Usability evaluation of autodilution for ARCHITECT HBsAg quantitative assay

Abstract

A number of studies have shown that the amount of HBs antigen (HBsAg) is useful for determining the incidence of hepatocellular carcinoma and the effect of therapeutic strategies. Therefore, the HBsAg concentration can serve as an indicator of treatment efficacy for hepatitis B virus (HBV) infection or in the follow-up of patients with persistent HBV infection. In a clinical setting, reporting the results quickly is extremely important. However, in patients with high HBsAg levels, retesting by manual dilution using conventional methods is essential, which often takes longer to perform than other methods that require automatic dilution. Samples positive for HBsAg at concentrations greater than 250 IU/mL require dilution to decrease the concentration to within the dynamic range of the Abbott ARCHITECT HBsAg assay. The aim of this study is to determine the usefulness of autodilution for the ARCHITECT HBsAg quantitative assay in comparison with manual dilution for the HBsAg method. The reproducibility of autodilution for the ARCHITECT HBsAg quantitative assay is follows. A coefficient of variation (CV) in the range of 2.9 to 4.8% and an intra-assay precision in the range of 6.1 to 7.7% were obtained, which indicated overall good results with dilution linearity. In addition, for samples in which the HBsAg amount is less than 5,000 IU/mL, the correlation was also good in the comparison between the manual dilution for the HBsAg method and the autodilution for the ARCHITECT HBsAg quantitative assay (n = 38, y = 1.0616 x + 54.524, r = 0.983). Hence, autodilution for the ARCHITECT HBsAg quantitative assay leads to labor-saving during routine examination and shortening of the turnaround time in clinical laboratories.