Abstract Number: PB0643
Meeting: ISTH 2020 Congress
Background: Reliable measurement of factor VIII activity is essential for monitoring patients with hemophilia A during FVIII replacement therapy. Factor VIII extended half-live products can lead to discrepancies when assayed with different one-stage clotting and chromogenic FVIII assays.1 The effect of different FVIII replacement drugs on the analytical performance of the FVIII assay on cobas t 511/711 analyzers has been investigated.
Aims: To evaluate the performance of the FVIII one-stage clotting assay on cobas t 511/711 analyzers to measure samples containing different FVIII recombinant drugs.
Methods: Severe hemophilia A plasma samples (George King Bio-Medical) were spiked with recombinant FVIII products at defined concentrations (0.01 – 1.2 IU mL-1). FVIII activity was determined using a cobas t 711 analyzer in combination with the FVIII assay kit (Roche Diagnostics). Both sample preparation and measurements were conducted in triplicates. To evaluate the result the following acceptance criteria were used [>25% ± 20 % (relative); >25% ± 5 % (absolute)].
Results: The correlation for most of FVIII replacement drugs between the measured FVIII activity and the theoretical activity was within the defined acceptance limits across the complete analyzed range. Values for Jivi® and ADYNOVI® were slightly higher than the upper deviation limit between 10-80% and a significant underestimation was observed for samples spiked with AFSTYLA® above 20% (Figure 1).
[Figure 1 Recovery of different FVIII replacement drugs in the FVIII assay on cobas t 711.]
Conclusions: Overall, most of the FVIII replacement drugs can be reliably measured with the FVIII assay on cobas t 511/711 analyzers without the need for a product specific reference standard. The recorded data set allows the interpretation of FVIII assay results of samples containing different FVIII products on cobas t 511/711 analyzers.
References: 1 S. Kitchen et al., Semin Thromb Hemost 43 (2017)
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To cite this abstract in AMA style:
Ketteler C, Hoffmann I, Jagdhuber F, Davidson S, Richter N. Monitoring of Different FVIII Replacement Drugs Using the FVIII One-stage Clotting Assay on Cobas t 511/711 Analyzers [abstract]. Res Pract Thromb Haemost. 2020; 4 (Suppl 1). https://abstracts.isth.org/abstract/monitoring-of-different-fviii-replacement-drugs-using-the-fviii-one-stage-clotting-assay-on-cobas-t-511-711-analyzers/. Accessed November 29, 2023.« Back to ISTH 2020 Congress
ISTH Congress Abstracts - https://abstracts.isth.org/abstract/monitoring-of-different-fviii-replacement-drugs-using-the-fviii-one-stage-clotting-assay-on-cobas-t-511-711-analyzers/