Urinary N-acetyl-beta-D-glucosaminidase and beta 2-microglobulin excretion in primary nephrotic children.
Enzymuria and low molecular weight proteinuria reflect tubular damage and dysfunction, respectively. We examined urinary N-acetyl-beta-D-glucosaminidase (U-NAG) and beta 2-microglobulin (U-beta 2M) excretion in 17 steroid-resistant and 39 steroid-sensitive children with nephrotic syndrome whose glomerular filtration rates were within the normal range. Fourteen healthy children were taken as controls. U-NAG and U-beta 2M levels did not show a difference between the steroid-resistant and steroid-sensitive groups but were significantly higher in the nephrotic groups compared to the controls (p < 0.0001 and p < 0.01, respectively). In the steroid-sensitive group, U-NAG levels were significantly higher in patients in the relapse phase than in those in remission (p < 0.0001). This finding was also valid for U-beta 2M excretion, but reached significance only for patients in remission who did not receive steroids (p < 0.01). There was a positive correlation between proteinuria and U-NAG and U-beta 2M excretion in all patients (rs = 0.69, p < 0.001 and rs = 0.39, p < 0.001, respectively). In conclusion, massive glomerular proteinuria may cause a marked U-NAG excretion and a moderate urinary U-beta 2M elevation independent of primary renal disease.
Department of Pediatrics, Cerrahpaşa Faculty of Medicine, University of Istanbul, Turkey.
S
S
Calişkan
M
M
Hacibekiroğlu
L
L
Sever
G
G
Ozbay
N
N
Arisoy
D000118:Acetylglucosaminidase / Q000652:urine*; D000293:Adolescent; D015415:Biomarkers / Q000652:urine; D002648:Child; D002675:Child, Preschool; D005919:Glomerular Filtration Rate; D005920:Glomerular Mesangium / Q000473:pathology; D015432:Glomerulonephritis, Membranoproliferative / Q000652:urine; D006801:Humans; D007223:Infant; D009404:Nephrotic Syndrome / Q000201:enzymology / Q000652:urine*; D012008:Recurrence; D012016:Reference Values; D001613:beta 2-Microglobulin / Q000652:urine*
D015415:Biomarkers; D001613:beta 2-Microglobulin; D000118:Acetylglucosaminidase