RESUMEN
BACKGROUND: In cystic fibrosis (CF) patients a duodenal impaired bicarbonate secretion and unbuffered gastric acid are always described and the development of duodenal ulceration is uncommon (CF paradox). Helicobacter pylori (HP) infection is the main cause for duodenal ulceration and its prevalence in CF patients is controversial. AIM: The objective of this study is to evaluate HP prevalence, gastric histology, and duodenal ulceration in adult FC patients. METHODS: 32 adult CF patients were submitted to (13)C-urea breath test and serum immunoblotting test for HP diagnosis. Among them, 20 patients were submitted to endoscopy. RESULTS: 19/32 (68%) patients showed positive serology. Endoscopy showed erosive duodenitis (15%), and duodenal ulcer scar in 10%. On duodenal histology, 94.5%, showed active inflammation and 66.7% gastric metaplasia. CONCLUSION: HP infection prevalence in adult CF patients was similar to that of general Brazilian population. CF patients have all the duodenal spectrum of alterations, including duodenal ulcer. CF paradox may not exist.