Analytical and Clinical Performance of a New Point of Care LABGEOIB D-Dimer Test for Diagnosis of Venous Thromboembolism

Abstract

LABGEO(IB) D-dimer Test is a newly developed POC D-dimer assay and the first commercially available POC immunoassay instrument that exploits the disk rotation method for extraction of plasma. Citrate plasma was obtained from 201 apparently healthy subjects and 91 patients suspected for VTE, and their D-dimer level was measured by the LABGEO(IB) D-Dimer Test (LABGEO D-dimer) and HemosIL D-dimer test as a comparative method. To examine the effect of blood cells and anticoagulant, paired blood samples anticoagulated by heparin and citrate were obtained from various postoperative patients. The overall diagnostic performance of LABGEO(IB) D-dimer and HemosIL was comparable with similar area under ROC curve (p=0.79). The cut-off levels recommended by manufacturers (LABGEO D-dimer: 0.45 μg/ml fibrinogen equivalent unit (FEU), HemosIL: 0.23 μg/ml D-dimer unit (DDU)) and those yielding highest diagnostic efficiency (LABGEO D-dimer: 1.41 μg/ml FEU; HemosIL: 0.85 μg/ml DDU), were chosen for the evaluation. For LABGEO D-dimer negative predictive value (NPV), positive predictive value (PPV), sensitivity, specificity, and negative likelihood ratio (LR-neg) were 93-100%, 67-89%, 93-100%, 53-89% and 0.00-0.08. For HemosIL D-dimer, NPV, PPV, sensitivity, specificity and LR-neg were 90 - 100%, 76-95%, 89-100%, 70-96% and 0.00-0.12, all comparable to results for LABGEO D-dimer. LABGEO D-dimer test demonstrated acceptable performance when used for the VTE diagnostic work-up.