Research and Follow-up of the Determinants of the Progression and Complications of Inflammatory Bowel Diseases Treated or Not With Immunosuppressants.

Inflammatory Bowel Diseases (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), are chronic, disabling conditions affecting young adults, marked by flare-ups and remissions. Traditionally, IBD was treated with immunosuppressants like thiopurines, but new biological treatments, such as anti-TNFa antibodies (e.g., infliximab, adalimumab), have transformed management. Biologics often combine with thiopurines but come with risks, like increased chances of skin cancers and lymphomas, especially for prolonged use in young patients. Recently, newer biologics (e.g., ustekinumab, vedolizumab) and small molecules like JAK inhibitors have expanded treatment options.

The exact cause of IBD remains unknown, though an inappropriate immune response to the intestinal microbiota in genetically predisposed individuals is suspected. Dysbiosis, or imbalance in gut microbiota, has been linked to IBD, with reductions in 'beneficial' bacteria and increases in harmful ones. Certain bacteria, like Faecalibacterium prausnitzii, may serve as markers for disease activity or progression.

Due to the heterogeneity of UC and CD, it is crucial to identify early predictive factors for complications and treatment response. This study aims to identify biological markers of disease course and complications in IBD and to deepen understanding of its pathophysiological mechanisms.