Objective: To evaluate whether some duodenal ulcers (DU) classified as idiopathic according to standard criteria may be causally related to isolated duodenal colonization by H. pylori.
Methods: We studied consecutive ambulatory patients undergoing upper gastrointestinal endoscopy in a secondary care setting. Gastric and duodenal biopsies for diagnosing H. pylori infection were taken from all patients. Independently from the findings of duodenal biopsies, DU patients without gastric infection were classified as having idiopathic ulcers, and underwent urea C13 breath test and subsequent eradication therapy. Endoscopy was repeated 6 months after eradication treatment.
Results: Among 608 DU patients, 42 (6.9%) were classified as idiopathic: 24 (3.9%) were free from gastric and duodenal infection (group A) and 18 (3.0%) (group B) had isolated duodenal colonization. Urea C13 breath test was positive in one (4.2%) group A patient and in 3 (16.7%) group B patients. After eradication therapy, DU were detected in 14 out of 20 group A patients (70%) (four patients did not perform control endoscopy) and in 2 group B patients (11.1%): OR 18.66, 95% CI 3.23-107.82, P= 0.002. The difference was still detectable after multivariate analysis taking into account possible confounding factors: OR 15.79, 95% CI 2.48-100.53, P= 0.001.
Conclusions: Isolated duodenal colonization by H. pylori is detectable in a substantial proportion of patients with so-called idiopathic DU, and eradication therapy is effective in these patients.