S100A8 and chronic atrophic gastritis: In our previous study, the CagA seropositivity ratio was 75.0%, and CagA antibody titers were associated significantly with the serum pepsinogen level, atrophic gastritis, and GC.(35) Shimoyama et al.(36) reported CagA antibody positivity rates of 60% (49/81) for GC cases and 44% for non-GC cases (36/81) in a Japanese sample.