Journal of clinical microbiology 2017 01 25() pii 10.1128/JCM.02193-16
Antiviral treatment efficacy for chronic HCV infection is determined based on measurement of HCV RNA at specific time points throughout therapy by highly sensitive and accurate HCV RNA assays. This study evaluated the performance of two recently-developed real-time PCR HCV RNA assays, the cobas HCV for use on the cobas 6800/8800 systems (cobas 6800/8800 HCV) and the cobas HCV for use on the cobas 4800 system (cobas 4800 HCV) in comparison to two established assays, the COBAS AmpliPrep/COBAS TaqMan HCV Quantitative Test, version 2.0 (CAP/CTM v2) and the COBAS TaqMan HCV Test, version 2.0 for use with the High Pure System (HPS/CTM v2). Limit of detection (LOD) and linearity at lower concentrations (5-1000 IU/mL) were assessed for cobas 6800/8800 HCV and cobas 4800 HCV using WHO standard traceable panels representing HCV genotypes (GT) 1-4. Pairwise assay comparisons were also performed using 245 clinical samples representing HCV GT 1-4.cobas 6800/8800 HCV and cobas 4800 HCV were linear at low HCV RNA concentrations (<0.3 log10 IU/mL difference between expected and observed results) with LOD of 8.2 IU/mL and 11.7 IU/mL, respectively, for GT1. The new assays showed excellent agreement with CAP/CTM v2 and HPS/CTM v2 results in samples with quantifiable viral load. Concordance across the 6 million IU/mL cutoff was high among all four assays (90-94%). In conclusion, both cobas 6800/8800 HCV and cobas 4800 HCV tests are sensitive and linear, and correlate well with established Roche assays used in clinical practice.