Assay of Human Coagulation Factor VIII

Case Study

Factor VIII (FVIII) is an essential clotting factor in the coagulation cascade. The lack of normal FVIII causes Hemophilia A, an inherited bleeding disorder. FVIII harvested from donated blood/blood plasma or recombinant FVIII can be given to hemophiliacs to restore hemostasis. Thus, FVIII is also known as Anti-Hemophilic Factor.

The human coagulation factor VIII is assayed by its biological activity as a cofactor in the activation of factor X by activated factor IX (factor IXa) in the presence of calcium ions and phospholipids. The assay consists of two consecutive steps: the factor VIII-dependent activation of factor X and the enzymatic cleavage of a chromogenic factor Xa substrate that can be quantified photometrically. Many commercial kits are available for this purpose.

The validity of this assay should be checked and the potency of a test preparation should be calculated with the usual statistical methods given in chapter 5.3 of the European Pharmacopoeia or in <1034> of the US Pharmacopeia. PLA 3.0 provides you with an easy and convenient approach for this purpose.