Systemic humoral anti-Helicobacter pylori immune response in patients with gastric malignancies and benign gastroduodenal disease.

Background/aims: Helicobacter pylori elicits a strong local and systemic humoral immune response, but it is not able to eliminate bacteria. Immune response may be important for the course of infection that may lead to different gastroduodenal disease. In order to investigate differences in systemic humoral immune response between patients with different gastroduodenal diseases, we conducted clinical and serological studies.

Methodology: From 1999 to 2001 we enrolled 80 patients with dyspeptic symptoms: 26 with gastritis, 12 with duodenal ulcer, 29 with gastric cancer and 13 with gastric lymphoma. In all patients during diagnostic work-up we performed ELISA test with Helicobacter pylori-specific IgG and IgA. We investigated difference in stimulation of different immunoglobulin classes in patients with different gastroduodenal diseases, particularly benign and malignant. We estimated significance of differences with Mann-Whitney and Fisher exact probability test.

Results: All patients enrolled in the study were seropositive. Patients with gastritis had statistically significant higher level of IgG than patients with gastric cancer (p=0.0001), and gastric lymphoma (p=0.006). Patients with duodenal ulcer had statistically significant higher level of IgG than patients with gastric cancer (p=0.02), and gastric lymphoma (p=0.046). IgA level was significantly higher in patients with gastritis than in patients with gastric cancer (p=0.03). IgA>IgG ratio was significantly more frequent in patients with gastric cancer and gastric lymphoma than in patients with gastritis and duodenal ulcer (p=0.0002).

Conclusions: Result of our study suggested that Helicobacter pylori elicits different systemic humoral immune response in patients with gastritis and duodenal ulcer than in patients with gastric cancer and gastric lymphoma at least in intensity of stimulation of different immunoglobulin classes.