Chemokines in the gastric mucosa in Helicobacter pylori infection

Abstract

Background: Although chemokines have been suggested to play an important role in Helicobacter pylori associated gastritis, few studies have investigated the role of chemokines other than interleukin 8 (IL-8) in gastric mucosa.

Aims: To investigate the expression and production patterns of various chemokines using gastric biopsy specimens.

Methods: In 192 patients, expression patterns of C-X-C chemokines (IL-8 and growth regulated alpha (GRO alpha)) and C-C chemokines (regulated on activation, normal T cell expressed and presumably secreted (RANTES), monocyte chemotactic and activating factor (MCAF), macrophage inflammatory protein 1 alpha (MIP-1 alpha), and MIP-1 beta) were examined using reverse transcription polymerase chain reaction (RT-PCR) and enzyme linked immunosorbent assay (ELISA). cagA gene was identified using PCR.

Results: H pylori infection was associated with increased rates of expression of mRNA for IL-8, GRO alpha, RANTES, and MIP-1 alpha and with increased levels of mucosal IL-8 and GRO alpha. IL-8 and GRO alpha levels correlated with the density of H pylori in both the antrum and corpus. The levels of these chemokines correlated with cellular infiltration in the antrum but not the corpus. cagA gene positive H pylori infection was associated with increased rates of expression of mRNA for IL-8 and GRO alpha and with increased levels of these chemokines.

Conclusion: H pylori infection is associated with increased expression rates and production of C-X-C chemokines (IL-8 and GRO alpha), but not with increased production of C-C chemokines. Although H pylori infection is associated with increased C-X-C chemokines in the antrum and corpus, there is a difference in the inflammatory response between these two areas of the stomach.

Figure 1

H pylori infection and production of GROα. Bars indicate median values for each group.

Figure 2

Relation between mucosal levels of IL-8 and GROα protein in H pylori positive patients.

Figure 3

Production of C-X-C chemokines and histological findings in H pylori positive patients with chronic gastritis are expressed as box plots. The ends of the bars indicate the 25th and 75th percentiles. The 50th percentile is indicated with a line, and the 10th and 90th percentiles are indicated with error bars. Data outside the 10th and 90th percentile are displayed using symbols. Correlation coefficients were calculated with the Spearman rank test.

Figure 4

Production of GROα and eradication of H pylori. *p<0.005 by Wilcoxon's matched pairs test. Before, before eradication therapy; after, after eradication therapy.