Summary
Although D-dimer has gained widespread clinical use as a parameter for detection of
in vivo fibrin formation, the issue of standardization of D-dimer assays remains to
be resolved. The FACT study was performed to generate basic data for development of
calibrators and standard preparations.
A set of 86 samples, including plasma samples from patients with DIC, DVT, and other
clinical conditions, serial dilutions of pooled plasma samples, and plasma samples
containing fibrinogen- and fibrin derivatives, were distributed to 12 manufacturers
of D-dimer assays.
D-dimer assays differ concerning specificity for crosslinked fibrin, and preference
for either high molecular weight fibrin complexes, or low molecular weight fibrin
degradation products. Terminal plasmin digests of fibrin clots for calibration produce
aberrant results in some assays, especially those with preference for high molecular
weight crosslinked fibrin derivatives. The best conformity is achieved by the use
of pooled plasma samples from patients with high levels of D-dimer antigen in plasma.
In vitro preparations containing a comparable composition of fibrin derivatives to
clinical plasma samples may also serve as reference material.
Keywords
Fibrinogen-fibrin degradation products - D-dimer - fibrinogen - fibrin - standardization
