Performance evaluation of cobas HBV real-time PCR assay on Roche cobas 4800 System in comparison with COBAS AmpliPrep/COBAS TaqMan HBV Test

Background: Hepatitis B virus (HBV) nucleic acid amplification testing (NAAT) is important for the diagnosis and management of HBV infection. We evaluated the analytical performance of the cobas HBV NAAT (Roche Diagnostics GmbH, Mannheim, Germany) on the cobas 4800 System in comparison with COBAS AmpliPrep/COBAS TaqMan HBV Test (CAP/CTM HBV). Methods: Precision was evaluated using three levels of cobas HBV/HCV/HIV-1 Control Kit, and linearity was evaluated across the anticipated measuring range (10.0-1.0 x 10(9) IU/mL) at seven levels using clinical samples. Detection capability, including limit of blank (LOB), limit of detection (LOD) and limit of quantitation (LOQ), was verified using the 4th WHO International Standard for HBV DNA for NAT (NIBSC code: 10/266). Correlation between the two systems was compared using 205 clinical samples (102 sera and 103 EDTA plasma). Results: Repeatability and total imprecision (coefficient of variation) ranged from 0.5% to 3.8% and from 0.5% to 3.5%, respectively. Linearity (coefficient of determination, R-2) was 0.999. LOB, LOD and LOQ were all acceptable within the observed proportion rate (85%). Correlation was very high between the two systems in both serum and plasma samples (correlation coefficient [r] = 0.995). Conclusions: The new cobas HBV real-time PCR assay on the cobas 4800 System showed reliable analytical performances.