Urine xanthine oxidase activity in urinary tract infection.

Abstract

SUMMARY Xanthine oxidase (XO) activity was found to be negligible in sterile human urines (less than 480 units, as presently defined, per litre). Significant XO (Brenner and Gilbert, 1963;Bank and Bailine, 1965;Mirabile et al., 1966;Montgomerie et al., 1966;Gault et al., 1967;Kallet and Lapco, 1967;Roberts et al., 1967). The diagnostic value of these methods is limited by the potential derivation of the respective urinary enzymatic activities from renal and urinary tract tissues and from blood cells and plasma (Bank and Bailine, 1965;Montgomerie et al., 1966;Gault et al., 1967;Mattenheimer, 1971;Wolf et al., 1973). As shown in the present study, xanthine oxidase (XO) activity is a correlate of urinary tract infection, the enzyme being derived from the pathogenic bacteria exclusively, while the above-mentioned enzyme sources are non-contributory. Material and methodsUrine samples were collected from 115 random patients admitted to hospital for a variety of disorders and whose urines had been sent for a variety of reasons for urine culture. In addition, urines were obtained from 12 jaundiced patients with acute hepatitis without urinary tract infection (serum bilirubin ranging from 3-5 to 11 7 mg/100 ml, SGOT from 253 to 1330 mU/ml), and from 18 patients with acute and chronic renal failure, three of the latter with urinary tract infection and 15 without. Received for publication 21 August 1977Urine samples were collected in the morning by midstream catch or by a catheter with strict aseptic technique. Gram-stained smears of unspun urine were examined in order to assess the presence of bacteria and leucocytes, as a guide to the presence of infection. The urines were cultured quantitatively on MacConkey's agar and blood agar plates. Arbitrarily, concentrations of 105 and more bacteria per 1 ml of urine were considered as significant for urinary tract infection. Bacteria isolated in cultures were subjected to further identification procedures. The urines were assayed for XO activity within one hour after collection. In addition, XO activity was measured in the sera obtained from the patients with acute hepatitis, and in renal and liver tissue samples obtained at necropsy from five patients with myocardial infarction without urinary tract infection and without jaundice.XO activity was assayed by incubation of 100 ,pI of the urine, serum or homogenised tissue samples in a total volume of 250 ,ul of 0 04 M potassium phosphate buffer, pH 8-0, containing 10 nmol of (8 -14C) hypoxanthine (25 mCi/mmol). After incubation at 370C for three hours, 100 tkI of 20% perchloric acid was added and the tubes were put in boiling water for 15 minutes, chilled, and centrifuged for 10 minutes at 3000 rev/min. The free purine bases in the supernatant were separated in the presence of carriers by thin-layer chromatography on Avicel (microcrystalline cellulose), using n-butanol :methanol :water :NH40H 25 % (60 :20:20:

New Markers: Urine Xanthine Oxidase and Myeloperoxidase in the Early Detection of Urinary Tract Infection

“…XO enzyme is confined in man mainly to the liver; a significant but lower activity has been found also in jejunal mucosa and colostrum; on the other hand, the kidney, prostate, and blood elements, as well as normal serum, are virtually devoid of XO activity [ 9 – 14 ]. Indeed, we showed that urine XO activity was increased in patients with UTI, conforming to previously reported results, indicating that plasma XO is transferred to the urine, probably due to its low molecular weight.…”

Biomarkers of urinary tract infections: state of the art, and promising applications for rapid strip-based chemical sensors

“…100,107 XOR has been shown to be elevated in tissue and blood under certain conditions such as viral hepatitis, 108 intestinal infection, 109 jaundice, 108,110 renal inammation, 111 and ischemia/reperfusion injury. 101,112,113 XO has also been observed in urine during UTI, 114,115 but there has generally not been much focus on XO in urine or in relation to UTI.…”

Enzymatic Study in Sera of Chronic Renal Failure Patients Undergoing Hemodialysis

“…This enzyme is involved in the pathogenesis of tissue injury by the production of superoxide anion radicals and hydrogen peroxide or both [16,17] . Or may be indicating that plasma X.O is not transferred to the urine, probably due to its high molecular weight [18] . The studies by Borges et al, 2002, had used xanthine oxidase inhibitors as a means to prevent (CRF) in animals, also showed that the X.O levels in blood had significantly increased in different pathological cases, like aging, ischemia reperfusion, inflammation and cancer, and that reactive oxygen species generated in the enzymatic process were involved in oxidative damage [19] .…”