Cytokines in urine in elderly subjects with acute cystitis and asymptomatic bacteriuria

Objective. Searching for useful diagnostic tools to discriminate between asymptomatic bacteriuria (ASB) and acute cystitis, this study compared urinary levels of cytokines/chemokines and leukocyte esterase in three groups of elderly subjects; those with acute cystitis, those with ASB, and those without bacteriuria. Design. Comparative laboratory. Setting. Primary care. Subjects. A total of 16 patients with acute cystitis, 24 subjects with ASB, and 20 controls without bacteriuria, all of whom were aged 80 or over. Main outcome measures. Urinary levels of IL-1, TNF-, IL-12, IL-18, CXCL1 (GRO-), CXCL8 (IL-8), CCL2 (MCP-1), IL-6, IL-10, and leukocyte esterase. Results. Urinary levels of CXCL1, CXCL8, and IL-6 were significantly higher in acute cystitis patients than in the ASB group. The sensitivities and specificities for CXCL8, IL-6, and leukocyte esterase to discriminate between acute cystitis and ASB were 63% (95% CI 36-84) and 96% (95% CI 77-100) (cut-off 285 pg/mg creatinine), 81% (95% CI 54-95) and 96% (95% CI 77-100) (cut-off 30 pg/mg creatinine), and 88% (95% CI 60-98) and 79% (95% CI 57-92) (cut-off 2, on a scale of 0-4), respectively. Conclusions. The results indicate that measurement of urinary cytokines, and also leukocyte esterase, when using a cut-off value 2, could be useful in clinical practice to discriminate between symptomatic and asymptomatic urinary tract infections in the elderly. A combination of IL-6 and leukocyte esterase could be even more useful. This needs to be evaluated in prospective studies on the diagnosis and treatment of urinary tract infections in an elderly population.