Quantitative Measurement of D-dimer by VIDAS System in Patients with Suspected DIC

Kim, Hyun Kyung; Song, Kyung Soon; Park, Quehn

Abstract

BACKGROUND
D-dimer, cross-linked fibrin degradation fragment, is an important parameter for the diagnosis of disseminated intravascular coagulation (DIC). The commonly used method for detecting D-dimer levels is latex agglutination, which is rapid but lacks sufficient sensitivity. Recently, quantitative and rapid D-dimer assay have been available for routine laboratory use.
METHODS
We compared quantitative D-dimer by VIDAS system with semiquantitative latex D-dimer. Sixty-six patients at risk for DIC were classified as DIC and subclinical DIC based on the modified DIC criteria by Mant et al. VIDAS D-dimer (BioMerieux, Marcyl'Etiole, France), latex D-dimer (Diagnostica Stago, Asnieres, France), fibrinogen (Diagnostica Stago), prothrombin time (Diagnostica Stago), activated partial thromboplastin time (Diagnostica Stago), and platelet count (Sysmex SE9000, Japan) were measured.
RESULTS
In 9 patients with documented DIC it was found that VIDAS D-dimer level was markedly elevated (>2,000 ng/mL) in 100%, with the mean D-dimer level being 10,720+/-7,727 ng/mL and that latex D-dimer was markedly elevated in 33.3%. There was no significant difference of VIDAS D-dimer level according to the clinical diagnosis. The concordance rate between VIDAS and latex D-dimer is 33.3% (22/66). Thirty-four (51.5%) of all patients had VIDAS D-dimer level of more than 2,000 ng/mL and latex D-dimer of 1000-2000 ng/mL. There was negative correlation between VIDAS D-dimer levels and APTT (or fibrinogen).
CONCLUSIONS
We concluded the quantitative VIDAS D-dimer to be more sensitive than latex D-dimer and to be a useful parameter in diagnosing DIC. It is needed to set cutoff value of D-dimer in order to get more specific information for the diagnosis of DIC.