LOCAL AND SYSTEMIC IMMUNE-RESPONSE IN HELICOBACTER-PYLORI-ASSOCIATED CHRONIC GASTRITIS BEFORE AND AFTER TREATMENT

Ten patients with Helicobacter pylori-associated chronic gastritis wer e given combination therapy for 6 weeks with a bismuth subnitrate-cont aining compound and bacampicillin. The eradication rate was 40% 6 week s after the end of treatment. Two patients remained H. pylori-negative at long-term follow-up after 6 and 17 months; that is, H. pylori was only eradicated in 20% of the patients after long-term observation. By dot blot and immunoblotting both urease and an urease-associated heat shock protein (HSP62) were found to be specific and constant immunodo minant H. pylori antigens. The immunohistologic pattern showed induced expression of HLA-DR and HSP62, but not of ICAM-1, in all but two bio psy specimens of gastric epithelial cells. This study suggests i) that long-term observation is important when evaluating the efficacy of an ti-H. pylori therapy; ii) that the immune defense mechanisms in the ga stric mucosa differ from those in inflammatory conditions affecting ot her organs, where ICAM-1 and HLA-DR seem to be governed by a common re gulator; and iii) that the immunopathologic effects of H. pylori may b e caused by autologous and/or bacterial HSPs, which act as triggering factors in the development and persistence of the chronic inflammation in the gastric mucosa.