Characterization and Application of a New Monoclonal Antibody with High Specificity for Helicobacter hepaticus

Background and Aims: Infection with Helicobacter hepaticus is suggested to play a role in the pathogenesis of chronic liver disease in humans. However, reactive antigens among Helicobacter species make the development of an H. hepaticus ELISA test with high specificity difficult. A new monoclonal antibody from a hybridoma clone (HRII‐51) showed high specificity to H. hepaticus without cross‐reaction to other gastrointestinal bacteria. Methods: The molecular weight of HRII‐51 immunoreactive antigen was examined by Western blot of H. hepaticus probed with the monoclonal antibody HRII‐51. A HRII‐51‐immunoreactive antigen capture ELISA was prepared in which the specific antigen was anchored by HRII‐51‐immobilized ELISA plate. Accuracy of HRII‐51 antigen capture ELISA was examined using sera obtained from mice inoculated with Helicobacter species. Specificity of HRII‐51 antigen capture ELISA was compared to that of H. hepaticus antigen‐based ELISA using human sera with absorption by H. pylori cell lysate. Results: HRII‐51 immunoreactive antigen had a molecular weight of 15 kDa. Sensitivity and specificity of HRII‐51 antigen capture ELISA were 87.0% and 97.6% in mice inoculated with Helicobacter species. In human sera, modification of the results by absorption with H. pylori lysate was smaller in HRII‐51 antigen capture ELISA comparing with H. hepaticus‐antigen‐based ELISA. Conclusion: Use of the HRII‐51 antigen capture ELISA would be a useful approach for the serodiagnosis of H. hepaticus infection in both experimental animals and humans.