Gut enzymes could hold key to producing universal blood

Expanding the pool of potential blood donors and making blood matching safer and easier.

Smear, human blood
Smear, human blood. Credit: Flickr

Scientists at the University of British Columbia have discovered a powerful group of enzymes that can turn any blood type into the universally usable type O. These enzymes also hold the potential of expanding the pool of potential blood donors and making blood matching safer and easier.

Lead researcher Stephen Withers, a professor of chemistry at UBC. “Antigens can trigger an immune response if they are foreign to the body, so transfusion patients should receive either their own blood type or type O to avoid a reaction. That’s why O blood is so important.”

Blood type is dictated by the presence of antigens on the surface of red blood cells; type A blood has the A antigen, B has the B antigen, AB blood has the two antigens and O blood has none.

What scientists discovered is, removing antigens from blood effectively transforms it into type O.

Withers said Researchers have been studying the use of enzymes to modify blood as far back as 1982. However, these new enzymes can do the job 30 times better.”

Recipient group Compatible donor group
O O
A A, O
B B, O
AB AB, A, B, O

Source: Compatible transfusions and acceptable substitutions. Credit: Canadian Blood Services

Scientists sampled DNA from different types of micro-organism using a technique called metagenomics. Through this, they discovered an environment in which the desired enzymes might be found. They eventually focused on the mucosal lining of the human gut, which contains sugars that are similar in structure to blood antigens.

Withers said, “By honing in on the bacteria feeding on those sugars, we isolated the enzymes the bacteria use to pluck off the sugar molecules. We then produced quantities of those enzymes through cloning and found that they were capable of performing a similar action on blood antigens.”

Scientists are now applying for a patent on the new enzymes and are hoping to test them on a larger scale in the future, in preparation for clinical testing.

Common blood types in Canada % of pop.
O+ 39
A+ 36
B+ 7.6
AB+ 2.5
A- 6.0
B- 1.4
O- 7.0
AB- 0.5

Source: Common Blood types in Canada: 36,627,140 Credit: Canadian Blood Services

Withers said, “Expanding global blood supply is critical in light of growing populations and the frequency of natural disasters. Our hope is that one day we can eventually render any type of donated blood, tissues or organs, safe for use by anyone regardless of their native blood type.”

The study, funded by the Canadian Institutes of Health Research, will be presented today at the American Chemical Society’s annual meeting in Boston.