Nested case-control study reveals increased levels of urinary proteins from human kidney toxicity panels in women predicted to develop preeclampsia.

PURPOSE: The aim of this study was to evaluate the usefulness of urine concentrations of 12 proteins as a risk parameter for developing preeclampsia (PE).
METHODS: A nested case-control study was designed to determine protein concentrations in urine from women predicted to develop PE (WPD-PE) and normotensive pregnancies (controls). Protein profiles were determined at 12, 16 and 20 gestational weeks (GW) using the Bio-Plex Pro human kidney toxicity Panel 1 and Panel 2 (Bio-Rad). Receiver operating characteristic (ROC) curve analyses were performed. Correlations between proteins and clinical parameters at the time of PE diagnosis were also assessed.
RESULTS: Significant differences were observed in urine cystatin C (Cys C) levels at 16 and 20 GW and clusterin at 20 GW between WPD-PE and controls (P < 0.05). ROC analysis revealed that Cys C at 16 GW had the highest area under the ROC curve (0.758). At 16 GW, patients with urine Cys C levels above 73.7 ng/mL had eightfold increased odds for developing PE (odds ratio 7.92; 95 % CI 1.3-47.5; P = 0.027). A positive correlation was found between urinary Cys C (at 16 and 20 GW) and leukocyte counts, total proteins, aspartate aminotransferase, alanine aminotransferase, bilirubin and lactate dehydrogenase at the time of PE diagnosis (P value < 0.05).
CONCLUSIONS: Urinary Cys C and clusterin showed predictive value for PE development in our cohort. Further studies are needed to validate their use as predictive biomarkers for PE and/or their participation in PE pathogenesis.