Research on detection limits and functional sensitivity of chemiluminescence immunoassay in detection of BNP

Objective To evaluate the detection limits and functional sensitivity performance of Siemens ADVIA Centaur 240 automated B-type natriuretic peptide(BNP) assay.Methods We followed the document EP-17A published in 2004 by American Clinical and Laboratory Standards Institution(CLSI).Each blank sample was performed tests for repeat 10 times and the low limit of detection(LLD) was calculated.For the determination of LoB,6 replicates of manufacturer′s dilution(0 pg/mL) on 5 separate runs(n=30) were assayed.The RLUs of blank and a serial diluted samples detected by Bayer Centaur 240 chemiluminescence immunoassay system would be calculated for average value,standard deviations and coefficient of variance,which to establish the biologic limit of detection(BLD) and functional sensitivity of BNP.The limit of detection(LoD) was determined by assaying 2 replicates of 8 plasma pools(low levels of BNP) on 5 separate runs(n=80).Results The LLD was 1.47 pg/mL and LoB was 0.86 pg/mL.They were both lower than the declaration of the manufacturer.The BLD was between 3.27 pg/mL and 3.71 pg/mL and the LoD was 3.54 pg/mL.The functional sensitivity of the cardiac biochemical markers that can reflect some pathological changes of the functional sensitivity was 4.64 pg/mL(the value of 10% CV).Conclusion The LLD,BLD,limit of blank(LoB) and LoD of BNP could meet the clinical requirements,which also validate the manufacture′s declare.At the same time,we set up the LoB and LoD of BNP in our laboratory,which can provide more accurate and trusty results for our hospital.The evaluation documents are simple and useful,so we suggest that the clinical laboratory use document EP17-A to set up LoB,LoD and FS which must accord with the precision.