Urinary N-acetyl-beta-D-glucosaminidase activity in healthy children.

Aim: The principal aim was to establish paediatric reference data for the urinary N-acetyl-beta-D-glucosaminidase (U-NAG) activity.

Method And Results: Two hundred and sixty-two healthy children aged 0-18 years (0-1 month, n = 38; 1 month-1 year, n = 50; 1-3 years, n = 50; 3-6 years, n = 46; 6-10 years, n = 29; 10-18 years, n = 49) had a urine sample collected and the U-NAG activity was evaluated by using fluorimetry and related to urinary creatinine as a nkat/mmol ratio. A strong age dependence of the U-NAG/creatinine ratio and its high interindividual variability in children was observed; the highest values of upper reference range being in the 0-1 month and 1 month-1 year groups (134.