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Background: The present study of Helicobacter pylori infection was conducted in family units of Japanese Brazilians living in São Paulo city. The authors attempted to determine the seroprevalence of H. pylori infection within family units of Japanese Brazilians and to identify risk factors associated with intrafamilial transmission., Methods: The seroprevalence was determined in 1037 healthy and asymptomatic volunteer subjects aged 0-69 years (530 adults and 507 children) of 265 families. Demographic data and details of living conditions were obtained from each family., Results: H. pylori seropositive infection was found in 39.2% of the parents and 9.3% of the children. A reduced risk of H. pylori infection was found for girls (odds ratio [OR] 0.45; 95% confidence interval [CI], 0.23-0.86). The prevalence of infection was 3.5% for children with uninfected parents; 9.9% (OR, 2.51; 95% CI, 0.95-6.61) for those with a seronegative mother and a seropositive father; 14.9% (OR, 4.93; 95% CI, 1.86-13.06) for those with a seropositive mother and a seronegative father; and 16.0% (OR, 5.29; 95% CI, 1.98-14.14) for those with seropositive parents. On multivariate analysis, the use of a pacifier, and mother's symptoms of nausea and vomiting were significantly associated with the risk of H. pylori infection for children, and the child having her/his own room was significantly associated with a reduced risk. Income was not associated with H. pylori infection in children and was inversely associated in parents., Conclusion: The prevalence of H. pylori infection in family units of Japanese Brazilians supports the hypothesis of a predominant role for mother-child transmission of H. pylori infection, mainly through contact with regurgitated gastric juice in the mother's mouth.

Associations between anti-Helicobacter pylori seropositivity (HP+) and interleukin 1B (IL-1B) C-31T polymorphism have been reported and little is known about the host factors involved in the development of atrophic gastritis (AG) among infected individuals. This study aimed to examine the IL-1B C-31T polymorphism among anti-HP antibody seropositive Japanese descendants with AG in Brazil and to investigate the interactions with lifestyle factors. Subjects were 455 seropositive from four cities in Brazil, aged 33-69 years. Sex-age-adjusted odds ratio (OR) of AG for 61 current smokers was 1.29, 95% confidence interval (CI): 0.18-9.26 for T/T, while that for 325 never smokers was 0.52, 95% CI: 0.27-0.98. A negative association for AG and never alcohol drinking, every day fruit consumption and milk drinking, and less frequently coffee drinking in individuals with C/T or T/T genotype was observed. This study suggested that host genetic constitution and lifestyle factors may influence the protective effect for AG development.

Background: Studies of lifestyle factors related to gastric atrophy development in Helicobacter pylori-infected individuals are limited. The present cross-sectional study aimed to examine the associations between lifestyle factors and serum pepsinogens (PGs) among anti- H. pylori antibody-seropositive Japanese in Brazil, where gastric cancer mortality was reported to be as high as in Japanese in Japan, and seropositive individuals were still frequently detected., Methods: The subjects were 291 seropositive individuals (129 males and 162 females; age, 30 to 69 years) out of 656 Japanese-Brazilian volunteers in São Paulo city. Information on lifestyle factors was obtained using a self-administered questionnaire. Atrophic gastritis was defined as a PG1 serum level less than 70 ng/ml and PG1/PG2 ratio less than 3., Results: The prevalence of atrophic gastritis was 31.9% (95% confidence intervals, 26.6%-37.6%). The proportion of subjects with atrophic gastritis increased with age, but there were no significantly marked differences in the proportions of subjects with atrophic gastritis among the three generations studied (first generation [Issei], second generation [Nisei], and third generation [Sansei]) for any 10-year age group. The associations with smoking and alcohol drinking were not significant. Length of education was inversely associated with gastric atrophy, while infrequent rice intake was preventive; the odds ratio relative to everyday rice intake was 0.13 (95% confidence intervals, 0.39-0.46) on multivariate analysis., Conclusions: The present study demonstrated that frequent rice intake was a risk factor for atrophic gastritis among the H. pylori-infected Japanese-Brazilians, suggesting that diet including rice plays a role in the step from H. pylori infection to gastric atrophy.

We reported previously that anti-Helicobacter pylori antibody seropositivity (HP+) had an association with interleukin 1B (IL-1B) C-31T genotype, especially among smokers. This study examined the association for Japanese Brazilians. In this cross-sectional study, voluntary participation was announced through Japanese Brazilian communities in Sao Paulo, Curitiba, Mogi das Cruzes, and Mirandopolis; 963 Japanese Brazilians (399 males and 564 females) aged 33-69 years participated. Lifestyle data and peripheral blood were collected. An anti-HP IgG antibody test and genotyping for IL-1B C-31T and IL-1RN 86 bp VNTR were independently conducted. The genotype frequency of the IL-1B polymorphism among 947 individuals was 23.9% for C/C genotype, 45.6% for C/T genotype, and 30.5% for T/T genotype. Sex-age-adjusted odds ratio (aOR) of HP+ was 1.30 (95% confidence interval, 0.94-1.81) for C/T genotype and 1.45 (1.02-2.07) for T/T genotype relative to C/C genotype. The aOR for 127 current smokers was 2.45 (0.91-6.55) for C/T and 3.49 (1.17-10.46) for T/T, while that for 667 never smokers was 1.21 (0.82-1.78) and 1.36 (0.90-2.05), respectively. The corresponding figures were 2.42 (1.16-5.02) and 3.00 (1.33-6.78) for 226 current drinkers, and 1.21 (0.82-1.78) and 1.36 (0.90-2.05) for 667 non-drinkers. The difference in the OR was observed for milk consumption, salty pickled vegetable eating, and physical exercise practice. 4/4 Genotype of IL-1RN 86 bp VNTR was 84.8%, and had no association with the HP seropositivity. The observed association between HP+ and IL-1B -31TT indicated that the genetic trait also influences the susceptibility to HP for Japanese in Brazil.