Purpose. To review the general state of knowledge of the pathogenesis of Helicobacter pylori infection, and to discuss its treatment modalitites and implications of eradication. Study selection. Ultrastructural studies, detection of multiple enzymes and toxins, and identification of a specific immune response were used, as well as epidemiological studies. Clinical studies were used to investigate the effects of therapy. Results of data analysis. H. pylori infection is unequivocally associated with chronic antral gastritis and is a major causal factor in peptic ulcer disease. Its pathogenic effects may be partly explained by its production of harmful enzymes, toxins and a cytotoxic local immune response. The spread of H. pylori to areas of gastric metaplasia in the duodenum may lead to duodenitis and ulceration. The most effective treatment regimens consist of combinations of three drugs. Eradication leads to regression of gastritis and a considerable reduction in duodenal ulcer relapses. Conclusion. H. pylori is a major factor in the pathogenesis of chronic gastritis and peptic ulcer disease. Successful eradication of the infection markedly alters the natural history of the disease.
