Serum Anti-Helicobacter pylori IgG Antibody Titer in H. pylori-negative Cases with a Different Gastric Mucosal Atrophy Status

Prevalence of Gastric Epithelial Tumors in Helicobacter pylori-uninfected Individuals Undergoing a Medical Checkup

Objective This study investigated the prevalence of gastric epithelial tumor in Helicobacter pylori-uninfected subjects who underwent esophagogastroduodenoscopy (EGD) as part of an annual checkup. Methods A total of 20,540 EGD examinations of H. pylori-uninfected individuals (12,917 men, 7,623 women; mean age 51.5±9.2 years old) were performed between April 2016 and March 2023. The prevalence of gastric epithelial tumor discovery and the size and location of each lesion type were analyzed. Results According to 20,540 examinations, 61 gastric epithelial tumors were endoscopically and histologically diagnosed in 58 of the subjects, with a prevalence rate of 0.28%. These tumors included signet-ring carcinoma (n=10, 0.05%), gastric adenocarcinoma of fundic-gland type (n=10, 0.05%), intestinal-type well-differentiated adenocarcinoma (n=2, 0.01%), and raspberry-type gastric foveolar tumors (n=36, 0.18%). One subject had two intestinal-type well-differentiated adenocarcinomas, and two each had two raspberry-type gastric foveolar tumors. The mean sizes of the signet-ring carcinomas, gastric adenocarcinoma of fundic-gland type, intestinal-type well-differentiated adenocarcinomas, and raspberry-type gastric foveolar tumors were 6.4, 4.7, 5.0, and 3.4 mm, respectively. Each lesion was located at a specific site in the stomach characteristic of its type. Conclusion In the present H. pylori-uninfected subjects, the prevalence of gastric epithelial tumors found on an EGD examination was 0.28%. Endoscopic examination should be performed in H. pylori-uninfected individuals to detect such tumors in characteristic locations.

Prevalence of Raspberry-type Gastric Foveolar-type Tumor in Individuals Undergoing Medical Checkups

Objective This study was performed to clarify the prevalence of raspberry-type gastric foveolar-type tumors, along with the time-course changes in the size and clinical course. Methods The subjects were 10,663 consecutive patients who underwent a medical checkup between April 2016 and March 2022, including an esophagogastroduodenoscopy (EGD) examination and determination of Helicobacter pylori infection status (uninfected, positive, post-eradication). The presence of characteristic reddish polypoid lesions in the stomach was investigated, and a diagnosis of raspberry-type gastric foveolar-type tumor was made based on histological findings. Results Thirty-eight cases had gastric polyps with a raspberry-like appearance on endoscopy, with 29 lesions in 28 cases endoscopically and histologically diagnosed as a raspberry-type gastric foveolar-type tumor. All of the affected subjects were determined to be H. pylori-uninfected. The prevalence of this type of lesion in all subjects was 0.26%, while that in the 6,635 H. pylori-uninfected subjects was 0.42%. An older age and the presence of a fundic gland polyp were found to be significant risk factors associated with the occurrence of the tumor. The mean size was 3.8±1.9 (range: 2-10) mm, and the location was in a fundic gland area in all affected subjects. Furthermore, examinations of previous EGD images revealed that two-thirds of the lesions had not changed in size, while follow-up EGD findings showed that lesions ≤5 mm in size had disappeared after a biopsy procedure. Conclusion The prevalence of raspberry-type gastric foveolar-type tumors was 0.42% in H. pylori-uninfected subjects. More than half of the lesions were too small to be removed by an endoscopic biopsy.

Serum Assay Findings after Successful Helicobacter pylori Eradication

Serum pepsinogen (PG), anti-Helicobacter pylori (H. pylori) immunoglobulin G (IgG), and gastrin-17 (G-17) are plasma biomarkers for gastritis. H. pylori serology titers and PG levels increase during active H. pylori infection; moreover, elevated PG II levels indicate a high risk for diffuse-type gastric cancer in East Asian populations. Serum PG I/II ratios and PG I levels decrease with the progression of gastric corpus atrophy; thus, a combination of serum PG I levels ≤70 ng/mL and a PG I/II ratio ≤3 (serologic atrophy) indicates a high risk of intestinal-type gastric cancer. Serum G-17 is often not used as an indicator in H. pylori-seroprevalent populations because it is usually elevated in subjects with H. pylori infections. When H. pylori is eradicated, most patients show a rapid decrease in serum PG II levels and anti-H. pylori IgG titers within a few months. Seroreversion is required for several months to years after regression of H. pylori. Moreover, seroreversion may not always be achieved in all eradicated cases. The serum PG I/II ratio starts to increase after eradication; therefore, serologic atrophy improves accordingly, unless severe atrophy is present. Thus, some eradicated patients may show normal serum assay findings but have a higher risk for developing gastric cancer than H. pylori-naive subjects. Furthermore, serum PG levels decrease after gastrectomy and increase with the intake of certain drugs (e.g., aspirin or acid suppressants) or in renal failure patients. Due to such wide variations, serum assays are inadequate for the confirmation of H. pylori eradication. It is useful when interpreted with gastroscopy and other H. pylori test findings.