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 h as prompted the development of quantitative assays, which allows the assess ment 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 w ith chronic hepatitis C, the noncommercially available SuperQuant assay (Na tional Genetic Institute), recently used in large international controlled trials, the most early and widely used Quantiplex HCV RNA v2.0 assay (branc hed DNA [bDNA] v2.0; Bayer Diagnostics, Puteaux, France), and the new gener ation Cobas Amplicor HCV Monitor assay (COBAS v2.0; Roche Diagnostics Syste ms, Meylan, France), which is a semiautomated reverse transcription-polymer ase chain reaction (RT-PCR) assay. The level and range of quantification we re similar between all assays and a strong correlation was observed over al l HCV genotypes among the assays. Recent publications have suggested that t he baseline cut-off level of 2 x 10(6) copies/mL as determined by the Super Quant assay, is able to discriminate between patients with low viral load f rom those with high viral load and can be used to predict responses to ther apy. Because all 3 assays use different testing technologies we examined ho w 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 t he 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 in dicate that the 2 commercial assays can be used to determine treatment sche dules in patients with chronic hepatitis C, providing a flexibility in mult icenter controlled trials by offering better accessibility of test results.