Quantitative urine proteomics in pregnant women for the identification of predictive biomarkers for preeclampsia

Background Preeclampsia (PE) is a life-threatening disease characterized by elevated blood pressure and proteinuria. Predictive biomarkers of PE are needed, especially those predicting PE in early pregnancy. The aim of this pilot study was to identify urine proteins that could be candidates for new non-invasive markers for PE. Methods Urine samples at three time points of pregnancy (12–14, 18–20 and 26–28 weeks of gestation) were prospectively collected from high-risk women who subsequently developed PE ( n = 7), high-risk women who did not develop PE ( n = 6), and women without known risk factors for PE ( n = 4). The samples were analyzed using mass spectrometry and we subsequently quantified 361 proteins used for further analysis. Rigorous statistical analysis with multiple methods was performed to identify biomarker candidates. Results Of the clinical risk factors analyzed, pre-pregnancy body mass index (BMIBP) was found to be the most important predictor of PE. We identified multiple proteins that correlated with BMIBP and could improve the prediction of PE in combination with BMIBP. Other statistical analyses identified six proteins that each could differentiate women who subsequently developed PE from those who did not at all three time points. Conclusions We identified multiple urine proteins that could be used to predict PE in combination with BMIBP. We also identified six proteins that are strong candidates for predicting PE already in early pregnancy.