Evaluation of a Soluble Fibrin Assay in Patients with Suspected Deep Vein Thrombosis

BACKGROUND: The objective of this study was to determine the clinical utility of an enzyme immunoassay (EIA) for soluble fibrin in patients with clinically suspected deep vein thrombosis (DVT). METHODS AND RESULTS: 101 unselected patients with clinically suspected DVT underwent blood sampling for measurement of plasma levels of soluble fibrin, and objective testing for DVT. According to results of the objective tests, patients were classified as DVT-positive (n = 34) or DVT-negative (n = 67). Using different cut-points of soluble fibrin results, the sensitivities, specificities, positive and negative predictive values of the soluble fibrin assay were calculated. A soluble fibrin result of < or = 0.75 mg/ml showed a sensitivity and negative predictive value of 100%, and a specificity of 17.9% for DVT, a soluble fibrin result of < or = 1.40 mg/ml showed a sensitivity of 91.2% and a negative predictive value of 93.6%, and a specificity of 65.7% for DVT, whereas a soluble fibrin result of < or = 8.0 mg/ml showed a specificity and positive predictive value of 100% for DVT. CONCLUSIONS: This study demonstrates that the soluble fibrin assay used in the study has potential clinical utility as a diagnostic test in patients with clinically suspected DVT and supports further evaluation of this assay.