IL6 and cystitis: Three studies found higher level of IL-6 in samples from patients with pyelonephritis than samples from healthy control subjects.37,39,57 Six studies compared samples from patients with cystitis or a non-specific UTI with those from controls.39,51,53,57,59,60 In 3 studies, samples from patients were between 3.8 and 37.5 times higher in samples from patients than those from controls.53,59,60 The remaining 3 found equivocal results,39 or no difference between groups.51,57