Background: The bactericidal/permeability increasing protein (BPI) is involved in the elimination of gram-negative bacteria. A functionally relevant single nucleotide polymorphism of the BPI gene causes an amino acid exchange (Glu216Lys).
Study: To evaluate whether this single nucleotide polymorphism contributes to the predisposition to inflammatory bowel disease, we compared the allele frequencies of 265 patients with Crohn's disease, 207 patients with ulcerative colitis, and 608 healthy controls.
Results: The Glu/Glu genotype frequency was decreased significantly in Crohn's disease patients as compared with controls (P < 0.027). No differences were obvious in patients with ulcerative colitis.
Conclusions: Failure of the innate intestinal immune system could be involved in the pathogenesis of Crohn's disease via reduced/impaired defense against gram-negative bacteria.