N-Acetyl-beta-D-glucosaminidase in urine of patients with renal disease, and after renal transplants and surgery.

The isoenzyme forms of N-acetyl-beta-D-glucosaminidase (NAG) have been studied in the urine of patients with renal disease, those with stable and rejecting renal transplants, and after surgery. Besides the increase in total urinary NAG excretion as an indicator of renal damage, changes were shown in the percentage of the intermediate isoenzyme forms of the enzyme, the greatest increase being demonstrated in the urine of patients following major surgery. Similar changes were found in some patients with rejecting renal transplants, suggesting that hypoxia may be the cause of the renal damage and enzyme release. More marginal increases in isoenzyme forms were found in urine of patients with renal impairment and nephrotic syndrome.