Antibody response to Helicobacter pylori CagA and heat-shock proteins in determining the risk of gastric cancer development

Objective. To investigate whether the systemic antibody response to Helicobacter pylori heat shock protein B can be considered, in addition to and cytotoxin-associated protein (CagA) antibody determination, a further serological marker of increased risk of gastric cancer development. Methods. A total of 98 Giemsa positive Helicobacter pylori patients (28 with gastric cancer: 30 with duodenal ulcer and 40 with nonulcer dyspepsia] were studied. Serum samples obtained from ail patients were tested for IgG antibodies to CagA (116 kDa) VacA (89kDa) and heat skock protein B (54 kDa) antigens of Helicobacter pylori by the Western blot technique. Results, 26/28 patients (92.9%) with gastric carcinoma, 29/30 patients (96. 7%) with duodenal ulcer and 30/40 patients (75.0%) with non-ulcer dyspepsia were seropositive for CagA protein. The prevalence of serum IgG antibody to CagA in the cancer patients was not significantly higher then in duodenal ulcer and non-ulcer dyspepsia patients. The prevalence of antibodies to VacA was not significantly different between gastric carcinoma and non-ulcer dyspepsia patients. In contrast the prevalence of systemic antibodies to heat skock protein B was significantly higher in gastric cancer patients (78.6%) than in duodenal ulcer (36.7%, p=0.002) or non-ulcer dyspepsia patients (52.5%, p=0.029). Conclusions, The detection of antibodies to heat shock protein B is proposed as an additional test which, in association with the determination of serum antibodies to CagA, could help in determining the risk of developing severe gastroduodenal disease, and gastric cancer: in particular.