Validation of the Assay for D-dimer in Plasma by D-Dimer PLUS

Objective Validate the plasma d-dimer assay by D-Dimer PLUS.Methods According to the related documents of NCCLS,evaluate the performance of the plasma d-dimer assay by D-Dimer PLUS on the automated coagulation analyzer Sysmex CA7000.Results The low limit of the test was 83.86 μg/L;the linearity interval,0～2 000 μg/L;the recovery,93%～113%.The within-run precisions(coefficient of variability CV%) were 5.31%(low value) and 2.67%(high value);the total precisions 4.69%(low value) and 4.14%(high value).The test results of the D-Dimer PLUS were compared with those of mini-VIDAS(enzyme-linked immunosorbent assay ELISA).The coefficient of correlation was 0.915;the percentage of average bias was 634.6%.Endogenous interfering substances were also estimated in this experiment.The concentrations of conjugated bilirubin,chylomicra and hemoglobin which influenced the d-dimer test were 299 mg/L,882 FTU and 7.8 g/L.The test results didn't greatly alter when the plasma concentrations of direct bilirubin and rheumatoid factor reaching to 362 mg/L and 540,000 U/L.The validation reference value was 0～398 μg/L,higher than 0～324 μg/L offered by the manufacturer.So the reference interval needs to be reestablished.Conclusion The plasma d-dimer assay by D-Dimer PLUS had proper precision,accuracy and sensitivity for clinical requirement.It was applicable for the clinical diagnosis test.