[Immunohistologic changes of the intestinal mucosa in chronic inflammatory bowel diseases]

In the pathogenesis of inflammatory bowel disease abnormally increased immune reactions in the intestinal mucosa play a basic role. The revealing of these reactions was facilitated by the rapidly spreading immunohistological methods in last decades. This review discusses in detail the characteristic distribution of lymphocyte subsets and plasma cells in Crohn's disease and ulcerative colitis. Results indicating increased expression of adhesion molecules are also presented, as well as the different patterns of cytokine production in Crohn's disease and ulcerative colitis. The rapid epithelial turnover developing as a consequence of increased rate of proliferation and apoptosis in inflammatory bowel disease is also shown. The epithelial expression of MHC II antigen in colonic mucosa which is not observed in healthy subjects is also discussed. In addition, the pathogenetic role of lost oral tolerance in the development of inflammatory bowel is reviewed in detail.