Performance evaluation of a new rapid quantitative assay system for measurement of D-dimer in plasma and whole blood:...

D-dimer is an indicator for in vivo fibrin formation, reflecting the formation of fibrin crosslinked by factor XIIIa. D-dimer assays are frequently used in emergency situations, such as diagnosis of venous thrombosis and pulmonary embolism, or disseminated intravascular coagulation. In these conditions, short sample turnaround times are essential. The PATHFAST D-dimer assay allows rapid quantitative measurement of D-dimer in plasma and whole blood. The study shows an excellent correlation between whole blood and plasma measurement of D-dimer both in the high range, as well as in the normal range. Intra-assay and inter-assay coefficients of variation (CV) were below 10%. The upper limit of normal (ULN = mean value measured in 100 samples from healthy blood donors + 2 x S.D.) was approximately 1 microg/ml FEU, using the assay-specific calibration. The maximal value measured in 20 replicates of calibrator 1 containing no D-dimer antigen was 0.00052 microg/ml FEU, and this 10-fold lower than the declared detection limit of 0.005 microg/ml FEU. In conclusion, the PATHFAST D-dimer assay is the first automated fully quantitative D-dimer assay, which can use plasma and whole blood as sample materials in parallel.