
a predictive indicator of severe PE12-15. Using
aptamer-based technology, we attempted to develop a point-of-care test
quantifying nephrin excretion in urine, which could be used to rapidly
diagnose PE. The purpose of this study was to develop an assay to verify
the accuracy and performance of this test in the diagnosis of PE.