Acute and Transient Podocyte Loss and Proteinuria in Preeclampsia

Glomerular podocytes are known to regulate proteinuria and podocyturia correlated with proteinuria. Podocyturia, the urinary excretion of viable podocytes (glomerular epithelial cells), has been associated with proteinuria in preeclampsia. This study is the first to investigate the time course alterations of podocyturia in patients with preeclampsia (11 cases) and normotensive pregnant women (45 cases). Urinalysis was performed at 35 weeks of gestation, 4 days after delivery, and 1 month after delivery. In patients with preeclampsia, podocyturia was evident at 35 weeks of gestation and 4 days after delivery, while proteinuria had already decreased at 4 days after delivery. At 1 month after delivery, almost no patients exhibited podocyturia. In control cases, proteinuria was not significant throughout the study period. However, 9 of the 45 controls exhibited transient and mild podocyturia at 4 days after delivery without proteinuria or hypertension. Statistics indicated a correlation between urinary podocyte number and blood pressure, but not with proteinuria. In conclusion, podocyturia in preeclampsia is transient and almost synchronous with heavy proteinuria. The results suggest that acute podocyte loss implicates podocyturia as the possible mechanism of proteinuria in women with preeclampsia.