Characterization of the quantitative HCVNASBA assay

A quantitative nucleic acid sequence-based amplification assay (NASBA-QT) f or detection of hepatitis C virus RNA (HCV-RNA) was evaluated and compared with the HCV branched-DNA (bDNA) assay (Chiron Corporation) and the HCV MON ITOR assay (Roche Diagnostic Systems). For this evaluation five panels were designed: (1) serial dilutions of genotype 1b in-vitro HCV-RNA; (2) standa rds of in-vitro HCV-RNA genotypes 1a, 1b, 2, 3, 4, and 5; (3) a proficiency panel consisting of 12 HCV-RNA positive plasma samples of different genoty pes and HCV-RNA concentrations and a genotype 1a and 1b 3-fold dilution ser ies; (4) a panel of 67 HCV-RNA positive plasma samples obtained from patien ts with HCV infection and (5) an HCV-RNA positive control sample, diluted 5 0-fold in 25 different HCV-RNA negative plasma samples. The quantitative de tection limit was found to be 10(3) copies per 100 mu l and the qualitative detection limit 10(2.3) per 100 yl. The amplification efficiency was indep endent of the plasma matrix, but dependent on the HCV genotype. The HCV NAS BA-QT assay was more than 10 times as sensitive as the bDNA assay while the quantitative results of both assays were highly concordant. The HCV NASBA- QT assay was comparable in sensitivity with the HCV MONITOR assay, but the HCV MONITOR assay yielded consistently lower values. It is concluded that t he HCV NASBA-QT assay is a reliable assay for quantitative HCV-RNA detectio n in various settings. (C) 1999 Elsevier Science B.V. All rights reserved.