Changing blood types comes closer

Canadian researchers, including one of Indian origin, have now developed a way to transform all donated blood into a neutral type that can be given to any patient. The researchers have created an enzyme that could potentially pave the way for changing blood types. The enzyme works by snipping off the sugars, also known as antigens, found in Type-A and Type-B blood, making it more like Type-O.

Type-O blood is known as the universal donor and can be given to patients of all blood types. With this enzyme, Jayachandran Kizhakkedathu from the University of British Columbia and colleagues were able to remove the wide majority of the antigens in Type-A and B blood.

"We produced a mutant enzyme that is very efficient at cutting off the sugars in A and B blood, and is much more proficient at removing the subtypes of the A-antigen that the parent enzyme struggles with," said lead author of the study David Kwan from the University of British Columbia in Canada.

To create this high-powered enzyme capable of snipping off sugars, researchers used a new technology called directed evolution that involves inserting mutations into the gene that codes for the enzyme, and selecting mutants that are more effective at cutting the antigens. In just five generations, the enzyme became 170 times more effective.

While the researchers were able to remove the wide majority of the antigens in Type-A and B blood, before it can be used in clinical settings, the enzyme used would need to remove all of the antigens. The immune system is highly sensitive to blood groups and even small amounts of residual antigens could trigger an immune response.

(The findings appeared Journal of the American Chemical Society)