Presence of gastric autoantibodies impairs gastric secretory function in patients with Helicobacter pylori-positive duodenal ulcer

BACKGROUND: Although the association between Helicobacter pylori infection and gastric autoimmunity is now well established, to date little is known about the significance of anticanalicular autoantibodies in patients with duodenal ulcer (DU). We therefore investigated the prevalence of serum antiparietal cell autoreactivity in DU patients as well as the relationship between these autoantibodies, gastric histopathology and gastric secretory function in this setting. METHODS: Forty-one consecutive patients with H. pylori-positive DU were initially recruited. In all patients, basal (BAO) and pentagastrin stimulated acid output (PAO), fasting and meal-induced serum gastrin levels, as well as serum pepsinogen I concentrations, were measured. Antral and body gastritis was evaluated according to the Sydney system. Serum anticanalicular autoreactivity was determined by the indirect immunoperoxidase technique. RESULTS: Serum anticanalicular autoantibodies were found in 7 out of 34 patients (20%). The presence of these antibodies was associated with a significantly higher grade of body gastritis (activity: 1.9 versus 0.9) as well as with significantly higher fasting and meal stimulated gastrin levels (mean fasting gastrin, 76.4 (15.2) microg/ml versus 59.3 (20.5) microg/ml). In addition, PAO values were significantly lower in patients with gastric autoantibodies than in those without this autoreactivity (mean 0.35 (0.16) mmol kg(-1)h(-1) versus 0.49 (0.16)mmol kg(-1)h(-1)). In contrast, no significant differences were found between patients with and without anticanalicular autoantibodies as regards fasting serum pepsinogen I concentrations. CONCLUSIONS: Serum anticanalicular autoantibodies can be detected in 20% of patients with DU and are associated with a more severe pattern of body gastritis, higher gastrin levels and decreased peak acid secretion values. Their presence could account for the normal or reduced acid output which can be seen in a subset of DU patients.