Study design and participants
From March 2016 to May 2018, the study was conducted in patients aged 20 to 80 who visited the CHA university hospital who underwent gastroscopy for gastric cancer screening. We exclude the patients who underwent gastroduodenal surgery and with a history of taking medications such as proton pump inhibitor, histamine-2 receptor antagonist, or non-steroidal anti-inflammatory drugs. We also excluded patients with severe systemic disease including chronic liver disease or uncontrolled coagulopathy.
Informed consent was obtained from all patients before the procedure and this study protocol was approved by institutional review board of CHA Medical Center, CHA university (approved number: 2015-114).
Endoscopic evaluation
Chronic gastritis was classified according to the MV pattern of gastric mucosa observed by gastroscopes. The study was performed by HR gastroscopes (GIF-HQ290; Olympus or IMAGE 1; Karl Storz). The MV of gastric mucosa is known that can be distinguished by regular arrangement of collecting venules (RAC) and subepithelial capillary network (SECN).
The three patterns of MVs were observed in the gastric mucosa, and classified chronic gastritis accordingly (Fig. 1); Class I: present with RAC and SECN which is normal gastric mucosa, Class II: loss of RAC with uneven SECN which is chronic superficial gastritis, Class III: loss of RAC with loss of SECN which is chronic atrophic gastritis.
Histopathological evaluation
Four biopsies were performed and compared with endoscopic findings. The biopsy was performed on the greater curvature (GC) and lesser curvature (LC) of antrum, GC and LC of body, respectively. Biopsy was classified according to updated Sydney classification.7 Neutrophils, mononuclear cells, glandular atrophy, and intestinal metaplasia were recorded. Chronic superficial gastritis (CSG) was diagnosed with an increase in mononuclear cells (lymphocytes and plasma cells). Chronic atrophic gastritis (CAG) is defined as glandular atrophy or gastric mucosa replaced by metaplastic columnar absorptive cells and goblet cells. Steiner silver stain was used to assess the presence of HP. HP infection was also compared with the Campylobacter-like organism (CLO) test.
Serological evaluation
The three classifications for chronic gastritis were also compared with serum pepsinogen (PG), which indirectly assesses the secretory capacity of gastric cells. PG I / PG II of serum is collected and radioimmunoassay is performed and evaluated. According to a previous study, the serological degree of atrophic gastritis was also defined as follows: Normal, PG I > 70 ng/mL, PG I/II ratio > 3.0; Mild, PG I ≤ 70-51 ng/mL, PG I/II ratio ≤ 3.0; Severe, PG I ≤ 30 ng/mL, PG I/II ratio ≤ 2.0
Statistical analysis
Patients were performed on clinical characteristics and data were expressed as total number and/or percentage of total, median (interquartile range (IQR)). For comparison of PG I/II ratio, SPSS was used and P < 0.05 was regarded as significant. A subgroup analysis of diagnostic performance was performed with respect to the presence of HP infection.
Ethics
Written informed consent was obtained from all study subjects prior to study commencement. All methods were carried out in accordance with relevant guidelines and regulations that was approved by the Institutional Review Board of Inha University Hospital (2019-11-008).