Performance evaluation of the nanoquant real-time HCV assay for quantitation of hepatitis C virus RNA by real-time RT-PCR
Keywords:HCV, molecular assay, NanoQuant real-time HCV, real-time RT-PCR, RNA quantitation.
Accurate quantitation of Hepatitis C virus (HCV) RNA level is essential for measurement of active viremia in chronic HCV-infected patients undergoing antiviral therapy. In Vietnam, two molecular assays based on real-time reverse transcription-polymerase chain reaction (RT-PCR) technique are widely used to quantify HCV RNA level: Cobas Taqman HCV (Roche) and Abbott RealTime HCV (Abbott). Recently, a third assay has been introduced for HCV RNA quantitation: NanoQuant real-time HCV. In this study, performance characteristics of this assay were evaluated using methods for validation of newly developed molecular assays for infectious diseases. Evaluating results showed that NanoQuant real-time HCV was able to quantify HCV in a linear range from 102 to 108 IU/mL with the detection limit of 28.2 IU/mL. None of the other viruses, bacteria, fungi and human genetic materials showed cross-reactivity with HCV. The assay gave no positve result with HCV-negative sera. No interference in the performance of the assay was observed in the presence of inhibitory endogenous and exogenous substances. Intra-assay and interassay coefficients of variation were 4.18% and 9.18%, respectively. All of HCV genotypes (1a, 1b, 2a, 2b, 3a, 6a, 6e, 6f) which are prevalent in Vietnam were detected by the assay. HCV quantitation results showed a good correlation with those determined with Cobas Taqman HCV (R2=0.94). These results indicate that NanoQuant real-time HCV is reliable for monitoring HCV RNA level in the treatment of patients with chronic HCV infection.