The tracability and uniform unit of hepatitis C virus RNA quantification by domestic made real-time fluorescence quantitative PCR method

Abstract

Objective To determine the conversion equation for X(copies/ml, lg) quantity values of domestic HCV RNA quantitative fluorescence amplification assays approved by SFDA and Y( IU/ml, lg)reference values of standard substance. Methods The second generation WHO International Standard (NIBSC code:96/798) was mixed with human AB blood type serum to create 7 different dilutions which included 100 000, 50 000, 25 000, 10 000, 5 000, 2 500 and 1 000 IU/ml. Two different batches of each three domestic hepatitis C virus RNA real-time fluorescence quantitative PCR assays and 2 different batches of each assay were employed to detect the 7 different concentration samples with real-time PCR. Each test was performed 4 times repeatedly. Results The correlations between X( copies/ml,lg) values of domestic HCV RNA assays and Y(IU/ml,lg) reference values of standard substance were as follow,Assay A:Y =0. 902 0 X+0.284 9,R2 =0.953 3,P＜0. 01,n =56;Assay B: Y=0. 875 7 X +0.562 4,R2 =0.956 5,P＜0.01,n =56; Assay C: Y = 0. 843 8 X + 0. 560 5, R2 = 0. 945 8, P ＜ 0. 01, n = 56. Conclusions All the conversion equations are different among the quantity value of three assays and the reference values of standard substance, that suggests it is necessary to perform more stringent traceability analysis for the quantity values of 3 assays. Through standardizing the quantity values preliminarily, the conversion equation can enhance the comparability between the quantity values of different assays, and provide a standard of HCV RNA virus load detection for clinical diagnosis and treatment monitoring of HCV infection. Key words: Hepacivirus; RNA,viral; Reagent kits,diagnostic; Polymerase chain reaction