Measuring FVIII activity of glycopegylated recombinant factor VIII, N8-GP, with commercially available one-stage clotting and chromogenic assay kits : A two-centre study
(2017) In Haemophilia 23(3). p.458-465- Abstract
Introduction: Factor VIII activity (FVIII:C) assays of samples containing glycoPEGylated recombinant FVIII such as turoctocog alfa pegol (N8-GP) can be associated with differences in FVIII recovery in vitro between various one-stage activated partial thromboplastin time (APTT)-based clotting assays and some chromogenic assays. Careful validation and qualification of specific assays and conditions is therefore necessary for the assessment of FVIII:C in samples containing modified FVIII molecules. Aim: To assess the ability of various one-stage clotting and chromogenic FVIII:C assays to measure samples containing N8-GP compared to unmodified recombinant FVIII (rFVIII) across two laboratory sites. Methods: Factor VIII activity in severe... (More)
Introduction: Factor VIII activity (FVIII:C) assays of samples containing glycoPEGylated recombinant FVIII such as turoctocog alfa pegol (N8-GP) can be associated with differences in FVIII recovery in vitro between various one-stage activated partial thromboplastin time (APTT)-based clotting assays and some chromogenic assays. Careful validation and qualification of specific assays and conditions is therefore necessary for the assessment of FVIII:C in samples containing modified FVIII molecules. Aim: To assess the ability of various one-stage clotting and chromogenic FVIII:C assays to measure samples containing N8-GP compared to unmodified recombinant FVIII (rFVIII) across two laboratory sites. Methods: Factor VIII activity in severe haemophilia A (HA) plasma spiked with a range of concentrations (from low, 0.20 IU mL-1, to high, 0.90 IU mL-1) of N8-GP and rFVIII, was determined at two laboratory sites using 12 commercially available one-stage clotting and chromogenic FVIII:C assays. Assays were performed using a plasma calibrator and different analysers. Results: Acceptable N8-GP recovery was observed in the low to high concentration samples tested using the majority of the tested APTT reagents with only one reagent causing a significant underestimation as compared to rFVIII. For the chromogenic assays, a slight overestimation was observed with some of the kits. Variability between the two laboratory sites are likely attributable to the use of different analysers with the respective APTT reagents. Conclusions: These results highlight the need to investigate the performance of modified factor products using standard assays. The performance of different one-stage clotting assays, APTT reagents, reference calibrators and instrumentation should also be evaluated.
(Less)
- author
- Hillarp, A. LU ; Bowyer, A. E. ; Ezban, M ; Persson, P. and Kitchen, S.
- publishing date
- 2017
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Chromogenic FVIII assay, N8-GP, One-stage FVIII assay, Polyethylene glycol, Turoctocog alfa, Turoctocog alfa pegol
- in
- Haemophilia
- volume
- 23
- issue
- 3
- pages
- 458 - 465
- publisher
- Wiley-Blackwell
- external identifiers
-
- pmid:28198071
- scopus:85013149291
- ISSN
- 1351-8216
- DOI
- 10.1111/hae.13168
- language
- English
- LU publication?
- no
- id
- e9c3aec7-6f62-44ec-b5d6-922d48e16ed0
- date added to LUP
- 2017-03-02 10:11:34
- date last changed
- 2024-04-29 06:51:39
@article{e9c3aec7-6f62-44ec-b5d6-922d48e16ed0,
abstract = {{<p>Introduction: Factor VIII activity (FVIII:C) assays of samples containing glycoPEGylated recombinant FVIII such as turoctocog alfa pegol (N8-GP) can be associated with differences in FVIII recovery in vitro between various one-stage activated partial thromboplastin time (APTT)-based clotting assays and some chromogenic assays. Careful validation and qualification of specific assays and conditions is therefore necessary for the assessment of FVIII:C in samples containing modified FVIII molecules. Aim: To assess the ability of various one-stage clotting and chromogenic FVIII:C assays to measure samples containing N8-GP compared to unmodified recombinant FVIII (rFVIII) across two laboratory sites. Methods: Factor VIII activity in severe haemophilia A (HA) plasma spiked with a range of concentrations (from low, 0.20 IU mL<sup>-1</sup>, to high, 0.90 IU mL<sup>-1</sup>) of N8-GP and rFVIII, was determined at two laboratory sites using 12 commercially available one-stage clotting and chromogenic FVIII:C assays. Assays were performed using a plasma calibrator and different analysers. Results: Acceptable N8-GP recovery was observed in the low to high concentration samples tested using the majority of the tested APTT reagents with only one reagent causing a significant underestimation as compared to rFVIII. For the chromogenic assays, a slight overestimation was observed with some of the kits. Variability between the two laboratory sites are likely attributable to the use of different analysers with the respective APTT reagents. Conclusions: These results highlight the need to investigate the performance of modified factor products using standard assays. The performance of different one-stage clotting assays, APTT reagents, reference calibrators and instrumentation should also be evaluated.</p>}},
author = {{Hillarp, A. and Bowyer, A. E. and Ezban, M and Persson, P. and Kitchen, S.}},
issn = {{1351-8216}},
keywords = {{Chromogenic FVIII assay; N8-GP; One-stage FVIII assay; Polyethylene glycol; Turoctocog alfa; Turoctocog alfa pegol}},
language = {{eng}},
number = {{3}},
pages = {{458--465}},
publisher = {{Wiley-Blackwell}},
series = {{Haemophilia}},
title = {{Measuring FVIII activity of glycopegylated recombinant factor VIII, N8-GP, with commercially available one-stage clotting and chromogenic assay kits : A two-centre study}},
url = {{http://dx.doi.org/10.1111/hae.13168}},
doi = {{10.1111/hae.13168}},
volume = {{23}},
year = {{2017}},
}