H. pylori virulence factors: Genetic polymorphism and disease

Helicobacter pylori (H. pylori) virulence factors are important for clarifying the role of H. pylori in the regional differences in the gastric cancer distribution and the pathogenesis of clinically significant diseases such as gastric cancer or peptic ulcer. Genetic polymorphism of H. pylori virulence factors differs by geographic region, in which East-Asian-type cagA is known to be more virulent than Western type. As there are more repetitions of Glu-Pro-Ile-Tyr-Ala (EPIYA)-C segment in cagA, H. pylori becomes more virulent, which is associated with gastric cancers in the West. Between genotype m1 and m2 of vacA middle region, m1 is more virulent, which is thought to be the cause of the increased prevalence rate of gastric cancers in many East-Asian regions. If all the studies to date are put together, cagA, vacA, and oipA are the factors associated with gastric cancer and dupA can be considered to be an important virulent factor for duodenal ulcer, but because different studies have showed different results and particularly results were different by geographic region, more research is needed.