Immune response and gene polymorphism profiles in Crohn's disease and ulcerative colitis.

Background: Polymorphisms in genes linked to the innate and adaptive immune response may be involved in inflammatory bowel disease pathogenesis. Our aim was to investigate associations among IL1B-511, IL1B-31, IL1RN, TNFA-307, TLR-2, TLR-4, IL2-330, NOD2 G908R, NOD2 L1007fsinsC polymorphisms and both Crohn's disease (CD) and ulcerative colitis (UC) in a Brazilian population.

Methods: We studied 43 patients with CD, 42 with UC, and 541 blood donors. Polymorphisms were evaluated by PCR, PCR-CTPP, or PCR-RFLP. Data were analyzed in multivariate models adjusting for confounding factors.

Results: IL1RN VNTR (P = 0.00, odds ratio [OR] = 2.43, 95% confidence interval [CI] = 1.50-3.90), as well as TNFA-307 polymorphic allele (P = 0.05, OR = 1.70, 95% CI = 1.00-2.94) were associated with UC. Both NOD2 mutations (G908R, P = 0.02, OR = 6.83, 95% CI = 1.62-25.45, and L1007fsinsC, P = 0.00, OR = 20.00, 95% CI = 3.21-124.69) were associated with CD.

Conclusions: Our analyses showed positive associations between proinflammatory polymorphisms at IL1RN and TNFA-307 loci and UC, as well as polymorphisms in the NOD2 gene and CD. These results highlight the importance of different genetic profiles associated with CD and UC.