Comparison of Two Thrombin Generation Methods, CAT and ST-Genesia, in Liver Transplant Patients

Abstract

Background During liver transplantation (LT), thrombin generation (TG) is altered. The most frequently used assay for TG is the Calibrated Automated Thrombogram (CAT). It is designed for series of plasmas and is semi-automated. Complete automation has led to a new device, the ST-Genesia, enabling quantitative standardized TG evaluation. Objective The aim of this observational study was to compare the TG results of the CAT and the ST-Genesia on frozen-thawed plasma samples prepared from the blood of LT patients. Patients and Methods Poor platelet plasma aliquots were prepared from blood samples from six LT patients selected to get the whole range of TG and were assessed with CAT (recombinant human tissue factor [TF] concentration 5 pm) and with ST-Genesia Bleedscreen assay (BS, using ‘low’ recombinant human TF concentration) and Thromboscreen assay (TS, using ‘medium’ recombinant human TF concentration). The TG parameters studied were: lag time, peak, time to peak, endogenous thrombin potential, velocity index and start tail. Results BS and TS did not differ significantly from each other whatever the parameter studied, whereas most of the CAT parameters were significantly different from those obtained with BS and TS. Hierarchical clustering analysis of the different parameters of TG showed three homogeneous groups. One cluster gathered TG quantitative parameters from ST-Genesia. A second cluster gathered all the kinetic parameters. The last cluster isolated the quantitative parameters of CAT. Conclusion In patients undergoing LT, TG performed with CAT and with ST-Genesia provided different results, for unknown reasons.

Anticoagulated patients exhibit intact endogenous thrombin potential using ST Genesia unlike the Calibrated Automated Thrombogram

“…We detected opposite results using the DrugScreen, which showed higher peak and ETP values, perhaps because it has a high TF concentration and low factor VII levels, which are common in liver disease. The lag time was shortest using the ThromboScreen reagent, while BleedScreen and CAT exhibited similar results 9 . In the present study, DrugScreen exhibited a shorter lag time than CAT, as well as higher ETP and peak values.…”

“…Few studies have compared CAT with ST Genesia 9 . Recently, the plasma levels of direct oral anticoagulants (DOACs) were shown to correlate with the lag time and peak height of the DrugScreen test 7 .…”

Inhibition of thrombin generation 12 hours after intake of direct oral anticoagulants

“…Currently, only one study compared TG measurements of CAT and ST‐Genesia. The results of ST‐Genesia differed from results obtained with the CAT in a cohort of patients with liver transplants 26 . Thus, ST‐Genesia and CAT cannot be compared directly in terms of absolute measurements.…”

Direct oral anticoagulant plasma levels and thrombin generation on ST Genesia system

“…Two recent publications compared CAT with STG‐BleedScreen (BLS) and STG‐ThromboScreen (TS). TG parameters obtained with CAT using blood samples from patients undergoing liver transplant showed different results compared to those with ST Genesia BLS and TS 22 . In contrast, in another study on healthy volunteers, BLS showed a positive correlation with peak thrombin and ETP in CAT using 1 pM tissue factor, while TS correlated only with peak thrombin in CAT with 5 pM TF in the absence of thrombomodulin and with ETP in the presence of thrombomodulin 23 .…”