IL-8 Production During Urinary Tract Infection

Abstract

Infection of the urinary tract leads to a local inflammatory response mediated at the mucosa. In patients with natural urinary tract infection (UTI) and in patients deliberately colonized with Escherichia coli in the urinary tract there is a rapid recruitment of neutrophils into the urine. We have shown previously that urinary tract epithelial cell lines produce a range of cytokines including IL-8 following stimulation with E. coli (1). In this study we analyzed the urine of patients following deliberate colonization of the urinary tract with three E. coli strains, for the influx of PMNs and presence of IL-8. IL-8 was found in the urine of all patients following UTI. There was a strong correlation of 0.7 between levels of IL-8 and numbers of PMNs in the urine. IL-8 was not found in the serum of patients during the period of colonization. The J82 bladder and A498 kidney epithelial cell lines and neutrophils collected from fresh human blood produced large amounts of IL-8 in response to the same E. coli strains. These results suggest that IL-8 may play an important role in neutrophil influx during UTI and that local epithelial cells as well as activated neutrophils may be involved in the production of this protein at the site of infection.