Results Of the 96 investigated genes, 9 were significantly up-regulated in the high inflammation group of samples. Four of them were significantly correlated with the inflammation score: CCR7, CD40LG, CTLA4 and ICOS (the IL17 up-regulation was not significant). In the urine samples, ICOS protein expression was easily quantified by ELISA and was associated with a higher post-void residual (93.2 vs 37.2ml; p=0.020) and a lower maximum urinary flow rate (9.1 vs 12.7ml/s; p=0.033). Grégoire ROBERT 1,2, Frank SMIT 3, Kees JANSEN 1, Tilly AALDERS 1, Alexandre de la TAILLE 4, Jack SCHALKEN 11. Radboud University Nijmegen Medical Center, Experimental Urology, Nijmegen, The Netherlands2. Bordeaux Pellegrin University Hospital, Department of Urology, Bordeaux, France3. Noviogendix, Nijmegen, The Netherlands4. Henri-Mondor Hospital, AP-HP , Department of Urology, Créteil, FranceIntroduction and ObjectivesChronic prostatic inflammation (CPI) may be a central mechanism in prostateenlargement and benign prostatic hyperplasia (BPH) progression 1, 2.Until today CPI can only be diagnosed by prostatic biopsies. But to furtherinvestigate the link between CPI and BPH in clinical trials, a less invasivediagnostic tool in needed.As a first step towards the identification of non invasive biomarkers forprostatic inflammation, our objectives were:study the inflammatory and immune responses-To correlate the mRNA expression with an histological inflammation score-To investigate the protein expression of these potential biomarkers in urinesamplesMaterial and Methods90 BPH tissue samples were investigated in two steps.First a hypothesis was generated using a profiling procedure with a panel of96 genes on an initial set of 30 BPH samples.Then the candidate biomarkers were validated on a large number of samples(n=90).A histological inflammation score based on the density and the confluence oflymphoid inflammation.The relative expression of the genes were calculated and compared with theFigure 1: Quantitative real-time PCR gene target relative quantification (RQ) in 90 BPH samples according to the histological inflammation score (none (n=6), mild (n=19), moderate (n=39) or severe (n=26) prostatic inflammation) Figure 2: Post-void residual and maximum uroflowmetry according to the ICOS protein expression (<357 pg/ml versus >357 pg/ml) in 45 urine samples collected after digital rectal examination Conclusions Four genes were significantly up regulated at the mRNA level in the prostatic tissue of patients with severe inflammation: CCR7, CD40LG, CTLA4 and ICOS. In urine, and at the protein level, ICOS was easily measured by ELISA and was associated with a higher post-void residual and a lower maximum urinary flow rate.G. Robert has been granted by the EAU Scholarship Program (EUSP grant S03-2009) and by the French Urological Association (Association Française d’Urologie - AFU) References: 1. Nickel JC et al: The Relationship between Prostate Inflammation and Lower Urinary Tract Symptoms: Examination of Baseline Data from the REDUCE Trial. Eur Urol 2008 2. Robert G et al. Inflammation in benign prostatic hyperplasia: a 282 patients' immunohistochemical analysis. The Prostate 2009。
