Helicobacter pylori infection is associated with variable clinical outcomes, including gastroduodenal diseases, and genetic factors may be relevant in this process.
Dr Ohyauchi and colleagues undertook a study in order to investigate the effects of an interleukin 8 (IL-8) gene polymorphism on the risk of gastroduodenal diseases, the degree of H pylori induced gastritis, and IL-8 gene transcription.
The investigators included 244 healthy control subjects and 690 H pylori positive patients with non-cardia gastric cancer, gastric ulcer, duodenal ulcer, or gastritis.
The researchers identified the IL-8 –251 A/T polymorphism by direct sequence analysis, and measured the gastritis score and serum pepsinogen (PG).
| IL-8 –251A showed enhanced promoter activity in response to IL-1ß or tumour necrosis factor|
The researchers assessed the transcriptional promoter activity of the IL-8 gene by luciferase assay.
The research team found that IL-8 –251A was associated with a higher risk of gastric cancer and gastric ulcer.
The team observed that patients carrying IL-8 –251A showed an increased risk of gastric cancer and gastric ulcer.
In addition, the researchers noted that compared with patients younger than 49 years, atrophy and metaplasia scores in the antrum were significantly higher and the PG I/II ratio significantly lower in –251A carriers than in T/T carriers.
In the in vitro assay, IL-8 –251A showed enhanced promoter activity in response to IL-1ß or tumour necrosis factor.
Dr Ohyauchi concluded, "The IL-8 –251A allele may be associated with progression of gastric atrophy in patients with H pylori infection, and may increase the risk of gastric cancer and gastric ulcer in Japanese people."