A new step toward standardization of serum hepatitis C virus-RNA quantification in patients with chronic hepatitis C.

The need to improve efficacy of antiviral therapy for chronic hepatitis C has prompted the development of quantitative assays, which allows the assessment of viral load before therapy. The aim of our study was to evaluate the clinical relevance of 3 serum HCV-RNA quantitative assays in 87 patients with chronic hepatitis C, the noncommercially available SuperQuant assay (National Genetic Institute), recently used in large international controlled trials, the most early and widely used Quantiplex HCV RNA v2.0 assay (branched DNA [bDNA] v2.0; Bayer Diagnostics, Puteaux, France), and the new generation Cobas Amplicor HCV Monitor assay (COBAS v2.0; Roche Diagnostics Systems, Meylan, France), which is a semiautomated reverse transcription-polymerase chain reaction (RT-PCR) assay. The level and range of quantification were similar between all assays and a strong correlation was observed over all HCV genotypes among the assays. Recent publications have suggested that the baseline cut-off level of 2 x 10(6) copies/mL, as determined by the SuperQuant assay, is able to discriminate between patients with low viral load from those with high viral load and can be used to predict responses to therapy. Because all 3 assays use different testing technologies we examined how many of our patients fell above this defined cut-off level when tested by the other assays; of 22 patients measured below 2 x 10(6) copies/mL with the SuperQuant assay, 17 of 22 and 19 of 22 patients were eligible with the bDNA v2. 0 and the COBAS v2.0 assays, respectively (P >.05). Our results indicate that the 2 commercial assays can be used to determine treatment schedules in patients with chronic hepatitis C, providing a flexibility in multicenter controlled trials by offering better accessibility of test results.