EVALUATION OF A NEW RAPID D-DIMER ASSAY FOR CLINICALLY SUSPECTED DEEPVENOUS THROMBOSIS (LIATEST D-DIMER)

In previous studies, enzyme-linked immunosorbent assays (ELISA) for pl asma D-dimer analysis have demonstrated high sensitivity, suggesting t heir potential usefulness in excluding deep venous thrombosis (DVT). W e evaluated the usefulness of a new D-dimer test (Liatest D-dimer) for suspected DVT in a prospective study of patients admitted to the hosp ital because of recent (not exceeding 1 week before admission) clinica l signs. Contrast venography or compression ultrasonography or both we re performed within 24 hours of admission. A new quantitative determin ation of D-dimer concentrat ion using a suspension of microlatex parti cles coated with specific antibodies was tested. A standard plasma D-d imer ELISA measurement was also performed. Of 464 patients, 276 had a proven DVT (distal, 74; proximal, 202). For a cutoff level of 400 ng/m L, sensitivity of the Liatest method in the diagnosis of overall DVT w as 94.6% (95% confidence interval, 92.0%-97.0%), and the specificity w as 35% (95% confidence interval, 28%-42%). The sensitivity and negativ e predictive value were 98.5% and 95.6%, respectively, in the diagnosi s of proximal DVT, but only 83.8% and 84.6%, respectively, in the diag nosis of distal DVT. This new rapid Liatest D-dimer assay seems to be highly sensitive and could replace the ELISA method in excluding patie nts with proximal DVT. Both methods provide lower sensitivity for dist al DVT.