Abstract

The capacity of circulating phagocytes for activation by complement was investigated in consecutive, untreated cases of chronic inflammatory bowel disease. The major complement derived chemotactic factor, C5a, served as chemoattractant in dose response studies of neutrophil chemotaxis. A similar, significantly decreased sensitivity and peak response was revealed in patients with Crohn's disease and ulcerative colitis. This subnormal function of neutrophils could be shown even in cases of complete clinical remission. Chemotactic response to casein and spontaneous motility was within the normal range showing an unaffected basic cell function of neutrophils in the patients. The study shows a dysfunction of phagocytic cells, related to potentially important phlogistic mediators, in chronic inflammatory bowel disease.