External quality assessment for the quantitative detection of HCV RNA in China

Abstract

Objective Anti-RNase virus-like particles containing HCV RNA 5'-UTR were used as positive samples in national external quality assessment ( EQA ) to evaluate the competency of clinical Laboratories for the quantification of HCV RNA and analyze the possible problems of domestic kits. Methods The quality control samples with target values in EQA panels were distributed nationally twice by National Center of Clinical Laboratory (NCCL) to participating laboratories for the quantification of HCV RNA in 2008 and 2009. Each panel consisted of 5 samples. All participants were required to carry out the detection and to return results in expected time. Positive samples were virus-like particles which had been calibrated against the WHO HCV International Standard (NIBSC96/798)and the results of positive samples from participants should be in the range of target value of logarithm ± 0. 5. The 2nd panel in 2008 contained the common HCV genotypes and the 2nd panel in 2009 contained serial diluted samples of genotype 1b. The results of positive samples detected with 3 different lots reagent (21001,21078 and 21097) from the 2nd EQA in 2009 were statistically analyzed using the analysis of variance, then Dunnett'S T3 and Tamhane'S T2 were used if heterogeneity of variance was found. Results There was 390 participating laboratories in 2008 and 428/426 in 2009. The percentages of laboratories within the range of target value of logarithm ± 0. 5 for varied genotypes were different. The percentages of laboratories for 1b were more than 91%, for 2a were 93.7% and 74. 2% ,for6 were 83.3% and 80. 3%. The CVfor the low-level sample was higher than that for the high-level sample in the same year. The numbers of laboratories reporting false-negative samples in 2008and the 2nd in 2009 were 5, 1 and 10 respectively. Statistical differences were found among the results of four quality control serum samples using 3 different reagents( F = 288.23, 324. 79, 291.98 and 261.16,P ＜0. 01 ). Conclusion The competency for detecting low concentration samples and samples with genotype 2a or 6 needs to be improved. Key words: Hepacivirus; RNA,viral; Vinon; Quality control