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What are blood groups, and how do they work?
The study of blood cells is truly exciting, that you can easily understand what blood groups are and how they work, it can help you in certain situations.
Also, it is the responsibility of each person to know their blood type, not because you are in a delicate health situation, but that you can help other people by donating blood.
How many blood groups are there?
An important point to clarify is that the difference between one type of blood and another is the antigen that is expressed on the surface of the red blood cell or erythrocyte.
Thus, there are blood groups O, A and B, with A and B being antigens, since group O has a unique characteristic in the erythrocyte.
So how do you know a person's blood group? When analyzing an individual's erythrocyte, the following findings can be found.
If there are A antigens on the surface of the red blood cell, then the blood type is A.
On the other hand, if there is B antigen in the red blood cell, the blood type is B.
When antigen A and B are missing from the surface of the red blood cell, the blood group is O.
An erythrocyte that has both A and B antigens, the blood type is AB.
What are blood antibodies?
Blood antibodies are components that are responsible for destroying antigens that are foreign to the body.
Find out what is the reason why a person with blood type A cannot donate blood to a person whose type is group B.
Blood antibodies work in the following way.
People who do not have the A antigen on the surface of the red blood cell, the anti-A antibody appears in their plasma.
Likewise, it occurs with people who do not have the B antigen on the surface of the erythrocyte, the anti-B antibody appears in the plasma.
For their part, those who do not have either the A or B antigen, in their plasma there is the anti-A and anti-B antibody.
In the same vein, individuals who have the two antigens on their surface, both A and B, in plasma will not have antibodies.
How are blood antibodies formed?
Antibodies are made directly in the bone marrow, just like other blood cells.
In technical terms, they are IgM and IgG immunoglobulins. Although, you may ask, why do they form?
The answer is simple: through food, microorganisms and other sources, the body comes into contact with small amounts of antigen A and B. The result is the production of anti-A and anti-B.
Importance of blood groups
Now, what is the use of all this information? With an example you will see everything clearer.
A person who is blood type A means that there is anti-B antibody in his plasma.
So, if type B blood were to be transfused by mistake, what would happen immediately is an antigen-antibody reaction.
Anti-B antibodies would bind to the surface of type B blood where it is on B antigen and the red blood cell would be destroyed, ie, hemolysis.
Why does this happen? Because the body recognizes type B blood as foreign, because in the red blood cells produced by your bone marrow, the antigen that is present on the surface of the erythrocyte is A and not B.
This same process occurs with all blood types. Still can't understand? With another example you will understand better.
Universal recipient and donor
An individual with type AB blood does not have antibodies in their plasma, their body does not recognize type A or B blood as strange, because both antigens exist in their erythrocytes.
In this way, people who have this blood type are known as universal recipients, since they can receive blood types A, B, O and of the same group.
On the contrary, blood group O is a special case, it is called a universal donor.
The reason for this is that there are no antigens on its surface, if this type of blood is transfused, the antibodies in the person will not destroy the blood cells, because there are no antigens on its surface.
However, they cannot receive from a blood group other than their own. Remember that in the plasma of these people there are anti-A and anti-B antibodies. Consequently, an antigen-antibody reaction would occur.
Blood typing
Of course, before being able to transfuse blood to a person it is necessary to know what type of blood they have and the type of blood that the donor has.
It consists of a process carried out by a hemotherapist, in which blood is drawn from both people.
The red blood cells are then separated from the plasma, placed in separate test tubes, and diluted in saline.
The next step is to mix it with the antibodies, in a test tube anti-A antibody is placed and in the other anti-B antibody.
After a few minutes, it is observed with the help of an instrument that allows the globules with the antibody to be seen clearly.
If they clumped together, this is that agglutination occurred, it means that an antigen-antibody reaction occurred.
Diseases related to blood groups
One of the most frequent pathologies associated with blood groups is blood group incompatibility.
Blood incompatibility is a disease of the neonatal stage, it can physically manifest itself as a yellowing of the newborn's skin.
Basically, the incompatibility occurs in mothers with a blood type O, regardless of the Rh factor.
In addition to this, there is a passage of maternal anti-A and anti-B antibodies into the fetal circulation, causing a reaction with the surface antigens of fetal red blood cells.
Another disease, also related to antigens on erythrocytes, is Rh factor incompatibility. In this the same process happens, but with the Rh factor.
