Effect of Helicobacter pylori infection on gastric cell proliferation and genomic instability in a paediatric population of southern Italy.

BACKGROUND: The incidence of gastric cancer is high in areas with a high prevalence of Helicobacter pylori infection. Cell transformation and tumour progression occur over a long period of time and markers of genomic instability usually precede morphological changes. AIM: To evaluate the effect of Helicobacter pylori infection on cell proliferation, DNA status and oncogene expression in children. PATIENTS AND METHODS: Morphometric and immunohistochemical techniques were used to analyse DNA content, p53 and c-myc oncogene expression and cell proliferation on gastric biopsies of 53 children (27 Helicobacter pylori-negative and 26 Helicobacter pylori-positive). RESULTS: Gastric mucosa was normal in 11% of Helicobacter pylori-positive and in 33% of Helicobacter pylori-negative subjects. Most children had chronic non-atrophic gastritis regardless of Helicobacter pylori infection, and only a minority of children affected by Helicobacter pylori had mild atrophic gastritis. Cell proliferation was significantly higher in children with Helicobacter pylori-positive gastritis than in those with Helicobacter pylori-negative gastritis. No metaplasia, dysplasia, p53 overexpression or altered DNA content was found in any child. Interestingly, 46% of children with and 29% without Helicobacter pylori infection had c-myc overexpression closely related to the cell proliferation rate. CONCLUSION: Helicobacter pylori infection in children may coexist with a normal gastric mucosa, and it is not associated with genomic instability markers in cases of chronic gastritis.