Clinical and genetic factors associated with disease course in inflammatory bowel disease

Inflammatory bowel disease (IBD), consisting of Crohn’s disease (CD) and ulcerative colitis (UC), is a chronic immune-mediated inflammatory disease of the gastro-intestinal tract that is characterized by its heterogeneous presentation and relapsing character. This highly variable presentation makes it very important to identify the clinical and genetic factors that can be used to predict disease course in individual patients. Many factors whose effect on disease phenotype and disease course has not yet been intensively researched, including the influence of ethnicity and sex differences (this thesis). The second part of this thesis focuses on genetic variants that are associated with a specific IBD phenotype, such as hidradenitis suppurativa in IBD, recurrent stenosis in CD, and the formation of anti-drug antibodies in patients treated with anti-TNF-alpha (this thesis). Ultimately, we want to incorporate both clinical and genetic risk factors into an algorithm that can predict whether a given patient will be at risk of a severe disease course, also called “precision medicine”. With such a prediction model, we could prevent unfavorable outcomes by starting harsher medical treatment earlier in the disease course in patients at high risk for severe disease outcome.