Urine interleukin-8 is a marker for urinary tract infection in postoperative patients.

BACKGROUND: Urine of patients with urinary tract infection (UTI) contains high levels of interleukin (IL)-6 and IL-8. However, knowledge of the kinetics of their release in urine is limited. We therefore compared the appearance of IL-6 and IL-8 in urine after uncomplicated surgery and surgery complicated by UTI. PATIENTS AND METHODS: 165 patients undergoing abdominal surgery who received a urinary catheter were studied. Urine IL-6 and IL-8 were prospectively measured in patients who did (n = 10) or did not (n = 20) develop UTI. Statistical analysis was done by one-way ANOVA and the Mann-Whitney test. RESULTS: Although urine IL-6 increased in the 2 to 4 days preceding the bacteriological documentation of UTI, a similar increase was observed in patients who did not develop UTI. Urine IL-8 was elevated on the day UTI was diagnosed, while remaining low in controls. CONCLUSION: In this patient group with postoperative UTI, urine IL-8 was a better marker for the early host response than urine IL-6.