Evaluation of a Newly Developed Immunochromatographic Assay, for the Detection of HBsAg with Sensitivity and Specificity Equivalent to Those of Chemiluminescent Immunoassays

We evaluated a new immunochromatographic assay (ICA) for the detection of hepatitis B surface antigen (HBsAg) (Alere HBsAg；Alere Medical Co., Ltd) using 275 serum and 40 whole blood (EDTA) samples screened in our hospital. Five seroconversion panels and a reference panel according to the WHO International Standard for HBsAg were also tested. The performance of the ICA was compared with that of the conventional ICA (ICA2), chemiluminescent enzyme immunoassay (qualitative CLEIA), and chemiluminescent assay (quantitative CLIA). The sensitivity of the ICA in 54 HBV DNA positive specimens with a RT-PCR (TaqMan assay) was 98.1% (53/54), better than the ICA2 -92.6%- (50/54) and the CLEIA -96.3%- (52/54), and equivalent to the CLIA -98.1%- (53/54). The specificity in 221 HBV DNA negative specimens was 100%, better than the ICA2 -99.5%- (220/221), and equivalent to the CLEIA and CLIA. The ICA indicated a de-tectability superior to the ICA2 and CLEIA, and equivalent to the CLIA in the seroconversion panels. The limit of detection of the assay was calculated as 0.1IU/mL based on the results of the CLIA assay with the seroconversion panels. This assay using an avidin-biotin format demonstrated to show an excellent sensitivity and specificity in the clinical specimens and the panels. We conclude that this simple and rapid assay with a capability for whole blood sample application is suitable and applicable for use in risk management in patients with resolved HBV infection as well as in emergency and resource-limited settings.