Basic Study
Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Aug 21, 2015; 21(31): 9317-9327
Published online Aug 21, 2015. doi: 10.3748/wjg.v21.i31.9317
Reciprocal impact of host factors and Helicobacter pylori genotypes on gastric diseases
Sahar Honarmand-Jahromy, Farideh Siavoshi, Reza Malekzadeh, Taher Nejad Sattari, Saeid Latifi-Navid
Sahar Honarmand-Jahromy, Taher Nejad Sattari, Department of Biology, Tehran Science and Research Branch, Islamic Azad University, Tehran 1477893855, Iran
Farideh Siavoshi, Department of Microbiology, School of Biology, University College of Sciences, University of Tehran, Tehran 1417614411, Iran
Reza Malekzadeh, Digestive Disease Research Institute, Tehran University of Medical Sciences, Tehran 1411713135, Iran
Saeid Latifi-Navid, Department of Biology, Faculty of Sciences, University of Mohaghegh Ardabili, Ardabil 5619911367, Iran
Author contributions: Siavoshi F and Latifi-Navid S designed the study; Honarmand-Jahromy S performed the research; Malekzadeh R provided the gastric biopsy specimens; Nejad Sattari T analyzed the data; and Siavoshi F wrote the paper.
Supported by Research Council of the University of Tehran.
Institutional review board statement: The study was approved by the research Ethics Committee of Tehran University of Medical Sciences. All patients signed written informed consent.
Conflict-of-interest statement: The authors declare no conflicts of interest.
Data sharing statement: Parts of the study have been presented at the XXVIIth International Workshop on Helicobacter and Microbiota in Chronic Digestive Inflammation and Gastric Cancer.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Farideh Siavoshi, PhD, Department of Microbiology, School of Biology, University College of Sciences, University of Tehran, Enghelab Avenue, Tehran 1417614411, Iran. siavoshi@khayam.ut.ac.ir
Telephone: +98-21-61112460 Fax: +98-21-66492992
Received: January 3, 2015
Peer-review started: January 4, 2015
First decision: February 10, 2015
Revised: March 22, 2015
Accepted: May 7, 2015
Article in press: May 7, 2015
Published online: August 21, 2015
Processing time: 228 Days and 18.2 Hours
Abstract

AIM: To assess the impact of Helicobacter pylori (H. pylori) genotypes and patient age and sex on the development of gastric diseases.

METHODS: H. pylori-infected patients (n = 233) referred to the endoscopy unit at Tehran University of Medical Sciences (Tehran, Iran) were diagnosed with chronic gastritis (CG), gastric ulcer (GU), or duodenal ulcer (DU). Brucella blood agar was used for biopsy cultures and H. pylori isolation under microaerobic conditions. H. pylori isolates were confirmed with biochemical tests and through amplification of the 16S rRNA gene. DNA was extracted from fresh cultures of the H. pylori isolates and used for amplification of vacA alleles and the cagA gene. Statistical analysis was performed to determine the association between H. pylori genotypes, age (< 40 years vs > 40 years) and sex of the patient, and gastric diseases.

RESULTS: CG was the most prevalent gastric disease (113/233; 48.5%), compared to GU (64/233; 27.5%) and DU (56/233; 24%). More patients were male, and gastric diseases were more frequent in patients > 40 years (P < 0.05). The percentage of CG and GU patients that were male and female did not show a significant difference; however DU was more common in males (P < 0.05). Interestingly, a diagnosis of CG in patients > 40 years was more common in females (18.5%) than males (11.6%) (P = 0.05), whereas a diagnosis of GU or DU in patients > 40 years was more frequent in males (14.6% vs 10.7% and 12.4% vs 4.3%, respectively). Overall, genotyping of the H. pylori isolates revealed that the vacA s1 (82%), vacA m2 (70%), and cagA+ (72.5%) alleles were more frequent than vacA s2 (18%), vacA m1 (29.2%), and cagA- (all P < 0.05). The vacA s1m2cagA+ genotype was the most prevalent within the three disease groups. vacA s1m2 frequency was 56.2% with a similar occurrence in all diagnoses, while vacA s1m1 appeared more often in DU patients (33.9%). A genotype of vacA s2m2 occurred in 15% of isolates and was more common in CG patients (21.2%); vacA s2m1 was the least common genotype (3%). The vacA s1 allele was found to be a risk factor for DU, vacA s2 for CG, and vacA s1 and vacA s2 for GU (all P < 0.05). The vacA s2m2 genotype was associated with the development of CG and GU compared to DU (P < 0.05). No correlation was found between vacA m or cagA and gastric diseases.

CONCLUSION: The outcome of H. pylori infection is the result of interaction between bacterial genotypes and the age and sex of infected individuals.

Keywords: Age; Gastric disease; Gender; Genotype; Helicobacter pylori

Core tip:Helicobacter pylori (H. pylori) genotype and host and environmental factors have emerged as the risk factors of H. pylori-associated diseases. However, controversies exist regarding the reciprocal interaction between these factors. Results of this study demonstrate that increased age is an important risk factor for gastric ulcers in both males and females, for chronic gastritis in females, and for duodenal ulcers in males. Genotypes vacA s1 and vacA s2m2 emerged as significant risk factors for duodenal ulcers, and chronic gastritis and gastric ulcers, respectively. No correlation was found between vacA m or cagA and gastric diseases.