Enabling accurate measurement of activated factor XI (FXIa) in therapeutic immunoglobulin products.
Vox Sang
; 116(6): 656-664, 2021 Jul.
Article
en En
| MEDLINE
| ID: mdl-33277936
ABSTRACT
BACKGROUND AND OBJECTIVES:
In 2010, an intravenous immunoglobulin (IVIG) product was removed from the market due to an association with serious thromboembolic events. Investigations revealed that factor XIa (FXIa) was present as a process-related impurity. This study investigated the ability of two commercial FXIa assays to measure FXIa in immunoglobulin preparations and conducted a survey of FXIa activity in marketed immunoglobulin products. MATERIALS ANDMETHODS:
Factor XIa assays were modified to include spiking of samples with FXIa before testing. An immunoglobulin product and its excipient were used to assess the ability of the assays to recover the spiked FXIa levels.RESULTS:
The Biophen FXIa assay required a high pre-dilution of the sample to obtain statistically valid results and complete FXIa recovery. The ROX FXIa assay was more sensitive, giving statistically valid results at a lower sample pre-dilution and FXIa spike level. This modified ROX FXIa assay was used to assay 17 lots of immunoglobulin products for FXIa. Two product lots had measurable FXIa levels without the need for spiking. A further 3 lots produced detectable but not statistically valid FXIa results when left unspiked. Spiking produced statistically valid assays and recoveries above 100%, demonstrating inherent FXIa.CONCLUSION:
This study shows marketed immunoglobulin products can contain detectable levels of FXIa. Spiking brings the FXIa levels into the quantifiable range of the assay, allowing measurement of inherent FXIa. Accurate measurement is important to inform on 'safe' levels of FXIa in these products and allow future safety guidelines to be set.Palabras clave
Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Tromboembolia
/
Factor XIa
/
Inmunoglobulinas Intravenosas
Tipo de estudio:
Qualitative_research
Límite:
Humans
Idioma:
En
Revista:
Vox Sang
Año:
2021
Tipo del documento:
Article
País de afiliación:
Reino Unido