Lectin binding patterns in normal, dysplastic and Helicobacter pylori infected gastric mucosa

To analyze the glycoprotein binding sites of the gastric mucosa and its secreted mucus using lectin histochemistry in patients with chronic non-atrophic gastritis (CNAG) associated or not-associated with Helicobacter pylori infection with or without dysplasia.

In order to identify the areas with glycoconjugates expression in gastric mucosa, 6 lectins (Canavalia ensiformis agglutinin - Con A, Sambucus nigra agglutinin - SNA, wheat germ agglutinin - WGA, soybean agglutinin - SBA, Helix pomatia agglutinin - HPA, peanut agglutinin - PNA) were used. Carbohydrate determinants were visualized according to the lectin-peroxidase-diaminobenzidine staining protocol. Biopsy material was obtained and processed by conventional histological methods. The samples from 84 patients (54 with CNAG) with low (n = 34) and high grade (n = 20) dysplasia, 38 patients were H. pylori-infected and 26 patients - H. pylori-noninfected) were used. The comparison group included 30 persons with CNAG without dysplasia (16 patients H. pylori-infected and 14 - noninfected).

In comparison to normal gastric mucosa, a low affinity of Con A was shown in 80% of patients with non-infected CNAG and 90% of H. pylori associated CNAG. In 70% of H. pylori-infected patients with CNAG and low grade dysplasia there was an increase of SNA expression compared with non-infected patients (p < 0.05). Regarding SBA labeling no differences were detected in the studied groups (p < 0.05). In H. pylori infected patients with CNAG and low grade dysplasia, WGA, HPA and PNA showed a strong reactivity with the gastric mucosa cells in 80; 75%, and 60% of patients, respectively.

We suggest that a set of lectins in reaction with gastric epithelial and glandular cells can be used as a tool to obtain information about the dysplastic changes of the gastric mucosa and may offer new insight into gastric carcinogenesis and precancerous lesions treatment.