Scientists at the Technical University of Denmark (DTU) and Lund University have gotten one step closer to cracking the code to making universal donor blood after discovering enzymes that can remove specific sugars comprising the A and B antigens in A, B, and AB blood types when the enzymes are mixed with red blood cells.
“Universal blood will create a more efficient utilization of donor blood, and also avoid giving [ABO]-mismatched transfusions by mistake, which can otherwise lead to potentially fatal consequences in the recipient,” professor Martin L. Ollson, leader of the study at Lund University, said in a press release. “When we can create [ABO]-universal donor blood, we will simplify the logistics of transporting and administering safe blood products, while at the same time minimizing blood waste.”
How Enzymes Can Help Create Universal Donor Blood
The idea of enzymes being used to make blood has been around for over 40 years. The theory is that the enzymes work as they would in the stomach, eating away the sugar structures in the blood that make it type A, B, or AB. The sugar structures of each of these three blood types are called antigens; if these antigens are mixed with incompatible blood, it can trigger a dangerous immune response. Type O blood lacks any of these antigens, so it is possible to transfer this type to any person, regardless of their blood type.According to the American Red Cross, only 7 percent of people in the United States have type O negative blood, which is why it is always in great demand and short supply. Consequently, developing a way to remove the A and B antigens from A, B, and AB blood types is highly desired to meet the demand.
Although researchers have been working with antigen-removing enzymes for four decades, and more efficient enzymes have been discovered, problems eliminating all immune reactions remain. Hence, the enzymes have yet to be used in clinical practice.
The research team at DTU and Lund University, however, discovered a new cocktail of enzymes extracted from the human gut bacterium Akkermansia muciniphila. This bacterium breaks down the mucus covering the gut’s surface, structurally similar to the complex sugars found at the surface of blood cells.
They tested 24 enzymes on hundreds of blood samples.
“What is special about the mucosa is that bacteria, which are able to live on this material, often have tailor-made enzymes to break down mucosal sugar structures, which include blood group [ABO] antigens. This hypothesis turned out to be correct,” professor Maher Abou Hachem, study lead at DTU and one of the senior scientists, said in a press release.
The research team admitted that, while the findings are promising, more work remains. They noted that they are close to perfecting universal blood from type B donors, but issues remain with type A blood, which is more complex.
“Our focus is now to investigate in detail if there are additional obstacles and how we can improve our enzymes to reach the ultimate goal of universal blood production,” Mr. Hachem said.
