Immunohistochemical detection of Helicobacter pylori in the surface mucous gel layer and its clinicopathological significance

Abstract

Background: Attempts have been made to develop an accurate method for detecting Helicobacter pylori in histological sections.

Materials and methods: Biopsy specimens were obtained from the stomachs of 167 patients with gastric ulcer (33), duodenal ulcer (52), gastroduodenal ulcer (15), chronic gastritis (45), and normal mucosa (22) before antimicrobial treatment and from 108 of these patients after treatment. Biopsy specimens were (1) cultured, (2) fixed in 10% buffered formalin, or (3) fixed in Carnoy's solution. The latter method was employed to preserve the surface mucous gel layer (SMGL) covering gastric surface mucous cells. Histological sections were stained with hematoxylin and eosin (H&E), with immunostaining using a commercially available polyclonal anti-H. pylori antibody.

Results: Cultures were positive for H. pylori in 61% of the cases before treatment and in 16% after treatment; by H&E staining using formalin-fixed materials: 70% and 9%; by immunostaining using formalin-fixed materials: 78% and 21%; and by immunostaining using Carnoy-fixed materials: 85% and 41% of biopsy specimens, respectively. The difference in detection rates between materials fixed in formalin and those in Carnoy's solution was due to the detection of H. pylori in the SMGL by the latter, especially after antimicrobial treatment.

Conclusions: Immunostaining for H. pylori using materials fixed in Carnoy's solution revealed H. pylori in the SMGL as well as on the surface mucous cells and in the gastric pits and permitted the optimal detection of H. pylori in tissue sections.