[en] Examinations for parietal cell antibody (PCA) were performed on 1334 subjects of the Adult Health Study (AHS), Hiroshima, during a 1-year period. Findings revealed PCA in 112 subjects (8.4%), but no difference in frequency was noted by sex. The relationship of PCA to age showed the positive rate to be significantly higher in those age 50 or over than in those under 50. No correlation was noted between estimated A-bomb exposure dose and PCA frequency. PCA was found in 58 (11.6%) of the 502 cases presenting achlorhydria on tubeless gastric analysis, and particularly in the age 50 and over group, PCA was demonstrated in 43 (14.2%) of the 302 subjects presenting achlorhydria, which is a significant difference compared with the under 50 age group in which PCA was demonstrated in 15 (7.5%) of 200 such subjects. PCA was detected in 11 (7.2%) of 152 subjects with abnormal, or low, serum pepsinogen levels and in 20 (16.3%) of 123 subjects with high levels. The frequency of positive PCA was higher in patients diagnosed on upper gastrointestinal (GI) series as atrophic gastritis than in patients diagnosed as some other gastric disorder. PCA was negative in both of the two cases in whom a definite diagnosis of stomach cancer was established. However, in light of the finding of abnormal Diagnex Blue (DB) tests and positive PCA at a high frequency in the gastritis group and reports that gastritis provides the groundwork for stomach cancer, it is considered that care should be taken in cases with findings of abnormal DB test, abnormal serum pepsinogen levels, and positive PCA. (author)