Helicobacter pylori multiplex serology in patients with autoimmune atrophic gastritis negative for Helicobacter pylori at histology: A case-control study

BACKGROUND: Autoimmune atrophic gastritis (AAG) is an immune-mediated disorder affecting the gastric oxyntic mucosa. Two pathogenetic models are proposed: a pure autoimmune disorder or gastric autoimmunity triggered by Helicobacter pylori (Hp)-infection. In AAG, histological diagnosis of Hp may be challenging and serology can help assess exposure to Hp-infection. This study aimed to determine seroreactivity to Hp-antigens in AAG patients by using Hp-multiplex serology assay. METHODS: A single-centre case-control study on 178 adults: 75 patients with serological and histological AAG diagnosis, 25 controls with histologically Hp-positive-non-atrophic gastritis (Ctr-NAG-Hp+) and 78 subjects with a healthy stomach (Ctr-HS). Sera were analysed using Hp-multiplex serology assay allowing simultaneous detection of antibodies to 13 Hp-proteins. Overall positivity cutoff: seroreactivity to more than 3 Hp-antigens. RESULTS: The number of seroreactive Hp-antigens was higher in AAG than in Ctr-HS(mean±SEM 2.2±0.3 vs 1.4±0.22,p=0.02) and lower than in Ctr-NAG-Hp+ patients (mean±SEM 5.4±0.5,p