Urinary N-acetyl-beta-D-glucosaminidase (U-NAG) activity in children with vesicoureteral reflux.

OBJECTIVES

The aim of this study was to measure U-NAG in children with vesicoureteral reflux (VUR) and examine the relationship between selected clinical parameters.

BACKGROUND

U-NAG/creatinine ratio is a marker of renal tubular impairment and an increase in this ratio have been reported to affect the kidneys in various diseases.

METHODS

The U-NAG/creatinine ratio was measured in the spot urine of 22 children (10 boys and 12 girls, mean age 2.83 +/- 2.42 years) with VUR. In 8 patients The VUR was unilateral grade I-IV (8 patients), and it was was bilateral, grade I-V in 14 patients. In patients with bilateral reflux and different VUR grade on each side, the highest grade of VUR was taken into consideration.

RESULTS

The U-NAG/Cr levels were significantly higher in VUR patients compared to the reference (p = 0.0001). There was no difference in U-NAG/Cr between children with unilateral (n = 8) and bilateral (n = 14) VUR (p = 0.66). There was no difference in U-NAG/Cr between patients with VUR grades I-III and IV-V (p = 0.67). The U-NAG/Cr activity was higher in patients with reflux nephropathy (RN; n = 9) when compared to reference data (p = 0.0001), however there was no difference in comparison to children without RN (p = 0.84).

CONCLUSIONS

U-NAG/Cr increased in children with VUR grade I-V and there is a very weak relationship with the grade of VUR. U-NAG/Cr is a useful marker of renal tubular impairment, however there is poor relationship with the degree of kidney damage in patients with VUR (Tab. 1, Ref. 25). Full Text (Free, PDF) www.bmj.sk.