Journal: Gut. 2007 Apr 11; [E-publication ahead of print]
Authors and affiliation: Langhorst J, Wieder A, Rueffer A, Michalsen A, Musial F, Dobos GJ. Department of Internal and Integrative Medicine, University of Duisburg-Essen, Kliniken Essen-Mitte, Germany.
The discovery of antimicrobial peptides [proteins produced by the immune system that kill microbes] has extended the knowledge of unspecific defense mechanisms. In addition to the physical barrier, the intestinal epithelium contributes to host defense by producing antimicrobial peptides to limit access to enteric [gastrointestinal] bacteria and other microorganisms. The production of inducible antimicrobial peptides offers a first and rapid defense response of epithelial cells against invading microbes.
Human beta-defensin-2 (HBD-2) was the first inducible human anti-microbial protein discovered. It can be induced by probiotic microorganisms and pro-inflammatory cytokines.
Recent results suggest that HBD-2 is expressed in active intestinal inflammation, especially in ulcerative colitis. Thus far, the expression of beta-defensins has been quantified in the intestinal mucosa by using polymerase-chain reaction. Our aim was to evaluate fecal measurements of HBD-2 in patients with active ulcerative colitis, compared to irritable bowel syndrome as a non-inflammatory clinical control and healthy controls (HC).
We expected that faecal HBD-2 levels would show a similar pattern compared to mucosal HBD-2 and thus should be elevated in ulcerative colitis selectively.