According to a recent study published in Blood magazine, scientists have discovered a new set of blood groups, Er. The discovery sheds light on the mystery of 30 years ago when a woman tragically lost her babies.
What happened 30 years ago?
According to Wired, British hospital scientists suspected problems with a pregnant woman's foetus, and they decided to perform an emergency caesarean section many weeks before the birth, but despite the surgery that had to be performed, the subsequent blood transfusion and other emergency measures, the baby suffered a brain hemorrhage and died.
However, in the mother's blood, the doctors noticed some strange antibodies, and the medics tried to get more information about them and sent a sample to the hematology lab in Bristol, and the experts made a remarkable discovery: the woman's blood was an ultra-rabid group, which could have made her child's blood incompatible with her own. Perhaps it prompted her immune system to produce antibodies against the blood of the foetus. They entered through the placenta and hurt the unborn baby, the child, which eventually led to his death.
By examining the mother's blood sample, among others, scientists were able to determine exactly what distinguished her blood, and in the process confirmed a new set of blood groups, the "Ar" system, 44 of which were described.
What types of blood are there?
Because of the differences in antigens in the transmission of incompatible blood from the donor, the recipient's immune system defines the antigens as alien and reacts to them. It's very dangerous, so the donor blood should be the same group.
On average, over the past decade, researchers have annually described one new system of blood classification, which typically includes incredibly rare groups, and now scientists have solved the mystery of the latest blood system.
Very rare blood.
As early as 1982, researchers first described an unusual antibodies in a blood sample, so scientists realized that there might be another mysterious group, and no more biologists learned anything, only assumed the existence of an unknown molecule or structure that encouraged the human immune system to produce an antibodies.
Over the years, scientists found more and more carriers of unusual blood, after which Nicole Thornton and her colleagues at NHS Blood and Transplant in the UK decided to find out what was going on.
Mysterious antibodies were so rare that scientists had only 13 historical blood samples collected in 40 years. Back in 2020, Thornton and her colleagues described a new blood type called MAM-negative, which at that time was confirmed by only 11 people worldwide. And, some of the newly discovered blood groups were found in individual families. Both "MM" and "Er" were vague references to the names of patients whose samples were examined by experts.
What did the scientists find out?
Turns out the new 44th qualification system is tied to a certain Piezo1 protein found on the surface of the red blood cells.
Scientists have learned that the gene responsible for this protein differs among people with different blood groups Er. Due to genetic differences, a small number of people in the Piezo1 protein have alternative amino acids or building blocks. As a result, blood cells with more common Piezo1 protein seem alien to their immune system.
The scientists then checked whether antibodies were responding to laboratory crops that contained or did not contain mutant versions of Piezo1, which they created by editing genes, so they confirmed that changes in protein were really the cause of the incompatibility of blood in the people they studied. A few years ago, it was impossible to find out.
Secrecy of the Mystery
There are five antigens of Er, five possible variations of Piezo1 on the surface of the red blood cells, which lead to incompatibility. Two antigens have just described Thornton and her fellow researchers, one of which is found in the blood of a pregnant woman in the UK who lost her child.
What's next?
The results of the study are likely to be officially ratified as defining the new blood group system later this year at the meeting of the International Blood Transfusion Society. The effort needed to discover it was "high," says Neil Avent, an honorary professor of blood diagnostics at the University of Plymouth, who did not participate in the work. It also revealed the complexities associated with this rare blood — for example, multiple genetic mutations.
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