Decrease in Ornithine Decarboxylase Activity after Eradication of Helicobacter pylori

Objective: Our aim was to determine whether gastric mucosal ODC activity is altered after successful eradication of HP. Recent reports have suggested that Helicobacter pylori (HP) infection of the stomach is associated with the development of gastric cancer. Gastrointestinal cancers usually do not arise de novo; a series of mucosal changes leading to neoplastic transformation and degrees of dysplasia are believed to precede the development of cancer. These conditions are associated with increased cellular proliferation. Ornithine decarboxylase (ODC) activity is induced by factors that stimulate cellular proliferation, and has been shown to be elevated in gastrointestinal neoplasia, including gastric cancer. Methods: Gastric antral and body biopsies were obtained from 17 HP-positive patients at endoscopy, for ODC activity and histology (including Warthin Starry stain) before and 4–6 wk after successful triple therapy. Results: Patients included 12 males and five females, with a mean age of 55 yr (27–73 yr). Mean ODC activity (in pmol CO₂/mg protein/h) was significantly decreased after eradication of HP, compared with pretreatment levels in antral (147 ± 26 vs . 80 ± 15) and body mucosa (76 ± 21 vs . 20 ± 5) ( p < 0.05). Conclusion: Successful eradication of HP decreases mucosal proliferative activity, as reflected by decreased ODC activity. We speculate that by decreasing mucosal proliferative activity, HP eradication may help decrease the subsequent risk of gastric cancer.