Seven studies compared ASB to an non-specific UTI group26,53, -55,57,60,61, 1 study compared ASB to a cystitis and a pyelonephritis group,59 and the final study compared ASB with a pyelonephritis group only.56 Fourteen biomarkers were investigated; IL-6 7 times, IL-8 4 times, and the remainder only once. This evidence concerns the gene IL6 and pyelonephritis.