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Abstract

We appreciate the opportunity to respond to the comment in the Letter to the Editor accompanying our article titled “Anti-H. pylori therapy increases the prevalence of autoimmune disorders including IBD.” We are glad that the author agrees with us that this finding may impact clinical practice. We and others have reported a negative association between Helicobacter pylori infection and inflammatory bowel disease (IBD) and have described the mechanisms how H pylori leads to systemic induction of regulatory T cells, which may render an infected individual “hypoinflammatory” and at lower risk of developing inflammatory disorders, such as autoimmune diseases and IBD.1Luther J. et al.Inflamm Bowel Dis. 2010; 16: 1077-1084Crossref PubMed Scopus (172) Google Scholar, 2Kao J.Y. et al.Gastroenterology. 2010; 138: 1046-1054Abstract Full Text Full Text PDF PubMed Scopus (236) Google Scholar, 3Arnold I.C. et al.Front Cell Infect Microbiol. 2012; 2: 10Crossref PubMed Scopus (92) Google Scholar There are growing concerns of a rapidly rising incidence of immune-mediated conditions across the globe especially in developing countries, which comprises more than 50% of the world's population.4Ng S.C. et al.Lancet. 2018; 390: 2769-2778Abstract Full Text Full Text PDF PubMed Scopus (2501) Google Scholar Although several meta-analyses have reported a lower risk of developing IBD in H pylori–infected individuals,1Luther J. et al.Inflamm Bowel Dis. 2010; 16: 1077-1084Crossref PubMed Scopus (172) Google Scholar, 5Rokkas T. et al.United European Gastroenterol J. 2015; 3: 539-550Crossref PubMed Scopus (62) Google Scholar the critical question in regards to the rapidly rising incidence of IBD in developing countries is whether treating H pylori is associated with a higher risk of these diseases. To do this, it is necessary to perform the study in a patient population with a high prevalence rate of H pylori infection but those patients tend to have a low incidence of IBD. Therefore, a large longitudinal dataset, such as the National Health Insurance Research Database in Taiwan, is required to estimate the effect size of H pylori treatment. That said, there are limitations to using national insurance dataset, such as the lack of clinical laboratory data to verify H pylori infection status pretreatment and post-treatment. The specific issue raised by the author in the Letter to the Editor is that we need to take into consideration that not everyone but ∼90% of those treated for H pylori will be rid of H pylori. Although this is a valid concern, we like to point out that our study examines the effect of H pylori treatment and not H pylori eradication because H pylori eradication testing results are not available in the insurance database. We do believe that excluding treatment-refractory patients (∼10%) in our H pylori treatment group will not significantly alter the main finding of the study because the inclusion of these treatment-refractory patients in the H pylori treatment group likely underestimates the effect size of H pylori treatment. Removing them from our analysis is expected to result in an even larger effect size of H pylori treatment. We agree that further research using clinical databases that contain H pylori eradication testing results is needed to validate the implication of our study that H pylori eradication may lead to an increased risk of autoimmune diseases including IBD. A Comment on Anti–Helicobacter pylori Therapy and Autoimmune DiseasesClinical Gastroenterology and HepatologyVol. 17Issue 8PreviewI have read with great interest the retrospective cohort study by Lin et al1 that was conducted by using the National Health Insurance Research database in Taiwan. The authors reported that patients with Helicobacter pylori treatment had a higher incidence of autoimmune diseases than untreated patients or those with unknown H pylori status. As reported, in this database, data on the outcome of H pylori treatment were not available. Full-Text PDF