Evaluation of immunohistochemical labelling and detection of intestinal mucin antigens in the gastric epithelium with and without intestinal metaplasia – Correlation to microscopical diagnosis

Background: Intestinal metaplasia (IM) is associated with the development of gastric carcinomas. Recently, immunhistochemical labelling techniques appeared to detect intestinal mucin products in routine gastric histological sections. The correlation between traditional microscopic, histochemical and the new immunhistochemical detection methods is not defined, yet.

Methods: 5 um routine histological sections were prepared from 5o gastric biopsy specimen. The presence of intestinal metaplasia was determined by H/E, histochemical stainings. In additio SIMA and LIMA expression were investigated by semiquantitative immunohistochemistry Normal gastric, small and large intestine biopsy specimens (5, 5 and 5), were used as controls.

Results: Our results showed SIMA and LIMA were not detected in normal gastric epithelium. In GEIM a positive staining for SIMA was observed mostly in the goblet cell mucus, rarely in the cytoplasm of columnar cells of the IM (23/35). LIMA was seen occasionally in the goblet cells, the columnar cells or the luminal border of the metaplastic glands (12/35). A very similar pattern was observed in large intestine specimens. In contrast, SIMA reacted with small intestinal mucin, but not with large intestinal mucin. The metaplastic areas in 10 GEIM samples showed both SIMA and LIMA.

Discussion: In the gastrointestinal tract following chronic irritation, epithelial cells as a result of cytogenetic instability may revert to different type of epithelium producing different type of mucins, some of which are fetal. The broad reactivity of panel of SIMA would be an advantage for their use. The new immunhistochemical stainings are useful for the classification of intestinal metaplasia.