Associations of TNF-A-1031TT and -857TT genotypes with Helicobacter pylori seropositivity and gastric atrophy among Japanese Brazilians.

BACKGROUND

Our previous study in a Japanese population showed elevated Helicobacter pylori seropositivity in those with tumor necrosis factor (TNF) A -1031TT and -857TT genotypes. This study examined the associations of this seropositivity and serum pepsinogen (PG) levels with these genotypes in Japanese Brazilians.

METHODS

The subjects were 963 individuals (399 males and 564 females), aged 33 to 69 years, from four regions (Sao Paulo, Curitiba, Mogi das Cruzes, and Mirandopolis) in Brazil. Gastric atrophy was evaluated with serum pepsinogens (PGI < 70 ng/dl and PGI/II < 3), and TNF T-1031C and C-857T were genotyped by polymerase chain reaction with confronting two-pair primers (PCR-CTPP).

RESULTS

The frequency of TNF-A T-1031C was 68.4% TT, 28.4% TC, and 3.3% CC, and that of C-857T was 64.5% CC, 31.7% CT, and 3.8% TT, whose distributions were in Hardy-Weinberg equilibrium. No significant associations of the genotypes with H. pylori seropositivity or gastric atrophy were found. However, male participants with TNF-A -1031CC and -857CC showed the lowest seropositivity (43.8% out of 16), and males with TNF-A -1031TT and -857TT showed the highest (61.5% out of 13).

CONCLUSION

This study demonstrated that the associations between H. pylori seropositivity and TNF-A genotypes were not marked for Japanese Brazilians. The genotypes were not associated with gastric atrophy among the seropositive individuals.