Universal Red Blood Cells Could Relieve Blood Bank Shortages

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Main Category: Blood / Hematology
Article Date: 02 Apr 2007 - 0:00 PDT

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An international team of academic and industry scientists has come up with a feasible way of making universal red blood cells that are stripped of their blood type. The hope is that it can be developed into a viable way of relieving blood bank shortages.

The study is published in the early online edition of the journal Nature Biotechnology.

There are four types of red blood: A, B, AB and O, each with a different combination of antigens on the surface of each blood cell. Antigens provoke immune systems into creating antibodies that bind to them.

If a person receives blood of a type that is not compatible with their own, there is a risk their immune system will attack it, destroying the red blood cells, producing kidney failure, and the person could die.

Compatibility of blood group is a bit complicated and depends on who is giving and who is receiving.

A person with blood group AB has both A and B antigens on the surface of their red blood cells, and they do not have antibodies against either A or B antigen, so they can receive blood from any group but can only give blood to a person with blood group AB.

Blood group A people have antigen type A on the surface of their red blood cells and have antibodies against type B antigen. So a type A person can have blood from people of type A (preferred) or O and can give blood to people of type A or AB.

A person with blood group B has the B antigen on the surface of their red blood cells and antibodies against type A antigen. So a type B person can have blood from type B (preferred) or O people and can give blood to people of blood type B or AB.

People with blood type O have neither A nor B antigens on the surface of their red blood cells, but they have high levels of antibodies against type A and type B antigens. So a type O person can only have blood from another type O person, but they can can give blood to people with blood types A, B, AB or O.

When a person with blood type A, B or AB needs a blood transfusion the first priority is to match their blood type. If there is not enough time and their type is not available and type O is, then they are given type O.

The wrong blood is given by mistake about once in every 15,000 transfusions and blood banks sometimes have shortages of one type of blood.

The idea of "universal red blood cells" has been around for some time and its feasibility has been demonstrated in clinical trials. For example, scientists in the US about 25 years ago managed to use a coffee bean glycosidase enzyme to strip the B antigen from red blood cells. But the process proved to be impractical.

In the new study, a team of scientists led by Professor Henrik Clausen from the University of Copenhagen in Denmark, found a more abundant source of glycosidase enzymes in bacteria. They found two bacterial glycosidase gene families with enzymes that efficiently remove A and B antigens from red blood cells (RBCs).

Prof Clausen and colleagues conclude that "The enzymatic conversion processes we describe hold promise for achieving the goal of producing universal RBCs, which would improve the blood supply while enhancing the safety of clinical transfusions".

The university scientists worked with US industry scientists from ZymeQuest in Beverly, Massachusetts. The next step is to start clinical trials to test the method's treatment safety and efficiency.

"Bacterial glycosidases for the production of universal red blood cells."
Qiyong P Liu, Gerlind Sulzenbacher, Huaiping Yuan, Eric P Bennett, Greg Pietz, Kristen Saunders, Jean Spence, Edward Nudelman, Steven B Levery, Thayer White, John M Neveu, William S Lane, Yves Bourne, Martin L Olsson, Bernard Henrissat & Henrik Clausen.
Nature Biotechnology Published online: 1 April 2007
doi:10.1038/nbt1298

Click here for Abstract.

Written by: Catharine Paddock
Writer: Medical News Today
Copyright: Medical News Today
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