Urinary Neutrophil-Gelatinase Associated Lipocalin is a Potential Noninvasive Marker for Renal Scarring in Patients With Vesicoureteral Reflux

Purpose: Renal scarring is a serious complication that often occurs with chronic pyelonephritis in the presence of vesicoureteral reflux. In a previous study we established a rat model of renal scarring in which we found the up-regulation of neutrophil-gelatinase associated lipocalin at the mRNA and protein levels. In this study we evaluated urinary neutrophil-gelatinase associated lipocalin as a potential biomarker for progression of renal scarring in patients with vesicoureteral reflux. Materials and Methods: A total of 34 patients diagnosed with vesicoureteral reflux without evidence of current urinary tract infection and 28 normal healthy children were enrolled in this study. Renal scars were evaluated by ^99mtechnetium dimercapto-succinic acid renal scan in 24 of the reflux cases. Urinary neutrophil-gelatinase associated lipocalin levels were monitored by ELISA. Results: In normal subjects urinary neutrophil-gelatinase associated lipocalin was high during infancy, decreased rapidly within the following year and reached a low stable level from age 3 years onward. Urinary neutrophil-gelatinase associated lipocalin levels, normalized to age matched standards, were significantly increased in patients with vesicoureteral reflux compared to controls. These levels did not correlate with reflux grade, but were significantly higher in patients with radiological evidence of renal scarring irrespective of reflux grade. Conclusions: Estimation of urinary neutrophil-gelatinase associated lipocalin may be useful as a noninvasive diagnostic or prognostic biomarker for renal scarring.