Comparison of Immunochromatography Assays and Quantitative Immunoassays for Detecting HBsAg and Anti-HBs

Whang, Dong Hee; Um, Taehyun

Abstract

BACKGROUND
Various assays including an enzyme immunoassay (EIA) are used to detect hepatitis B surface antigen (HBsAg) and antibody (anti-HBs). Recently, an increasing number of institutions have been utilizing an immunochromatography assay (ICA), which is rapid and easy to use and does not require special instrumentation; however, it is known to be less sensitive than EIA. In this study, we evaluated two different ICA kits for the detection of HBsAg and anti-HBs, and the results were compared with EIA. METHODS: A total of 400 serum samples, 100 each from HBsAg (+), HBsAg (-), anti-HBs (+) and anti-HBs (-) subjects, were assayed using two ICA kits (Daewoong, Genedia), and two chemiluminescence immunoassay (CIA) kits (ADVIA Centaur, ARCHITECT). The HBsAg and anti-HBs status had been determined by a microparticle enzyme immunoassay (AxSYM MEIA) at Seoul Paik Hospital. RESULTS: When compared with the results of AxSYM MEIA, the sensitivity, specificity, and concordance rate of both of the ICAs for HBsAg were 97%, 100% and 98.5%, respectively. The concordance rate, sensitivity, and specificities of Daewoong rapid Anti-HBs were 84.5%, 83%, and 86%, and the respective figures for Genedia rapid Anti-HBs were 85%, 96% and 74%. CONCLUSIONS: The diagnostic performances of two ICAs for HBsAg were more than 97%; however, both ICAs failed to detect HBsAg in low reactive samples. The concordance rate of two ICAs for anti- HBs was lower than that of three quantitative immunoassays. The results of ICAs should be interpreted with caution, because the samples containing a relatively low reactivity by the quantitative immunoassay can show negative results for anti-HBs.