Interleukin-1 and TNF-alpha polymorphisms and Helicobacter pylori in a Brazilian Amazon population.
OBJECTIVE
To study the association between Interleukin-1 (IL-1) and tumor necrosis factor (TNF)-alpha 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-1beta and TNF-alpha 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.


CONCLUSIONS
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.
Melo Barbosa
Hivana-Patricia
HP
Laboratory of Immunogenetics, Federal University of Pará, 66075-110 Belém, Brazil. hivana@ufpa.br
Martins
Luisa-Caricio
LC
Dos Santos
Sidney-Emanuel-Batista
SE
Demachki
Samia
S
Assumpção
Mônica-Baraúna
MB
Aragão
Charliana-Damasceno
CD
de Oliveira Corvelo
Tereza-Cristina
TC