Investigation into the aetiology and pathogenesis of inflammatory bowel diseases

This investigation concerns some facets of the aetiology of Crohn's disease and ulcerative colitis, two chronic inflammatory diseases of the alimentary canal. The working hypothesis assumes that both of these conditions are caused by immune allergic reactions to antigens normally present in the alimentary canal. These antigens, possibly of microbial (bacterial or viral) or dietary nature, could produce antibodies which react with the patient's own tissues, in this case the alimentary tract. Also because food probably is of an inconstant composition and that of the colonising bacteria is definably more consistant, we concentrated on the bacterial antigens to the endogenous flora. This antigen source is under normal circumstances held under control by the host defence mechanism (both local and systemic). The local defence mechanism tries to keep the antigen inside the lumen of the digestive tract using secretory immunoglobulin A (s-IgA); the systemic immune mechanism (reacting to endogenous bacterial antigens with circulating antibodies) is depressed by T-suppressor cell activity. ... Zie: Summary