Ricerc@Sapienza

Autoimmune gastritis (AIG) is characterized by an immunologically-driven destruction of gastric glands with atrophy of the oxyntic mucosa with reduced gastric acid secretion. Late stage AIG is often associated with pernicious anaemia (PA). AIG, in particular when associated with intestinal metaplasia (IM), is considered a risk factor for gastric cancer, according to the described multistep progression. Corpus-restricted AIG and PA is not considered part of the precancerous cascade. A systematic review showed in AIG patients with PA a pooled GC incidence-rate of 0.3% person-year and an estimated 7-fold RR of GC. In AIG, gastric cancer risk may be increased due to intra-gastric changes as increased pH and oxidative stress as a consequence of Hp leading to overgrowth of other bacteria than Hp. The altered composition of gastric microbiota may have a role in gastric carcinogenesis, but data are conflicting. Pathological evaluation of gastric biopsies is the gold-standard for AIG diagnosis, non-invasive serological tests include fasting gastrinaemia, pepsinogen I levels and parietal cells autoantibodies (PCA) and complete blood count and serum cobalamin levels. PCA are often used to screen patients with other autoimmune disorders for AIG albeit data on their reliability are lacking. Autoantibodies against ATP4A and ATP4B antigens have been reported to be virtually always present in patients which known diagnosis of AIG by an innovative luminescent immunoprecipation system. Reliable serological markers for the presence of AIG, a condition at increased risk for gastric neoplasias, may be useful as it could be easily used in large settings and positive patients should undergo gastroscopy in order to optimize the use of endoscopic resources to rule out possible neoplasms associated with AIG.