No allelic variant associations of the IL-1 and TNF gene polymorphisms in the susceptibility to duodenal ulcer disease.

Recent studies have reported the association of a pro-inflammatory profile of genetic polymorphisms in IL-1B, IL-1RN, TNF-A, and IL-10 genes with an increased risk of non-cardia gastric cancer. Because gastric cancer and duodenal ulcer are mutually exclusive outcomes of Helicobacter pylori infection, we aimed to investigate possible allelic variant associations of several functional polymorphisms in the IL-1B, IL-1RN, TNFA, and LTA genes in the susceptibility to duodenal ulcer. Genomic DNA from 118 patients with duodenal ulcer and 97 healthy controls was typed for the IL-1B polymorphisms at positions -511, -31, and +3954, the VNTR polymorphism in intron 2 of the IL-1RN gene, the TNFA-308, TNFA -238, and the NcoI and BsI LTA polymorphisms by PCR, SSCP and TaqMan assays. H. pylori infection and non-steroidal anti-inflammatory drugs (NSAIDs) use was investigated in patients and controls. Logistic regression analysis identified H. pylori infection (OR: 12.86; 95%CI: 3.85-43), NSAID use (OR: 11.95; 95%CI: 4.19-34.05), and family history-ulcer (OR: 3.79; 95%CI: 1.68-8.54) as independent risk factors for duodenal ulcer. When the effect of the combinations of IL-1 and TNF genotypes was studied we found that the distribution of all possible combinations of these eight polymorphisms was similar in duodenal ulcer patients and controls. The simultaneous carriage of alleles IL-1RN*2/IL-1B -31T/IL-1B -511C/IL-IB +3954C/TNF-HaplotypeE negative (termed in some studies as 'low-producing' alleles) was increased in H. pylori-positive duodenal ulcer patients compared to H. pylori-infected healthy controls (10.5% vs. 5.9%) although the difference did not reach statistical significance (OR: 1.85; 95%CI: 0.57-5.99, P = 0.41). Moreover, no differences were found with respect to H. pylori status, NSAID use, age, gender, smoking habit, type of complication, recurrence of the ulcer, and need for surgical treatment. Our data show no association between allelic variants of IL-1 and TNF gene polymorphisms in the susceptibility to and final outcome of duodenal ulcer.