Consistency of quantitation of HCV genotype 4 from egypt across three HCV-RNA amplification assays

Different quantitative assays for HCV-RNA are available that report test results in International Units (IU)/ml based on the WHO International Standard. Thus, assays have been calibrated with standard material containing HCV genotype 1, so the consistency of quantitation might differ between assays for other HCV genotypes. Three commercial HCV nucleic acid amplification techniques (HCV–NAT) were compared for quantitation consistency of genotype 4 and 1 specimens from an Egyptian blood donor panel (n = 92). Consistency of quantitation between HCV–NATs was higher for genotype 1 than for genotype 4. Most quantitative results reported by the assays were in the same range, but some genotype 4 samples were missed by two of the assays. The Abbott assay showed higher concentrations for genotype 4 than the two Roche assays. Follow-up investigations of individuals should use the same assay unless another assay has been validated properly. Standardization of HCV–NAT assays remains an issue. J. Med. Virol. 80:2086–2091, 2008. © 2008 Wiley-Liss, Inc.