Helicobacter pylori was recognized in 1994 as a class I carcinogen by the International Agency for Research on Cancer (IARC). The prevalence of H. pylori infection varies from 20 to 50% in industrialized countries to over 80% in developing countries. The cagA strains are more virulent than others, being able to induce morphological changes, vacuolization and degeneration of in vitro cultured cells.
Aim: During this study we investigated the possible correlations between the presence of H. pylori cagA (cytotoxin associated gene antigen)-IgG antibodies and the severity of clinical and endoscopical findings.
Methods: Anti-cagA IgG was screened by ELISA in 104 selected patients exhibiting resistance to first line therapy for H. pylori, bleeding gastroduodenal ulcers, non cardia gastric cancer and gastric polyps.
Results: A statistically significant association between resistant cases to first line therapy for H. pylori, bleeding gastroduodenal ulcers, non cardia gastric cancer, gastric polyps and cag A Ig G antibodies (p value 0.02 calculated by T-Test) was observed. As Cag A antibodies titer persist up to four months, their level could be an useful marker in detecting previous long-term H pylori infection especially in gastric cancer patients.
Conclusions: CagA positive H. pylori are virulent strains and the cagA IgG antibodies titer is associated with persistence of infection after treatment, upper gastroduodenal ulcers or gastric cancer. The presence of these antibodies, associated with positive biopsy for H. pylori, indicates the need of H. pylori treatment.