Thrombin Generation Assays: Possibilities and Limitations

Thrombin generation assays (TGA) provide a dynamic and integrative assessment of thrombin generation in clotting plasma ex vivo. The method is characterized by triggering coagulation, typically via the extrinsic pathway, and continuously measuring thrombin activity using a fluorogenic peptide substrate to derive key parameters such as peak thrombin and the endogenous thrombin potential. Several assay platforms are currently available, with the original Calibrated Automated Thrombogram (CAT) still being widely used in clinical and research settings, not least due to its flexibility and ability to analyze both platelet-poor as well as platelet-rich plasma. Thrombin generation assays have the potential to support the evaluation and monitoring of treatment of bleeding disorders, including hemophilia A and B and other inherited or acquired coagulation factor deficiencies. They may contribute to risk stratification in thrombotic disorders, and support the assessment of anticoagulant therapies. However, besides ongoing developments and optimization of trigger reagents, inter-assay variability and susceptibility to pre- and analytical variables challenge assay standardization and inter-laboratory comparability. Continued refinement, harmonization, and prospective clinical validation will be essential to unlock the full diagnostic potential of TGA.