Key Proteins in Urine Samples Detect Preeclampsia

A simple measurement of key proteins in spot urine samples and changes in the urinary protein profile early in pregnancy might predict the development of preeclampsia, which typically does not appear until later in pregnancy.

Preeclampsia is a condition in pregnancy characterized by abrupt hypertension (a sharp rise in blood pressure), albuminuria (leakage of large amounts of the protein albumin into the urine) and edema (swelling) of the hands, feet, and face. Preeclampsia is the most common complication of pregnancy.

Scientists from the Leicester General Hospital, (Leicester, UK), analyzed urine samples obtained before 20 weeks of gestation from 145 pregnant women who either did or did not develop preeclampsia. The prospective longitudinal study involved pregnant women from a high-risk obstetric outpatient clinic. Urine samples were taken and analyzed the same day with surface enhanced laser desorption/ionization time-of-flight mass spectrometry.

After delivery, patients were categorized as having had preeclampsia or a normal pregnancy. A spectral analysis of the urine samples of preeclampsia and nonpreeclampsia pregnancies taken before 20 weeks of gestation was performed with an artificial neural network algorithm and multivariate nonlinear regression. A random sampling of 50 test datasets validated the model. The results identified a panel of five protein peaks that predicted preeclampsia with 92% accuracy; the test datasets showed a sensitivity of 87% and a specificity of 82%.

Matt Hall, MBChB, of the University of Leicester (Leicester, UK), and the lead author of the study, said, "Given that proteinuria is a key diagnostic and prognostic factor in preeclampsia, the renal morphological changes occur early in the disease, and the initiation of this process begins four to five months before the clinical manifestations."

Arlene Chapman, MD, professor of medicine at Emory School of Medicine (Atlanta, GA, USA), said, "Numerous biomarkers have been investigated to try to detect the condition early, most notably soluble FMS-like tyrosine kinase and soluble endoglin, peptides that are produced by the placenta. The identification of a urinary proteomic fingerprint could help with the diagnosis.” The study was presented on November 19, 2010, at the Annual Meeting of the American Society of Nephrology held in Denver (CO, USA).

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Leicester General Hospital
Emory School of Medicine
University of Leicester