Profile of Helicobacter pylori cytotoxin derived from two areas of Japan with different prevalence of atrophic gastritis.

Abstract

Background andAim-To clarify the roles of Helicobacter pylorn cytotoxin in gastric atrophy, the cytotoxin positive rate and cytotoxin activity in Fukui and Okinawa, where the prevalence of atrophic gastritis and gastric cancer risk are quite different, were studied. Materials-Seventy three strains from Fukui and 51 from Okinawa were examined. Methods-The validation of atrQphy was done by endoscopy, being confirmed with histology. The supernatant of liquid H pylori culture media was concentrated 20-fold, serialiy diluted, using doubling dilutions, and scored from 1 to 8. The semi-quantitated cytotoxin activity was expressed as the maximum dilution score yielding >50% A431 cell vacuolation, being standardised with bacterial density. Results-The cytotoxin activity of the strains from Fukui was highly diverse compared with that from Okinawa, although the cytotoxin positive rate was not different. In Fukui strains, the grade of atrophy and the cytotoxin activity were correlated (p<0.05). In addition, the cytotoxin activity of the strains from all patients in Okinawa, most of whom showed closed-type/mild atrophy, was significantly lower than that of the strains from the patients with open-type/severe atrophy in Fukui (6.46 (5.53) v 9.76 (8.80), p<005), (mean (SEM)). Conclusion-The difference in profile of the cytotoxin activity in the two areas was related to the difference in the prevalance of atrophic gastritis.

The role of the HLA-DQA1 gene in resistance to atrophic gastritis and gastric adenocarcinoma induced byHelicobacter pylori infection

“…However, two dispase, vacuolating cytotoxin, and cytotoxin-associated antigen (CagA). [27][28][29][30][31][32] Blaser et al reported that infection tinct potential mechanisms can be proposed. First, the HLA-DQA1 gene itself may be one of the genes responwith a cagA positive H. pylori strain in comparison with a cagA negative strain increases the risk of the sible for the association.…”

Association between Helicobacter pylori Virulence Factors and Gastroduodenal Diseases in Okinawa, Japan

“…Although the prevalence of H. pylori in Okinawa is not significantly different from other parts of Japan (17,25), the incidence of gastric cancer (6.3 deaths/100,000 population) in Okinawa is the lowest in Japan (mean mortality rate of Japan, 11.8 deaths/100,000 population in 2009) ( . The different environmental factors and diets in Okinawa compared to mainland Japan are thought to be one reason for the lower incidence of gastric cancer (43).…”

Association of the Extent of Atrophic Gastritis With Specific Dyspeptic Symptoms

“…Atrophic gastritis is a quite common consequence of H. pylori gastritis in South Korea and Japan. 23 It will develop on a multifactorial basis including dietary factors and aging. 24 Autoimmune mechanisms are very rare in 25 When H. pylori infection spreads to oxyntic mucosa, it induces atrophy of the gastric corpus, which results in reduced secretion of gastric acid.…”