ARTICLEHelicobacter Pylori Infection Does Not Protect Against Eosinophilic Esophagitis: Results From a Large Multicenter Case-Control StudyMolina-Infante, Javier MD, PhD1,2; Gutierrez-Junquera, Carolina MD3; Savarino, Edoardo MD, PhD4; Penagini, Roberto MD, PhD5; Modolell, Ines MD, PhD6; Bartolo, Ottavia MD2; Prieto-García, Alicia MD, PhD7; Mauro, Aurelio MD5; Alcedo, Javier MD8; Perelló, Antonia MD, PhD9; Guarner-Argente, Carlos MD, PhD10; Alcaide, Noelia MD11; Vegas, Ana M. MD12; Barros-García, Patricia MD13; Murzi-Pulgar, Marianette MD10; Perona, Monica MD14; Gisbert, Javier P. MD, PhD2,15; Lucendo, Alfredo J. MD, PhD2,16 on behalf of the Upper GI Tract Study Group from the Spanish Gastroenterological Association (AEG)Author Information 1Department of Gastroenterology, Hospital Universitario San Pedro de Alcantara, Caceres, Spain. 2Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBEREHD), Madrid, Spain. 3Department of Pediatrics, Pediatric Gastroenterology Unit, Hospital Universitario Puerta de Hierro-Majadahonda, Madrid, Spain. 4Department of Surgery, Division of Gastroenterology, Oncology and Gastroenterology, University of Padua, Padua, Italy. 5Gastroenterology and Endoscopy Unit, Università degli Studi di Milano, Milan, Italy. 6Department of Gastroenterology, Consorci Sanitari Terrassa, Barcelona, Spain. 7Department of Allergy, Hospital Universitario Gregorio Marañon, Madrid, Spain. 8Department of Gastroenterology, Hospital Universitario Miguel Servet, Zaragoza, Spain. 9Department of Gastroenterology, Hospital de Viladecans, Barcelona, Spain. 10Department of Gastroenterology, Hospital de la Santa Creu I Sant Pau, Barcelona, Spain. 11Department of Gastroenterology, Hospital Clinico Universitario, Valladolid, Spain. 12Clinical Analysis and Pediatrics, Hospital Universitario Río Hortega, Valladolid, Spain. 13Department of Pediatrics, Hospital Universitario San Pedro de Alcantara, Caceres, Spain. 14Department of Gastroenterology, Hospital Quirón, Marbella, Spain. 15Departement of Gastroenterology, Hospital Universitario de La Princesa, Instituto de Investigación Sanitaria Princesa (IIS-IP), and CIBEREHD, Madrid, Spain. 16Department of Gastroenterology, Hospital General de Tomelloso, Tomelloso, and CIBEREHD, Ciudad Real, Spain. These authors contributed equally as senior authors: Javier P. Gisbert, Alfredo J. Lucendo. Correspondence: J.M. (email: email@example.com) SUPPLEMENTARY MATERIAL accompanies this paper at http://links.lww.com/AJG/A239 Received 8 September 2017; accepted 9 January 2018; Published online 15 March 2018 see related editorial on page 941 American Journal of Gastroenterology: July 2018 - Volume 113 - Issue 7 - p 972–979 doi: 10.1038/s41395-018-0035-6 Buy SDC Metrics Abstract OBJECTIVES: Rising trends in eosinophilic esophagitis (EoE) have been repeatedly linked to decliningHelicobacter 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 forH. pyloriwere included. Cases were EoE patients, whereas controls were defined by esophageal symptoms and <5 eos/HPF on esophageal biopsies.H. pyloristatus 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. OverallH. pyloriprevalence was 38% (45% children vs. 37% adults,p0.009) and was not different between cases and controls (37% vs. 40%,p0.3; odds ratio (OR) 0.97; 95% confidence interval (CI) 0.73-1.30), neither in children (42% vs. 46%,p0.1) nor in adults (36% vs. 38%,p0.4). 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 withH. pyloriinfection in EoE patients. This trend was not confirmed for asthma or food allergy. CONCLUSIONS: H. pyloriinfection 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 ofH. pyloriinfection against allergic disorders, including EoE. © The American College of Gastroenterology 2018. All Rights Reserved.