CHIT1 and AMCase expression in human gastric mucosa: correlation with inflammation and Helicobacter pylori infection.

OBJECTIVES In this study, we analysed the expression of chitotriosidase (CHIT1) and acidic mammalian chitinase (AMCase) genes in human gastric mucosa biopsies to establish the function of the corresponding enzymes in patients with gastritis associated or not with Helicobacter pylori infection. METHODS All 27 patients who took part in this study suffered from dyspeptic symptoms and postprandial pain, and sought to undergo gastroscopy. Antral and corpus biopsy specimens were taken to analyse stomach inflammation and detect H. pylori. RNA was extracted from antral gastric biopsies and expression of genes for CHIT1 and AMCase was analysed by quantitative real-time PCR. RESULTS In human inflamed gastric mucosa, CHIT1 and AMCase genes were expressed on average at a very low level (approximately 10 pg), and a correlation was shown among expression of CHIT1 gene and both positivity to the H. pylori test (P = 0.016) and gastric mucosa inflammation (P = 0.026). No correlation was found among AMCase gene expression and presence of H. pylori and inflammation. CONCLUSION In this study, we showed the presence of CHIT1 and AMCase mRNA in gastric mucosa and the correlation with the presence of H. pylori was significant only for CHIT1 but not for AMCase expression. This study has shown for the first time that CHIT1 mRNA is present in gastric mucosa and confirms the participation of such an enzyme in the human immune response to inflammation in general, and to H. pylori infection in particular.