[Immunological aspects of inflammatory bowel diseases (author's transl)].

The gastrointestinal tract is replete with immunocompetent tissue represented by appendix, Peyer's patches and nonaggregated lymphocytes in the intestinal epithelium. This local immune system plays a vital role in the physiologic immune response and in the control of food, drug, microbial or viral antigens. Under certain situations this lymphoid tissue may contribute to the immunological reactions underlying the pathogenesis of various diseases. Generalised deficiencies of the immune apparatus frequently give rise to disturbances of gastrointestinal function. Furthermore plenty of immune reactions occurring in connection with human inflammatory bowel disease have been described. Some immunologic features are reported as typical for a disease, the majority seems to indicate only nonspecific autoimmune reactions. The relevance of immunological mechanisms for the pathogenesis of these diseases is still not full evaluated.