[Evaluation of N-acetyl-beta glucosaminidase in upper and lower urinary tract infections in childhood. Clinical study of 168 children].

BACKGROUND: Urinary N-acetyl-beta-glucosaminidase (NAG) is a renal tubular enzyme that may be used as a marker of tubular damage. METHODS: We studied 96 patients 1 to 8 years old and considered NAG excretion to distinguish cystitis from pyelonephritis. Whenever urinary NAG values were expressed in relation to urinary creatinine concentration and compared with urinary NAG values in 72 normal controls 1 to 14 years old grouped by age. RESULTS: Our results demonstrate that urinary NAG levels are elevated in children with pyelonephritis in the presence or absence of urinary tract abnormality. CONCLUSIONS: Therefore, we conclude that NAG may be considered as a further criteria in the diagnosis of upper urinary tract infection and interstitial tubular damage.