Urinary N-Acetyl-beta-D-Glucosaminidase and beta 2-Microglobulin in Children with Various Renal Diseases

ABSTRACT

PURPOSE: Urinary N-acetyl-beta-D-glucosaminidase(NAG) and beta 2-microglobulin(B2M) is considered to be a marker of tubulointerstitial injury. The aim of this study was to examine the urinary levels of NAG and B2M in children with various renal diseases. METHODS: We studied 21 children(8.9+/-4.5 years, MaleFemale=147) and they were divided into three groups group I(steroid-sensitive nephrotic syndrome-4 patients), group II(various kinds of glomerulonephritis-4 patients), and group III(normal urinalysis or non-glomerular renal diseases-13 patients). RESULTS: Urinary NAG levels in groups I and II were significantly higher than those in group III(19.4+/-11.5 and 30.0+/-30.1 vs. 4.7+/-3.9, P=0.01), while urinary B2M levels did not differ among the 3 groups, although urinary NAG levels were positively correlated with urinary B2M levels(r=0.49, P=0.03). Urinary NAG and B2M levels were all correlated with proteinuria(r=0.79, P<0.001 and r=0.68, respectively, P=0.001) serum albumin(r=-0.72, P<0.001 and r=-0.57, respectively, P=0.01) and cholesterol(r=0.58, P=0.006 and r=0.56, respectively, P=0.013) levels. Conclusions: Urinary excretions of NAG and B2M are increased in children with steroid-sensitive nephrotic syndrome and various kinds of glomerulonephritis, suggesting tubular dysfunction might be present in these diseases.