The lack of influence of CagA positive Helicobacter pylori strains on gastro-oesophageal reflux disease

Helicobacter pylori infection of the gastric mucosa may influence gastro-oesophageal reflux disease (GORD). The protein of cytotoxin associated gene A (CagA) is assumed to be a virulence factor of H. pylori. CagA positive strains may induce severe gastroduodenal peptic ulcer disease. The aim of this study was to evaluate the association between H. pylori strains expressing CagA and GORD.Nine hundred and thirty patients were examined by endoscopy. Antral and corpus biopsies for the urease test and serum samples for the detection of IgG antibodies to CagA were taken. Serum samples were assayed by using the western blot technique.The results from 811 patients were analysed statistically. This study population consisted of 264 H. pylori infected patients (264/811, 32%). The H. pylori prevalence was 33% (89/266) in patients with reflux oesophagitis and did not differ from those patients without oesophagitis (175/545, 32%). In contrast, patients with Barrett's oesophagus showed a significantly lower prevalence of H. pylori infection than the other three groups (8/35, 23%). There was no significant influence of CagA, as one of the H. pylori virulence factors, on GORD. Antibodies against CagA were slightly, but insignificantly, more frequent in patients with oesophagitis (55/89, 62%) than in patients without oesophagitis (94/175, 54%).In a large cohort of GORD patients no significant difference in the prevalence of H. pylori in patients with and without GORD was found. In addition, there is no correlation between patients carrying CagA positive strains and development of reflux oesophagitis. However, in the case of histopathologically proven Barrett's oesophagus the prevalence of H. pylori was significantly lower. The influence of CagA positive strains on oesophageal mucosa is discussed.