Estudo de genes de virulência do Helicobacter Pylori em mucosa oral e biópsia gástrica de pacientes submetidos à endoscopia digestiva alta

Abstract

Objective: To describe the sociodemographic and clinical profile of patients infected with Helicobacter pylori, as well as to analyze the presence of the bacterial virulence gene cagA in gastric biopsy and oral cavity samples from patients undergoing upper gastrointestinal endoscopy (UGE), and to assess the level of agreement between these anatomical sites. Methods: This cross-sectional study included adult individuals (≥18 years), of both sexes, who completed an epidemiological and symptom-based questionnaire containing sociodemographic, clinical, and housing-related variables. Oral cavity samples were collected, and gastric biopsies were obtained during UGE. Detection of H. pylori DNA in oral samples was performed using polymerase chain reaction (PCR) and nested PCR, as well as for the detection of the cagA gene. In gastric biopsies, the bacterium was identified by histopathological examination. Statistical analysis consisted of frequency distribution of descriptive variables, calculation of the prevalence of cagA positivity, and assessment of agreement between anatomical sites, adopting a 95% confidence interval. Results: A total of 74 individuals who tested positive for H. pylori in at least one of the analyzed sites were included, of whom 10 tested positive in both sites. There was a predominance of females (69.9%), individuals older than 60 years (42%), households with three or more residents (52.8%), urban residents (90.4%), and a previous history of UGE (71.2%). The prevalence of the cagA gene was 6.81% in oral samples and 20.0% in gastric samples. The agreement analysis for cagA detection in oral cavity samples and gastric biopsies demonstrated weak agreement between the evaluated sites, with a Kappa coefficient of 0.13. Conclusion: Patients infected with Helicobacter pylori were predominantly women and individuals older than 60 years. The virulence gene cagA was detected in both the oral cavity and gastric mucosa, with a higher prevalence in the latter site. The weak agreement observed between the evaluated anatomical sites suggests low correspondence in the detection of the cagA gene between the oral cavity and the stomach, indicating that the presence of this marker in one site does not necessarily reflect its presence in the other. However, the low frequency of cagA-positive samples represents a limitation of the study and highlights the need for further investigations with a larger number of cases to confirm these findings.