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Rapid D-Dimer Methods Comparable To ELISA For Detecting Deep Vein Thrombosis
Blood Coagulation and Fibrinolysis
09/19/2003
By Emma Hitt, PhD
Rapid D-dimers assays appear to be highly sensitive for detecting deep vein thrombosis (DVT), according to new research.
Enzyme-linked immunosorbent assay (ELISA), currently the gold standard for detecting DVT, requires specialised equipment, technical expertise, and 2 to 3 hours to perform. In contrast, newer methods for measuring D-dimers, based on ELISA and immunoturbidometry, allow diagnosis in less than 1 hour, and require only limited technical expertise.
To compare these newer methods with ELISA, Robert C. Gosselin, MD, with the University of California Davis Medical Center, Sacramento, United States, and colleagues evaluated 151 patients suspected of DVT.
A whole blood D-dimer test (SimpliRED, Agen) was performed, and then tested using enzyme-linked immunosorbent assay (VIDAS D-Dimer, BioMerieux; Asserachrome D-Di, Stago International; Dimertest Gold, Agen) and automated immunoturbidometric methods (Advanced D-Dimer, Dade Behring; MiniQuant, Biopool). The researchers then compared each D-dimer method with radiographic results to determine sensitivity and negative predictive value (NPV).
Of the patients, 23.2% had a positive Doppler ultrasound, with 26 proximal, 8 distal thromboses. One patient had both proximal and distal thromboses. Two patients were excluded due to inconclusive results.
Overall, the sensitivities for the rapid D-dimer methods were: SimpliRED, 82.3%; VIDAS D-Dimer, 91.4%; MiniQuant D-Dimer, 96.3%; and Advanced D-Dimer, 97.1%.
In the inpatient only population, the sensitivity was increased: SimpliRED (86.4%), VIDAS D-Dimer (95.5%), MiniQuant D-Dimer (100%), and Advanced D-Dimer (100%).
"The VIDAS D-Dimer, MiniQuant D-Dimer, and Advanced D-Dimer all demonstrate high sensitivity and NPV in patients suspected of DVT," the researchers conclude. "All D-dimer methods compared favourably with the more traditional ELISA methods, yet have the advantage of being quicker and easier to run," they add.
According to the researchers, these D-dimer methods could be safely substituted for ELISA tests as part of the DVT work-up. However, the SimpliRED whole-blood method was only moderately sensitive and "therefore must be used in conjunction with probability estimates and other radiographic studies to be of clinical value," they note.
"Further clinical management studies are necessary to determine the thrombotic risk in patients with negative Advanced D-dimer and Mini-Quant D-dimer results to assure that these tests can safely exclude DVT in symptomatic patients," they suggest.
Blood Coagul Fibrinolysis 2003;14:545-550.
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