QUEST FOR THE UNIVERSAL BLOOD TYPE

Hundreds and thousands of lives are lost in India yearly for want of blood, or more specifically, the right type of blood. With bloods banks and hospitals often running out of the right blood types, finding universal donors is often a daunting task.

But there is light at the end of this particular tunnel.

Scientists have discovered that a particular type of enzyme can cut away antigens in blood types A and B, to make them more like Type O — considered the “universal” blood type, because it’s the only type that can be donated to anyone without the risk of provoking a life- threatening immune response.

A SUPER ENZYME

The team, from the University of British Columbia of Canada, worked with a family of enzymes called 98 glycoside hydrolase, extracted from a strain of Streptococcus pneumoniae. They were able to engineer a super high- powered enzyme strain that can snip away blood antigens. “A major limitation has always been the efficiency of the enzymes,” one of the team, Stephen Withers, said. “Large amounts of enzyme were needed.”

Getting the right type of blood has to do with the different types of residue that can accumulate the surface of red blood cells. Both A and B have this residue — A has an N- acetylgalactosamine residue, and B has a galactose residue — and AB has a mixture of both. Type O is free from this residue, which means it can be received by any patient, no matter what type they’re carrying.

The enzyme strain using a technology called directed evolution, allows them to insert many different types of mutations into the gene that codes for it, and by selecting strains that are the best at snipping away the blood antigens.

STILL A

WAY TO GO

The concept is not new, but until now we needed so much of the enzyme to make it work that it was impractical,” said Withers. “Now I’m confident that we can take this further.”

While the current enzyme strain is not yet capable of removing 100 percent of the antigens from Blood Types A and B, which is where it needs to get if the researchers want to make any real use of it, the team is confident that they’ll get it there. Even the smallest amount of antigen in donated blood can set off a dangerous immune response in the recipient. “Given our success so far, we are optimistic that this will work,” says Withers. They published their results in the Journal of the American Chemical Society.

A particular type of enzyme can cut away antigens in blood types A and B, to make them more like Type O