BACKGROUND Helicobacter pylori affects gastric epithelium integrity by acceleration of apoptosis. However, it remains unclear what product of the bacteria causes apoptosis, or whether or not the apoptosis is involved in the development of ulcers.

AIMS To elucidate the factor from H pylori that causes acceleration of apoptosis and the role of apoptosis in the development of duodenal ulcer in H pylori infection.

PATIENTS FiveH pylori negative healthy volunteers, 47H pylori positive patients with duodenal ulcer, and 35 H pylori positive patients with gastric ulcer.

RESULTS There was a significant correlation between the urease activity of theH pylori strain and the level of apoptosis induced by this bacterial strain. Moreover, in duodenal ulcer patients infected with H pylori, the patients with an active ulcer exhibited a significantly higher level of apoptosis than those with ulcers at both the healing and scarring stages.

CONCLUSION These findings suggest that acceleration of apoptosis in the antral mucosa caused by the urease of H pylori plays a crucial role in the development of ulcers in the duodenum.