Cellular and humoral immune responses in Campylobacter pylori-associated chronic gastritis

Gastric cellular and humoral immune responses investigated by immunoperoxidase staining of 53 antral biopsies showed significant differences in Campylobacter pylori‐associated gastritis as compared with non‐bacterial chronic gastritis and normal controls. IgA, secretory component, and complement C3 coated bacilli were seen in all cases of active chronic gastritis. C3 was always associated with coating by IgA, IgM, or both, which were rarely seen in gastritis without polymorphonuclear neutrophil infiltration. Intraepithelial mononuclear cellular infiltration was seen in 18 of 26 cases of C. pylori‐associated chronic gastritis. The intraepithelial mononuclear cells stained positively for T cells and histiocytes.