4 Inflammatory Bowel Disease G-Protein Coupled Receptors (GPCRs) Expression Profiling with Microfluidic Cards Nathalie Taquet 1 , Claude Philippe 1 , Jean-Marie Reimund 2,3 and Christian D. Muller 1 1 Laboratoire d'Innovation Thérapeutique UMR CNRS 7200, Faculté de Pharmacie, Université de Strasbourg, 2 CHU de Caen, Service d'Hépato-Gastro-Entérologie et Nutrition 3 Université de Caen Basse-Normandie, EA 3919, SFR ICORE, UFR de Médecine France 1. Introduction Crohn's disease (CD) and chronic ulcerative colitis (UC) are considered as two distinct forms of inflammatory bowel disease (IBD). In IBDs, the first clinical signs of disease begin typically between adolescence and the third decade of life (Andres & Friedman 1999; Baldassano & Piccoli 1999). CD is a non-specific granulomatous inflammatory disease affecting the lower end of the ileum and often involving the colon and other parts of the intestinal tract (Podolsky 2002). CD was first reported by B. Crohn and his colleagues in 1932 and called Regional Enteritis (Matsuura et al. 1993). CD is diagnosed in four patients per 100 000 in the Northern Europe and the incidence and prevalence is rising (Elson et al. 1995). UC is a chronic disease of unknown etiology characterized by inflammation of the mucosa and sub-mucosa of the rectum (altimes) with a continuous extension to upper parts of the colon without healthy mucosa between inflammatory mucosa, which can be limited to the rectum (proctitis) to the colon below the lefts angle (left colitis), beyond the left angle (extensive colitis) or affect all the colon (pancolitis). UC is mostly characterized by bloody diarrhea. UC may have a prevalence of 100 case per 100 000 population in Northern Europe (Satsangi et al. 1996) The causes of CD and UC remain to be clarified. However, genetic factors in combination with environmental factors are suspected to be involved in the pathogenesis of Crohn's disease (Baker et al. 1981; Podolsky 2002). Inadequate or prolonged activation of the intestinal immune system plays an important role in the pathophysiology of chronic mucosal inflammation (Elson et al. 1995; Matsuura et al. 1993). CD and UC are characterized by periods of remission followed by episodes of clinical relapse, characterized by an increase in symptoms usually due to acute intestinal inflammation. Treatment is primarily aimed at reducing inflammation during relapse and secondarily at prolonging the time-spent remission. Conventionally both of these aims are governed by consideration of clinical symptoms rather than objective evidence of inflammatory activity. Gastroenterologists are often faced with the difficulty of differentiating patients with irritable bowel syndrome from those with organic intestinal www.intechopen.com