Stealth blood

Stealth blood

Researchers at the University of British Columbia (UBC) aim to make blood transfusions safer by camouflaging red blood cells
January 1, 2006
Every minute of every day, someone in Canada needs blood.
 

Many Canadians with blood disorders such as thalassemia get regular blood transfusions to manage their condition. These transfusions are a life-sustaining process, but they can leave some recipients with complications such as fever, rash, and back pain. There is also a danger of developing an allergy to transfusions.

“For these regular recipients of transfused red cells, it can be difficult if not impossible to find blood that is suitably matched,” says Dana Devine, Director, Research and Development, Canadian Blood Services (CBS); UBC Professor of Pathology and Laboratory Medicine; and member of the Centre for Blood Research (CBR).

The CBR is a multidisciplinary centre with a long-term research goal of making Canada a blood-donor-free society. Today, developing what’s being described as camouflage or stealth blood is one of the most visible ways CBR is modernizing Canada’s blood system.

Stealth blood could eliminate many of the problems linked to traditional blood transfusions. With stealth blood transfusions, a recipient’s immune system won’t react to the blood as a threat. Stealth blood could also address one of the major challenges facing Canada’s blood system: how do you provide the right blood to the right patients at the right time?

“Canada is a huge country,” says Ross MacGillivray, UBC Professor of Biochemistry and CBR’s Director. “It’s hard to maintain an adequate supply of all the right blood types in every community. Stealth blood could mean we have a universal red blood cell that could work for everyone. It would make a huge difference.”

Four major blood groups exist: A, O, B, and AB. Every person’s blood has a combination of elements from the different systems used to classify blood. Two of these blood group systems are the ABO system and Rh system. The group you belong to depends on the presence or absence of proteins and sugars (called antigens) on the surface of your blood cells, as well as the proteins (called antibodies) in the watery part of your blood. Classifications are important because not all blood types are compatible.

Stealth blood involves coating the membrane surface of red blood cells with a molecular shield to make them invisible to a patient’s immune system. This could stop transfused blood from being rejected. The shield is made of a non-toxic flexible polymer that is glued to the red blood cell with non-toxic compounds. This polymer coat physically camouflages the red blood cells’ antigens but does not change the cells’ ability to perform vital functions such as carry oxygen.

By making it easier to match available blood with recipients, stealth blood could help increase supply. The shelf life of red blood cells is around 42 days. This means that unused cells of one blood type may be discarded while at the same time there is a shortage of cells for another blood type. Stealth cells could allow for more efficient use of scarce blood cells by masking whatever type is available—and play an important role in making the best use of Canada’s blood supply.

Stealth blood would also mean health care workers wouldn’t have to worry about blood types when they’re trying to save lives. Because much of the blood that is transfused every year is done under emergency or trauma situations, matching blood types can be a huge burden that costs lives.

Benefits

Duane Tulk contracted HIV from tainted blood in 1984. Today, the 34-year-old hemophiliac is living a full life in Prince Edward Island. But for many of his friends with hemophilia, transfused blood cut short their lives.

The long-term research goal of the CBR is to develop a donor-free blood system by 2025. It’s too late for Tulk and others affected by the tainted blood scandal. But for future Canadians, like the next generation of Tulk’s cousins and other blood relatives who could inherit hemophilia and may need regular transfusions, a safer more reliable blood supply would be more than welcome.

“It’s our responsibility to always push medicine to be safer,” says Tulk. “Kids can’t choose to protect their health. It’s up to all of us to bring them up in a safer world.”

The safety of our blood supply doesn’t just relate to the quality of the blood products in the system. The quantity and availability of blood products is crucial too. That’s why the goal of a donor-free society is ideal because it will eliminate our reliance on an already overstretched system.

“Ninety percent of Canadians will receive a blood product at some point in their lives, but less than four percent of Canadians donate blood regularly. There is a profound disconnect there,” says MacGillivray. In fact, CBR researchers argue that if this trend continues, today’s shortages of blood and blood products could become chronic, and Canada will likely experience a much more significant shortage.

The development of stealth blood and synthetic blood substitutes to make better use of existing supplies are important examples of how Canada is improving the management of its blood supply. Another example is CBR’s efforts to extend the shelf life of platelets. Currently, these critical blood products have to be discarded after five days.

To achieve its ambitious goals, CBR is taking an interdisciplinary approach that is putting Canada on the global blood research map. CBR researchers are drawn from a wide variety of disciplines. There are chemists looking for better ways to design containers for blood products, dentistry faculty working with drugs and their interaction with blood, and sociologists determining new ways to encourage blood donations. The CBR contains members from seven faculties at The University of British Columbia: Applied Science, Arts, Dentistry, Education, Medicine, Pharmaceutical Sciences and Science.

Their combined efforts could transform the way Canada manages its blood supply so that stories like Tulk’s are never repeated.

Partners

Canadian Blood Services (CBS), the agency responsible for Canada’s blood supply outside Quebec, is central to the CBR’s operation and provides general infrastructure support. The Michael Smith Foundation for Health Research provides support for the specialized hubs and suites located in the CBR. The Canadian Institutes of Health Research and the Heart & Stroke Foundation of Canada provide funding for the CBR’s Strategic Training Program in Transfusion Science.

Scientists from the CBR, CBS, and Bayer HealthCare continue to collaborate on blood research. This continuous exchange of information between academics and industrial partners is crucial in the development of new technologies and medicines and ultimately will further the long-term research goal of making Canada a blood-donor-free society.