Factor VIII determination in patient's plasma and concentrates: a novel test equally suited for both matrices
Eich, S.; Kusch, M.; Grundmann, C.; Hanker, C.; Seitz, R.; König, H.
Blood Coagulation and Fibrinolysis An International Journal in Haemostasis and Thrombosis 14(4): 347-353
2003
ISSN/ISBN: 0957-5235 PMID: 12945876 Document Number: 559965
A novel assay for the determination of factor VIII (FVIII) is described. The assay uses a fluorescence-based detection system comparable with the common chromogenic test. At the same time, the assay is analogous to the clotting test as it does not involve pre-activation of FVIII. The assay was adjusted to perform equally well with patient's plasma and FVIII concentrates as samples. The combined employment of two different FVIII-deficient plasmas turned out to be of crucial importance in order to render the matrices as similar as possible to patient's plasma and, simultaneously, to obtain maximum sensitivity. Samples with a FVIII content down to 0.01 IU/ml are readily measured as are samples with a FVIII content of 1 IU/ml or somewhere in between. Upon dilution of samples, concentrates and plasma exhibited the same dose-response characteristics.