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 studyMethods: 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.