The use of frozen plasma samples in thromboelastometry

Abstract

Thromboelastometry is increasingly used in the clinical and scientific setting. The use of frozen plasma samples may be useful in overcoming certain limitations such as local and timely availability. Whole blood (WB) samples of 20 healthy volunteers were obtained, and plasma was generated. NATEM (n = 20), EXTEM (n = 20) and INTEM (n = 8) analyses were performed in WB, fresh plasma and frozen and thawed plasma. Dabigatran (500, 1000 ng/ml), rivaroxaban (100, 200 ng/ml) or alteplase (333 ng/ml) were added ex vivo to WB, and thromboelastometry was performed in WB and in frozen and thawed plasma samples. Clot formation time, mean clot firmness and the area under the curve were significantly altered in plasma compared to WB. In INTEM and EXTEM analysis, clotting time (CT) was comparable between WB (100%) and fresh (INTEM 114% and EXTEM 93%, ratio of the means) and frozen plasma samples (85 and 99%), whereas in NATEM analysis, the CT increased in fresh (193%) and frozen plasma samples (130%). Dabigatran dose-dependently increased the CT approximately 5- and 9-fold in WB and even more pronounced 10- and 26-fold in plasma. Accordingly, rivaroxaban dose-dependently increased the CT 2- and 2.7-fold in WB, and 3.5- and 4-fold in plasma samples. Hyperfibrinolysis was achieved by addition of alteplase in all WB samples and was reproducible in plasma samples. In conclusion, thromboelastometry, especially INTEM and EXTEM analyses, is possible using frozen and stored plasma samples with comparable results to the corresponding whole blood samples.

Patho- physiological role of BDNF in fibrin clotting

“…In particular, we found that CHD patients have lower BDNF levels, higher fibrin clot strength and greater fibrin fibers complexity compared to healthy control subjects, all data consistent with previous reports 41,43 . In particular, others have showed that the range of MCF detected in control subjects and CHD patients (∼20–30 mm 44,45 and ∼25–38 mm 45 , respectively), which confirms our data. In addition, the negative correlation between plasma BDNF levels and fibrin clot properties is suggestive of a new mechanism by which BDNF influences cardiovascular prognosis.…”

Normalization of Blood Clotting Characteristics Using Prothrombin Complex Concentrate, Fibrinogen and Fxiii In an Albumin Based Fluid: Experimental Studies In Thromboelastometry.

“…A further limitation of our experimental studies is the complete absence of red blood cells. Red blood cells seem to exert a more important role in primary hemostasis, whereas their modulating effect on secondary hemostasis seems to be negligible 13 . In fact, viscoelastic studies can be reliably performed in plasma samples 12,13 .…”

“…Red blood cells seem to exert a more important role in primary hemostasis, whereas their modulating effect on secondary hemostasis seems to be negligible 13 . In fact, viscoelastic studies can be reliably performed in plasma samples 12,13 . Altogether, the transfer of our data into a clinical context must therefore be done very carefully.…”

“…The obtained plasma reference range for A 10 and MCF was 17-24 mm and 18-26 mm, respectively. Previously published reference ranges for standard TEM parameters for plasma and whole blood and usually accepted treatment thresholds are shortly summarized in Table 1 for comparison 13,14,16,17 .…”

“…In this study we used a thromboelastometric approach to analyze modi cations of viscoelastic parameters in a plasma-, and blood cell-free environment. It is technically feasible to perform thromboelastometric analysis in such conditions, although this approach has been limited to its use in laboratory investigations 12,13 .…”