Increased fecal eosinophil cationic protein in inflammatory bowel disease.

Eosinophil cationic protein (ECP) is a cytotoxic substance released by eosinophilic granulocytes. Serum and body-fluid levels may be elevated in some allergic and inflammatory conditions characterized by heavy infiltration of eosinophils. ECP has not previously been measured in feces. Because pronounced infiltration with eosinophils is often seen in ulcerative colitis, we examined fecal excretion of ECP in 29 patients with active inflammatory bowel disease (IBD) and in 10 healthy persons. Mean fecal ECP levels were more than 14 times higher in the patients than in the healthy persons (p < 0.001). Fecal ECP was similarly elevated in ulcerative colitis and Crohn's disease. During storage, ECP in feces was relatively stable. Steroid treatment may suppress fecal ECP excretion. The possible value of fecal ECP as an IBD activity parameter warrants further studies. ECP may also be involved in the pathogenesis of IBD.