Development of an interstitial cystitis risk score for bladder permeability.

BACKGROUND: Interstitial cystitis/bladder pain syndrome (IC) is a multifactorial syndrome of severe pelvic and genitalia pain and compromised urinary function; a subset of IC patients present with Hunner's lesions or ulcers on their bladder walls (UIC). UIC is diagnosed by cystoscopy, which may be quite painful. The objective of this study was to determine if a calculated Bladder Permeability Defect Risk Score (BP-RS) based on non-invasive urinary cytokines could discriminate UIC patients from controls and IC patients without Hunner's ulcers. METHODS: A national crowdsourcing effort targeted IC patients and age-matched controls to provide urine samples. Urinary cytokine levels for GRO, IL-6, and IL-8 were determined using a Luminex assay. RESULTS: We collected 448 urine samples from 46 states consisting of 153 IC patients (147 female, 6 male), of which 54 UIC patients (50 females, 4 male), 159 female controls, and 136 male controls. A defined BP-RS was calculated to classify UIC, or a bladder permeability defect etiology, with 89% validity. CONCLUSIONS: The BP-RS Score quantifies UIC risk, indicative of a bladder permeability defect etiology in a subset of IC patients. The Bladder Permeability Defect Risk Score is the first validated urine biomarker assay for interstitial cystitis/bladder pain syndrome.

Urine CXCL1 as a biomarker for tumor detection and outcome prediction in bladder cancer.

BACKGROUND AND OBJECTIVE: To clarify the clinical usefulness and diagnostic accuracy of urine chemokine (C-X-C motif) ligand 1 (CXCL1) as a biomarker for tumor detection and outcome prediction in patients with bladder cancer (BCa). METHODS: We measured urine CXCL1 levels in 175 patients with BCa and 30 healthy controls. The value of urine CXCL1 concentration normalized by urine creatinine (CXCL1/Cre) was analyzed in terms of detecting bladder tumors and predicting intravesical recurrence after transurethral resection (TUR). RESULTS: CXCL1/Cre was significantly higher (3-fold) in BCa patients than in healthy participants and the difference from control samples was greater in patients with advanced BCa. Although the urine cytology test generally lost diagnostic power in patients with low-grade superficial tumors, the sensitivity of CXCL1/Cre was not compromised in this patient population. Patients with higher CXCL1/Cre were significantly more likely to develop intravesical recurrence after TUR and multivariate analysis identified CXCL1/Cre as an independent predictor of post-TUR intravesical recurrence. Importantly, CXCL1/Cre could successfully classify the probabilities of post-TUR recurrence among patients with intermediate-risk according to EORTC risk criteria into two groups equivalent to its high- and low-risk groups. CONCLUSIONS: Urine CXCL1 is a promising, non-invasive molecular marker for tumor detection and outcome prediction in patients with BCa.

Urinary CXCL1: a novel predictor of IgA nephropathy progression.

BACKGROUND: IgA nephropathy (IgAN) is the most common form of primary glomerulonephritis worldwide. In recent years, consistent efforts have been made to develop new non-invasive biomarkers for IgAN progression. In our previous in vitro study we found mesangial derived CXCL1 as a contributor for kidney injury, and observed higher urinary CXCL1 levels in patients with IgAN. It implied that the urinary CXCL1 might be a potential biomarker. METHODS: In the present study, we enrolled 425 IgAN patients with follow-up data and detected their urinary CXCL1 levels at the time of renal biopsy, to explore the predictive value of urinary CXCL1 in IgAN progression. Urinary CXCL1 levels were measured using enzyme-linked immunosorbent assay. RESULTS: Urinary CXCL1 levels were associated with presently well established predictors of IgAN progression, including SBP (r = 0.138, p = 0.004), DBP (r = 0.114, p = 0.019), proteinuria (r = 0.155, p = 0.001), eGFR (r = -0.259, p<0.001) and tubular atrophy and interstitial fibrosis (r = 0.181, p<0.001). After adjusted for them, higher levels of urinary CXCL1 were independently associated with a greater risk of deterioration in renal function (HR, per s.d. increment of natural log-transformed CXCL1: 1.748; 95% CI: 1.222-2.499, P = 0.002). Furthermore, time-dependent receiver operating characteristic (ROC) curve showed that urinary CXCL1, when combined with proteinuria and eGFR, could enhance the prognostic value of these traditional predictors for IgAN progression. CONCLUSIONS: The results in our present study suggested urinary CXCL1 as a new non-invasive predictor of IgAN progression.

Synergistic effect of mesangial cell-induced CXCL1 and TGF-ß1 in promoting podocyte loss in IgA nephropathy.

Podocyte loss has been reported to relate to disease severity and progression in IgA nephropathy (IgAN). However, the underlying mechanism for its role in IgAN remain unclear. Recent evidence has shown that IgA1 complexes from patients with IgAN could activate mesangial cells to induce soluble mediator excretion, and further injure podocytes through mesangial-podocytic cross-talk. In the present study, we explored the underlying mechanism of mesangial cell-induced podocyte loss in IgAN. We found that IgA1 complexes from IgAN patients significantly up-regulated the expression of CXCL1 and TGF-ß1 in mesangial cells compared with healthy controls. Significantly higher urinary levels of CXCL1 and TGF-ß1 were also observed in patients with IgAN compared to healthy controls. Moreover, IgAN patients with higher urinary CXCL1 and TGF-ß1 presented with severe clinical and pathological manifestations, including higher 24-hour urine protein excretion, lower eGFR and higher cresentic glomeruli proportion. Further in vitro experiments showed that increased podocyte death and reduced podocyte adhesion were induced by mesangial cell conditional medium from IgAN (IgAN-HMCM), as well as rhCXCL1 together with rhTGF-ß1. In addition, the over-expression of CXCR2, the receptor for CXCL1, by podocytes was induced by IgAN-HMCM and rhTGF-ß1, but not by rhCXCL1. Furthermore, the effect of increased podocyte death and reduced podocyte adhesion induced by IgAN-HMCM and rhCXCL1 and rhTGF-ß1 was rescued partially by a blocking antibody against CXCR2. Moreover, we observed the expression of CXCR2 in urine exfoliated podocytes in IgAN patients. Our present study implied that IgA1 complexes from IgAN patients could up-regulate the secretion of CXCL1 and TGF-ß1 in mesangial cells. Additionally, the synergistic effect of CXCL1 and TGF-ß1 further induced podocyte death and adhesion dysfunction in podocytes via CXCR2. This might be a potential mechanism for podocyte loss observed in IgAN.

Urine cytokines suggest an inflammatory response in the overactive bladder: a pilot study.

PURPOSE: To study the hypothesis of detecting bladder inflammation associated with overactive bladder (OAB) through altered urine levels of cytokines, chemokines, and growth factors. METHODS: Midstream urine specimens were collected from a prospective study done on eight asymptomatic control subjects and 17 idiopathic OAB patients. The urine was analyzed by a multiplex panel screen for 12 chemokines, cytokines, growth factors, and soluble receptors using Luminex™ xMAP(®) technology. Protein concentration values were normalized to the levels of creatinine. RESULTS: This analysis revealed a significant elevation of seven key proteins in the urine of OAB patients relative to controls (*P < 0.05). A greater than tenfold elevation was measured in OAB, relative to controls, in the levels of monocyte chemotactic protein-1 (MCP-1), soluble fraction of the CD40 ligand (sCD40L) in urine was obtained from OAB patients relative to controls. At least five fold elevations were detected in the levels of macrophage inflammatory protein (MIP-1ß), IL-12p70/p40, IL-5, epidermal growth factor (EGF), and growth-related oncogene GRO-α compared to controls. Significant threefold elevation was also noticed in the urine levels of sIL-2Rα, and IL-10 in the OAB group. The levels of the remaining proteins tested were not statistically significantly different from control values. CONCLUSIONS: The presence of elevated levels in urine of inflammatory biomarkers involved in inflammation and tissue repair suggests a role for inflammation in OAB, and may help in diagnosis and treatment of this disease.

Secreted CXCL1 is a potential mediator and marker of the tumor invasion of bladder cancer.

PURPOSE: The purpose of this study was to identify proteins that are potentially involved in the tumor invasion of bladder cancer. EXPERIMENTAL DESIGN: We searched for the candidate proteins by comparing the profiles of secreted proteins among the poorly invasive human bladder carcinoma cell line RT112 and the highly invasive cell line T24. The proteins isolated from cell culture supernatants were identified by shotgun proteomics. We found that CXCL1 is related to the tumor invasion of bladder cancer cells. We also evaluated whether the amount of the chemokine CXCL1 in the urine would be a potential marker for predicting the existence of invasive bladder tumors. RESULTS: Higher amount of CXCL1 was secreted from highly invasive bladder carcinoma cell lines and this chemokine modulated the invasive ability of those cells in vitro. It was revealed that CXCL1 regulated the expression of matrix metalloproteinase-13 in vitro and higher expression of CXCL1 was associated with higher pathologic stages in bladder cancer in vivo. We also showed that urinary CXCL1 levels were significantly higher in patients with invasive bladder cancer (pT1-4) than those with noninvasive pTa tumors (P = 0.0028) and normal control (P < 0.0001). Finally, it was shown that CXCL1 was an independent factor for predicting the bladder cancer with invasive phenotype. CONCLUSIONS: Our results suggest that CXCL1 modulates the invasive abilities of bladder cancer cells and this chemokine may be a potential candidate of urinary biomarker for invasive bladder cancer and a possible therapeutic target for preventing tumor invasion.