soluble platelet endothelial cell adhesion molecule 1 (specam-1) improves diagnostic accuracy of d-dimer in patients with suspected deep vein thrombosis (dvt)

D-dimer has a high sensitivity but a low specificity for the diagnosis of deep vein thrombosis (dvt) which limits its implementation as a general screening parameter. there is a demand for additional biomarkers to improve its diagnostic accuracy. soluble platelet endothelial cell adhesion molecule 1 (specam-1) is generated at the site of venous thrombosis, thus, represents a promising biomarker. patients with clinically suspected dvt (n = 159) were prospectively recruited and underwent manual compression ultrasonography (ccus) to confirm or exclude dvt. the diagnostic value of d-dimer, specam-1 and the combination of both was assessed. specam-1 levels were significantly higher in patients with dvt (n = 44) compared to patients without dvt (n = 115) (85.9 [76.1/98.0] ng/ml versus 68.0 [50.1/86.0] ng/ml; p < 0.001) with a diagnostic sensitivity of 100% and a specificity of 28.7% at the cut point > 50.2 ng/ml. specam-1 improved the diagnostic accuracy of d-dimer: the combination of both biomarkers yielded a roc-auc of 0.925 compared to 0.905 for d-dimer alone and 0.721 for specam-1 alone with a reduction of false-positive d-dimer cases 72- > 43 (δ =  − 31.9%). the discrimination mainly occurred in a subgroup of patients characterized by an inflammatory background (defined by c-reactive protein level > 1 mg/ml). specam-1 represents a novel diagnostic biomarker for venous thrombosis. it does not qualify as a diagnostic biomarker alone but improves the diagnostic accuracy of d-dimer in patients with suspected dvt.