Elevated CXC Chemokines in Urine Non-invasively Discriminate OAB from UTI

Overlapping symptoms of overactive bladder (OAB) and urinary tract infection UTI often complicate the diagnosis and contribute to over- prescription of antibiotics. Inflammatory response is a shared characteristic of both UTI and OAB and here we hypothesized that molecular differences in inflammatory response seen in urine can help discriminate OAB from UTI.

Subjects in the age range of (20-88 years) of either sex were recruited for this urine analysis study. Urine specimens were available from 62 UTI patients with positive dipstick test before antibiotic treatment. Six of these patients also provided urine after completion of antibiotic treatment. Subjects in cohorts of OAB (n= 59) and asymptomatic controls (n=26) were negative for dipstick test. Urinary chemokines were measured by MILLIPLEX MAP Human Cytokine/Chemokine immunoassay and their association with UTI and OAB was determined by univariate and multivariate statistics.

Significant elevation of CXCL-1, CXCL-8(IL-8) and CXCL-10 together with reduced levels for receptor antagonist of IL-1a (sIL-1RA) were seen in UTI relative to OAB and asymptomatic controls. Elevated CXCL-1 urine levels predicted UTI with odds ratio of 1.018 and showed a specificity of 80.77% and sensitivity of 59.68%. Post-antibiotic treatment, reduction was seen in all CXC chemokines with significant reduction for CXCL-10.

Strong association of CXCL-1 and CXCL-10 for UTI over OAB indicates mechanistic differences in signaling pathways driving inflammation secondary of infection in UTI compared to a lack of infection in OAB. Urinary chemokines highlight molecular differences in the paracrine signaling driving the overlapping symptoms of UTI and OAB.

American journal of physiology. Renal physiology. 2016 Jun 22 [Epub ahead of print]

Pradeep Tyagi, Vikas Tyagi, Xianggui Qu, Yao-Chi Chuang, Hann-Chorng Kuo, Michael B Chancellor

University of Pittsburgh ., ERAS medical., Oakland University., Kaohsiung Chang Gung Memorial Hospital., Hualien Tzu Chi Medical Center., William Beaumont Hospital.