A new method for measuring D-dimer using immunoturbidometry: a study of 255 patients with suspected pulmonary embolism and deep vein thrombosis

D-Dimer testing has been suggested as a non-invasive method for the exclusi on of pulmonary embolism (PE) and deep vein thrombosis (DVT). In this study , we compared a new method, the Miniquant D-dimer (Biopool International, V entura, California, USA) to other previously validated D-dimer methods used for the purpose. Patients who were undergoing a definitive diagnostic stud y for thromboembolism had a blood sample drawn at that time. A whole-blood D-dimer (SimpliRed; Agen Biomedical Ltd, Brisbane, Australia) test was perf ormed, and residual plasma was frozen and later analyzed using two enzyme-l inked immunosorbent assay (ELISA) methods (D-dimer Gold; Agen, and Asserach rome D-Di; Stage International, Parsippany, New Jersey, USA) and the Miniqu ant D-dimer. Once all samples were analyzed, the correlation and accuracy o f the Miniquant was compared with the ELISA method using Spearman's regress ion and Dunn's multiple paired comparison. All D-dimer methods were compare d with radiographic studies. The data was analyzed collectively and segrega ted into in-patient (n=112) and out-patient (n=143) populations. The Miniqu ant D-dimer sensitivity, specificity and negative predictive value (NPV) fo r all patients were 95, 21, and 94% for DVT, and 100, 26, and 100% for PE. This new D-dimer method demonstrates acceptable sensitivity in patients wit h PE and DVT and, based on the high NPV of this method, it can be used for the exclusion of thromboembolism. Blood Coagul Fibrinolysis 11:715-721 (C) 2000 Lippincott Williams & Wilkins.