Identification of Gastric Cancer-Related Strains of Helicobacter pylori: Findings from Single Biopsy Specimens for PCR and Campylobacter-Like Organism Test

Abstract

Background: Transmission of Helicobacter pylori occurs within families. It is known that elimination of H. pylori may reduce the risk of peptic ulcer disease (PUD) and gastric cancer (GC) and increase the risk of gastro-esophageal reflux (GERD), Barrett’s esophagus, and esophageal adenocarcinoma. Objectives: The present study aimed to determine gastric cancer-related strains of H. Pylori by precise diagnostic methods in patients with gastritis and PUD in East Azerbaijan, Iran, where the incidence of GC and esophageal cancer is high. Methods: The PCR assay was performed on the same biopsy samples used for Campylobacte-like organism test (CLO test), using the vacA d region (a gene predictor of gastric adenocarcinoma and peptic ulcer disease) and 16S rDNA gene in patients referring to the department of endoscopy at Imam Reza hospital in Tabriz, Iran. This study was conducted on individuals who had not received non-steroidal anti-inflammatory drugs or any anti-Helicobacter therapy at least for 3 months prior to endoscopy. The collected data were analyzed using SPSS version 19. Results: The rate of false negative results by CLO test was 8.3%. However, no false-positive results were found by CLO test. Among those patients infected with H. pylori, vacA d1 -positive strains, one case had a history of gastric cancer and another one had a history of gastric ulcer in first-degree relatives. However, no family history of gastric cancer or gastric ulcer was found in the patients with strains carrying the vacA d2 genotype. Conclusions: This study suggests that the vacA PCR can be very useful in diagnosis, treatment, and follow-up of patients with gastritis and PUD. The PCR assay and CLO test can complement and confirm each other in identification and eradication of cancer-related strains of H. pylori. The exclusion of patients with suspected achlorhydria from the study is likely a reason for the lack of false positive results in CLO test.