Factor VIII and haemophilia A

Published on October 1, 2007 Updated on May 31, 2016   31 min

Other Talks in the Category: Diseases, Disorders & Treatments

My name is Geoff Kemball-Cook and I work in the hemostasis and thrombosis group of the Clinical Sciences Center in London. My talk is on Factor VIII and hemophilia A.
I'd like to touch on three main areas. First is to review the normal coagulant function of factor VIII. The second is to move on to describe the molecular pathology that we find in patients with hemophilia A. And lastly, to briefly mention a rare bleeding disorder, combined factor V- factor VIII deficiency.
So a brief review of factor VIII function in coagulation. The cartoon in this slide shows blood flowing from left to right in the upper part within a vessel. This is demarcated by the endothelial cell layer, marked as ECs in the slide, which presents an anticoagulant surface to flowing blood, including the soluble coagulation factors shown. For example, factor VIII, VII, X, et cetera. And the various blood cells, which are also immersed in plasma. Outside the endothelial cell layer, in the vascular tissue, are found cells bearing tissue factor, or TF, which is a potent initiator of coagulation.
In the event to vascular damage, blood flows out under pressure through a breach in the endothelial cell layer and contacts the extravascular tissues. In particular, coagulation factor VII forms a tight complex with tissue factor, and this constitutes the initiates of coagulation.