Thromboelastographic assessment of hypofibrinolysis in stored plasma samples: A novel spike-in method

Congenital or acquired dysregulation of fibrinolytic system can lead to bleeding (hyperfibrinolysis) or thrombosis (hypofibrinolysis), with increased risk for multi-organ failure. Standard clotting-based assays provide limited insight into fibrinolytic status. In contrast, thromboelastography (TEG), a whole blood assay, offers a comprehensive assessment of the coagulation and fibrinolytic systems. While freezing plasma samples enables later investigation of plasmatic coagulation factors, viscoelastic testing (VT) requires immediate testing. In this study, we evaluated a new diagnostic approach to assess fibrinolysis in frozen plasma samples spiked into healthy whole blood using VT.

Citrated whole blood and corresponding frozen platelet-poor plasma (PPP) samples from patients with hypofibrinolytic disorders were analyzed using thromboelastography (TEG). The spike-in method involved reconstituting patient-derived frozen PPP into plasma-depleted blood from healthy subjects. In addition, the Lysis Timer®, a global fibrinolysis capacity assay, was used to assess fibrinolysis in plasma samples.

The validation study showed strong correlation between lysis time (LT) of VT in healthy whole blood and spiked samples (r = 0.6720, p = 0.0012). Hypofibrinolytic patients exhibited significantly increased LT in the tissue plasminogen activator-test of VT (LT-TPA) when their PPP was spiked into healthy whole blood, confirming hypofibrinolytic activity (LT-TPA whole blood of healthy donors vs. spike-in with patients, PPP: 165.7 ± 16.6 s vs. 218.3 ± 39.6 s, p < 0.0001). The Lysis Timer assay supported these findings, suggesting a plasmatic factor rather than cell-derived resistance to fibrinolysis.

The spike-in approach can be used to retrospectively detect hypofibrinolysis in frozen samples using TEG. This method is particularly useful for clinical studies when immediate VT is not available.