Elevated levels of soluble fibrin or D-dimer indicate high risk of thrombosis

Background: Fibrin-related markers such as soluble fibrin (SF) and D-dimer are considered useful for the diagnosis of thrombosis. However, the evidence for diagnosis of thrombosis by fibrin-related markers is not well-established. Objective: To evaluate the cutoff values of D-dimer and SF in the diagnosis of thrombosis. Patients and Methods: Plasma concentrations of SF and D-dimer were measured in 784 inpatients suspected of having thrombosis between 1 August 2003 and 31 December 2004, and then correlated with thrombosis. Results and Conclusions: Plasma concentrations of D-dimer and SF were significantly higher in patients with disseminated intravascular coagulation (DIC), deep vein thrombosis (DVT) and cerebral thrombosis, compared with those in patients without thrombosis. When cutoff values of > 3.0 mu g mL(-1) for D-dimer and > 6.0 mu g mL(-1) for SF were used for the diagnosis, more than 50% of patients (with the exception of liver transplant patients and postoperative patients) had thrombosis. Receiver operating characteristic analysis showed that SF was more useful than D-dimer for the diagnosis of thrombosis (i.e. DVT and DIC). The cutoff value of D-dimer (7.87 mu g mL(-1)) was the same for DVT and DIC, while that of SF was slightly lower for DVT (7.05 mu g mL(-1)) than for DIC (8.60 mu g mL(-1)). Our findings suggest that high levels of plasma fibrin-related markers reflect high risk for thrombosis.