Analyses of the association betweenHelicobacter pyloriantibody titre and pathogenicity before and after eradication: results of the Kyushu and Okinawa population study, a retrospective observational cohort study

Abstract

ObjectivesTo assess the utility ofHelicobacter pyloriantibody testing, we evaluated the correlation between theH. pyloriantibody titre andH. pylori-associated pathogenicity and the changes in antibody titre afterH. pylorieradication therapy.DesignA retrospective observational cohort study.Setting and participantsFrom 2004 to 2016, medical check-ups were performed in different regions of Japan. In total, 324 subjects infected withH. pyloriwho receivedH. pylorieradication therapy were enrolled;H. pyloriwas eradicated in 266 of these subjects. We examined the associations betweenH. pyloriantibody titre with pepsinogen and the presence or absence ofH. pylori-associated pathogenic proteins, such as cytotoxin-associated gene A and vacuolating cytotoxin gene A, at baseline and afterH. pylorieradication therapy.ResultsTheH.pyloriantibody titre showed a positive correlation with pepsinogen II and a negative correlation with the pepsinogen I/II ratio. Moreover, theH.pyloriantibody titre significantly correlated with the positive rates ofH. pylori-associated pathogenic protein before eradication therapy. Antibody titres decreased after eradication, the pepsinogen I/II ratio increased and theH. pylori-associated pathogenic protein-positive rate decreased in patients with successful eradication. The determination of eradication using the decline in antibody titre 6 months after eradication therapy was useful (area under the receiver operating characteristic curve: 0.98).ConclusionsOur data indicate that theH. pyloriantibody titre may represent the degree of pathogenicity. TheH. pyloriantibody titre was associated with attenuation of pathogenicity in patients withH. pylorieradication, indicating the clinical utility ofH. pyloriantibody testing.