Evaluation of renal damage by urinary enzyme dosage

The analysis of urinary enzymes levels in renal parenchyma involves noninvasive test to evaluate possible renal damage. This laboratory method is useful for establishing the extent of renal damage, distinguishing between lower and upper urinary tract infections, and determining the nephrotoxicity of drugs. We are currently investigating NAG and AAP which are predominantly found in the renal tubular cells particularly at the brush-border and lysosomal level. On the basis of our experience, we conclude that enzymuria evaluation is a sensible index and early marker of renal impairment, sensitive in showing early renal damage in patients, even in the absence of variations in creatinine clearance.