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Background and aims: A number of Helicobacter pylori outer membrane proteins (OMPs) undergo phase variations. This study examined the relation between OMP phase variations and clinical outcome. Methods: Expression of H pylori BabA, BabB, SabA, and OipA proteins was determined by immunoblot. Multiple regression analysis was performed to determine the relation among OMP expression, clinical outcome, and mucosal histology.Results: H pylori were cultured from 200 patients (80 with gastritis, 80 with duodenal ulcer (DU), and 40 with gastric cancer). The most reliable results were obtained using cultures from single colonies of low passage number. Stability of expression with passage varied with OipA . BabA . BabB . SabA. OipA positive status was significantly associated with the presence of DU and gastric cancer, high H pylori density, and severe neutrophil infiltration. SabA positive status was associated with gastric cancer, intestinal metaplasia, and corpus atrophy, and negatively associated with DU and neutrophil infiltration. The Sydney system underestimated the prevalence of intestinal metaplasia/atrophy compared with systems using proximal and distal corpus biopsies. SabA expression dramatically decreased following exposure of H pylori to pH 5.0 for two hours. Conclusions: SabA expression frequently switched on or off, suggesting that SabA expression can rapidly respond to changing conditions in the stomach or in different regions of the stomach. SabA positive status was inversely related to the ability of the stomach to secrete acid, suggesting that its expression may be regulated by changes in acid secretion and/or in antigens expressed by the atrophic mucosa.

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BACKGROUND Multifocal atrophic gastritis (MAG) is currently considered a precancerous lesion leading to intestinal type gastric carcinoma. The current study aimed to describe the topography of atrophy in stomachs with early gastric carcinoma. METHODS Resected stomachs from patients with intestinal type gastric carcinoma were routinely processed, sectioned (an average of 108 sections/stomach), and stained with a triple stain. Sections were scored on a visual analog scale for Heliobacter pylori and intestinal metaplasia. The type of epithelium (antral, oxyntic, transitional) was recorded. Atrophy was defined as the loss of normal glandular components and included intestinal metaplasia and/or pseudo‐pyloric metaplasia of the corpus. Pseudo‐pyloric metaplasia was identified by the presence of pepsinogen I in mucosa that was topographically corpus but phenotypically antrum. RESULTS Sixteen stomachs with intestinal type gastric carcinoma were examined. In none of the specimens examined was MAG (independent foci of atrophy) identified. In the majority (88%), atrophy was present as a continuous sheet. Islands of intestinal metaplasia (multifocal intestinal metaplasia) were present within a sheet of pseudo‐pyloric metaplasia. A few specimens (12%) had a non‐atrophic corpus with almost total replacement of antral epithelium with intestinal metaplasia. Multifocal dysplasia distant from the original tumor was found both in areas with and without intestinal metaplasia. CONCLUSIONS Contrary to popular belief, atrophy in intestinal type gastric carcinoma is not present as independent foci, but rather as a continuous sheet. Previous studies failed to identify pseudo‐pylori metaplasia as a marker for atrophy. Cancer 2002;94:1428–36. © 2002 American Cancer Society. DOI 10.1002/cncr.10375