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 Helicob acter pylori heat shock protein B can be considered, in addition to and cyt otoxin-associated protein (CagA) antibody determination, a further serologi cal marker of increased risk of gastric cancer development. Methods. A tota l of 98 Giemsa positive Helicobacter pylori patients (28 with gastric cance r: 30 with duodenal ulcer and 40 with nonulcer dyspepsia] were studied. Ser um samples obtained from ail patients were tested for IgG antibodies to Cag A (116 kDa) VacA (89kDa) and heat skock protein B (54 kDa) antigens of Heli cobacter 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 patien ts was not significantly higher then in duodenal ulcer and non-ulcer dyspep sia patients. The prevalence of antibodies to VacA was not significantly di fferent between gastric carcinoma and non-ulcer dyspepsia patients. In cont rast the prevalence of systemic antibodies to heat skock protein B was sign ificantly 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). Conclusi ons, The detection of antibodies to heat shock protein B is proposed as an additional test which, in association with the determination of serum antib odies to CagA, could help in determining the risk of developing severe gast roduodenal disease, and gastric cancer: in particular.