IL-1 RN 2/2 genotype and simultaneous carriage of genotypes IL-1 RN 2/2 and IL-1β-511 T/T associated with oesophagitis in Helicobacter pylori-negative patients

Background: Interleukin-1 receptor antagonist genotype 2/2 is associated with a prolonged and enhanced inflammatory response. It is suspected of being a risk factor for atrophic gastritis and gastric cancer and for some autoimmune diseases. No specific genetic risk factors for oesophagitis have been identified so far and there are no reports of IL-1 polymorphism in relation to oesophageal disease. Methods: We studied the IL-1RN, IL-1beta-511 and IL-1beta + 3953 polymorphisms in an unselected series of 142 adult patients scheduled for gastrointestinal endoscopy because of dyspepsia. The control group consisted of university staff and students (n = 179). Helicobacter pylori status was determined by antibody testing and bacterial detection. Results: Endoscopic oesophagitis was noted in 40 patients. The IL-1RN 2/2 genotype was significantly more prevalent in the patients with H. pylori-negative oesophagitis than in the control subjects (27% versus 9%; OR 3.574, CI 1.23 - 10.35, P = 0.034) or in the dyspeptic patients (27% versus 7%; OR 5.089, CI 1.51 - 17.11, P = 0.009). IL-1beta-511 T/T genotype tended to be more frequent in the H. pylori-negative patients with oesophagitis than in the control subjects ( P = 0.071). The strongest association was between the simultaneous carriage of genotypes IL-1RN 2/2 and IL-1beta - 511 T/T and H. pylori-negative oesophagitis, where the combined genotype was more prevalent than in the control subjects (23% versus 6%; OR 4.492, CI 1.40 - 14.46, P = 0.012) or the dyspeptic patients without oesophagitis ( 23% versus 3%; OR 9.706, CI 2.12 - 44.42, P = 0.003). Conclusion: The results indicate that the IL-1RN 2/2 genotype and the carriage of combined genotypes IL-1RN 2/2 + IL-1beta-511 T/T are associated with H. pylori-negative oesophagitis. This is the first report on the association between IL-1 gene polymorphism and oesophagitis.