The American Red Cross announced last year that there is a global shortage of blood, which has put transfusions, life-saving surgeries, and other procedures on hold.
This shortage is not only due to a lack of volunteer donors but the demand for blood has also increased due to the aging population.
However, giving blood is not as simple as it sounds as different people have different blood types, which determines the type of donor blood they can receive.
In total, there are 45 known blood types, all of which are identified based on the type of antigen attached to the surface of the red blood cells. For example, someone with type A-positive blood will have A-positive antigens attached to their red blood cells.
When someone receives a blood transfusion, the donor blood must match the blood type of the recipient, otherwise, the immune system will identify the blood as foreign, and attack the cells, causing a potentially lethal reaction.
Type O blood, however, is universal as it carries no antigens, meaning it can be received by anyone. However, only 7 percent of the population has O- blood.
The good news is that researchers have recently found a way to strip away the sugars that make up the A and B antigens on red blood cells. This means that one day we could have universal donor blood, which would solve the global blood shortage issues.
Enzymes Can be Used to Remove Blood Antigens
Researchers at Lund University and the Technical University of Denmark successfully developed a technique that allows them to strip the antigens on red blood cells – the same ones that differentiate between the different blood types – using gut bacteria.
More specifically, they used the enzymes from the bacterium Akkermansia muciniphilia, which normally feeds on the mucosal lining inside the guts.
This was done after they determined that the complex sugars present in the mucosal lining of the gut share many chemical characteristics to the antigens found on some types of red blood cells.
According to professor Maher Abou Hachem, who led the study at the University of Denmark, the bacteria present in the mucosal lining have specialized enzymes that allow them to break down the complex sugar structures found on the mucosal lining of the gut and that these sugar structures are the same ones seen in ABO blood antigens.
In the study, which was published in the scientific journal Nature Microbiology, researchers tested 24 types of enzymes with blood samples and found that they were capable of stripping away type A and B blood antigens, in addition to a few other variants, which up until now, have not been usable for blood transfusions.
While more work is still needed, researchers believe they are close to being able to produce a universal blood type for blood transfusions.
Universal Blood Donations: 40 Years in the Making
The team that discovered the sugar-removing enzyme based their study on work that was published over 40 years ago, when scientists first came up with the idea of generating universal donor blood using enzymes.
Since then, scientists have identified several highly efficient enzymes that can be used for the process. However, they are still unable to explain all of the blood-related immune reactions.
Professor Martin Olsson, who led the study at Lund University, however, remains hopeful that they will one day be able to create a universal blood, which will help lower the risk of ABO-mismatched transfusions.
The scientific team that worked on the study have already applied for a patent on their enzyme technique and will be continuing their work on the study over the next three to four years.
