Soluble P-selectin: A potential serum biomarker for Inflammatory Bowel Disease and useful guide for Infliximab therapy: P-0023.

Assessment of disease activity in inflammatory bowel disease (IBD) is primarily based on subjective evaluation of symptoms and non-specific markers of inflammation. The discovery and validation of specific serological markers that accurately reflect disease severity may represent a valuable tool for the assessment and management of patients with IBD. Given the natural history of IBD, which is characterized by periods of remissions and flares, a reliable marker of disease activity may help in decision analysis regarding diagnosis as well as treatment. Several cell adhesion molecules (CAM), known to be upregulated in both Crohn's disease and ulcerative colitis, are shed into the circulation, where they are detectable by ELISA in their soluble forms (soluble CAM). Previous studies have demonstrated that soluble P-selectin, which is present on endothelial and platelet surfaces and shed during the process of neutrophil recruitment, may be the most promising soluble CAM to be used as a biomarker. Additionally, within the last few years biological therapies have for the treatment of IBD have been developed. The first biological therapy developed was infliximab, a chimeric monoclonal antibody against TNF-α. Reports document up to a 70% response rate after a single infusion. Reinfusion at 8-week intervals results in sustained clinical response in most patients. The aim of the present study is to investigate whether circulating levels of CAM, including ICAM-1, VCAM-1, P-and E-selectin could discriminate between patients with CD versus normal volunteers. Patients with Crohn's disease, ulcerative colitis, or indeterminate colitis (n = 36) referred for infliximab infusion, were enrolled in this study. Ten healthy volunteers were also recruited as controls. A blood sample was collected from both groups prior to infliximab administration in those patients with IBD. The serum was subsequently separated and stored at -70°C. Circulating levels of soluble ICAM-1, VCAM-1, P-and E-selectin were determined by specific ELISA. Demographic data and information regarding concomitant therapy with 5-ASA compounds, immunomodulators, and steroids was also collected. Significant differences (p