Role of faecal calprotectin as non-invasive marker of intestinal inflammation

Background/aim. Faecal calprotectin, a neutrophil granulocyte cytosol protein, is considered a promising marker of intestinal inflammation. We assessed and compared the faecal calprotectin concentration in patients with organic and functional chronic intestinal disorders. Patients and methods. The study was carried out, using a commercially available ELISA test, measuring calprotectin in stool samples collected from 131 patients with inflammatory bowel diseases, 26 with intestinal neoplasms, 48 with irritable bowel syndrome and 34 healthy subjects. Results. Median faecal calprotectin was significantly increased in Crohn's disease (231 mug/g, 95% confidence interval (CI) 110-353 mug/g), ulcerative colitis (167 mug/g, 95% Cl 59-276 mug/g), and neoplasms (105 mug/g, 95% Cl 0-272 mug/g), whereas normal values were found in patients with irritable bowel syndrome (22 mug/g, 95% CI 9-35 mug/g) and in healthy subjects (11 mug/g, 95% Cl 3-18 mug/g). A positive correlation was observed with clinical activity scores in Crohn's disease and ulcerative colitis. In both groups, patients with clinically active disease showed higher calprotectin levels than those observed in patients with quiescent disease (405 mug/g, 95% CI 200-610 mug/g vs. 213 mug/g, 95% CI 85-341 mug/g in CD patients, p<0.05, and 327 mug/g, 95% Cl 104-550 mug/g vs. 123 mug/g, 95% CI 40-206 mug/g in UC patients, p<0.001) Conclusions. Faecal calprotectin appears to be a promising and non-invasive biomarker of intestinal inflammation. If these findings are confirmed, it may provide a useful test for the diagnosis and follow up of inflammatory bowel diseases. (C) 2003 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.