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.
