IMMUNOLOGY OF INFLAMMATORY BOWEL-DISEASE

Several theories have been proposed to explain the chronic inflammatory process leading to tissue injury in Crohn's disease and ulcerative colitis. Among them, some abnormality of the immune system is believed to be involved in the pathogenesis of inflammatory bowel disease. Such abnormality is not likely to be systemic, but localized instead at the level of the intestinal mucosa. Whether a putative immune defect is restricted to a particular function or a unique cell type is still unknown. Consequently, current investigation in the immunology of inflammatory bowel disease is broad based, and includes cellular and humoral pathways in addition to a large number of immunoregulatory molecules. In this section, selected reports are discussed based on their relevance to mucosal immunity, inflammation, and inflammatory bowel disease pathogenesis.