The significance of the levels of D-dimer in thrombotic conditions

A D Dimer ELISA test (Asserachrom D Di Stago) was used to quantify the modification of plasmatic D Dimer levels in two kinds of thrombotic diseases: DIC and deep venous thrombosis. Very high values were obtained in these two situations (m +/- sd): DIC (n = 22): 15.2 +/- 18.5 micrograms/ml. (Normal values were defined in 20 healthy subjects: 0.15 +/- 0.04 micrograms/ml). In DIC highest values were a bad prognosis, they were found in patients who died during the ten days following the diagnosis. In deep venous thrombosis the increase was not related to the size of the clot but to the endogenous fibrinolysis. An elevated concentration of D Dimer was often related to a good phlebographic evolution. During heparin therapy with standard heparin or low molecular weight heparin (LMWH) a greater decrease of D Dimer level was observed in patients with a good phlebographic evolution. Results expressed in percentage of decrease were (successful group against the failure group): J3/J10: 46.4 +/- 29.2 p. cent/13.4 +/- 11.0 p. cent (p less than 0.05); J7/J10: 52.3 +/- 31.5 p. cent/24.2 +/- 26.3 p. cent (p less than 0.05). The intensity of the decrease may have an indicative value for in vivo thrombolysis. This could be explained by a smaller clot mass to be lysed in successful group. During streptokinase treatment the D Dimer levels were very high (greater than 50 micrograms/ml). A problem of specificity could be evoked in presence of a massive quantity of fibrinogen degradation products levels.