Performance evaluation of the re-standardized Abbott Architect anti-HBs assay

Abstract

BackgroundAs defined by World Health Organization (WHO), an antibody level of ≥ 10mIU/mL to hepatitis B virus confers protection. With the launching of Abbott anti-HBs assay re-standardized to the 2nd WHO International Reference Preparation, a positive bias in antibody level would be anticipated. Manufacturer provides limited data for samples around the immune cut-off which has potential implication on vaccine guidance. ObjectivesTo evaluate the performance of the re-standardized Abbott Architect anti-HBs assay and to determine the impact of the upward shift. Study designA total of 52 samples, including 12 external quality assurance programme samples and 40 clinical samples were tested with both the Abbott 1st WHO standardized and the 2nd WHO re-standardized assay and results compared. The 2nd WHO anti-HBs standard and Acometrix anti-HBs control were also included for comparison. ResultsVerification of the re-standardized assay with the 2nd WHO anti-HBs standard revealed positive bias with mean closer to target value. Overall, the positive bias introduced by the new assay will only affect interpretation of samples with anti-HBs levels > 5.00 to < 10.00 mIU/mL previously tested on the Abbott 1st WHO standardized anti-HBs assay. ConclusionsFinal interpretation of immune status to hepatitis B was not affected by the upward shift following introduction of the new Abbott anti-HBs assay except for previously negative samples with anti-HBs levels between >5.00 to <10.00 mIU/mL.