Comparing concentration of urinary inflammatory cytokines in interstitial cystitis, overactive bladder, urinary tract infection, and bladder cancer

Abstract

Purpose: We sought to determine if urinary cytokine concentration profiles were different between various bladder conditions. Materials and Methods: Participants at three clinical sites completed a demographics survey and provided a urine sample in a collection cup containing a room-temperature urine preservative. Participants were divided into the following categories based on physician-documented diagnosis: asymptomatic control, nonulcerative interstitial cystitis (IC), overactive bladder with incontinence (OAB wet), urinary tract infection (UTI), and bladder cancer. Urinary cytokines were measured through Luminex multiplex assay. Results: Two hundred and seventy-seven urine samples were collected from three clinical sites. Urinary pro-inflammatory cytokines had an increasing trend in bladder disease versus control, with a significant increase for chemokine (C-X-C) ligand 1 growth-regulated protein alpha CXCL1 (GRO). Further analyses demonstrated that patients with UTI had significantly higher levels of GRO and interleukin-8 (IL-8) in comparison to control, nonulcerative IC, OAB wet, and bladder cancer. Both are chemokines that stimulate chemotaxis resulting in the rapid accumulation of immune cells such as neutrophils. IL-6 levels overall were at the lower limit of assay range but were significantly increased in urine of UTI patients versus IC patients. MCP-1 (CCL2) had the least separation among the control group and the various bladder diseases. Conclusion: Urinary concentrations of GRO were higher in disease state compared to control. Specifically, levels of GRO and IL-8 were higher in urine samples from patients with UTI compared to controls and other bladder conditions. Comparing and contrasting urinary cytokines may help improve our understanding of these important bladder diseases with great unmet needs.