Clinical evaluation of the COBAS Ampliprep™/COBAS TaqMan™ for HCV RNA quantitation in comparison with the branched‐DNA assay

Diagnosis and monitoring of HCV infection relies on sensitive and accurate HCV RNA detection and quantitation. The performance of the COBAS AmpliPrep™/COBAS TaqMan™ 48 (CAP/CTM) (Roche, Branchburg, NJ), a fully automated, real‐time PCR HCV RNA quantitative test was assessed and compared with the branched‐DNA (bDNA) assay. Clinical evaluation on 576 specimens obtained from patients with chronic hepatitis C showed a good correlation (r = 0.893) between the two test, but the CAP/CTM scored higher HCV RNA titers than the bDNA across all viral genotypes. The mean bDNA versus CAP/CTM log 10 IU/ml differences were −0.49, −0.4, −0.54, −0.26 for genotype 1a, 1b, 2a/2c, 3a, and 4, respectively. These differences reached statistical significance for genotypes 1b, 2a/c, and 3a. The ability of the CAP/CTM to monitor patients undergoing antiviral therapy and correctly identify the weeks 4 and 12 rapid and early virological responses was confirmed. The broader dynamic range of the CAP/CTM compared with the bDNA allowed for a better definition of viral kinetics. In conclusion, the CAP/CTM appears as a reliable and user‐friendly assay to monitor HCV viremia during treatment of patients with chronic hepatitis. Its high sensitivity and wide dynamic range may help a better definition of viral load changes during antiviral therapy. J. Med. Virol. 80:254–260, 2008. © 2007 Wiley‐Liss, Inc.