We used four different H. pylori strains isolated from patients with gastritis or duodenal ulcer disease to examine their differential effects on signaling pathways and IL-8 gene response in gastric epithelial cells.
Since such cytokine production is often determined by the genetic polymorphism of regions regulating cytokine gene expression, we investigated the relationship between TNF-alpha and IL-8 polymorphisms and the development of duodenal ulcer disease.
The present study demonstrates that in Helicobacter pylori-infected human gastric mucosa, cag+ infection is associated with enhanced Interleukin-8 expression, higher levels of active gastritis and bacterial density, and presence of duodenal ulcer.
IL-1beta and IL-8 levels in the antrum were greater in DU than in gastritis; in the corpus the cytokine level/H pylori differed irrespective of similar H pylori densities.
In summary, the present meta-analysis suggests that IL-8 gene -251 T/A polymorphism is associated with increased PUD risk among Asians, and especially for the subgroups of H. pylori+, DUD and GUD.
A total of 153 H. pylori isolates from patients with chronic gastritis (n = 74) or gastro-duodenal ulcers (n = 79) was examined for vacA genotypes and cagA status by polymerase chain reaction (PCR) and dot blot, and for their ability to induce IL-8 secretion by HEp-2 cells.
The IL-8 heterozygote mutant variant was detected with a significantly higher frequency among the DU patients and those with gastritis than among the H. pylori-positive controls.
These results might explain the clinical studies in which patients with duodenal ulcers had higher levels of IL-8 in the antral gastric mucosa than patients with simple H. pylori gastritis.
The IL-8 heterozygote mutant variant was detected with a significantly higher frequency among the DU patients and those with gastritis than among the H. pylori-positive controls.