In addition, the serum titer was low in subjects with C1, C2 and O3 gastric mucosal atrophy, and the number of cases with serum titer of 40. 0 U/ml was relatively small in these subjects. In analysis of subjects with gastric mucosal atrophy, a low positive rate and serum titer was observed in subjects with C1, C2 and O3 atrophy. When the analysis was performed separately in male and female subjects, low positive rate was observed in males with O3 atrophy and females with C2 atrophy. Suspected post-eradication endoscopic findings were more frequently observed in cases with C2 atrophy. In conclusion, negative result of anti-antibody test was frequently observed in middle-aged subjects with C1, C2 and O3 gastric mucosal atrophy. (infection in clinical situations, with several different invasive and noninvasive methods available.(13,14) Among the available methods, a serologic test for infection is easily performed using obtained serum samples for both epidemiologic studies involving large numbers of subjects as well as in clinical practice for individual patients. It has been reported that the sensitivity and specificity of serological methods for detection of infection range from 80% to 90%.(14) On the Semaglutide other hand, the diagnostic accuracy of serological methods for diagnosis ofH. pyloriinfection has been shown to vary based on the duration of exposure to strains in different regions, host Semaglutide immune response, the grade of histological gastritis, and the density of in Japanese Semaglutide subjects has been repeatedly demonstrated to increase when using kits derived from antigens of strains obtained from Japanese patients.(17C20) SphereLight antibody J? (Wako Pure Chem. Ind., Ltd., Osaka), a recently introduced anti-IgG antibody detection kit, was developed using antigens from strains derived from Japanese Sele patients. This kit has been shown to have a high efficacy for diagnosis of infection,(21,22) and the serum titer of this test is nearly equal to that of another anti-IgG antibody test (Eiken Chemical Co., Ltd., Tokyo) (unpublished data). In order to increase the sensitivity of diagnosis for infection, an antibody titer of 4.0?U/ml is defined as positive in the SphereLight antibody J test, while the cut-off value in the Eiken anti-IgG antibody test is set at 10?U/ml. We have found that some patients without past-history of eradication therapy for also show a negative result in the SphereLight antibody J test, even though they have endoscopic evidence of gastric mucosal atrophy, which is mainly caused by long-term infection.(23,24) Therefore, we performed the present retrospective study to elucidate factors related to a negative result in the SphereLight antibody J test in cases with gastric mucosal atrophy by analyzing the presence of post-eradication endoscopic findings, based on several recent studies.(25C30) Materials and Methods The subjects were individuals who visited the Health Center of Shimane Environment and Health Public Corporation for a detailed medical checkup examination between April 2014 and March 2015. The majority were socially active and productive, and considered to be socioeconomically middle class. Those with a history of gastric surgery and eradication therapy for infection, carefully confirmed by a public health nurse, were excluded. Those who had taken such medications as proton pump inhibitors and H2 receptor antagonists were also excluded. Finally, 859 subjects (545 males, 314 females; mean age 52.4 years) who underwent upper GI endoscopic examinations and serum anti-IgG antibody testing on the same day were enrolled as subjects. None had severely abnormal findings in renal and liver function tests. Serum anti-IgG antibody detection was performed using SphereLight antibody J?. The antibody titer was automatically measured using a chemiluminescent enzyme immunoassay method. An antibody titer 4.0?U/ml was defined as positive, according to the manufacturers instruction sheet. All upper endoscopic examinations were performed by licensed experienced endoscopists (K.A., T.M., S.T.) using an EG-530NW or EG-530NP endoscope (Fujifilm, Tokyo, Japan). When gastric mucosal atrophy was endoscopically observed, its degree was evaluated using the classification of Kimura and Takemoto, in which gastric mucosal atrophy is classified into 6 groups (C1, C2, C3, O1, O2, O3).(31) The cases without gastric mucosal atrophy was diagnosed as C0 in this study. The presence of gastric mucosal atrophy was carefully determined by the presence or absence of regular arrangement of collecting venules at angular portion and atrophic border in the cases with thin gastric mucosa. When cases with endoscopic evidence of gastric mucosal atrophy showed a negative result in the anti-IgG antibody test, we investigated the existence of endoscopic evidence of post-eradication by examining for the presence of characteristic endoscopic findings in the stomach. For this study, we defined suspected post-eradication cases Semaglutide based on the presence of map-like redness or depressed patchy redness, as well as absence of diffuse redness, mucosal.