Performance of the COBAS AMPLICOR HCV MONITOR test, version 2.0, an automated reverse transcription-PCR quantitative system for hepatitis C virus load determination

A clinical evaluation of an automated quantitative PCR assay, the COBAS AMP LICOR HCV MONITOR test, version 2.0 (v2.0), was carried out to assess the p erformance of this test in comparison with that of the previous, manual ver sion, the AMPLICOR HCV MONITOR test, and with that of nested PCR. Serial di lutions of serum samples infected with genotype 1b, 2a, or 3, as well as sy nthetic RNA transcripts and serum samples derived from 87 patients with chr onic hepatitis C and infected with genotype 1a, 1b, 2a, 2b, 3a, 3b, 4, or 5 , were analyzed to determine the ability of the system to efficiently quant ify various hepatitis C virus (HCV) genotypes, These experiments showed tha t the COBAS AMPLICOR HCV MONITOR test, v2.0, has mean intra-assay, interass ay, and interoperator coefficients of variation that range from 22 to 34.5% and a 3-logarithm dynamic range, which spans from 10(3) to 10(6) copies/ml . Compared to the previous, manual version of the test, the COBAS AMPLICOR HCV MONITOR test, v2.0, showed an improved efficacy for all genotypes, espe cially genotypes 2, 3, and 4, whose estimated concentrations were on averag e 1 logarithm higher. When used to monitor patients under treatment, howeve r, both versions showed the same patterns of viremia. Indicating that the C OBAS AMPLICOR HCV MONITOR test, v2.0, and the AMPLICOR HCV MONITOR test wer e equally effective at detecting relative viremia changes in serial samples . As expected, the automated test was less sensitive than nested PCR; among specimens from a cohort of patients treated with interferon, nested PCR id entified three more viremic specimens, which probably contained very lour c oncentrations of HCV RNA.