[Local procoagulant activity--an important pathogenic mechanism in Crohn disease?]

The etiology of Crohn's disease is unknown. Observations suggest that some sort of luminal agent enters the intestinal mucosa and elicits the special inflammatory reaction. Immunological mechanisms seem to be important. A related but so far largely unrecognised reaction is local activation of the external coagulation system by induction of thromboplastin (tissue factor) activity on the surface of endothelial cells and macrophages. This local procoagulant activity might initiate the formation of thromboses in small arteries in the intestinal wall. Recent studies indicate that microinfarcts due to arterial thromboses at the level of the muscularis propria may be an important pathogenetic mechanism in Crohn's disease.