The Comparative Study Between ELISA And NAT Testing Of The Blood

Objective：To compare the advantages and disadvantages of ELISA and PCR beaddetection, thereby to learn how many blood samples could be missed by ELISA tests.Methods：First, the two-time ELISA test was given to30315donors’ blood samples andNAT test was performed on samples negative and positive for HBsAg, HCVAb andHIVAg-Ab by ELISA. Second, the donors’ samples were pooled by HAMILTON STARsampling processor and extracted nucleic acid by EZbead System-32. HBV DNA, HCVRNA and HIV RNA were amplified and detected by ABI quantitative Fluorescence PCRinstrument. The third step was to make statistic analysis as calculating ELISA falsenegative rate, TWO DOUBLE AND HALF Test and Roche Quantitative Test of thesamples with negative ELISA but positive PCR test were made, the patients were tracedfor their missing blood sample, statistic detection rates between ELISA and PCR test ofthe blood samples were done, the relative sensitivity and relative specificity of ELISAwere calculated.Results：Among the30315donors blood samples a total of29852ELISA, ALT andSyphilis negative donor samples were tested by PCR and15samples were HBV DNApositive, the false negative rate was0.50‰. The results of TWO DOUBLE AND HALFTest and Roche Quantitative Test showed that none of those15donor samples werepositive for HBsAg,7of them were positive for HBsAb,1of them was positive forHBeAg,7of them were positive for HBeAb,11of them were positive for HBcAb.Oneresult of them tested by Roche Quantitative Test was2520IU/mL and the correlationcoefficient of Ct value and Roche test value was r=-0.82761. After a year,9bloodsamples of patients were followed up,6copies of ELISA were positive. The HBV ELISAdetection rate and HBV PCR test detection rate were2.78‰and2.21‰respectively, theHIV ELISA detection rate and HIV PCR test detection rate were1.37‰and0.05‰respectively, there were significant differences between them. The sensitivity of ELISAtest was90.07%and the specificity was99.95%.Conclusion：1. There was missed test in HBV ELISA samples according to the PCRbead detection and Roche quantitative detection of virus;2. The relatively sensitivity ofELISA was little lower and the method need to be improved. The relative specificity washigher and reducing false positive results was necessary;3.ELISA and PCR beaddetection each had their own advantages and disadvantages, the complementaryapplication on blood transfusion safety in clinical detection was necessary.Figure11; Table11; Reference52...