Defining the components of transfusable plasma that reduce bleeding

Volunteer donors give whole blood to Canadian Blood Services. This blood is then separated into its components so that as many patients as possible can benefit. The whole blood is made up of solid components like red blood cells and platelets and a liquid component called plasma. Plasma can be frozen and then thawed in hospitals and given to patients in need. This medical practice has been carried out since before WWII. Plasma contains proteins called coagulation factors. These proteins help blood to clot. Doctors give plasma to patients who are bleeding or about to bleed. Unfortunately good evidence that plasma works is not available from clinical trials. This makes it hard for Canadian Blood Services to be certain that the plasma we produce is of a high quality. Health Canada provides a guide to plasma quality - the coagulation factor VIII concentration. With support from a Canadian Blood Services Intramural Operating Grant, we have established a mouse model with which to test plasma quality. Anesthetized mice are used for all experiments. We take whole blood out of these mice and inject red blood cells. This makes them low on coagulation factors by 80%, and they lose ten times as much blood as normal mice from a standard tail cut. We can reduce this bleeding to normal by transfusing plasma or a plasma replacement product called a prothrombin complex concentrate (PCC). We have shown that the plasma does not have to contain factor VIII but does need to contain fibrinogen to halt bleeding. We propose to continue to map what needs to be in the plasma and what does not in order to fmd better tests of plasma quality.

SHEFFIELD, William

McMaster University

Intramural Research Grant Program

Ontario

218230.0