UBC researchers transform blood types with human gut enzyme

A new discovery by a group of UBC researchers may make blood transfusions simpler in the future.					Bruce Edwards  Postmedia News

Researchers at Vancouver-based University of British Columbia discovered a new method to create Type O blood, using an enzyme found in the human stomach, according to research presented at the American Chemical Society's annual meeting August 21 in Boston.

In contrast, type A, B and AB red blood cells have specific antigens on their surfaces, meaning that people with type A blood can donate only to type A or type AB recipients, and people with type B blood can donate only to those with type B or type AB. This could help scientists make universal donor blood from other blood types.

Withers collaborated with his colleague at UBC to use metagenomics in his search for the enzyme, Eurekalert reports. The O negative blood type is used extensively in blood transfusions because it can be used in replacement of all blood types. Their search for that enzyme took them into the human gut.

However, as researcher Stephen Withers noted in a press release, they hadn't yet discovered an enzyme that was efficient, safe, and economical.

O-type blood has no antigens attached to it, which is why it can be donated to anyone without adverse effects.

Some of the mucin sugars are similar in structure to the antigens on A- and B-type blood.

The study, funded by the Canadian Institutes of Health Research, was presented Tuesday at the American Chemical Society's annual meeting in Boston.

The team isolated an enzyme that removes sugars from blood types B and A, which enables its conversion to type O. This method is astonishingly 30 times more effective than the previous enzyme.

Removing antigens from blood effectively transforms it into type O. Withers and his team previously developed enzymes that were capable of doing so, but this latest study identifies a more powerful group of enzymes found in the human gut.

"It just becomes another step and another cost", Ziman said. "The Red Cross must collect more than 13,000 blood and platelet donations each day to meet the needs of accident victims, people undergoing heart surgery, cancer patients, people with blood disorders and others". That's why O blood type donations are so important: as their red blood cells contain no A or B antigens, the antibodies of other groups won't attack them. But that particular enzyme, which could convert only type B blood, was too expensive and inefficient for real-world use, said a 2008 review in the British Journal of Haematology.

"Obviously, the next stages are all about safety, making sure this doesn't cause any inadvertent effects", Mr Withers said. "This technique could broaden the utility of the current blood supply because O type blood can be donated to anybody", Withers told. "We are hopeful that technology can support in alleviating numerous issues around blood shortages faced by blood collection centers such as Red Cross and others to meet patient needs".

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