[Immunology in medical practice. IV. Inflammatory bowel diseases: pathogenic starting points for specific therapy].

The cause of inflammatory bowel diseases is unknown, but T-cells play an important part in the pathogenesis of Crohn's disease. It was shown in recent years that activated T-cells produce certain cytokines that cause inflammation (interferon-alpha, tumour necrosis factor-alpha or TNF-alpha), but also cytokines (interleukin-10 or IL-10, transforming growth factor-alpha) which on the contrary inhibit inflammation. On the basis of this knowledge, the mucosal inflammatory reaction can be counteracted in a rational manner: antibodies against TNF-alpha in most patients with Crohn's disease who failed to respond to corticosteroids led to substantial reduction of disease activity. The first experiences with IL-10 treatment of Chrohn patients are also encouraging. It is expected that in the near future still more forms of immunotherapy directed against cytokines will become available.