A study carried out by the National Health Service for Blood and Transplantation (NHSBT) and published in the journal “Blood” reports the discovery of a new blood type called “Er”, reports La Repubblica, as cited by Rador.

The four main known blood groups are A, B, 0 and AB. But there are several ways of grouping erythrocytes based on differences in sugars or proteins that cover their surface, antigens.

The discovery of a new blood type is important for doctors, because in this way they can correctly diagnose a problem such as incompatibility between a pregnant mother and her child.

To date, the International Society of Blood Transfusion (ISBT) defines 43 different classifications of blood group systems in humans.

Teaching

Blood type can cause immune cells to attack the wrong cells, which happens when blood types are incompatible, according to the study. Experts believe that this can be extremely useful for all doctors when they have difficulties in diagnosing their patient.

The deaths of two infants prompted scientists to investigate a rare blood type first discovered in humans 40 years ago.

The discovery is more specific to a specific subset of Er, which now opens new doors to prevent similar tragedies in the near future.

Doctors focus on the ABO blood group system and the Rh factor, a specific antigen (substance that causes a specific immune response in the body) that some people have and others don’t.

In the first case, we are talking about Rh-positive, in the second – about Rh-negative. Familiarity with blood types and Rh factor systems is critical when it comes to blood transfusions.

However, the great variety of cell surface antigens and their variants complicates the situation, and little is known about their clinical impact.

Most of the major antigens were identified in the early 20th century, and Er was only identified in 1982.

Immune system and hemolytic diseases of newborns

In 1988, a version called Erb was opened. The code Er3 was used to describe the absence of Era and Erb.

When a blood cell is in the presence of an antigen that our body has not classified as our own, our immune system is activated, sending antibodies to signal the destruction of cells containing the suspect antigen.

In rare cases during pregnancy, it can happen that the tissues of the fetus are recognized as foreign and therefore attacked.

The formed antibodies penetrate through the placenta, causing hemolytic disease in the unborn child. Currently, several methods of prevention or treatment of hemolytic disease of newborns are implemented.

13 patients / 5 variations of Er antigens were studied

A team of researchers led by serologist Nicole Thornton from the National Health Service for Blood and Transplantation (NHSBT) in Great Britain analyzed the blood of 13 patients for the presence of suspicious antigens, identifying five variants of Er antigens: the known variants Era, Erb, Er3 and two new ones : Er4 and Er5.

By sequencing the patients’ genetic codes, experts were able to identify a gene that codes for cell surface proteins.

This is a gene already familiar to medical science: PIEZO1, which is already associated with several known diseases. The researchers confirmed their results by removing PIEZO1 from the erythroblast cell line, a precursor of red blood cells, and testing the antigens.

This study really emphasizes the antigenic potential of proteins and their importance for transfusion.

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