Objective: Rheumatoid arthritis (RA) is an autoinflammatory disease caused by genetic susceptibility and environmental triggers, which include infectious agents. Helicobacter pylori, a bacterium that frequently colonizes the stomach, is associated with the development of certain autoinflammatory disorders. This study examined a possible association between H. pylori infection and RA.
Method: This cohort study was performed in the Central Denmark Region. Patients were enrolled from primary healthcare centres after a urea breath test (UBT) for H. pylori and followed for a median of 8 years. Nationwide administrative registries provided information about the patients' diagnoses, country of birth, and gender. Comorbidity was determined using the Charlson Comorbidity Index. We compared the prevalence of RA via odds ratios (ORs) and incidences using Cox regression to calculate the hazard ratios (HRs) by comparing H. pylori-positive and H. pylori-negative individuals and adjusting for confounding variables.
Results: A total of 56 000 people diagnosed as H. pylori positive or negative had similar rates of comorbidity. No link was found between H. pylori and RA. There was no difference in RA prevalence until time of UBT [OR = 0.91, 95% confidence interval (CI) 0.70-1.19)] or incidence of new RA cases after UBT (HR = 0.80, 95% CI 0.56-1.13) between H. pylori-positive and -negative subjects. Validation via four other RA definitions provided similar results.
Conclusion: This study found no association between H. pylori infection and RA. This result does not support the involvement of H. pylori in a gut-joint axis of importance for RA development.