Introduction: Congenital and acquired dysregulations in fibrinolysis system can lead to hyperfibrinolysis
(increased bleeding) or hypofibrinolysis (increased thrombosis), with potential for
multi-organ failure. Traditional laboratory methods provide limited insight onto the
function of the fibrinolysis system. Viscoelastic testing (VT) offers rapid and comprehensive
assessment of both coagulation and fibrinolysis systems. This study evaluates the
performance of VT to test frozen plasma samples spiked into healthy whole blood.
Method: In an observational single-center study,15 patients with suspected fibrinolytic disorders
were included. Citrated whole blood and platelet-poor plasma (PPP) samples were collected.
Whole blood samples were tested immediately using thromboelastography (TE) via EX-
and TPA-test, whereas PPP were frozen, and analyzed later using spike-in experimental
setting. In brief, frozen PPP from patients were thawed up and reconstituted into
healthy plasma-depleted blood samples. A global fibrinolysis capacity (GFC) assay
using a Lysis Timer was performed to confirm fibrinolysis disruption in patient plasma
samples.
Results: First, the validation of the spike-in approach with 20 healthy donors showed significant
correlation in lysis time (LT) between primary results of healthy whole blood samples
and reconstituted PPP-spike-in samples (r=0.67, p=0.001). Moreover, the lysis time
of the original whole blood of the patients correlates with the spike-in samples (r=0.63;
p=0.01). The spike-in samples of hypofibrinolytic patients showed an increase in lysis
time compared to spike-in of healthy controls (LT in TPA-test: 218.3±39.5 sec vs.
165.7±16.4 sec , p<0.0001). The Lysis Timer assay and ELISA testing supported these
findings, suggesting a plasmatic factor, likely PAI-1, as the cause. Interestingly,
shorter lysis time was observed in spike-in samples with hypofibrinolytic PPP compared
to original measurement in whole blood samples (LT in original TPA-test: 218.3±39.5
sec vs. 391.5±333.0 sec, respectively, p<0.0001). These data suggest hypofibrinolysis
in patients with thrombosis might be mediated by dysregulation of plasmatic as well
as cellular coagulation systems.
Conclusion: The spike-in approach for thromboelastography is effective for retrospective hypofibrinolysis
diagnosis especially in laboratories with no immediate access to viscoelastography
[1]
[2]
[3]
[4]
[5]
[6]
[7].
Our data suggest that a plasmatic factor and a cellular factor might be responsible
for the hypofibrinolytic activity. To prove this, further investigations are needed
to identify the role of cellular components in the fibrinolysis system.
