Role of Helicobacter pylori serology in atrophic body gastritis after eradication treatment

BACKGROUND: It has been reported that 50% of patients with atrophic body gastritis have positive Helicobacter pylori antibody titres only. In atrophic body gastritis, a decrease in H. pylori antibodies after eradication treatment has been reported, suggesting that serology may indicate an active H. pylori infection. AIM: To investigate the time course of H. pylori antibodies and gastric inflammation after eradication treatment in patients with atrophic body gastritis, and to determine whether serology alone can be considered as a valid tool to assess the efficacy of eradication treatment in patients with atrophic body gastritis. METHODS: Twenty-seven patients with atrophic body gastritis (12 serologically H. pylori-positive only, ABG-S+; 15 H. pylori-positive at histology and serology, ABG-H+) were included in the treatment group, and 17 patients (all ABG-S+) in the no treatment group. All patients had gastroscopy plus biopsies evaluated according to the updated Sydney system and H. pylori immunoglobulin G determination: in the treatment group, at baseline and 6 and 24 months after eradication (bismuth-based triple regimens); in the no treatment group, at baseline and after 3 years. RESULTS: In the treatment group, in ABG-S+ patients, H. pylori antibodies decreased significantly 6 months after treatment 37.5 U/mL (16-100 U/mL) vs. 15 U/mL (0--100 U/mL), P < 0.01], but 2 years after treatment no further decrease occurred. In addition, in ABG-H+ patients, a significant decrease in H. pylori antibodies occurred 6 months after treatment 45 U/mL (12.5-100 U/mL) vs. 31 U/mL (0-65 U/mL), P < 0.01], but a further decrease was also observed 2 years after treatment 20 U/mL (0-56 U/mL), P < 0.01]. In ABG-S+ patients, no correlation was observed between the H. pylori antibodies and gastric inflammation score, whereas, in the ABG-H+ group, this correlation was extremely significant (r=0.5991, P < 0.0001). In the no treatment group, at follow-up, a significant decrease in H. pylori antibodies was observed 26 U/mL (15-100 U/mL) vs. 22 U/mL (0-53 U/mL), P < 0.05], but the gastric body inflammation remained unchanged. CONCLUSIONS: This study shows that, in ABG-S+ patients after eradication treatment, serology does not keep in step with gastric inflammation. This suggests that, in patients with atrophic body gastritis, serology alone may not be valid for the assessment of the efficacy of eradication treatment.