Helicobacter pylori cytotoxic genotype is associated with peptic ulcer and influences serology.

Abstract

We studied 146 patients with peptic ulcer disease (n = 72), antral gastritis (n = 58), or duodenitis (n = 16) to ascertain whether the cytotoxic genotype of Helicobacter pylori (Hp) is associated with peptic ulcer disease and/or antral gastritis and whether it influences the circulating levels of total anti-Hp antibodies, anti-cagA antibodies, and pepsinogens. A gastric juice sample was obtained from each patient. After DNA extraction, polymerase chain reaction was used to amplify the genes urease A (ureA), cagA, and vacA of Hp. A significant association was found between peptic ulcer disease and the cytotoxic genotypes, characterized by the presence of s1 and m1 alleles of vacA and by cagA. Patients with a cagA-positive genotype showed a significant increase in anti-cagA antibodies and also had significantly increased circulating levels of pepsinogen C. Cytotoxic Hp strains are mainly involved in determining peptic ulcer disease, but not antral gastritis. The higher levels of circulating pepsinogen C found in patients infected with cytotoxic genotypes may reflect the higher degree of inflammation sustained by these strains.