Aberrant epithelial expression of trefoil family factor 2 and mucin 6 in helicobacter pylori-infected gastric antrum, incisura and body: a useful marker for antralization

Abstract

BACKGROUND: Trefoil family factors (TFF), a group of small secretory peptides, and mucins, the major components of the mucous viscous gel covering the epithelial surface, play an important role in mucosal defense and healing. H. pylori infection causes gastric mucosal inflammation and injury. This study aimed to To determine the expression of TFF2 and MUC6 in normal and H. pylori infected gastric epithelium at the gastric antrum, incisura and body, and to explore the association between the aberrant expression of TFF2 and MUC6 and antralization in the incisura. METHODS: Gastric biopsy specimens taken from the gastric antrum, incisura and body of 76 patients with dyspeptic and reflux symptoms were examined by immunohistochemistry for TFF2 and MUC6 expression in the gastric foveola and deeper glands. H. pylori infection was determined by both a rapid urease test and histology. RESULTS: Of the 76 patients, 27 were positive for H. pylori infection. In the foveola,TFF2 and MUC6 expression, were significantly greater in positive patients with infection, than in H. pylori negative patients at the antrum (59.3% vs. 4.1%, OR = 34.2, 95% CI: 6.83–171.0, c2 = 29.30, P < 0.001, and 63.0% vs. 4.1%, OR = 40.0, 95%CI: 7.94–201.1, c2 = 32.19, P < 0.001, respectively) and the incisura (44.4% vs. 2.0% OR = 38.4, 95% CI: 4.61–320.2, c2 = 19.19, P < 0.001 and 48.1% vs. 0%, c2 = 25.17, P < 0.001, respectively). In the deeper glands, TFF2 and MUC6 expression was significantly higher in H. pylori infected patients than uninfected patients at the incisura (both 85.2% vs. 22.4%, OR = 19.9, 95% CI: 5.66–69.8, 27.71, P < 0.001, respectively). Antral type mucosa was present at the incisura in 36.8%) of patients. The rates of expression of TFF2 and MUC6 in the foveola were 39.3%, 5.9% and 0%, respectively, in antral type, transitional type and body type mucosa (df = 2, c2 = 43.74, P < 0.001). In the deeper glands, the rates were 92.9%, 23.5%, and 0%, respectively (df = 2, c2 = 15.62, P < 0.001). CONCLUSIONS: H. pylori infection increases the expression of TFF2 and MUC6 in the gastric epithelium, which may be a protective response of host to the mucosal damages induced by H. pylori infection. Over-expression of TFF2 and MUC6 is associated with antralization of gastric incisura, thus may be involved in and used as a biological marker for the process.