Urinary excretion of N-acetyl-glucosaminidase and beta-2-microglobulin as early markers of gentamicin nephrotoxicity in neonates.

A prospective study in 16 healthy and 16 gentamicin-treated neonates was undertaken to compare the urinary excretion of proximal tubular markers such as beta 2-microglobulin (beta 2-m) and total N-acetyl-beta-D-glucosaminidase (NAG) and its isoenzymatic form NAGB. beta 2-m excretion was not related to postnatal age in control full-term neonates; it was significantly increased in gentamicin-treated full-term neonates. The urinary excretion of the lysosomal markers, total NAG and NAGB, rose significantly with postnatal age in control group. fMean values for total NAG and NAGB were significantly higher in the treated group but the isoenzymatic profile (NAGB/total NAG X 100) was not modified by gentamicin treatment.