CO-43 | VALIDATION OF THROMBIN GENERATION MEASUREMENT IN PLATELET-RICH PLASMA: EVOLUTION IN THE ST GENESIA® SYSTEM

F. Bocchi^1|2, R. Pastorino^1|2, G. Murante^1|2|3, S. Bergonzi^1|2|3, M. Capetta^1|2|3, F. Valeri^2|3, C. Dainese^2|3, A. Valpreda⁴, B. Bruno^1|3, A. Borchiellini^2|3 | ¹Department of Molecular Biotechnology and Health Sciences, University of Turin, Italy; ²Regional Centre for Thrombotic and Hemorrhagic Diseases, AOU Città della salute e della Scienza di Torino, Italy; ³Division of Hematology, AOU Città della Salute e della Scienza, University of Turin, Italy; ⁴Central Lab Baldi and Riberi, AOU Città della salute e della Scienza di Torino, Italy

Background and Aims. Thrombin generation assay (TGA) is a promising tool for monitoring novel non-replacement therapies in hemophilia. The ST Genesia^® system (Stago, Asnières-sur-Seine, France) is validated for thrombin generation (TG) measurement in platelet-poor plasma (PPP), but no standardized method is currently available for platelet-rich plasma (PRP). PRP testing could improve the assessment of platelet–drug interactions and provide a more comprehensive evaluation of hemostatic function. This study aimed to validate the technical reliability of TG measurement in PRP using the ST Genesia^® system by assessing intra- and inter-run reproducibility, PRP sample stability, normalization by reference plasma, absence of platelet-related methodological interference, and overall method robustness.
Materials and Methods. The procedure employed CAT PRP-Reagent (Stago), containing relipidated tissue factor for reaction initiation, a homemade PPP reference plasma (RefPlasma) prepared from a pool of at least 20 healthy donors for normalization, analytical variability monitoring and internal calibration, and PRP samples under investigation. RefPlasma validation included calculation of intra-run (≥10 replicates) and inter-run (≥3 days) coefficients of variation (CV%), together with routine coagulation testing (PT, aPTT, fibrinogen, antithrombin). PRP stability was evaluated by measuring TG at baseline (T0), 1 hour (T1), and 3 hours (T2) after collection.
Results. RefPlasma validation showed acceptable intra-run and inter-run CV%, with most values below 10% (Table 1). Routine coagulation parameters were within normal reference ranges. PRP stability testing demonstrated a progressive decline in Peak Height, ETP, and Velocity Index from T0 to T2, associated with increased Lag Time, Time to Peak, and Start Tail.
Conclusions. The RefPlasma showed satisfactory reproducibility both within single runs and across different days, supporting its suitability for normalization and quality control. The progressive reduction of TG parameters over time indicates that PRP samples should ideally be analyzed within 3 hours of collection to minimize pre-analytical degradation. This aspect deserves further investigation, particularly regarding the feasibility of centralized testing for samples from external centers. Overall, this procedure represents a validated approach for TGA in PRP and may provide a more physiologically relevant assessment of drug–coagulation interactions and global hemostatic function.