The diagnostic value of a new fecal marker, matrix metalloprotease-9, in different types of inflammatory bowel diseases.

BACKGROUND Only limited data are available regarding the diagnostic accuracy of fecal matrix metalloprotease-9 [MMP-9] for inflammatory bowel disease [IBD]. The aims of our study were to assess the diagnostic accuracy of fecal MMP-9 in patients with active Crohn's disease [CD], ulcerative colitis [UC], and pouchitis, and to compare the diagnostic accuracy of fecal MMP-9 and fecal calprotectin [CP] in IBD. METHODS Stool and blood samples were collected in 50 CD, 54 UC, and 34 ileal pouch-anal anastomosis patients before control endoscopies were performed. Biopsies were taken for histologic purposes. The activities of CD, UC, and pouchitis were defined with the use of clinical, endoscopic, and histologic activity scores. Fecal CP and MMP-9 levels were quantified by enzyme-linked immunosorbent assay. RESULTS Active CD, UC, and pouchitis were detected in 38%, 54%, and 29% of the patients, respectively. A significant correlation was revealed between fecal CP and the clinical activities of CD and UC, and between fecal CP and the endoscopic activity of UC and pouchitis. Fecal MMP-9 did not correlate with any of the activity indices of CD; however, strong associations were shown between fecal MMP-9 and clinical, endoscopic, and histologic activities of both UC and pouchitis. CONCLUSIONS This is the first study assessing the diagnostic accuracy of MMP-9 in different types of IBD. Our results showed that fecal MMP-9 has high sensitivity in the detection of endoscopically active UC and pouchitis. These non-invasive methods help assess intestinal inflammation.