New device to boost supply and quality of blood platelets

Feb 21 2006

Cancer and open-heart surgery patients, disaster victims, organ or bone marrow transplant recipients, and others who require life-saving blood platelet transfusions will benefit from equipment invented by a researcher at the University of British Columbia's Centre for Blood Research (CBR).

The device has the potential to minimize the loss of donated platelets and effectively increase platelet supply by up to 20 per cent, in Canada alone.

The instrument, called a Dynamic Light Scattering Platelet Monitor (DLS-PM), is the first to measure the quality of blood platelets - a key blood component that is transfused specifically to improve clotting and stop bleeding.

Currently, there is no routine test to measure quality of platelets. World standards dictate that platelets must be used within five days to avoid possible risk of bacterial infection. Using the DLS-PM, in conjunction with improved platelet storage practices and changes to blood operator regulations, platelets could be stored for 8-14 days, following a single-step quality test.

Platelets have the shortest shelf life of any blood component because refrigeration destroys their viability. In addition, although platelets less than five days old are viable, there are variations in quality. The monitor will allow blood analysts to improve the way blood products are matched to the patient.

Elisabeth Maurer, a UBC clinical assistant professor of pathology and Canadian Blood Services scientist, designed the instrument, and Keddie Brown, a fourth-year UBC engineering physics student, fabricated the prototype. Canadian Blood Services has patented the DLS-PM.

"We hope to dramatically increase the storage time for platelets with this instrument," says Maurer, an expert in physical chemistry. "Also, we'll now know within 15 minutes which is the best platelet product for the patient."

The DLS-PM, roughly the size of a large shoebox, contains a unique holder that grips a tiny vial - about the diameter of a toothpick - of platelet concentrate. When a beam of light is passed through the vial, platelet particles scatter light in all directions.

Using a computer attached to the instrument, technicians can determine platelet viability by analyzing patterns of scattered light that measure platelet shape, response to change in temperature, and the number of microparticles shed from platelets over time.

Canada is currently meeting the platelet needs of Canadian patients, but there will be increasing pressure to avoid shortages given the aging population and anticipated increase in demand, says Maurer.

Platelets constitute only five to seven per cent of total blood volume and four to six whole blood donations are needed to provide a single platelet transfusion. A donation of only platelets is also possible, through a procedure called plateletpheresis. The five-day storage limitation applies to both collection methods.

"The next big breakthrough in blood research will be increased availability of platelets to make crisis-driven blood donor drives in various areas of the world, a thing of the past," says Dana Devine, executive director of research and development at Canadian Blood Services and a UBC professor of Pathology. "Dr. Maurer's contribution is a fine example of how a community of researchers with diverse expertise can bring new solutions to transfusion science."

Maurer will complete further testing of the instrument in the first quarter of this year and, once a commercial partner is secured, will work to make the equipment available within five years.