Antibody to a Helicobacter pylori species specific antigen in patients with adenocarcinoma of the stomach

This study attempted to identify a possible antibody response to Helicobacter pylori, which is associated with patients with adeno-carcinoma of the stomach, By using proteins of H. pylori as the antigen, pooled sera from gastric cancer and non-cancer patients were used as the first antibody for Western blot analysis, Antibody responses to a 26 kD secreted protein were observed in pooled cancer sera, but not in pooled sera from non-cancer patients, The protein was purified, while amino acid sequences revealed that it was a H. pylori species specific protein, The gene of this protein was cloned and a recombinant protein was expressed in E. coli. In addition, an antibody to the recombinant protein was tested in each individual patient using Western blot analysis, None of the forty non-gastric cancer patients were positive for the antibody to the recombinantly expressed 26kD species specific protein, Meanwhile, six of the twenty four cancer patients tested positive (0/40 vs 6/24, p<0.01). Results presented herein demonstrate that the species specific protein of H. pylori can be useful in detecting H. pylori associated with adenocarcinoma of the stomach. (C) 1998 Academic Press.