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 beta, TNF-alpha, IL-12, IL-18, CXCL1 (GRO-alpha), 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.