Pediatric reference data on activity of urinary N-acetyl-β-D-hexosaminidase and its isoenzymes

Area of Science:

• Biochemistry
• Pediatric Nephrology
• Biomarker Discovery

Background:

• Lysosomal exoglycosidases, including N-acetyl-β-D-hexosaminidase (HEX), play crucial roles in cellular metabolism.
• Establishing normative data for urinary enzyme activity is essential for identifying potential health deviations in pediatric populations.
• Urinary HEX isoenzymes A (HEX A) and B (HEX B) are of interest as potential biomarkers.

Purpose of the Study:

• To determine age-dependent reference values for urinary N-acetyl-β-D-hexosaminidase (HEX) and its isoenzymes A (HEX A) and B (HEX B) in healthy children and adolescents.
• To provide a baseline for future clinical investigations involving these enzymes in pediatric populations.
• To analyze the correlation between urinary HEX activities and chronological age.

Main Methods:

• A cohort of 203 healthy children and adolescents (6 months to 17.9 years) was studied.
• Urinary activities of HEX, HEX A, and HEX B were quantified using a colorimetric assay.
• Enzyme activities were normalized to urinary creatinine and expressed as pKat/μg Cr.

Main Results:

• Urinary HEX, HEX A, and HEX B activities were highest in children under 3 years of age.
• Statistically significant negative correlations were observed between urinary HEX, HEX A, HEX B activities and increasing age.
• Reference values for urinary HEX, HEX A, and HEX B activities were established in centiles across different age intervals.

Conclusions:

• This study provides the first reported reference values for urinary HEX, HEX A, and HEX B activities in children and adolescents.
• These established reference ranges are critical for the accurate interpretation of urinary lysosomal exoglycosidase activity in pediatric health assessments.
• The findings highlight the significant age-dependent decline in these enzyme activities during childhood and adolescence.