Hepatitis B virus (HBV) genotype determination by the COBAS® AmpliPrep/COBAS® TaqMan® HBV Test, v2.0 in serum and plasma matrices

Background: Viral load quantification is established in the clinical management of chronic Hepatitis B virus (HBV) infection for assessing efficacies and resistance developments in anti-viral drug treatment. Objectives: The fully automated COBAS (R) AmpliPrep/COBAS (R) TaqMan (R) HBV Test, v2.0 was evaluated for the linear measuring range and the inclusivity of HBV genotype determination in EDTA plasma and serum samples. Study design: Two kit lots of the test were used to determine the linear measuring range as well as linearity and limit of detection applying different concentration levels of specimens representing HBV genotypes A to H along with a pre-core mutant and the WHO Standard. Results: The COBAS (R) AmpliPrep/COBAS (R) TaqMan (R) HBV Test, v2.0 displayed a linear measuring range of seven log(10) steps from 20 IU/mL(lower limit of quantification) to 2.3E+08 IU/mL(upper limit of quantification) yielding similar results for EDTA plasma and serum. Inclusivity was shown by reliable quantification of HBV genotypes A to H at different concentration levels. The >= 95% hit rate LOD was 15 IU/ml for genotypes C, D, F, C, the pre-core mutant and the WHO Standard and 20 IU/ml. for genotypes A, B, E and H matching the test's lower limit of quantification. 95% PROBIT analysis yielded concentrations of 8.9 IU/mL for the WHO Standard and of 6.0-16.4 IU/mL for the genotypes. Conclusions: The COBAS (R) AmpliPrep/COBAS (R) TaqMan (R) HBV Test, v2.0 provides genotype inclusivity for accurate viral load monitoring in serum and EDTA plasma samples and supports clinical routine in the management of HBV infection. (C) 2009 Elsevier B.V. All rights reserved.