Urinary exoglycosidases, reference values in healthy children.

PURPOSE: The purpose of the study was to determine the effect of age on lysosomal exoglycosidase activities: α-fucosidase, ß-galactosidase, ß-glucuronidase and α-mannosidase in healthy children and adolescents. MATERIAL AND METHODS: Urine samples were collected from 203 healthy children and adolescents (girls = 99, boys = 104), aged six months to 17.9 years. The activities of α-fucosidase, ß-galactosidase, ß-glucuronidase and α-mannosidase were determined by colorimetric method and expressed in pKat/µg of creatine (pKat/µg Cr.). RESULTS: Urinary α-fucosidase, ß-galactosidase, ß-glucuronidase and α-mannosidase activities (pKat/µg Cr.) were the highest in children below 3 years of age in comparison to the remaining age groups. There was a statistically significant negative correlation between urinary α-fucosidase, ß-galactosidase, ß-glucuronidase and α-mannosidase (pKat/µg Cr.) and age (r = -0.36; r = -0.36; r = -0.35; r = -0.35; at p < 0.0001, respectively). In addition, we constructed the reference values for urinary activity of α-fucosidase, ß-galactosidase, ß-glucuronidase and α-mannosidase (pKat/µg Cr.) in percentiles according to age in 3-year intervals. CONCLUSIONS: Our study is the first to show reference values for urinary α-fucosidase, ß-galactosidase, ß-glucuronidase and α-mannosidase in children and adolescents.