Chronic gastritis: its clinical and physiopathological meaning.

Chronic gastritis (CG) is the chronic inflammation of gastric mucosa associated with varying degrees of damage of superficial and glandular epithelia. The causes of CG are exogenous (mainly Helicobacter pylori) and endogenous. The process is concluded by atrophy of parenchyma. CG is associated with dyspepsia in approximately 50% of cases, but frequently with gastric and duodenal ulcer. The role of chronic atrophic gastritis (AG) is relevant in development of cancer or of other tumors like carcinoids and polyps. The specific secretive cells of the glandular parenchyma and of the superficial epithelium reveal a good correlation with secretory component behavior, but they are only partially influenced by H. pylori. It emerges that CG is an anatomic-functional condition. The cytofunctional profile in AG causes achlorhydria and therefore chronic luminal alkalosis. This condition favors intestinal metaplasia (IM) and important intraluminal troubles. Finally, nutritional deficiencies or H. pylori seem to interfere with the intragastric metabolism and therefore play a relevant role in the rise of IM.