Science advances and thanks to it we can learn more about everything around us and also about what is part of our body. There are still many things to study and discover, but with what is being achieved, at the health level, every day we can be a little more sure that there is a solution for any problem that may arise.
Recently, a group of researchers managed to solve a scientific enigma that lasted for five decades and they did so thanks to the discovery of a new blood group, the so-called MAL. This finding, following the work carried out by the team of scientists from the NHS Blood and Transplant (NHSBT), the International Blood Group Reference Laboratory (IBGRL) and the University of Bristol, has made and will make it possible to unravel the genetic origin of the AnWj antigen, a blood characteristic that was previously identified but whose genetic background remained unknown.
AnWj, quite an enigma
This rare antigen is found, according to the University of Bristol, in the discovered blood group, MAL, which is the 47th known. Until now it had not been possible to know which gene encoded it, but after this advance it will be possible to identify patients who lack it, thus facilitating their treatment and improving the safety of blood transfusions.
It should be taken into account that people who lack the AnWj antigen, who are AnWj-negative, run the risk of severe reactions if they receive blood from AnWj-positive donors. Therefore, this discovery will make it possible to develop new genetic tests to know exactly which people do not have it and thus avoid complications in transfusions.
The mystery of AnWj
The rare nature of the AnWj antigen was largely unknown. Some people could lose this antigen due to hematological diseases or certain types of cancer, but there are also rare cases of people who are born with this inherited characteristic.
In the study that was carried out, only five individuals with the inherited AnWj-negative phenotype were detected. Despite the scarcity of these cases, it is expected that the progress made will allow the identification of more people with this characteristic in the future.
Louise Tilley, principal investigator at IBGRL, highlighted the importance of this advance: “Resolving the genetic background of AnWj has been a challenge for more than 50 years. “This discovery is a significant achievement as we can now provide better care to these rare but important patients.”
The different blood types
There are different types of blood due to variations in the molecules, antigens, that are present on the surface of red blood cells. The blood types that refer to these specific antigens are A, B, AB and O, which are the most common. Additionally, there is an Rh factor, which can be positive or negative, resulting in blood types such as A+, A-, B+, B-, AB+, AB-, O+ and O-.
To all this we must add that there are more than 600 known antigens, as confirmed by a Red Cross study. The presence or absence of these creates “rare blood types”, which are considered as such if they lack antigens for which 99% of people are positive. And if a blood type lacks some antigen for which 99.99% of people are positive, it is considered “extremely rare.”
If incompatible blood types are mixed during a transfusion, the recipient’s immune system identifies the unknown antigens as a threat and launches an attack, which can lead to a transfusion reaction that can be life-threatening. This attack by the immune system can cause blood clots and kidney failure, among other serious complications.
