Agglutinogen is a blood protein. Antigens are formed already in the third month of fetal development. It is present in the 2, 3 and 4 blood groups. According to modern data, about 236 antigens are known, which are grouped into 29 systems. The blood group is determined based on 2 systems - ABO and Rh factor.
Composition of blood. Agglutinogen - what is it?
As you know, blood consists of water, plasma and formed elements: leukocytes, erythrocytes and platelets.
Agglutinogens are also called antigens (AGs). They are present in all cells of the body. Their protection is needed everywhere. Even in the brain. There are also antigens on the inner surface of red blood cells. Leukocytes also have their own agglutinogens (more than 90 types).
Agglutinogen is a chemical that stores and identifies information that is genetically alien to a particular individual and interacts with antibodies.
By their chemical nature, they are divided into:
- proteins (Rh protein, Colton, etc.);
- glycoproteins (Lutheran);
- glycolipids (ABO).
Agglutinogen isgamma globulin, which is inherited by the newborn. It, together with the agglutinin present in the plasma, determines the blood group, which will be discussed below.
Functions of agglutinogens and agglutinins
If agglutinogens, they are antigens, are inherited from parents, then agglutinins (antibodies or antibodies) are produced during the first year of a child's life. Antibodies are synthesized by the immune system, and they interact only with the antigen for which they are intended.
It is antibodies that cause an immune response. They agglutinate (in other words, stick together) microbial cells and thus destroy them. Then these lumps with dead foreign cells precipitate and are simply excreted from the body. And antigens give them all the information they need. So agglutinogens, blood agglutinins save the body from the invasion of foreign bodies. Without their work, survival in the environment is impossible.
Blood types
Distinguish groups by the presence or absence of antigens and antibodies. There are a lot of antigens. However, the most important for physicians are antigen A and B, as well as antibodies Alpha and Beta.
The second important characteristic of human blood is the Rh protein of the blood, i.e. its presence or absence.
| Group | Agglutinogens(AG) | Agglutinins(AT) |
| 1 | - | alpha and beta AT |
| 2 | A | beta AT |
| 3 | B | Alpha AT |
| 4 | A, B | - |
This is how blood groups are distinguished; agglutinogens and agglutinins are taken for classification only those that are related to agglutination.
To determine the group, conduct such an experiment. When mixing blood sera, an agglutination reaction occurs (or does not occur). Based on this reaction, they conclude.
Agglutination is a reaction in which antibodies and antigens that are incompatible with each other stick together and break down. For example, erythrocyte agglutinogens of the 2nd blood group are combined with Beta antibodies in plasma. If Alpha antibodies get into this blood, they will stick together. The cells will die. And Beta antibodies that get into a test tube with blood serum containing antigen B will also "start" the above reaction.
Research History
For the first time, blood groups were distributed according to the ABO system. This happened in 1901, when K. Landsteiner discovered antibodies. The classification was developed by K. Landsteiner and J. Jansky. They came to the conclusion that the agglutinogen is the particle, without knowing the characteristics of which it is impossible to continue experiments with transfusion. And we continued to work in this direction. In 1903, the 4th group was identified.
And in 1940, A. Wiener and K. Landsteiner discovered the Rh factor. This protein is found in about 85% of people with white skin. If the protein is present in the blood, it is Rh positive (Rh+), and when absent, it is negative (Rh-). Since then, blood type has been classified based on these 2 systems.
Transfusion rules
Blood transfusion even inour time, with all the medical knowledge of our age, is dangerous. Transfusion is resorted to only when blood loss is 25% or more of the total volume. There are many dangers - viruses, post-transfusion shock - anything.
Trying to find the most suitable blood, otherwise blood transfusion complications may occur. Although it is well known that people with group 1 are universal donors, nevertheless, if the volumes of transfused blood are rather big, it is better to refuse a different blood type. The same applies to people with group 4, who are recipients for other groups.
Carriers of the 1st group are called universal donors precisely because of the absence of blood agglutinogens significant for transfusion. After all, there will be no agglutination reaction in this case.
In general, the rules for transfusion are simple. But still, no one can say in advance the consequences of the transfusion. There may be latent agglutinogens in the blood, and during the analysis there is a chance that they will not be detected. Then a person after a transfusion of large volumes of blood will die from shock. Nevertheless, each person needs to know exactly his group and, of course, to know the presence of the Rh protein.
Rh factor and pregnancy
If a woman has a negative Rh blood protein, this means that problems may arise during pregnancy. A child with the presence of this protein will be a foreign object for the mother's body.
Women were once even advised not to marry a man with a Rh protein. Antibodiesmothers will destroy fetal red blood cells. After all, each agglutinogen is part of an "attack system" on cells that seem alien to them.
With a Rh conflict, the following complications are possible:
- hemolytic disease in a child;
- jaundice at birth;
- miscarriage.
Still, if a woman takes care of herself and is constantly under the control of doctors, the baby will be born quite he althy.
