The differential diagnostic value of urinary enzyme and amino acid excretion in children with nephrotic syndrome.
Urinary enzymes N-acetyl-beta-D-glucosaminidase (NAG) and gamma-glutamyl transpeptidase (gamma-GT) are sensitive markers of specific renal cell damage. Excessive urinary amino acid excretion may also be an indicator of renal tubular damage. We have evaluated urinary excretion of NAG, gamma-GT and 37 amino acids, phospholipids and dipeptides in 30 children (aged 2.3-18.1 years) with nephrotic syndrome (NS), 23 with minimal change nephrotic syndrome (MCNS), 7 with focal segmental glomerulosclerosis (FSGS) and 16 healthy age-matched controls. Nine MCNS patients were in relapse and 14 in remission. Enzyme activity is expressed as micromoles per milligram urinary creatinine. In FSGS, NAG excretion correlated with the following: blood urea nitrogen (BUN) (r = 0.8), serum protein (r = 0.57), serum cholesterol (r = 0.85), serum albumin (r = -0.68) and proteinuria (r = 0.56). In FSGS the gamma-GT excretion was not significantly different from MCNS in remission or in relapse. In FSGS, gamma-GT excretion correlated with the following: BUN (r = 0.48), serum creatinine (r = -0.66), serum protein (r = -0.54), serum albumin (r = -0.68) and serum cholesterol (r = 0.87). Compared with controls, the urinary excretion of 5 amino acids was increased in FSGS patients as a possible indicator of tubular damage. The value for 7 amino acids was reduced in MCNS patients. Urinary amino acid excretion was not different from controls for the other amino acids in either FSGS or MCNS.(ABSTRACT TRUNCATED AT 250 WORDS)
Panchenko
E L
EL
USSR Research Institute of Pediatrics, Moscow, Russia.
Chesney
R W
RW
Roy
S
S
Budreau
A M
AM
Boehm
K A
KA
D000118:Acetylglucosaminidase / Q000652:urine*; D000293:Adolescent; D000596:Amino Acids / Q000652:urine*; D002648:Child; D002675:Child, Preschool; D002851:Chromatography, High Pressure Liquid; D004796:Clinical Enzyme Tests; D003404:Creatinine / Q000652:urine; D003937:Diagnosis, Differential; D005260:Female; D005923:Glomerulosclerosis, Focal Segmental / Q000175:diagnosis / Q000201:enzymology / Q000652:urine; D006801:Humans; D008297:Male; D009404:Nephrotic Syndrome / Q000175:diagnosis* / Q000201:enzymology / Q000652:urine; D005723:gamma-Glutamyltransferase / Q000652:urine*
D000596:Amino Acids; D003404:Creatinine; D005723:gamma-Glutamyltransferase; D000118:Acetylglucosaminidase