Enzymuria as a Marker of Renal Injury and Disease

Abstract

We concur with the comments made by Dr. Kunin and colleagues in their article on N-acetyl-β-glucosaminidase (NAG) as a marker of renal injury (Pediatrics 62:751, 1978). Despite a correlation between enzymuria and proteinuria in Figure 6, we feel that both proteinuria and enzymuria reflect the underlying renal damage. In addition to NAG, we also studied three other urinary lysosomal acidic hydrolases—β-galactosidase, α-fucosidase, and arylsulfatase—in children with renal disease.1 In three children with orthostatic proteinuria, despite increased proteinuria in upright posture, enzymuria remained normal both in recumbent and upright posture.1