Increasing the Efficiency of Laboratory Performance by Using the Onboard Dilution Algorithm of the Elecsys Hepatitis B Surface Antigen II Quantitative Assay

Abstract

Background: The Elecsys hepatitis B surface antigen (HBsAg) II quantitative assay is a newly introduced electrochemiluminescence immunoassay incorporating an initial 1:400 onboard dilution and a simple algorithm to determine HBsAg levels in serum. We evaluated the performance of the Elecsys HBsAg II assay and determined the impact of its initial onboard dilution on laboratory efficiency.

Methods: HBsAg levels were determined using both Roche Elecsys and Abbott Architect HBsAg assays. Linearity and precision of the Elecsys HBsAg II assay and its correlation with the Architect HBsAg assay were evaluated. In particular, precision was verified at Samsung Medical Center, Severance Hospital, Seoul St. Mary's Hospital in Seoul, using the same pooled serum controls. The efficiency of the dilution algorithm for both methods was verified using data from 1,848 clinical samples.

Results: The Elecsys HBsAg II assay showed a good linearity from 0.1 to 48,000.0 IU/mL and a good correlation (r=0.9998) between expected and measured values. Precision analyses performed at Samsung Medical Center, Severance Hospital, Seoul St. Mary's Hospital showed excellent performance with coefficients of variation between 1.28% and 6.82%. The values of the Elecsys HBsAg II and Architect HBsAg assays were well correlated (n=506, r=0.987, P ＜0.001) and also reliably determined in hepatitis C virus- and hepatitis B virus-co-infected patient sera (n=27). In terms of efficiency, 64.0% of samples provided a final HBsAg result on the first run without the need for further dilution, when using the 1:400 onboard predilution protocol of the Elecsys HBsAg II assay.

Conclusions: Given the excellent precision and correlation with the Architect assay, the Elecsys HBsAg II assay showed a potential advantage for laboratory efficiency by significantly reducing the need for retesting samples with high HBsAg levels.