WEDNESDAY, Dec. 7 (HealthDay News) -- Reduced expression of Paneth cell (PC) alpha-defensins, such as HD5 and HD6, may compromise mucosal host defenses and cause Crohn's disease of the ileum, according to a study published online Dec. 5 in the Proceedings of the National Academy of Sciences.
Jan Wehkamp, M.D., of the University of California-Davis, and colleagues analyzed surgical specimens of ileal mucosa and pouch biopsies from The Cleveland Clinic Foundation and ileal biopsies from the Robert Bosch Hospital.
The researchers found that patients with Crohn's disease of the ileum had reduced antibacterial activity in their intestinal musosal extracts. Eight different compounds secreted by Paneth cells remained unchanged or increased compared to controls, but expression of alpha-defensins were lower in patients than in controls. The reduction was independent of inflammation, and was not seen in other types of Crohn's disease, or in ulcerative colitis or pouchitis.
"Ultimately, alterations in the composition of the intestinal flora may promote bacterial invasion of the mucosa and predispose to the chronic inflammation of ileal Crohn's disease," the authors conclude. "This view of disease pathophysiology suggests that therapeutic strategies aimed at restoring the host-microbe balance at the intestinal mucosa may prove superior to those that broadly suppress inflammation and adaptive immunity."
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