Urine xanthine oxidase activity in urinary tract infection

Abstract

Xanthine oxidase (XO) activity was found to be negligible in sterile human urines (less than 480 units, as presently defined, per litre). Significant XO activity was found in all urines containing more than 105 bacteria/ml, except for urines infected with Staphylococcus aureus, in which XO activity ranged from 347 to 715 units per litre. Plasma XO is not transferred to the urine, as demonstrated by the negligible XO activity found in sterile urines from patients with raised plasma XO activity. Determination of urinary XO activity is a suitable procedure for the detection of urinary tract infection.