TABLE 4.
Genetic polymorphisms and H. pylori infection
| Polymorphism site | Effect | Association with H. pylori infection | Reference(s) |
|---|---|---|---|
| Immune mediators | |||
| IL-1 gene cluster | IL-1B*-511T, IL-1B*-31C, and IL-1RN*2/*2 result in higher IL-1B expression | Higher expression of IL-1B results in a proinflammatory response coupled to hypochlorhydria, pangastritis, and increased risk of atrophic gastritis and gastric cancer | 156, 157, 159, 208, 283, 383, 517, 715 |
| IL-8 (−251A/T) | Presence of the −251A allele results in increased expression of IL-8 | In a Japanese population, increased risk of gastric cancer and gastric ulcer; in a Hungarian population, increased risk of duodenal ulcers | 247, 250, 377 |
| IL-10 (ATA/GCC haplotypes) | GCC haplotype results in increased expression of IL-10 | GCC haplotype is associated with colonization by more-virulent H. pylori strains (cagA+, vacA s1+, and babA2+); ATA haplotype is associated with increased risk of gastric cancer | 159, 250, 264, 377, 515, 697, 714 |
| TNF-A | TNF-A*-308A allele is associated with increased TNF-α expression and increased gastrin expression | TNF-A*-308A is associated with higher levels of H. pylori infection and increased risk of gastric cancer | 159, 252, 365, 375, 383, 696, 708, 714 |
| MPO | MPO*-463A allele is associated with low-level expression of myeloperoxidase | MPO*-463A genotype is associated with lower H. pylori infection rates | 251 |
| Other | |||
| CD14 | CD14*-159T polymorphism results in elevated expression of CD14 | CD14*-159T genotype is associated with higher H. pylori infection rates | 301, 319 |
| TLR4 | TLR4*Asp299Gly results in diminished immune response | TLR4*Asp299Gly allele may be involved in development of gastric MALT lymphoma | 263 |
| FUT2 and FUT3 | Polymorphisms in the fucosyltransferase genes affect synthesis of Lewis antigens | FUT2 secretor (Se) and FUT3 le/le genotypes increase risk of H. pylori infection | 284, 559 |
| CYP2C19 | Polymorphisms in cytochrome P450 influence metabolism of compounds such as antibiotics and PPIs | CYP2C19 polymorphism negatively affects eradication rates of H. pylori antibiotic treatment | 209-211, 315, 537, 538 |
| GST t1/m1 | GST t1 null and m1 null alleles are associated with decreased antioxidative capacity | GST t1 null genotype is associated with increased risk of gastric cancer and gastric lymphoma | 86, 304, 305, 484, 530, 560, 711 |