When a pregnant woman’s blood was taken in 1972, doctors discovered that a surface molecule found in all known red blood cells at the time was mysteriously missing.
Fifty years later, the absence of this strange molecule has finally led British and Israeli researchers to describe a new blood group system for humans. In September, the research team published a paper on their findings.
“Finally establishing this new blood group system, allowing us to provide the best care to rare but important patients, is a major achievement and the culmination of a long team effort.” said Louise Tilley, a haematologist at the National Health Service. saidafter personally researching this bloody weirdness for about 20 years.
We are all familiar with the ABO blood group system and rhesus factor (the positive or negative part), but in reality humans many different blood group systems It is based on the wide variety of cell surface proteins and sugars that coat our blood cells.
Our bodies use these antigenic molecules as identification markers to distinguish “self” from potentially harmful non-self, among other purposes.
This life-saving strategy is possible if these markers do not match when receiving a blood transfusion. can cause reactions and even ultimately be fatal.
Most major blood types were identified in the early 20th century. Many of those discovered since then, like the Er blood system first reported by researchers in 2022, only affect a small number of people. This also applies to new blood types.
“It has been difficult to study because hereditary cases are so rare.” explained Tilly.
Previous studies found that more than 99.9 percent of people had the AnWj antigen, which was missing from the 1972 patient’s blood. This antigen is myelin and lymphocyte proteinsresearchers began calling the newly described system the MAL blood group.
If someone has mutated versions of both copies Maru They, like pregnant patients, will have an AnWj negative blood type. Tilly and his team identified three patients with rare blood types who did not carry this mutation, suggesting that blood disorders may also suppress the antigen.
“MAL is a very small protein with some interesting properties that makes it difficult to identify and requires multiple studies to accumulate the evidence needed to establish this blood group system. did.” explained says Tim Satchwell, a cell biologist at the University of the West of England.
To determine whether they had the correct gene, the research team inserted the normal gene after decades of research. Maru Introduce the gene into AnWj-negative blood cells. This effectively delivered the AnWj antigen to those cells.
MAL proteins are known to play important roles in keeping cell membranes stable and aiding cell transport. moreover, Previous studies found AnWj is actually not present in newborns and appears soon after birth.
Interestingly, all AnWj-negative patients included in the study shared the same mutation. However, no other cellular abnormalities or diseases were found associated with this mutation.
Researchers have now identified the genetic marker behind it. Maru If a mutation is present, patients can be tested to see if their negative MAL blood type is due to inheritance or suppression. This may be a sign of another underlying medical problem.
These rare blood properties can have devastating effects on patients, so the more we understand them, the more lives we can save.
This research blood.
A previous version of this article was published in September 2024.
