VPB0997 - Analytical performance of different laboratory methods for measuring susoctog-alpha

Tuesday, July 12, 2022

6:30 PM – 7:30 PM

Location: Exhibition

Presentation Format: Virtual

Presenting Author(s)

Cristina Novembrino, PhD

BSc
Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Angelo Bianchi Bonomi Hemophilia and Thrombosis Center, Milan, Italy
Milan, Lombardia, Italy

Co-Author(s)

IQ

Ilaria Quaglia

biologist
Center for Thrombosis and Hemorrhagic Diseases, IRCCS Humanitas Researc Hospital, Rozzano, Milan
Milan, Lombardia, Italy
MB

Massimo Boscolo-Anzoletti

biomedical technician
Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Angelo Bianchi Bonomi Hemophilia and Thrombosis Center, Milan
Milan, Lombardia, Italy
EG

Eleonora Galbiati

biomedical technician
Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Angelo Bianchi Bonomi Hemophilia and Thrombosis Center, Milan
Milan, Lombardia, Italy
ED

Enrico Dosio

biomedical technician
Center for Hemorrhagic and Thrombotic Diseases - Clinical Biochemistry Laboratory - A.O.U. City of Health and Science, Turin
Turin, Piemonte, Italy
AV

Alessandra Valpreda

biologist
Center for Hemorrhagic and Thrombotic Diseases - Clinical Biochemistry Laboratory - A.O.U. City of Health and Science, Turin
Turin, Piemonte, Italy

Background: Acquired haemophilia A (AHA) is a severe bleeding disorder caused by the development of antibodies (inhibitors) to factor VIII (FVIII). Recombinant porcine factor VIII (rpFVIII, susoctocog alfa, Obizur®, Baxalta US Inc.-Takeda company- Bannockburn, IL, USA) is indicated for the treatment of acute bleeding episodes in AHA, but there are scanty data regarding the laboratory methods for adequately monitoring the treatment.

Aims: This study involving 3 different laboratories aimed to evaluate the analytical performance of different assays for measuring rpFVIII.

Methods: Five spiked samples at different rpFVIII concentrations (from 0.05 U/mL to 1.5 U/mL) were analysed on three distinct days, in triplicate every day, with nine different combinations of reagents (SynthasIL and SynthaFax -Werfen- for one-stage assay, Chromogenix Coamatic FVIII for chromogenic assay), FVIII depleted plasmas (with or without von Willebrand factor –vWF-) and calibrators (HemosIL human calibrator plasma, porcine calibrator diluted in FVIII deficient plasma with or without vWF). All the assays were performed on ACL Top analysers (Werfen, Bedford, MA). Intra- and inter assay and inter-laboratory Coefficient of Variation (CV%) were calculate together with percentage of recovery (% recovery) on the expected value.

Results: The results of the three laboratories are reported in table as total inter-laboratory CV% (mean of CV% obtained for all the measures of the 5 samples in the three laboratories) and % recovery (mean of % recovery obtained for all the measures of the 5 samples in the three laboratories).

Conclusion(s): The present study highlights the impact of the calibrator and of the deficient plasma used in the assay on the accuracy of the results. The use of porcine standard (when available) and FVIII deficient plasma with vWF is recommended.