Comparison of real-time quantitative polymerase chain reaction with three other assays for quantitation of hepatitis C virus.

Background and Aims: Evaluation of serum levels of hepatitis C virus (HCV) is important for predicting the response to interferon treatment and monitoring its therapeutic efficacy. The aim of this study was to evaluate real-time quantitative polymerase chain reaction (PCR) as a method for the measurement of HCV-RNA. Methods: The subjects were 50 patients with chronic hepatitis C: 36 with genotype 1b, eight with genotype 2a, and six with genotype 2b. Samples were tested for HCV-RNA by using real-time quantitative PCR with the ABI Prism 7700 sequence detection system, a branched DNA signal amplification assay, and an Amplicor monitor test; and for HCV core protein by using a fluorescent enzyme immunoassay. Results: The detection range of the real-time quantitative PCR was between 101–108 copies/mL of HCV-RNA. Hepatitis C virus RNA was detectable in all 50 samples by the use of real-time quantitative PCR, but was undetectable in 14 samples by the use of a branched DNA assay and in two samples by using the Amplicor monitor test; HCV core protein was undetectable in three samples. A significant correlation was found between the results of real-time quantitative PCR and those of the three other assays: branched DNA assay (r = 0.837, P < 0.0001), Amplicor monitor test (r = 0.853, P < 0.0001), and HCV core protein concentrations (r = 0.549, P < 0.0001). Conclusions: Our results showed that the real-time quantitative PCR was a highly sensitive assay for the measurement of HCV-RNA.