Abstract:
OBJECTIVE To assess the accuracy and correlation between chemiluminescent microparticle immunoassay(CMIA) and enzyme multiplied immunoassay technique(EMIT) in the determination of cyclosporine A(CSA) concentration in whole blood.
METHODS The low, medium and high level of whole blood immunosuppressant control were determined by CMIA and EMIT, then the accuracy, intra-assay and inter-assay precision of each method were analyzed. The known concentrations of CSA(49.5, 155.2, 395.8, 500.0, 995.0 and 1 390.1 ng·ml
-1) were added into the whole blood sample without CSA and measured, then the recovery rates of testing results were calculated. Whole blood samples of 100 patients were detected, the results were analyzed by Deming regression for linear regression analysis and analyzed by Bland-Altman for calculating bias.
RESULTS The relative error of the low, medium and high level of whole blood immunosuppressant control measured with CMIA was 5.8%, 5.2% and 9.1%, the intra-assay coefficient of variation(CV) was 7.4%, 6.9% and 8.6%, the inter-assay CV was 10.1%, 11.3% and 8.7%, and the recovery rate was 91%, 95%, 103%, 102%, 102% and 104%, respectively. While in EMIT, it was observed that the relative error was 2.8%, 2.3% and 4.3%, the intra-assay CV was 11.2%, 5.9% and 5.7%, the inter-assay CV was 11.3%, 9.2% and 8.3%, and the recovery rate was 90%, 92%, 97%, 98%, 99% and 102%, respectively. The bias of mean difference between CMIA and EMIT was 21.7 ng·mL
-1(95% CI:-125.1-168.4 ng·mL
-1). The relative value of EMIT/CMIA was 0.951(95% CI:0.56-1.34). The determination results of EMIT was 5% lower than that of CMIA in average.
CONCLUSION Determination of whole blood CSA concentration by CMIA and EMIT meet the requirement of accuracy in immune analysis. The results showed a good correlation between CMIA and EMIT. The effects of different types of detection methods should be taken into consideration for the rational dosage adjustment of drugs in clinic.