ABSTRACT
The normal immune response to Helicobacter pylori may involve mechanisms different from T-lymphocyte activation. The identification of H. pylori in the human stomach has crucially influenced our understanding of the gastric inflammatory diseases. The inflamed mucosa of H. pylori infection is characterized by a marked accumulation of peripheral neutrophil granulocytes (PMN) and a mononuclear cell infiltrate. H. pylori are able to activate complement in vitro, so an important component of PMN and monocyte inflammation in vivo is possibly C5a. The remote possibility exists that intramucosal monocytes/mac- rophages may harbor H. pylori, protected from immunoglobulins and other immune mediators. Initial studies showed that areas of gastric mucosa with H. pylori infection had a strong expression of aberrant HLA-DR molecules on gastric epithelial cells, in close proximity to mononuclear infiltrates. Very few data have been published comparing the cellular immune reactivity to H. pylori in patients infected with H. pylori and healthy controls.
