Association between interleukin-1β-511C/T polymorphism and reflux esophagitis in Japan

Background. Interleukin-1 beta (IL-1 beta) gene polymorphisms are related to hypochlorhydria and increase the risk of gastric cancer in the presence of Helicobacter pylori infection. However, little information is available about the genetic risk factors of reflux esophagitis. In this study we investigated its association with the IL-1 beta polymorphisms. Methods. We examined 48 patients with reflux esophagitis and 96 control subjects, 89 with gastric cancer. IL-1 beta-511C/T genotyping was performed by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Results. The frequency of IL-1 beta-511T alleles was significantly higher in reflux esophagitis patients (57.3%) than in controls (41.1%) (P = 0.0215, chi(2) = 5.289). The frequency of IL-1 beta-511T/T genotypes was also significantly higher in reflux esophagitis patients (31.3%) than in controls (15.6%). The odds ratio and the 95% confidence interval were 4.000 and 1.393-11.486, respectively. The frequency of IL-1 beta-511T/T genotypes was significantly higher in reflux esophagitis patients (31.3%) than in gastric cancer patients (21.4%). The odds ratio and the 95% confidence interval were 2.961 and 1.054-8.316, respectively. Conclusions. IL-1 beta-511T was associated with reflux esophagitis having hyperacidity. Differences of genetic background regarding gastric acid secretion may exist between Japanese and Caucasians.