TOPOGRAPHIC STUDY OF HELICOBACTER-PYLORI AND HLA-DR ANTIGEN EXPRESSION ON GASTRIC EPITHELIUM

Helicobacter pylori and HLA-DR antigen expression on gastric epitheliu m, identified by an indirect immunoperoxidase staining method using mo noclonal antibodies against H. pylori and HLA-DR antigens, were studie d topographically. Fifty-nine biopsy specimens from 41 patients who ha d neither gastric cancer nor peptic ulcers were examined. H. pylori wa s observed predominantly over or on the surface epithelium, while HLA- DR antigens were frequently expressed on the epithelium of the isthmus region. These observations led to the conclusion that there was no di rect topographic association between H. pylori and epithelial HLA-DR e xpression. However, the frequency of HLA-DR expression in H. pylori-po sitive (28/29) specimens was significantly higher than that in H. pylo ri-negative (18/30) specimens (P < 0.01). Furthermore, a greater numbe r of H. pylori was associated with a stronger expression of HLA-DR ant igens (P < 0.001). We conclude that H. pylori is indirectly related to HLA-DR expression on gastric epithelium. H. pylori is the first micro bial agent that has been suggested to be associated with epithelial HL A-DR expression in the human gastrointestinal tract.