Brief Articles
Copyright ©2009 The WJG Press and Baishideng. All rights reserved.
World J Gastroenterol. Mar 28, 2009; 15(12): 1465-1471
Published online Mar 28, 2009. doi: 10.3748/wjg.15.1465
Interleukin-1 and TNF-α polymorphisms and Helicobacter pylori in a Brazilian Amazon population
Hivana Patricia Melo Barbosa, Luisa Caricio Martins, Sidney Emanuel Batista dos Santos, Samia Demachki, Mônica Baraúna Assumpção, Charliana Damasceno Aragão, Tereza Cristina de Oliveira Corvelo
Hivana Patricia Melo Barbosa, Charliana Damasceno Aragão, Tereza Cristina de Oliveira Corvelo, Laboratory of Immunogenetics, Federal University of Pará, 66075-110, Belém, Brazil
Luisa Caricio Martins, Nucleus of Tropical Medicine, Federal University of Pará, 66055-240, Belém, Brazil
Sidney Emanuel Batista dos Santos, Laboratory of Human and Medical Genetics, Federal University of Pará, 66075-110, Belém, Brazil
Samia Demachki, Department of Pathology, João de Barros Barreto Universitary Hospital, Federal University of Pará, 66073-000, Belém, Brazil
Mônica Baraúna Assumpção, Department of Endoscopy, João de Barros Barreto Universitary Hospital, Federal University of Pará, 66073-000, Belém, Brazil
Author contributions: Melo Barbosa HP, Martins LC, dos Santos SE and Corvelo TC designed and performed the research; Melo Barbosa HP and Martins LC performed the majority of experiments; Aragão CD took part in the experiments and collected the control samples; Assumpção MB performed endoscopy and provided clinical advice; Demachki S performed the histological evaluation and provided clinical advice; Melo Barbosa HP and Martins LC wrote the paper.
Correspondence to: Hivana Patricia Melo Barbosa, Laboratory of Immunogenetics, Federal University of Pará, 66075-110, Belém, Brazil. hivana@ufpa.br
Telephone: +55-91-32696857
Fax: +55-91-32017568
Received: October 19, 2008
Revised: February 9, 2009
Accepted: February 16, 2009
Published online: March 28, 2009
Abstract

AIM: To study the association between Interleukin-1 (IL-1) and tumor necrosis factor (TNF)-α polymorphisms, infection by Helicobacter pylori (H pylori) and the development of gastrointestinal diseases.

METHODS: Genomic DNA was extracted from the peripheral blood of 177 patients with various gastrointestinal diseases and from 100 healthy volunteers. The polymorphisms in IL-1β and TNF-α genes were analyzed using the polymerase chain reaction-restriction fragment length polymorphism method (PCR-RFLP) and those from IL-1RN with PCR. The presence of infection due to H pylori and the presence of the CagA toxin were detected by serology. The histopathological parameters in the gastric biopsies of the patients were according to the Sydney classification.

RESULTS: A comparison of the frequencies of the different polymorphisms studied among the patients and the control group demonstrated that the allele IL-1RN*2 was more frequent among patients with gastric ulcers and adenocarcinoma. Carriers of the allele IL-RN*2 and those with reactive serology for anti-CagA IgG had a greater risk of developing peptic ulcer and gastric adenocarcinoma, as well as a higher degree of inflammation and neutrophilic activity in the gastric mucosa.

CONCLUSION: Our results indicate a positive association between IL-1RN gene polymorphism and infection by positive H pylori CagA strains and the development of gastric ulcers and adenocarcinoma.

Keywords: Helicobacter pylori; Interleukin 1β gene; Interleukin-1 receptor antagonist gene; TNF-α gene; Cag pathogenicity island