One study including renal transplant patients with non-specific UTI during follow up demonstrated that those with UTI had a median concentration of IL-8 4.4 times higher than samples from patients with ASB (P < .001).53 A study including patients with pyelonephritis and cystitis found that they had comparable Il-8 concentrations to patients with ASB.57 This evidence concerns the gene CXCL8 and chronic cystitis.