Association between bactericidal/permeability increasing protein (BPI) gene polymorphism (Lys216Glu) and inflammatory bowel disease.

Background: Increasing evidence suggests that innate immune system may have a key role in the pathogenesis of the inflammatory bowel disease (IBD). Bactericidal/permeability increasing protein (BPI) has an important role in the recognition and neutralization of gram-negative bacteria by host innate immune system. The polymorphism on BPI gene called Lys216Glu is on the suspected list of IBD pathogenesis.

Methods: We studied the Lys216Glu polymorphism on BPI gene, in a Turkish IBD patient population. A total of 238 IBD patients; 116 Crohn's disease (CD) and 122 ulcerative colitis (UC), besides 197 healthy controls were included in this study.

Results: The Glu/Glu genotype and allele frequencies were found to be statistically higher compared to healthy control group not only in CD patients [P: 0.03, OR: 1.87 (CI 95% 1.02-3.42) and P: 0.00001 (OR: 2.07 CI 95% 1.47-2.91) respectively] but also in UC patients [P: 0.0002, OR: 2.71 (CI 95% 1.53-4.80) and P: 0.00002 (OR: 2.71 CI 95% 1.53-4.80) respectively].

Conclusions: BPI polymorphism (Lys216Glu) is associated both to CD and UC. Our findings differ from the two Western European studies; one without any association and the other indicating an association only with CD. Our study is the first one reporting a novel association between BPI gene mutation (Lys216Glu) and UC.