Relationship between Helicobacter pylori virulence genes and gastroduodenal disease

OBJECTIVE: This study aimed to identify Helicobacter pylori virulence factors and examine their associations with clinical outcomes in Thai patients. Moreover, the association between these genotypes and gastric mucosa morphological patterns was investigated. METHODS: This retrospective study enrolled patients who underwent esophagogastroduodenoscopy at Suranaree University of Technology Hospital. The presence of the cagA and vacA genes was investigated by real-time polymerase chain reaction. RESULTS: The H. pylori-specific genes ureA and 16S rRNA were detected in all 698 gastric biopsy specimens. In total, 567 (81.23%) patients with H. pylori infection were positive for the cagA gene, 443 (63.46%) were positive for the vacA gene, and 370 (53.0%) were positive for both. The cagA genotype was significantly more common in patients with chronic gastritis and peptic ulcers (78.99% and 79.41%, respectively) than the vacA gene (51.48% and 55.88%, respectively) and combined genotypes (32.34% and 47.05%, respectively). Moreover, the cagA genotype was significantly more common in patients with type 4 or 5 gastric mucosa patterns (69.49% and 76.31%, respectively). CONCLUSIONS: The cagA genotype is the main cause of serious inflammation of the gastric mucosa. The cagA gene is possibly an important factor explaining gastroduodenal disease outcomes in Thai patients with H. pylori infection.