Associations Between Antiparietal Cell Antibody Values and Atrophy in a South and Southeast Asian General Population.
GOALS: To investigate the association between atrophy severity and antiparietal cell antibody (APCA) levels in South and Southeast Asia. BACKGROUND: APCA is an autoantibody that damages gastric parietal cells; autoimmune gastritis (AIG) is a chronic gastric inflammatory disease related to APCA and severe predominant corpus atrophy. Although a positive APCA result is a key clinical diagnostic tool for AIG, its rates vary widely among ethnic groups, and its exact relationship with AIG and predominant corpus atrophy remains unclear. STUDY: Associations between histopathology-assessed and endoscopy-assessed atrophy, APCA positivity rates, Helicobacter pylori status, and pepsinogen levels were investigated in 1982 symptomatic patients from Vietnam, Thailand, Myanmar, Bangladesh, and Nepal. RESULTS: Overall, 38.5% of participants were negative for Helicobacter pylori infection, while 57.6% had a current infection. A positive APCA result, defined as a titer >10, was present in 44.0% of participants (95% confidence interval: 41.8%-46.3%, 873/1982). Pathologic atrophy, corpus atrophy, and predominant corpus atrophy were found in 8.7% (169/1982), 5.1% (101/1982), and 4.1% (81/1982) of participants, respectively. Positive APCA rates significantly differed among countries (10.6% to 63.8%, P <0.001). No significant correlation was found between APCA results and the presence or severity of atrophy. CONCLUSIONS: Although APCA positivity was high among symptomatic patients from South and Southeast Asian countries, few had severe predominant corpus atrophy or positive pepsinogen tests, which suggests a low rate of AIG in this population. Long-term surveillance of APCA-positive individuals is necessary to determine the clinical significance of a positive APCA result without AIG.