Implications for Future Management of IBD, Lessons from Cohort Studies

Inflammatory Bowel Disease (IBD) is a chronic disabling disease of the gastrointestinal tract, comprising Crohn’s disease (CD), Ulcerative Colitis (UC) and unclassified colitis (IBDU). IBD is a multifactorial disease. Aside from the intestinal microflora, environmental triggers and the immune response, genetic susceptibility plays an important role in the development of IBD. Epidemiologic data suggest that the prevalence of IBD reaches up to 396/100,000 persons. The worldwide incidence of UC varies between 0.5-24.5/100,000, while that of CD varies between 0.1-16/100,000 persons. At present, no treatment exists that can lead to a definitive cure for IBD. As such, the treatment goal is to provide long-term clinical remission without disease progression or disease complications. Within the last decade there has been a shift in treatment goals from symptomatic control to sustained clinical and endoscopic remission and, even more recently, mucosal healing2-7. Treatment strategies have therefore changed, from conventional step-up to early introduction of immunomodulators and/or anti-TNFα, including a more stringent assessment of disease activity and rapid therapeutic escalation to achieve tight control of inflammation. Thus, instead of using a fixed strategy, a tailored treatment is increasingly considered to be more appropriate. However, for tailored treatment to be implemented, predictive factors related to adverse disease outcome are required. In this thesis, several aspects of IBD are considered, with a view to tailor treatment in order to achieve the most efficient strategy with currently available drugs. These aspects include diagno