ResearchObstetricsUrinary podocyte excretion as a marker for preeclampsia
Section snippets
Materials and Methods
This study was approved by the Institutional Review Board, and all women were consented before inclusion in the study. The diagnosis of preeclampsia was made in the presence of (a) hypertension after 20 weeks of gestation, which was defined as a blood pressure of ≥140/90 mm Hg, (b) proteinuria, which was defined as ≥300 mg of protein in a 24-hour urine specimen, and/or 1+ (30 mg/L) dipstick urinalysis in the absence of urinary tract infection and/or a predicted 24-hour urine protein of >300 mg
Podocyturia
In the women with urinary measures of podocyturia (ie, 15 cases and 16 control subjects), those women with preeclampsia or HELLP had podocin-positive cells in the urine (Figure 1A), whereas none of the normotensive control subjects had any podocin-positive cells. Thus, the sensitivity and specificity of podocyturia, as determined by the podocin-positive cells, for the diagnosis of preeclampsia were both 100%. A positive correlation between the degree of proteinuria and podocyturia, as
Comment
Our study demonstrates that podocyturia (ie, urinary excretion of podocytes) is present in patients with preeclampsia at the time of delivery. These cells retain the ability to attach to tissue culture plates in vitro, which indicates that they are viable. Urinary shedding of podocytes may contribute to proteinuria in preeclampsia, because these cells have a very limited regenerative capacity. Therefore, podocyturia may indicate podocyte loss from the glomerulus that may lead to a disruption of
Acknowledgments
We thank Mrs Angela K. Dalenberg and Mrs Catherine E. Gray from the Division of Nephrology and Hypertension for their help in developing and performing podocyturia assays, and Ms. Heather Wiste for assistance with statistical analyses.
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Supported in part by a CR-20 grant from the Mayo Foundation (V.D.G.).
Cite this article as: Garovic VD, Wagner SJ, Turner ST, et al. Urinary podocyte excretion as a marker for preeclampsia. Am J Obstet Gynecol 2007;196:320.e1-320.e7.