HELICOBACTER PYLORI AND EPSTEIN–BARR CO-INFECTION IN GASTRIC DISEASE

Abstract

The incidence of gastrointestinal diseases and in particular gastric cancer (GC) is high worldwide. Over the last few years, numerous studies have speculated that Helicobacter pylori (H. pylori) and Epstein-Barr virus (EBV) can be correlated with gastric cancerogenesis. Virulence factors of H. pylori can contribute to the variability of clinical outcomes: among the most important virulence factors is the pathogenicity island (CagPAI), vacA and oipA gene. EBV infection usually persists in B cells and induces an inflammatory reaction in cooperation with H. pylori. In Sicily, H. pylori and EBV infections are particularly prevalent, and to our knowledge no study has addressed this yet. The aim of our study was to examine the association of H. pylori and EBV infection in patients with gastric diseases in Sicily. Gastric biopsies were collected from 24 adult patients with chronic gastritis active (CGA) and from 24 adult patients without any gastric disease (NGD) who underwent upper gastrointestinal endoscopy. H. pylori infection was diagnosed by PCR for ureaseA gene while EBV-DNA was detected by Real time PCR for region Bam HI-W. Moreoever, we investigated the presence of CagPaI and the status of vacA and oipA genes. Percentage of resistance to Clarithromycin of H. pylori was evaluated also. We established that H. pylori and EBV infection was present in 42% of patients, while dual infection with H. pylori and EBV-DNA was present in 54% of the patients with CGA. In patients with NGD we found that H. pylori and EBV infection was present in 46% and in 21% of patients respectively, while co-infection was present in 33% of patients. CagPAI was present in only 20% of patients with GCA and in 9% of patients with NGD. As regards vacA alleles, s2i2m2 were predominant, present in 80% and 82% of patients with CGA and NGD respectively. The status “ON” of oipA gene was present in the same percentage. Finally, we found that 38% of patients positive for H. pylori infection showed resistance to Clarithromycin. In our study, there was a strong association between the simultaneous presence of H. pylori and EBV infection in patients with CGA compared to patients with NGD. Furthermore, our data confirmed the high percentage of resistance among H. pylori strains circulating in Sicily, underlining the importance of establishing a therapy that is effective in eradicating them and reducing the frequency of coinfections and evolution towards gastric cancerogenesis