Abstract
Recent studies indicate that Helicobacter pylori (HP) may exist in the oropharynx independently to the gastric infection. Comparison of genotypes of HP in the oral cavity, oropharynx, and stomach prooved that an individual can host more than one strain in various locations.
Differences were found in the presence of cagA gene and in the structure of vacA gene. The findings of HP in the oral cavity and oropharynx without demonstrable specific anti-HP antibodies in serum are remarkable.
This could be explained by an early detection of HP after primary infection, when the antibody response has not started yet. HP could also colonize the tisssues without inducing the host immune response.
Another explanation is the presence of HP coccoid forms. The question of transmission of HP has not been satisfactorily resolved yet.
Changes in the expression of some cytokines caused by HP were described in the gastric mucosa and were associated with malignit transformation. Similar mechanisms can be expected in case of oropharyngeal tissue.