Helicobacter pylori virulence markers in gastroduodenal disorders. Detection of cytotoxin-associated gene A and vacuolating cytotoxin-associated gene A genes in Saudi patients.

OBJECTIVE To detect the presence of virulence markers cytotoxin-associated (cagA) and vacuolating cytotoxin-associated (vacA) genes in gastric biopsy specimens of patients with gastroduodenal disorders. METHODS This study was conducted at the Department of Pathology, King Khalid University Hospital, Riyadh, Kingdom of Saudi Arabia between March 2008 and February 2009. A total of 118 gastric biopsy specimens from 81 males and 37 females (mean age: 55 +/- 18 years) with histological evidence for the presence of Helicobacter pylori (H. pylori) were included in the study. The H. pylori cagA and vacA genes were detected using polymerase chain reaction-enzyme-linked immunosorbent assay technique. RESULTS Both H. pylori cagA and vacA genes were detected in 60 (51%) patients. Forty-one (35%) patients had active chronic gastritis, 22 (54%) harbored cagA, and 25 (61%) had vacA gene. Twenty-six (22%) patients had duodenal ulcer, 14 (54%) had cagA, and 15 (58%) had vacA genes. Eighteen (15%) patients had active acute gastritis, 8 (44%) carrying cagA gene, and 12 (67%) had vacA gene. The cagA and vacA genes co-existed in all the 17 (100%) patients with adenocarcinoma. These genes coexisted in 44% biopsies from active acute gastritis, and 46% each in duodenal ulcer and active chronic gastritis. CONCLUSION The cagA and vacA genes as H. pylori virulence markers were detected in gastroduodenal disorders, and their remarkably high co-existence in adenocarcinoma prompt further investigations for evaluating H. pylori as a direct carcinogen.