Expression of CDX2, CK20 and CK7 in the epithelium of the gastric mucosa in schoolchildren with CagA H. pylori-associated gastritis

Aim. To study the association of protein expression CDX2, CK20, CK7 in the epithelium of the gastric mucosa in schoolchildren with CagA H. pylori-associated gastritis. Material and methods. Gastroscopy was performed with the collection of biopsy material from the mucous membrane of the antrum and body of the stomach in 89 schoolchildren (7-17 years old) with gastroenterological complaints. The morphological method confirmed the diagnosis of gastritis and determined the presence of H. pylori. Gastric biopsies were examined immunohistochemically to identify the proteins CDX2, CK20, CK7 in the epithelium. Blood was also collected to determine the CagA strain of H. pylori using enzyme immunoassay. Results. In schoolchildren infected with CagA H. pylori, higher expression of CK7 was found in both parts of the stomach (in the body (p = 0.044), in the antrum (p = 0.014)) compared to uninfected children. Changes in the expression of CDX2 and CK20 in children infected with H. pylori CagA have not been established. CDX2 protein was detected more often among schoolchildren aged 12-17 years with H. pylori infection than in children without H. pylori (p = 0.062) and in children with CagA H. pylori (p = 0.017). In the group of younger children with CagA H. pylori, there were higher levels of CK7 expression in the epithelium of the antrum of the stomach, compared with uninfected children (p = 0.033). They also had higher CK7 in the body than in CagA H. pylori-associated gastritis in children of the older age group (p = 0.001). Boys with CagA H. pylori had the highest expression of CK7 in the gastric body, which was higher than in uninfected boys (p = 0.021). Conclusion. Thus, in children, the features of the association of CDX2, CK20, CK7 with CagA H. pylori-associated gastritis have been established, including depending on the age and gender of the child.