O Bulla1, A Poncet2, L Alberio3, L M Asmis4, A Gähler5, L Graf6, M Nagler7,8, J-D Studt9, D A Tsakiris10, P Fontana1. 1. Division of Angiology and Haemostasis and Laboratory of Haemostasis, Geneva University Hospitals, Geneva, Switzerland. 2. CRC and Division of Clinical Epidemiology, Department of Health and Community Medicine, University of Geneva and University Hospitals of Geneva, Geneva, Switzerland. 3. Division of Haematology and Haematology Central Laboratory, CHUV Lausanne University Hospital, Lausanne, Switzerland. 4. Center for Perioperative Thrombosis and Haemostasis and Unilabs Coagulation Laboratory, Zurich, Switzerland. 5. Division of haematology and Laboratory of haematology, Lucerne Cantonal Hospital, Lucerne, Switzerland. 6. Centre for Laboratory Medicine, Haemostasis and Haemophilia Centre St Gallen, St Gallen, Switzerland. 7. Department of Haematology and Central Haematology Laboratory, Inselspital University Hospital, Bern, Switzerland. 8. Department of Clinical Research, University of Bern, Bern, Switzerland. 9. Division of Haematology, University Hospital Zürich, Zürich, Switzerland. 10. Diagnostic Haematology, University Hospital Basel, Basel, Switzerland.
Abstract
INTRODUCTION: Measuring factor VIII (FVIII) activity can be challenging when it has been modified, such as when FVIII is pegylated to increase its circulating half-life. Use of a product-specific reference standard may help avoid this issue. AIM: Evaluate the impact of using a product-specific reference standard for measuring the FVIII activity of BAX 855 - a pegylated FVIII - in eight of Switzerland's main laboratories. METHODS: Factor VIII-deficient plasma, spiked with five different concentrations of BAX 855, plus a control FVIII sample, was sent to the participating laboratories. They measured FVIII activity by using either with a one-stage (OSA) or the chromogenic assay (CA) against their local or a product-specific reference standard. RESULTS: When using a local reference standard, there was an overestimation of BAX 855 activity compared to the target concentrations, both with the OSA and CA. The use of a product-specific reference standard reduced this effect: mean recovery ranged from 127.7% to 213.5% using the OSA with local reference standards, compared to 110% to 183.8% with a product-specific reference standard, and from 146.3% to 182.4% using the CA with local reference standards compared to 72.7% to 103.7% with a product-specific reference standard. CONCLUSION: In this in vitro study, the type of reference standard had a major impact on the measurement of BAX 855 activity. Evaluation was more accurate and precise when using a product-specific reference standard.
INTRODUCTION: Measuring factor VIII (FVIII) activity can be challenging when it has been modified, such as when FVIII is pegylated to increase its circulating half-life. Use of a product-specific reference standard may help avoid this issue. AIM: Evaluate the impact of using a product-specific reference standard for measuring the FVIII activity of BAX 855 - a pegylated FVIII - in eight of Switzerland's main laboratories. METHODS:Factor VIII-deficient plasma, spiked with five different concentrations of BAX 855, plus a control FVIII sample, was sent to the participating laboratories. They measured FVIII activity by using either with a one-stage (OSA) or the chromogenic assay (CA) against their local or a product-specific reference standard. RESULTS: When using a local reference standard, there was an overestimation of BAX 855 activity compared to the target concentrations, both with the OSA and CA. The use of a product-specific reference standard reduced this effect: mean recovery ranged from 127.7% to 213.5% using the OSA with local reference standards, compared to 110% to 183.8% with a product-specific reference standard, and from 146.3% to 182.4% using the CA with local reference standards compared to 72.7% to 103.7% with a product-specific reference standard. CONCLUSION: In this in vitro study, the type of reference standard had a major impact on the measurement of BAX 855 activity. Evaluation was more accurate and precise when using a product-specific reference standard.
Authors: Steffen Rosen; Stefan Tiefenbacher; Mary Robinson; Mei Huang; Jaydeep Srimani; Donnie Mackenzie; Terri Christianson; K John Pasi; Savita Rangarajan; Emily Symington; Adam Giermasz; Glenn F Pierce; Benjamin Kim; Stephen J Zoog; Christian Vettermann Journal: Blood Date: 2020-11-26 Impact factor: 22.113