URINARY N-ACETYL-β-D-GLUCOSAMINIDASE ASSAY IN RENAL TRANSPLANT RECIPIENTS

Abstract

Urinary N-acetyl-.beta.-D-glucosaminidase (NAG) activities were measured in 181 patients with renal allografts during a 15 mo. period. Activities were high immediately after transplantation but decreased rapidly in the absence of complication. Urinary NAG activities increased by 50% or more in relation to 33 of 36 (92%) episodes of acute rejection diagnosed and treated by clinicians during the 1st 90 days after transplantation. The increase preceded clinical diagnosis in 70% of the cases, the median interval being 1.5 days. NAG activities decreased after treatment for rejection in 90% of the cases. Chronic rejection, renal vein thrombosis, renal artery stenosis, oliguria hypotension and the administration of gentamicin may also cause increased NAG activity. Urinary NAG assay is simple and inexpensive, and is a useful aid to the early diagnosis of rejection of renal transplants. Results must be interpreted by the clinican, bearing in mind other causes for increased activity.