Evaluation of the fibrinolytic capacity before and after venous occlusion performed by serum d-dimer test after standardized coagulation

Abstract number: P1350a

Paniccia R., Bandinelli B, Attanasio M., Rossi L., Lari B., Lombardi A., Falciani M., Gori A.M., Abbate R., Prisco D.

University of Florence, Italy

Serum D-dimer (s-DD) test after standardized coagulation (4 hr incubation of sample at room temperature - rt) is a global fibrinolytic test, related to different fibrinolytic parameters. A modification of standardized coagulation (2 hr incubation at 37°C) has been validated in unstimulated subjects, so allowing a more practical way of performing this test. Aim of this study was to evaluate whether a reduced time of incubation of blood at 37°C from 23 healthy subjects, studied before and after 10 minutes of venous occlusion (VO), produces s-DD levels comparable with the levels after 4 hrs at rt and the correlation between s-DD and different fibrinolytic parameters. Serum was obtained after 1, 2, 3 and 4 hrs of incubation both at rt and at 37°C. The following plasma fibrinolytic parameters were investigated: DD, ELT, t-PA activity (t-PA act) and antigen (t-PA ag) and PAI-1 activity (PAI-1 act). Before VO s-DD levels after 2 hrs at 37°C were increased (p<0.001) with respect to those after 2 hrs at rt and similar to those measured after 4 hrs at rt, so confirming previous results. After VO s-DD levels after 2 hrs at 37°C were similar to those after 4 hrs at rt, and remained unchanged after 3 and 4 hrs. Significant correlations were found between s-DD values after 2 hrs at 37°C and ELT (r=- 0.62, p<0.01), t-PA act (r=0.69, p<0.001), t-PA ag (r=0.52, p<0.01) and PAI-1 act (r=-0.57, p<0.01). The present study demonstrate that, as before VO, also after VO s-DD levels (after 2 hrs of incubation at 37°C) are similar to those measured after incubation for 4 hrs at rt and are correlated with different fibrinolytic parameters. A shorter incubation can facilitate a larger application of this method in general laboratories. However, the clinical use of s-DD determination still needs to be validated in "ad hoc" studies.