Did you know that there is a “golden blood”, present in less than 50 people in the world? If they can donate their blood to all the other groups, this exclusivity can also put them in danger…
First of all, to understand what makes “golden blood” so rare, a little reminder is necessary. There are 44 blood groups. The most widespread system is the ABO system, which defines four major groups: A, B, O and AB. They are determined by the presence of antigens, which are a substance capable of generating antibodies in a situation of incompatibility, on the surface of red blood cells.
Another major system is Rhesus, or Rh, in which there are 56 different antigens, positive or negative depending on the individual. Most people are Rh positive, meaning they have Rh antigens on their red blood cells. But when all the antigens of the Rh system are absent on the surface of the red blood cells, the person is said to be Rh null, or Rh-null. This blood group is extremely rare, since it only affects a few dozen people in the world. A final system is the Kell system, which also functions in positive/negative mode.
Who gives, who receives?
In the ABO system combined with the rhesus factor, people in the AB+ group have A, B and Rh antigens on the surface of their red blood cells, and can only donate to AB+ people. On the other hand, they can receive from all other groups, because they do not have anti-A or anti-B antibodies in their blood, unlike people in other groups: they are called universal recipients. Conversely, O- people have no antigen on the surface of their red blood cells, and can therefore donate to all other groups: they are called universal donors. To understand who a group can donate blood to and from, there is nothing better than a summary table!
The risk of universal donors
Due to the total absence of antigens, Rh-null individuals are absolutely universal donors, compatible with all rare blood groups of the Rhesus system. On the other hand, they can only receive blood from the same group as them, which requires them to be medically monitored, because transfusions are almost impossible to find within a reasonable time. But this is not the rarest group!French Blood Establishment (EFS) lists patients with blood group types that are sometimes unique in the world, found in a single individual or only in siblings.
It is therefore important to know your blood type to know who you can donate blood to, but also who you can receive it from! And don’t forget: blood is irreplaceable and its lifespan is limited, which means you need to donate throughout the year. This saves 1 million lives each year in France!
