Increased urinary N-acetyl-beta-D-glucosaminidase activity in children with hydronephrosis

Abstract

Objective: Hydronephrosis leads to deterioration of renal function. As urinary N-acetyl-beta-D-glucosaminidase (U-NAG) activity is considered a sensitive marker of renal tubular impairment, our aim was to measure U-NAG in children with hydronephrosis and to look for a relationship among selected clinical parameters. Materials and Methods: We studied 31 children (22 boys and 9 girls, mean age 2.3 ± 2.5 years) with hydronephrosis grade 1-4 that had U-NAG/ creatinine ratio (U-NAG/Cr) measured. Results: The U-NAG/Cr was significantly higher in patients with hydronephrosis compared to reference data (p=0.002). There was no difference in U-NAG/Cr between children with unilateral and bilateral hydronephrosis (p=0.51). There was no significant difference in U-NAG/Cr between children with grades 1-3 (pooled data) and grade 4, respectively (p=0.89). There was no correlation between U-NAG/Cr and the grade of hydronephrosis (r=0.01). Conclusions: U-NAG/Cr is increased in children with hydronephrosis grade 1-4, and there is no relationship with the grade of hydronephrosis. U-NAG is a useful marker of renal tubular dysfunction, however its relationship with the degree of kidney damage in patients with hydronephrosis should be considered as doubtful.