Abstract
AIMS: Patients with atrophic gastritis unrelated to autoimmune gastritis (AIG) and without active Helicobacter pylori (H.pylori) infection or previous eradication therapy are considered to have previous Helicobacter pylori infection-induced atrophic gastritis (PHIG). This study aimed to clarify the clinical characteristics of patients with PHIG. METHODS: Consecutive patients who underwent upper gastrointestinal endoscopy during the study period were enrolled in the study. Pepsinogen and gastrin levels, H. pylori serology, and endoscopic atrophic grade were assessed. Patients were divided into five groups based on their H. pylori status and disease history (PHIG, without H. pylori infection, with active H. pylori infection, with successful H. pylori eradication, and AIG). Their gastric cancer risk status was classified according to the ABC method of serological gastric cancer screening. RESULTS: Of 536 consecutive patients who underwent upper gastrointestinal endoscopy during the study period, 318 were included (31 with PHIG, 77 without H. pylori infection, 101 with active H. pylori infection, 80 with successful H. pylori eradication, and 29 with AIG). Of the 31 patients with PHIG, 21 (68%) were H. pylori-seronegative, and 20 (65%) were classified as group A (normal pepsinogen, H. pylori-seronegative). Patients with PHIG accounted for 90.1% of the patients at high risk for gastric cancer misclassified as group A. The pepsinogen and H. pylori serological profiles of patients with PHIG were similar to those of patients with successful H. pylori eradication more than six years previously. A receiver-operating characteristic curve (ROC) analysis that included 13 patients with AIG and without active H. pylori infection and no previous eradication therapy and 31 patients with PHIG revealed that an endoscopic atrophy grade of O-III or greater according to the Kimura-Takemoto classification can predict AIG. CONCLUSIONS: Two-thirds of the patients with PHIG were misclassified as being at low risk (group A) according to the ABC method, suggesting that endoscopy is necessary for group A patients. The results of the serological evaluation of PHIG indicated that patients with PHIG may have experienced spontaneous H. pylori eradication, possibly because of the use of antibiotics for other conditions. Autoimmune gastritis should be considered in the presence of grade 0-III or greater gastric mucosal atrophy in patients with suspected PHIG, even if the autoantibody and histological findings are not available.