Inflammation as a diagnostic keystone and its clinical implications, exemplified by the inflammatory bowel diseases.

Inflammation is a complex process following sublethal injury to tissue and ends with permanent destruction of tissue or with healing. Inflammation has long, long roots in the evolutionary process and as a concept reaches far back in the history of medicine. Inflammation can not be viewed solely in a teleological perspective. Refined by phylogenesis it serves the integrity and survival of groups (species etc.) and not primarily individuals. Inflammation has, in the history of science, been studied on the macroscopic, the microscopic, the dynamic cellular, the immunological, the biochemical/physiological, and the molecular level. Clinicians have for centuries relied on inflammatory signs and symptoms in their diagnostics, even to the extent of being seriously confused, when a subject's inflammatory preparedness is disturbed, as in agranulocytosis, alcoholism, HIV-infection etc. Chronic inflammatory bowel diseases (ulcerative colitis and Crohn's disease) have been studied intensively by inflammologists. The results are partly exchangeable with studies in, for instance, chronic rheumatoid arthritis. They try to answer the over-all question in these diseases: Are we dealing with a normal inflammatory preparedness confronted with a special (unknown) agent, or an abnormal inflammatory preparedness confronted with an ubiquitous agent? The answer will form the basis for the future treatment of these patients, whose diseases remind us of inflammation as man's fellow traveller on "the long phylogenetic march".