ABSTRACT
Objective To evaluate clinical significance of two real-time fluorescence quantitative PCR kits for quantitative detection of HBV DNA and detection performance at different viral load levels.Methods A series of calibrators with different concentrations(1×106,5×105,1×105,5×104,1×104,5×103,1×103,5×102,1×102,1×101 kIU/L) were prepared with AB-type sera using the second generation WHO international standard (NIBSC code:97/750). HBV viral load in the sera of 78 patients,30 healthy blood donors and 10 calibrators were detected by real-time fluorescence quantitative PCR HBV DNA test kit from PIJI Bio-Technical Development Company Ltd (PG kit) and Cobas AmpliPrep/Cobas TaqMan HBV test kit. The correlation of the two methods was evaluated, and the performance of the two kits different viral load levels was evaluated. The false negative rate was analyzed. Negative control, low positive control and high positive control were included in every batch. Results Both two kits showed the correct results for the 10 specimens from the WHO international standards. The lowest detection limit of HBV DNA for Roche Cobas AmpliPrep/Cobas TaqMan HBV test and PG kit were 2.00 (kIU/L, lg) and 3.00 (kIU/L,lg) ,respectively. There was linear correlation between the results from Roche Cobas AmpliPrep/Cobas TaqMan HBV test and PG kit ( R2=0.938 7, P 5.00 and≤7.00) kIU/L,Ig,R2=0. 779 7, P 7.00 ands≤9.00) kIU/L,lg,R2=0.603 7, P 3.00 and≤5.00) kIU/L, lg, R2=0. 417 3, P 3.00 and≤4.00) kIU/L,lg,the false negative rate was 33.3% (5/15). When HBV DNA ( > 1.08and≤3.00) kIU/L,lg,none of positive samples was detected with PG kit. Conclusions PG kit is not as good as Cobas AmpliPrep/Cobas TaqMan HBV test . The linear correlation between the results from the two kits is good. The correlation between the results detected with PG kit and Cobas AmpliPrep/Cobas TaqMan HBV test is higher in the high viral load groups than in the low viral load group. It is suggested that PG kit had a narrower linear range.