Prevalence and clinical relevance of Helicobacter pylori cagA and vacA genes in Lebanese patients with gastritis and peptic ulcer disease

Background: The prevalence and clinical relevance of H. pylori cagA and vacA virulence genes in the pathogenesis of disease phenotype was assessed by a novel approach for this organism consisting of determination and comparisons of H. pylori gene transcription levels directly in gastric biopsies according to disease phenotype.Methodology: Gastric mucosal biopsies were collected from patients with peptic ulcer disease (PUD), gastritis, and normal mucosa in an academic medical center in Lebanon. H. pylori was detected in these biopsies by rapid urease (CLO™) test and PCR amplification of the ureA gene. H. pylori virulence genes, their transcription and transcription levels were determined respectively by PCR, RT-PCR and real time RT-PCR. Results: Forty-five percent of patients were H. pylori positive by PCR of the ureA gene, 37.5% of whom had cagA and 59.4% vacA.Conclusions: The cagA and vacA genes were detected more frequently in PUD patients with significantly higher transcription levels than in gastritis and normal mucosa