D-dimer and thrombin/antithrombin III complex--diagnostic tools in deep venous thrombosis?

In order to evaluate the usefulness of determining D-dimer and thrombin-antithrombin III complex (TAT) in the diagnosis of deep venous thrombosis (DVT), three D-dimer assays were tried: one ELISA and one latex test from Diagnostica Stago and one new latex method from Biopool. TAT was assessed using an ELISA (Behringwerke). We studied 96 consecutive outpatients with suspected DVT, of whom 36 had phlebographically confirmed DVT. Statistical calculations showed high sensitivity and a negative predictive value for the D-dimer ELISA (97% for both), confirming the results obtained by others. The new latex method (Biopool) showed similar figures (96% for both). The latex method from Diagnostica Stago and TAT showed lower sensitivity and negative predictive values. No differences in the D-dimer results were found with or without antifibrinolytics in the tubes for blood sampling. Our data suggest that negative results when using the new simple and cheap latex method (Biopool) may reduce the number of phlebographic examinations.