Helicobacter pylori infection does not protect against eosinophilic esophagitis: results from a large multicenter case-control study.

Objectives: Rising trends in eosinophilic esophagitis (EoE) have been repeatedly linked to declining Helicobacter pylori (H. pylori) infection, mostly in retrospective studies. We aimed to prospectively evaluate this inverse association.

Methods: Prospective case-control study conducted in 23 centers. Children and adults naïve to eradication therapy for H. pylori were included. Cases were EoE patients, whereas controls were defined by esophageal symptoms and <5 eos/HPF on esophageal biopsies. H. pylori status was diagnosed by non-invasive (excluding serology) or invasive testing off proton pump inhibitor (PPI) therapy for 2 weeks. Atopy was defined by the presence of IgE-mediated conditions diagnosed by an allergist.

Results: 808 individuals, including 404 cases and 404 controls (170 children) were enrolled. Overall H. pylori prevalence was 38% (45% children vs. 37% adults, p 0.009) and was not different between cases and controls (37% vs. 40%, p 0.3; odds ratio (OR) 0.97; 95% confidence interval (CI) 0.73-1.30), neither in children (42% vs. 46%, p 0.1) nor in adults (36% vs. 38%, p 0.4). Atopy (OR 0.85; 95%CI 0.75-0.98) and allergic rhinitis (OR 0.81; 95%CI 0.68-0.98) showed a borderline inverse association with H. pylori infection in EoE patients. This trend was not confirmed for asthma or food allergy.

Conclusions: H. pylori infection was not inversely associated with EoE, neither in children nor in adults. A borderline inverse association was confirmed for atopy and allergic rhinitis, but not asthma of food allergy. Our findings question a true protective role of H. pylori infection against allergic disorders, including EoE.