Comparison of inflammatory urine markers in patients with interstitial cystitis and overactive bladder

Chronic inflammatory conditions seem to be a shared characteristic in patients with interstitial cystitis (IC) and overactive bladder (OAB). Thus, we measured 40 inflammatory urine markers in IC patients with or without Hunner's lesions (HIC and NHIC respectively) and OAB patients.

Urine was collected from consecutive HIC patients, NHIC patients, and age and gender-matched OAB patients with no history of IC, recurrent urinary tract infection or bladder cancer. The diagnosis of IC was based on the Asian IC guideline criteria. A representative 40 inflammatory growth factors, cytokines, and chemokines in urine were measured using a MILLIPLEX immunoassay kit. Statistical differences in these markers among the groups were determined by nonparametric ANOVA followed by multiple comparison test. The diagnostic efficiency of these markers was measured using receiver operating characteristic analysis.

Vascular endothelial growth factor (VEGF), interleukin-1α (IL-1α), IL-6, and chemokines including CCL2, CCL5, CXCL1, CXCL8, and CXCL10 were significantly increased in HIC (n = 30) and NHIC (n = 30) patients compared with OAB (n = 28) patients. The significant increases in CXCL8 and CXCL10 were also found in HIC patients compared with NHIC patients. However, there were no significant differences in the other urine markers among the groups. Area under the curves for VEGF, CXCL10, CXCL8, IL-1α, CCL5, CCL2, IL-6, and CXCL1 to detect IC in these patients were 0.87, 0.86, 0.81, 0.80, 0.80, 0.71, 0.66, and 0.50 respectively.

The increases in angiogenesis-associated proteins such as VEGF and CXCL10 may be pathophysiologically important for the development of IC.