N-acetyl-beta-glucosaminidase in the localization of the site of urinary tract infections.

Excretion of N-acetyl-beta-glucosaminidase was measured in 57 patients with urinary tract infections and in 19 normal subjects. The normal range was 0.17 to 1.16 iu/mmol creatinine. The mean NAG/creatinine ratio was 3.11 in 28 patients with upper, and 1.14 in 21 patients with lower urinary tract infection (p = 0.0006). However, even among those clinically defined as having lower urinary tract infections, 18% had NAG/creatinine ratios above the normal range. The mean NAG/creatinine ratio of 8 patients with lower urinary tract symptoms who had underlying uronephrological diseases/systemic diseases capable of causing nephropathy was intermediate between the value obtained in patients with upper, and that observed in patients with lower urinary tract infections.