title: Age dependence of serum beta-N-acetylhexosaminidase (NAG) activity.
abstract: Serum N-acetyl-beta-D-glucosaminidase (NAG; EC 3.2.1.30) is a hexosaminidase and may be a predictor of vascular injury, e.g., in infant respiratory distress syndrome, pneumonia, broncho-pulmonary dysplasia and necrotizing enterocolitis. To estimate the new diagnostic prospects we have modified our urinary NAG assay. In this sensitive colorimetric micro-assay, VRA-GlcNAc was used as a substrate. In the present study the age dependence of serum NAG activity was investigated in newborn babies, infants (1-24 months), children (2-18 years) and adults (19-80 years). Serum NAG activity was found to be age-dependent; it is higher in early childhood (11-59 U/l) but decreases to a constant value at the age of 1-2 years. After the age of 2 years it is similar to adults' NAG (10-30 U/l). In pediatrics age-matched reference ranges must be taken into consideration.
authors.affiliation: Department of Clinical Biochemistry and Molecular Pathology, University of Debrecen, Medical and Health Science Center, Debrecen, Hungary. olaha@jaguar.dote.hu
authors.forename: Anna V
authors.initials: AV
authors.lastname: Oláh
authors.forename: Robert G
authors.initials: RG
authors.lastname: Price
authors.forename: László
authors.initials: L
authors.lastname: Csáthy
authors.forename: Eva
authors.initials: E
authors.lastname: Országh
authors.forename: Eva
authors.initials: E
authors.lastname: Oláh
authors.forename: József
authors.initials: J
authors.lastname: Varga
mesh_terms: D000117:Acetylglucosamine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism; D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002384:Catalysis; D002648:Child; D002675:Child, Preschool; D004796:Clinical Enzyme Tests / Q000379:methods; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D013057:Spectrum Analysis; D016008:Statistical Distributions; D013844:Thiazoles / Q000737:chemistry / Q000378:metabolism; D001619:beta-N-Acetylhexosaminidases / Q000097:blood*
chemical_list: D013844:Thiazoles; C066473:5-(4-(2-acetamido-2-deoxyglucopyranosyloxy)-3-methoxyphenylmethylene)-2-thioxothiazolidin-4-one-3-ethanoate; D001619:beta-N-Acetylhexosaminidases; D000117:Acetylglucosamine