Mucosal peptic activity during Helicobacter pylori infection in pediatric patients.

Intramucosal peptic activity may participate in the genesis of acute and chronic superficial gastritis. The proteolytic activity of homogenates of gastric mucosa (antrum and body) and duodenum were measured at pH 2.0 (total peptic activity) after exposure to pH 8.0 (pepsinogen) and the activated pepsinogen (pepsin) was calculated in pediatric patients investigated for the presence of Helicobacter pylori (H pylori), 122 antral, 77 stomach body, and 74 duodenal biopsies were examined in 43 H pylori positive patients, 51 controls, and 28 H pylori negative gastritis patients. Activated pepsinogen was significantly reduced in the stomach of H pylori positive patients only. Pepsinogen values were similar in all the anatomical areas tested in all patients. In 13 H pylori positive patients reinvestigated three months after antibiotic therapy, antral mucosal activated pepsinogen activity increased significantly (mean pretreatment 1.56 (1.0) U/mg protein versus mean post-treatment 2.72 (1.7) U/mg protein) and reached values comparable with controls. The decreased activated pepsinogen activity in association with normal pepsinogen content observed in the antrum of H pylori positive gastritis patients indicate local pepsin inactivation or alternately enhanced removal into the gastric lumen or backflow into the circulation.