RESUMO
BACKGROUND: A range of well characterized materials are needed for validating the performance of hepatitis B surface antigen (HBsAg) immunoassays. These materials are purchased currently from overseas manufacturers at a high cost and with limited quantity. This study was conducted to establish an HBsAg low titer performance panel for use as a national standard for validation of HBsAg immunoassays in Korea. METHODS: 476 plasma units reactive on blood donor screening were collected HBsAg was tested using 3 enzyme immunoassays (EIA) and 1 chemiluminescence immunoassay (CIA). Units reactive on the CIA assay or on 2 or more immunoassays were subjected to hepatitis B virus (HBV) DNA quantification, HBV genotyping and subtyping. Units reactive on HBV DNA quantification were confirmed for HBsAg by neutralization. Candidates for the panel were subjected to a collaborative study performed at 7 laboratories using 7 immunoassays. RESULTS: Eleven HBsAg positive units were selected for the low titer performance panel based on HBsAg immunoassay, HBV DNA quantification, HBV genotyping and subtyping results. The range of the HBsAg concentration of the panel members was 0.05~1.28 IU/mL. Two HBsAg negative units were also included as negative controls. CONCLUSION: As a result of this study, a low titer performance panel [KFDA standard (08/028); HBsAg low titer performance panel (BTRL HBV/LP)] for validation of HBsAg immunoassays has been established as a Korean national standard. Use of this panel will improve performance assessment of HBsAg immunoassays. Because the performance of immunoassays cannot be assessed properly with a limited number of panels, continuous efforts are needed to develop a range of performance panels.
