Lessons from a multicentre study of the detectability of viral genomes based on a two-round quality control of GB virus C (GBV-C)/hepatitis G virus (HGV) polymerase chain reaction assay

The aim of this study was to determine whether multicentre quality controls for the detectability of viral genomes could contribute to the improvement of diagnostic performance in the participating laboratories. The study was carried out during two successive rounds, during which 18 laboratories spe cialized in nucleic acid testing analyzed, through a polymerase chain react ion (PCR) assay, a common panel of GB virus C (GBV-C)/hepatitis G virus (HG V) RNA-positive and -negative samples. During the first round, the laborato ries used either an 'in-house' PCR procedure or a partly standardized comme rcial test. After decoding the results of the first round, the procedures o f the participating laboratories were compared in order to establish a cons ensus procedure deduced from those of the laboratories which provided the b est results. During the second round, each participating laboratory could u se the resulting consensus procedure, or its own procedure, or both. The re sults of this quality control study indicated that, whatever method used, e ven specialized and trained laboratories may give false-negative or false-p ositive results. The commercial assay did not guarantee a systematic high q uality level of results. The striking heterogeneity of results observed amo ng laboratories using the same commercial assay confirm that molecular biol ogy methods need skilled technicians. The results of this quality control s tudy suggest that full standardization of viral genome detection, including all steps of the procedure, is necessary and that the laboratories perform ing PCR should participate in repeated quality control studies, whatever te chnique is being used. (C) 2000 Elsevier Science B.V. All rights reserved.