New insights in pediatric inflammatory bowel diseases: from disease pathogenesis to clinical and therapeutic management

Inflammatory bowel diseases (IBD), including Crohn’s disease (CD), Ulcerative colitis (UC) and IBD-unclassified (IBD-U) is a group of life-long chronic and relapsing inflammatory disorders of the gastrointestinal tract whose etiology has not been completely understood. The most recent evidences involve a complex interaction between host genetic, environmental and microbial influences, resulting in a dysregulated mucosal immune response against the commensal intestinal microbiota. Although the incidence and prevalence of IBD differ among countries, the general trend clearly highlights an overall increase over the past few decades in western countries, especially in adolescence and young adulthood. Paediatric IBD has several specific considerations when compared with adult IBD. These certainly include the relevant issues related to growth, development, pubertal maturation, bone health, and psychological impact on the patient and family, but also the unique features related to paediatric IBD phenotype, which is well-renowned to represent both a diagnostic and therapeutic challenge, being characterized by higher severity, including poor response to medical treatment, presence of extra-intestinal manifestations (EIM), and increased risk of surgery. This thesis project aims to provide new insights in paediatric IBD pathogenesis, to characterize the phenotype and the disease course of IBD in paediatric age and to improve the clinical and therapeutic strategies for the management of paediatric IBD.