CROHNS-DISEASE - PATHOGENESIS AND PERSISTENT MEASLES-VIRUS INFECTION

The Inflammatory Bowel Disease Study Group at the Royal Free Hospital School of Medicine has tested the hypothesis that the primary patholog ical abnormality in Crohn's disease is in the mesenteric blood supply. Early morphological studies involved arterial perfusion-fixation and either resin casting and scanning electron microscopy or vascular immu nostaining of resected intestine affected by Crohn's disease. Granulom atous and lymphocytic damage to intramural blood vessels, even in macr oscopically normal areas, was observed. We put forward possible mechan isms by which a chronic ischemic process might account for many of the idiosyncracies of Crohn's disease. It was proposed that persistent vi ral infection of the mesenteric microvascular endothelium might underl y this vasculitic process; based on certain behavioral characteristics of measles virus, including its tropism for the submucosal endotheliu m of the intestine, this agent was investigated further. This report r eviews the preliminary evidence from both epidemiological and basic sc ientific data for persistent measles virus in the intestine of patient s with Crohn's disease. Possible mechanisms for virus persistence and subsequent reactivation are discussed. In conclusion, we believe that Crohn's disease may be a chronic granulomatous vasculitis in reaction to a persistent infection with measles virus within the vascular endot helium. This granulomatous inflammation, perhaps aggravated by either a hypercoagulable state or mechanical stress, results in the clinical features of Crohn's disease.