The basis of immunosuppressive treatment in ulcerative colitis.

Clinical signs and immunological findings suggest that causation and subsequent progress of ulcerative colitis are related to the body's immune systems. Among the immunological findings, the following are of special importance: the appearance of humoral antibodies against colonic antigens, the presence of specific adapted lymphocytes against fetal colonic epithelium, the decrease of complement (especially in severe types of the disease), and immunohistological changes in the colonic mucosa. The histological changes in the region of the affected segment of intestine and the regional lymphnodes are also characteristic of an immuno-inflammatory disease. However, it is not yet known whether the immunological mechanism is responsible for causing the disease or whether it occurs together with a disease which has no immunological basis.