Helicobacter pylori causes hyperproliferation of the gastric epithelium: pre- and post-eradication indices of proliferating cell nuclear antigen.

OBJECTIVE

To assess the effect of Helicobacter pylori (HP) eradication on the proliferation of the gastric epithelium by the expression of the proliferating cell nuclear antigen (PCNA).

METHODS

Alcohol-fixed gastric biopsies taken before and after treatment for HP were immunostained with the PC-10 anti-PCNA monoclonal antibody and the labeling index was determined with an image analysis system.

RESULTS

The mean PCNA-labeling index (LI) of 16 patients who remained HP positive did not change significantly (18.95 +/- 1.71 on first visit vs. 17.96 +/- 1.91 on second visit, mean +/- SEM). The mean PCNA LI of 31 patients who cleared HP was reduced significantly (19.95 +/- 1.77 on first visit vs. 14.13 +/- 1.29 on second visit, p < 0.001). Patients who were positive for HP at both first and second visit showed a significantly higher PCNA LI than normal control biopsies (13.05 +/- 1.70) (p < 0.05).

CONCLUSIONS

These results indicate that the gastric mucosa infected with HP is in a state of hyperproliferation. Patients who cleared HP showed a significant histopathological improvement, reflected in the reduction in number of polymorphonuclear and mononuclear cell infiltrates, and a reduction in the amount of superficial mucosa damage. Prolonged hyperproliferation of the gastric epithelium exerted by HP infection could be a major factor for human gastric carcinogenesis.