Rapid elimination of Helicobacter pylori and reduction of histocompatibility leucocyte antigen-DR expression 12h after a single dose of omeprazole, amoxycillin and metronidazole triple therapy

Background: Studies of eradication of Helicobacter pylori and subsequent re solution of H. pylori-related gastritis, have focused mainly on medium and long-term change following eradication therapies. Results from those studie s have shown that both acute and chronic inflammatory changes found in gast ric mucosa eventually return to normal. However, the early events in the st omach, particularly the effects on bacterial density and acute inflammatory markers of anti-H. pylori treatment, are largely unknown. The objective of this study was therefore to examine changes in the number of H. pylori, an d the severity of gastric mucosal inflammation in the gastric biopsy specim ens of patients before (0 h group, n = 14) and 12h (12h group, n=14) after initiating anti-H. pylori treatment. Methods: Biopsies were assessed, either quantitatively or semi-quantitative ly, for the presence of H. pylori, neutrophils, mast cells, intraepithelial lymphocytes and the expression of histocompatibility leucocyte antigen (HL A)-DR by gastric epithelium and the results were compared between groups. Results: Median H. pylori scores were 5 (range 2-5) and 0 (range 0-2) in bi opsies from untreated and 12h post-treatment groups, respectively (P<0.001) . In most 12h post-treatment biopsies, H. pylori organisms could not be ide ntified. There was a significant reduction in HLA-DR expression by gastric epithelium (median 3.5 with range 2-4 at Oh group vs median 2 with range 0- 4, P<0.05), but there was no significant difference in the number of intrae pithelial lymphocytes, CD3+ cells, mast cells or the distribution and densi ty of neutrophils (all P>0.05). Furthermore, the severity of gastritis as s cored with the Sydney system was similar in both untreated and treated grou ps. Conclusions: The results of this study indicate that elimination of H. pylo ri organisms and resolution of some inflammatory markers occurs as early as 12 h following a single dose of omeprazole 40 mg, amoxycillin 1.0 g and me tronidazole 400 mg, which suggests that rational therapeutic strategies wit h shorter duration using the currently available drugs may be possible.