Single amino acid substitution in the hepatitis B virus surface antigen (HBsAg) 'a' determinant affects the detection sensitivity of an HBsAg diagnostic kit

摘要

Hepatitis B virus surface antigen (HBsAg) is one of the most important serological markers used in the diagnosis of HBV infection. HBV has been classified into 8 genotypes, designated A to H. In our previous report, we evaluated the sensitivity of 10 commercially available diagnostic kits to recombinant HBsAgs encoded by HBV of genotypes A to H. None of the diagnostic kits examined failed todetect HBsAg of all the genotypes (A to H) at a concentration of 1.0 IU/ml. When the HBsAg samples were tested at a lower concentration (0.2 IU/ml), 9 out of 10 kits gave positive results, i.e. cut-off index (COI) >= 1.0, but 1 kit, Lumipulse II HBsAg, failed to give positive results for genotypes E and F. In this study, we compared the amino acid sequences of the HBsAg "a" determinant among HBV genotypes.