APCA positivity not linked to AIG in Asian patients

A high positivity rate of antiparietal cell antibody (APCA) is seen among symptomatic patients from South and Southeast Asia, but only a few have severe predominant corpus atrophy or positive pepsinogen tests, reports a study. This finding suggests a low rate of autoimmune gastritis (AIG) in this population.

Researchers examined the associations between histopathology-assessed and endoscopy-assessed atrophy, APCA positivity rates, Helicobacter pylori (H. pylori) status, and pepsinogen levels in 1,982 symptomatic patients from Bangladesh, Myanmar, Nepal, Thailand, and Vietnam. Of these, 38.5 percent were negative for H. pylori infection, while 57.6 percent had a current infection.

Almost half of the participants (873/1,982; 44.0 percent, 95 percent confidence interval, 41.8‒46.3) had a positive APCA result, defined as a titre >10. Furthermore, pathologic atrophy was detected in 169 (8.7 percent) participants and corpus and predominant corpus atrophy in 101 (5.1 percent) and 81 (4.1 percent) individuals, respectively.

Positive APCA rates varied from one country to another, ranging from 10.6 percent to 63.8 percent; p<0.001). APCA results showed no significant association with the presence or severity of atrophy.

“Long-term surveillance of APCA-positive individuals is necessary to determine the clinical significance of a positive APCA result without AIG,” the researchers said.

“APCA is an autoantibody that damages gastric parietal cells, [and] AIG is a chronic gastric inflammatory disease related to APCA and severe predominant corpus atrophy,” they said.