Eradication treatment leads to improvement of gastritis. There is little information of its effect on changes in the topographic distribution and regression of actual mucosal alterations in dyspeptic patients. In a previous study we provided evidence of a complex of histopathological changes in the cardia, corpus and antrum in patients with H.pylori infection and non-ulcer dyspesia. Objective: To assess the effect of eradication treatment on the development of histological chan- ges in the lower oesophagus, in the gastric cardia, corpus and antrum in patients with non-ulcer dyspesia three and six months after treatment. Methods and patients. 251 consecutive dyspeptic patients (without ulcers or gastric malignity) with H.pylori infection were investigated prospectively. Endoscopy with eight biopsies (antrum, corpus, cardia and lower oesophagus) were made before, eradication treatment and three and six months after this treatment (Pantoprazole 40 mg 1x/day,Amoxycillin 1000 2x/day, Claritromycin 500 2x/day).The biopsies were stained ( H+E) and modified Giemsa to detect H. pylori. The inflam- mation, activity and other mucosal changess were examined semiquantitatively and evaluated according to the Sydney System. Results: in the cardia, corpus and antrum a significant decline of chronic inflammation was recorded as well as of the activity and H.pylori (p <0.001). Atrophy increased insignificantly in the cardia (p > 0.05) while in the corpus (p<0.05)and antrum it declined (p<0.001). Intestinal metapla- sia remained unaltered in the cardia and antrum, in the corpus it declined insignificantly. The number of patients with hyperplasia of the foveolae in the cardia increased, the increase was however not significant, contrary to the corpus (p < 0.01) and antrum (p<0.05), in particular between the first and second visit of the surgery.Lymphoid follicles receded significantly in the cardia (p<0.001) and in the antrum (p<0.01),while they did not change in the corpus. In the corpus and antrum was a significant increase of chemi- cal gastropathy between the second and third visit (p <0.001, and the same applies to haemorrha- ge in the oesophageal papillae (p<0.001). Conclusion. Eradication treatment had the most marked effect on decline of the activity of inflam- mation and number of Helicobacter pylori. Chronic inflammation, atrophy and intestinal metaplasia persisted, although with a lower inten- sity, and signs of chemical gastropathy with haemorrhage in the oesophageal papillae developed. Key words: Eradication treatment - Changes of histological findings - Gastritis - Non-ulcer dyspe- sia.

        Key words: Eradication treatment - Changes of histological findings - Gastritis - Non-ulcer dyspe- sia.