Helicobacter pylori Seroprevalence in Rheumatoid Arthritis Patients with Interstitial Lung Disease

Background: Rheumatoid arthritis (RA) is complicated with interstitial lung disease (ILD). Gastroesophageal reflux disease is prevented by Helicobacter pylori infection and is a predisposing factor for idiopathic pulmonary fibrosis. However, the prevalence of H. pylori infection in RA patients with ILD has not been sufficiently investigated. Objective: In this study, we analyzed anti- H. pylori antibodies in RA patients with ILD. Design: Case-control observational study Methods: Anti- H. pylori antibodies were analyzed in the sera of RA patients using a commercially available enzyme-linked immunosorbent assay kit. Results: The positivity of anti- H. pylori antibodies in RA with ILD ( n = 30 [18.0%], P = .0227), usual interstitial pneumonia ( n = 10 [14.3%], P = .0212), and airway disease ( n = 30 [18.0%], P = .0227) was significantly lower than that of RA without chronic lung disease ( n = 78 [27.5%]). The positivity of anti- H. pylori antibodies was also lower in RA with chronic lung disease ( n = 68 [18.2%], P = .0059). Multiple logistic regression analyses showed that the presence of anti- H. pylori antibodies was independently and protectively associated with chronic lung disease in RA. Conclusion: The seroprevalence of H. pylori was lower in RA with ILD. H. pylori infection prevented ILD in patients with RA by protecting them from gastroesophageal reflux disease.