Association of LEC and tnpA Helicobacter pylori genes with gastric cancer in a Brazilian population.
BACKGROUND
H. pylori seroprevalence in Brazilians varies and is dependent on socioeconomic status, sanitation conditions and ethnicity; furthermore, H. pylori is not always associated with the incidence of gastric cancer, suggesting the role of more virulent strains. The purpose of this study was to analyze the association of more virulent H. pylori strains with gastric cancer.


METHODS
DNA was extracted from gastric biopsies of thirty-four cases of gastric cancer (11 intestinal-type, 23 diffuse-type), and thirty-four of patients with endoscopic gastritis. The presence of cagPAI genes (cagA, cagA promoter, cagE, cagM, tnpB, tnpA, cagT and the left end of the cagII (LEC)) and babA were analyzed by PCR.


RESULTS
Comparison of H. pylori isolates from gastric cancer and gastritis patients showed significant associations of tnpA and LEC with gastric cancer (73.5% [OR, 6.66; 95% CI, 2.30-19.25] and 58.8% [OR, 10.71; 95% CI, 3.07-37.28] of cases, respectively). Other cagPAI genes were detected in both groups at similar frequencies.


CONCLUSIONS
tnpA and LEC of H. pylori cagPAI were associated with gastric cancer; nonetheless, these results were restricted within this group of patients and further studies are needed to confirm these results in a larger sample and determine their role in gastric carcinogenesis.
Mattar
Rejane
R
Department of Gastroenterology, University of São Paulo School of Medicine, Av Dr Enéas de Carvalho Aguiar 255, 9 degrees andar sala 9159, São Paulo, 05403-000, SP, Brazil. rejane-mattar@ig.com.br.
Monteiro
Maria S
MS
Marques
Sergio B
SB
Zilberstein
Bruno
B
Hashimoto
Cláudio L
CL
Carrilho
Flair J
FJ