Abstract

SILVA, Maria Reis; OLIVEIRA, Carla; RODRIGUES-SANTOS, Paulo  and  CARVALHO, Lina. Genotypes of Helicobacter pylori in Gastric Cancer and Chronic Gastritis. J Port Gastrenterol. [online]. 2011, vol.18, n.5, pp.218-225. ISSN 0872-8178.

Helicobacter pylori (Hp) infection is the major cause of chronic active gastritis type B and a pre-neoplasic condition to the development of gastric carcinoma and MALT lymphoma. The pathogenicity induced by different Hp strains are associated to the functions of some Hp genes and respective oligonucleotides, such as cagA, vacA and iceA. This study was designed to assemble these genes in gastric carcinoma and chronic gastritis biopsies. The Hp DNA was extracted from 39 formalin fixed paraffin embedded gastric samples, 26 from gastric carcinoma and 13 from chronic gastritis through 2 different methods: sections on glass slides and isolated sections cut to eppendorf tubes. The cagA, vacA and iceA genes were then detected by nested-PCR. The study of associations between the genotypes of the strains of H. pylori in GC and CG was found statistically significant differences for allele ice A1 (p < 0.05, OR = 4.25). Most of the GC with cagA + vacA are associated with s2/m2 (46%, 12/26). The combination s2/m2/cagA/iceA1 predominantly occurred in 35% of CG compared with 30% of GC (P > 0.05, OR = 1.19). For combinations s2/m2/cagA/iceA2 and s1/m2/cagA/ice2 obtained a value of 12% and 30% for GC and GC (P> 0.05, OR = 0.29). This knowledge is important for continuity of further studies aiming to define the characteristics of H. pylori genotype in pre-neoplasic lesions of the stomach.

Keywords : Helicobacter pylori; gastric carcinoma; chronic gastritis; cagA; vacA; iceA; nested-PCR.

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