Comparison of three luminescent immunoassays for hepatitis B virus surface antigen quantification during the natural history of chronic hepatitis B virus infection.

Hepatitis B surface antigen (HBsAg) quantification has garnered attention because of its high predictive value in determining treatment responses. The HBsAg quantification assays, such as Architect and Elecsys, are commercially available, and more assays are in development. We aimed to compare the results of the Architect and Elecsys assays with those of a new assay, WTultra. The WTultra HBsAg assay is a sandwich chemiluminescent microplate enzyme immunoassay and provides an alternative choice which is more cost-effective and potentially applicable in developing or resource-constrained countries and areas. A total of 411 serum samples were collected from patients during various phases of chronic hepatitis B (CHB) infection. The samples were assessed using the three assays, and the results were compared and analyzed. The results for the Architect, Elecsys, and WTultra assays were well correlated according to the overall results for the samples (correlation coefficients, rArchitect versus WTultra = 0.936, rArchitect versus Elecsys = 0.952, and rWTultra versus Elecsys = 0.981) and the various infection phases (rArchitect versus WTultra ranging from 0.67 to 0.975, rArchitect versus Elecsys ranging from 0.695 to 0.982, and rWTultra versus Elecsys ranging from 0.877 to 0.99). Additionally, consistent results were observed according to genotype (genotype B: rArchitect versus WTultra = 0.976, rArchitect versus Elecsys = 0.978, and rWTultra versus Elecsys = 0.979; genotype C: rArchitect versus WTultra = 0.950, rArchitect versus Elecsys = 0.963, and rWTultra versus Elecsys = 0.981) and hepatitis B virus (HBV) DNA levels (rArchitect = 0.540, rWTultra = 0.553, and rElecsys = 0.580). In conclusion, the Elecsys and WTultra assays were well correlated with the Architect assay, irrespective of the CHB infection phase or genotype. All of these assays are reliable for HBsAg quantification.