Autoimmune atrophic gastritis (AAG) is characterized by an immunologically-driven destruction of gastric glands leading to atrophy of corporal oxyntic mucosa with consequent reduced gastric acid secretion and increased gastrin levels. In AAG, gastric cancer (GC) risk is increased. The altered intra-gastric milieu may lead to an altered composition of gastric microbiota, possibly having a role in gastric carcinogenesis, but data are conflicting. Parietal cell autoantibodies (PCA) are used to screen patients with other autoimmune disorders for AAG, albeit data on reliability are lacking. Recent European guidelines include AAG as condition to be monitored for GC. In AAG with PA an association with extra-gastric tumours was described. To quantity the risk of AAG patients of developing gastric or extragastric malignancies and to find out risk factors would be important to optimize surveillance. Pseudopyloric metaplasia, in particular spasmolytic-polypeptide expressing metaplasia (SPEM) has been linked to gastric cancerogenesis, its role in AAG patients has not been addressed so far.
This project is composed of four parts:
1. To investigate in patients with AAG the role of dysbiosis of the gastric microbiota as possible risk factor for development of gastric neoplastic/preneoplastic lesions
2. To investigate in a cohort of AAG patients stratified according to risk groups the occurrence of gastric malignancies when monitored by gastroscopy/histology at 3 year-intervals and to assess the risk of extra-gastric malignancies.
3. To investigate the occurrence of gastric autoantibodies against parietal cells in patients with high clinical suspicion of AAG to assess diagnostic performance as serological markers
4.To investigate in a cohort of patients with AAG the occurrence of gastric SPEM and its role as possible predictor associated with potential development of neoplastic complications.
