Maarten Cozijnsen

24 Aim of this thesis The primary aim of this thesis is to compare the efficacy and safety of the top-down and step-up treatment strategies. Additional aims of this thesis are: • to develop a novel, Mucosal Inflammation Non-invasive (MINI) index that correlates with mucosal inflammation, and accurately discriminates endoscopic remission from active inflammation in children with CD. • to study differences in the immune responses of newly diagnosed pediatric CD patients to infliximab or prednisolone treatment. • to evaluate the real-world efficacy of ADA in pediatric CD patients and compare its efficacy in patients that were prior IFX non-responders or had lost response to IFX. • to review the scientific international literature to determine the benefits and risks of combining anti-TNF with immunomodulator therapy in pediatric IBD.