RESUMEN
There is a worldwide debate about the possible protective role of Helicobacter pylori against gastroesophageal reflux disease (GERD), especially in the severe esophageal forms. This bacterium, amd oits Cag A straom in particular, can induce inflammatory and atrophic changes in the stomach mucosa and the resulting hypochlorhydria may be responsible for this protective effect. Objectives: To assess patients with severe erosive esophagitis and /or Barrett's esophagus for the prevalence of H.pylori infection, as well as the presence of anti-Cag A antibodies, and of histopathological signs of gastric atrophy in the colonized patientes. Patients and metkhods: Thirty patientes with endoscopic and histopathological diagnosis of severe erosive esophagitis (Los Angeles grade C or D) and /or Barrete's esophagus were selected. These patients were submitted to the 13C-urea breath test for the detection of H. pylori, and to upper digestive endoscopy to collect gastric biopsies for the histopathological determination of atrophy. Sera from individuals infected with the bacterium were examined for the presence of anti-Cag A antibodies. Results: Twelve patients were infected with H. pylori(40por cento), and the prevalence of the anti-Cag A antibody in these indiviuals was 91.7por cento. Histopathological signs of gastic atrophy were observed in 33por cento of the patients colonized by the bacteria. conclusion: There is a predominance of the Cag A-positive strain (91.7por cento) among patients with severe esophageal forms of GERD infected with H. pylory. Histopathological signs of gastric atrophy were observed in 33.3por cento of the infected patients, but none of the uninfected patients. These findings suggest that the cag-positive stains of H. pylori may have, but do not necessarily have, a protective effect against the developmente of severe forms of GERD