The importance of vacA, cagA, and iceA genotypes of Helicobacter pylori infection in peptic ulcer disease and gastroesophageal reflux disease

OBJECTIVE: To study the relationship between the presence of H. pylori viru lence factors and clinical outcome in H. pylori infected patients. METHODS: DNA was isolated from an antral biopsy sample and vacA, cagA, and iceA genotype were determined by PCR and a reverse hybridization technique in 183 patients with culture-proven H. pylori infection: 51 with peptic ulc er disease (PUD), 62 with gastroesophageal. reflux disease (GERD), and 70 w ith a normal endoscopy (gastritis only; GO). RESULTS: Forty-four samples (24%) showed more than one allelic variant in t he vacA s- or m-region and/or both iceA1 and iceA2 genotypes, indicating mu ltiple strain infection. These were excluded from statistical analysis. vac A sl and cagA were significantly more common in PUD than in GERD and GO. Lo gistic regression analysis showed that GERD patients were more often infect ed with strains lacking both ca-A and iceA than GO patients (OR = 0.36; CI = 0.15-0.89). Trend analysis showed that GERD patients were most often infe cted with less virulent strains (p < 0.002). CONCLUSION: Multiple strain infection is common. H. pylori strains possessi ng the vacA sl genotype and/or cagA are associated with PUD. GERD patients, infected with H. pylori, mostly carry less virulent strains possessing nei ther ca-A nor iceA1. Our findings support the hypothesis that virulent stra ins protect against the development of GERD. (Am J Gastroenterol 2001;96:26 03-2608. (C) 2001 by Am. Coll. of Gastroenterology).