Who is a universal donor? Universal donor

People with the fourth blood group are universal recipients. Group II contains agglutinogen (antigen) A and agglutinin β (antibodies to agglutinogen B). Therefore, it can be transfused only to those groups that do not contain antigen B - these are groups I and II. Today, the recipient receives blood from a donor strictly with the same group and Rh factor.

In Russia, blood types are traditionally numbered using Roman numerals: group O is designated as I, A as II, B as III and AB as IV. Double designations are also used: O(I), A(II), B(III) and AB(IV). When transfusing blood components, the Rh affiliation of the donor and recipient is also taken into account.

Blood group according to the AB0 system is a sign that is given to a person at birth and will accompany him throughout his life, so it is worth knowing more about it. Nowadays, blood that is strictly suitable for such parameters as group and Rh factor is used for transfusion.

It is believed that the first one suits everyone. According to modern doctors, this compatibility is very conditional and as such universal group blood does not exist. It was considered compatible with any other, so its carrier could, on occasion, be used as a universal donor.

In carriers of the first group, this antigen is completely absent. If the donor has an antigen of the same name as the recipient's plasma antibodies, then red blood cells will stick together as a result of the attack of agglutinins on the foreign element. Since there are no antigens in group I blood, when it is transfused to a person from any other blood, red blood cells do not stick together.

Blood typesEveryone knows that blood can be different groups, but few people know what this means. As was established in Lately, blood groups are a trait that we inherited from very distant ancestors.

Your own blood type is something that a person must know. There are such antigens in the formed elements (erythrocytes, leukocytes, platelets) and blood plasma of every person. Antigens are grouped into groups called AB0, Rhesus and many others systems. People with the first blood group have leadership qualities. This group appeared later than the first, between 25,000 and 15,000 BC, when man began to master agriculture.

This blood group first appeared in the Mongoloid race. Over time, the group's carriers began to move to the European continent. And today there are a lot of people with such blood in Asia and Eastern Europe. People with this blood type are usually patient and very efficient. The fourth group is the newest of the four groups human blood. It appeared less than 1000 years ago as a result of the mixing of Indo-Europeans, carriers of group I, and Mongoloids, carriers of group III.

Blood groups (ABO system)

Here, a universal donor should be considered a person whose organs can be transplanted to any other person without causing a rejection reaction. Therefore, the chance of the existence of a universal donor is extremely small. But it can be created artificially - as a result of selection over many generations or using genetic engineering methods.

Nowadays, transfusions are performed almost exclusively “group to group”, i.e. The donor must have the same blood type as the recipient. Until the mid-20th century, it was assumed that group I was universal. Therefore, doctors have always been interested in the question of which blood group is universal.

The very first successful blood transfusion was recorded in the mid-17th century in France. Then the man's life was saved thanks to the lamb. But at that time, doctors had no idea about such a concept as blood type and, of course, they could not know which blood type suits everyone, so it is safe to say that the young man was simply lucky.

Only at the beginning of the 20th century, after numerous studies, the Austrian biophysicist Karl Landsteiner determined the principle of dividing human blood into 4 types, and also introduced the concept of “incompatibility”. Humanity owes millions of saved lives to him.

So, there are 4 main groups, they are usually designated as follows:

0 (I) - first (zero)
A (II) - second
B (III) - third
AB (IV) - fourth

What's inside?

Red blood cells (erythrocytes) are studded with various protein molecules. The set of such molecules is genetically programmed and individual for everyone. Among them are those that influence the formation of human blood. These molecules are called antigens. Their combinations are different.

So, people with group II (A) have antigen A, carriers III (B) have B, IV (AB) have both antigens, and those belonging to group I (0) do not have them at all. The opposite situation is observed in blood serum: it contains so-called agglutinins to “foreign” antigens (α and β).

Gluing of blood cells will not occur in the absence of the same antigens and agglutinins. But when a “foreign” element enters, agglutinins immediately attack it and provoke the gluing of foreign red blood cells. The result can be fatal - oxygen stops flowing, small vessels become clogged, and after some time the blood begins to clot.

About 40-50% of people are carriers of the first group. Owners of the second – 30-40%. The third - 10-20%, the least number of people with the fourth - only 5%.

Transfusion compatibility

To avoid the danger of coagulation, Landsteiner proposed transfusing recipients with the first group with the same donor blood. Thus, , due to the lack of antigens, it is universal, and its owners are considered universal donors.

People with group IV are called universal recipients: they are allowed to receive any blood. For those with II or III group You can pour a similar one, as well as the first one. It is important to remember about the Rh factor. People can only be given blood that matches their Rhesus test.

Blood rhesus is an antigen that is found on the surface of red blood cells. It was also discovered by Karl Landsteiner and his colleague A. Weiner. About 85% of Europeans are Rh positive. The remaining 15% (7% among Africans) are Rh negative.

How does positive and negative Rh factor:

It is also worth noting that today scientists distinguish more than 250 types of blood, which are combined into 25 systems. Therefore, the issue of compatibility continues to be the subject of research, and will be reviewed more than once.

Human blood is liquid and mobile connective tissue body. Its structure is divided into two components: the liquid part - plasma and shaped elements– red blood cells, leukocytes and platelets. Blood does a lot essential functions in the body, which include respiratory, protective, transport and excretory.

Blood movement in circulatory system body

In cases of severe blood loss, the patient requires a transfusion. donor material. This procedure saved great amount lives, but this would be impossible without knowledge of the characteristics of blood, ignoring which will lead to incompatibility between the material of the donor and the patient.

At this stage of development of medicine, it is known that there are two significant systems for classifying human blood - by Rh factor and group. Due to ignoring these parameters, the concept of “incompatibility” appeared.

First successful transfusion recorded in France in the middle of the 17th century. However, we can say with confidence that this was luck, because doctors of that era had no idea about groups, did not know which blood group could be transfused to everyone, and lamb biomaterial was used as a donor. And only by the beginning of the 20th century, through a huge number scientific research Scientist Karl Landsteiner proposed a classification into 4 groups, which is still used today.

Blood groups

The system that separates blood according to this indicator is known as the AB0 system. According to it, they distinguish:

The first group, sometimes called zero. Denoted by 0 (I).
The second group, designated A (II).
The third, designated B (III).
And the fourth, whose designation is AB (IV).

What was the basis for this division? Protein molecules were found on red blood cells that turned out to be individual for each person. Among them are those who provide significant influence on blood and its formation. These protein molecules are called antigens, or agglutinogens, and are designated A and B. Plasma may contain agglutinins, designated by the symbols α and β. The combination of these proteins determines the blood type.

People with the first group do not have agglutinogens, while those with the second group have antigen A. Those in the third group have an antigen called B. The fourth group has both A and B, but lacks agglutinins. It is considered the rarest. People with group I are considered to be common, which, given its versatility, has become the main reason for the availability of a large amount of donor material. It's not hard to get.

Attention! A person is born with a certain blood type, which does not change with age and remains so throughout life.

Classification of blood by groups

When transfusion of the wrong blood type occurs, red blood cells begin to stick together, they coagulate, and blockage occurs. small vessels. High risk of fatal outcome. This process is triggered due to the ingress of antigens of the wrong type.

Rhesus affiliation

Rhesus is another antigen found on red blood cells. If it is present, the blood is defined as Rh-positive; if the protein is absent, it is said to be Rh-negative. The majority of the population has a positive Rh factor; according to the latest information, the number of this part of people reaches 85%, the remaining 15% are Rh negative.

The indicator plays vital role in the development of hemolytic disease of newborns. Pathology - main reason formation of jaundice in the fetus. Due to Rh conflict, the child may begin to disintegrate his red blood cells, since his blood components are perceived as foreign to the woman’s body, resulting in the production of antibodies.

Prevalence of blood by group and Rh factor

To determine the group and Rh factor, it is necessary to take a sample for analysis on an empty stomach. Despite the fact that food intake does not affect them, as in many other laboratory research, material collection is done in morning time on empty stomach.

Blood transfusion by group

The blood transfusion scheme allows you to take into account its group in each individual case. Transfusion is called blood transfusion. The procedure is performed when critical condition human body, because, despite the millions of lives saved with its help, it poses a risk to the patient’s health. The branch of medicine that studies mixtures biological fluids organism and problems of their compatibility is called transfusiology.

The person who donates material for transfusion (donation) is called a donor, and the one to whom it is transfused is called a recipient. During blood transfusion, the Rh factor and blood groups are taken into account. The material is transferred taking into account the following features:

For people with the first blood group, the same group will be suitable.
Persons with the second group are allowed to transfuse the first and their own group.
Third, people with grades I and III are suitable as donors.
The fourth one can pour in all types of material.

Compatibility of human blood groups during transfusion has important

Based on the table with the data, we can conclude which blood group is suitable for everyone: people with blood 0 (I) do not have antigens, due to which the first blood group is considered a universal donor. However modern medicine blood transfusion in this group is not recommended. This practice is used only in critical situations. People with group IV are considered universal recipients, capable of receiving any biomaterial.

Important! For a successful blood transfusion procedure, it is not enough to know which blood group is suitable for all blood groups. Required condition compliance with the Rh factor becomes necessary; if inappropriate biomaterial is transfused, the risk of Rh conflict is high.

Indications for transfusion and risks

Blood transfusion is a test for the body, and for this reason, indications are needed to perform it. These include the following pathologies and abnormal conditions of the body:

Diseases based on a lack of red blood cells (anemia), as a result of which the body is unable to independently form a sufficient number of these elements.
Hematological diseases of malignant type.
Significant blood loss resulting from injuries or accidents.
Intoxication severe, the correction of which is impossible by other means.
Complex operations that involve tissue damage and bleeding.

The introduction of donor material into the body increases the load on many systems, increases metabolic processes, which provokes the development of pathologies. Therefore, a number of contraindications to the procedure are taken into account:

myocardial infarction;
previous thrombosis;
heart muscle defects;
disorders of the kidneys and liver;
acute form of cardiopulmonary failure;
violations in cerebral circulation etc.

Characteristics of a woman's blood and pregnancy

It is believed that the Rh factor does not have a negative effect negative influence in terms of conceiving a child. Also, the indicator does not threaten anything in the case of the first pregnancy or if both parents are Rh-positive.

The risk of Rh conflict is determined in a situation where the mother's blood with a negative Rh factor is combined with a positive Rh factor of the father. This is explained by the reaction of a woman’s blood to a protein present on the membrane of the red blood cells of a Rh-positive child, as a result of which in the body expectant mother Antibodies are produced, the target of which is the fetus developing in the womb.

Table of Rh conflicts during pregnancy

If for a woman with Rh negative blood This is the first pregnancy and the presence of specific antibodies is not observed. For this reason, there is no threat to the mother and baby, and pregnancy and childbirth will go perfectly.

Otherwise, for the purpose of monitoring possible development conflict of Rh indicators during the period of bearing a child, a woman should see a gynecologist in order to be under enhanced supervision. Monitoring by a specialist and compliance with recommendations will have a positive impact on the course of pregnancy and will minimize the risks of complications and consequences for the mother and child.

You can learn about the biology of blood, the discovery of its varieties and which blood group is considered universal and interchangeable in the video below:

IN medical practice Quite often there are cases when patients lose a large number of blood. For this reason, they need to transfuse it from another person - a donor. This process is also called transfusion. A large number of tests are performed before a transfusion is performed. It is necessary to select the right donor so that their blood is compatible. In case of complications, violation of this rule often leads to death. On this moment It is known that a universal donor is a person with the first blood group. But many doctors are of the opinion that this nuance is conditional. And there is no person in this world whose liquid-type connective tissue is suitable for absolutely everyone.

What is blood type

The blood group is usually called the totality of the antigenic properties of red blood cells present in a person. A similar classification was introduced in the 20th century. At the same time, the concept of incompatibility emerged. Due to this, the number of people who successfully underwent a blood transfusion procedure has increased significantly. In practice, there are four types. Let's briefly look at each of them.

First blood group

Zero or first blood group does not have antigens. It contains alpha and beta antibodies. It does not have foreign elements, so people with (I) are called universal donors. It can be transfused to people with other blood groups.

Second blood group

The second group has type A antigen and antibodies to agglutinogen B. It cannot be transfused to all patients. This is allowed to be done only by those patients who do not have the B antigen, that is, patients with the first or second group.

Third blood group

The third group has antibodies to agglutinogen A and type B antigen. This blood can be transfused only to owners of the first and third groups. That is, it is suitable for patients who do not have antigen A.

Fourth blood group

The fourth group has antigens of both types, but does not include antibodies. Holders of this group can transfer part of their blood only to those of the same type. It has already been said above that a universal donor is a person with blood group 0 (I). What about the recipient (the patient who receives it)? Those who have the fourth blood group can accept any, that is, they are universal. This is due to the fact that they do not have antibodies.

Features of transfusion

If antigens from a group that is incompatible enter the human body, the foreign red blood cells will gradually begin to stick together. This will lead to poor circulation. In such a situation, oxygen abruptly stops flowing to the organs and all tissues. The blood in the body begins to clot. And if treatment is not started in time, this will lead to quite serious consequences. That is why, before performing the procedure, it is necessary to conduct tests for the compatibility of all factors.

In addition to blood type, the Rh factor must be taken into account before transfusion. What is this? It is a protein that is part of red blood cells. If a person has a positive indicator, then he has antigen D in his body. In writing this is indicated as follows: Rh+. Accordingly, Rh- is used to mark a negative Rh factor. As is already clear, this means the absence of group D antigens in the human body.

The difference between blood group and Rh factor is that the latter plays a role only during transfusion and during pregnancy. Often, a mother with the D antigen is unable to bear a child who does not have it, and vice versa.

The concept of universality

During red blood cell transfusion, universal donors are people with blood type 1 and Rh negative. Patients with the fourth type and a positive presence of antigen D are universal recipients.

Such statements are only suitable if a person needs to receive a reaction of antigens A and B during a blood cell transfusion. Often such patients are sensitive to foreign cells positive rhesus. If a person has the NN system - the Bombay phenotype, then such a rule does not apply to him. Such people can receive blood from NN donors. This is due to the fact that their erythrocytes have antibodies specifically against N.

Universal donors cannot be those who have antigens A, B or any other atypical elements. Their reactions are usually not taken into account often. The reason is that during transfusion, sometimes a very small amount of plasma is transported, in which foreign particles are directly located.

Finally

In practice, most often a person is transfused with blood of the same group and the same Rh factor as his. The universal option is resorted to only when the risk is truly justified. Indeed, even in this case, an unforeseen complication may occur, which will lead to cardiac arrest. If in stock necessary blood no, and there is no way to wait, then doctors use a universal group.

In medical practice, there are cases when a patient loses a critical amount of blood (more than 30% of the total volume), and then there may be a need for blood transfusion from a donor.

The procedure is carried out taking into account group and Rh factor compatibility. Failure to comply with this condition leads to agglutination (gluing of red blood cells), leading to the fact that the recipient falls into state of shock, which can be fatal.

AB0 system

The group is determined according to a common scheme, which identifies a set of agglutinogens (antigens) located on the surface of red blood cells. When foreign antigens enter the body, the immune system begins to produce special antibodies. Based on the presence or absence of these proteins, the classification of blood groups is based - AB0.

The discovery of the phenomenon of agglutination made it possible to significantly reduce the incidence of fatal outcome as a result of blood transfusion. A person in need of blood transfusion (recipient), by receiving the group of which he himself is a carrier, avoids death.

Blood group compatibility

At the same time, scientists discovered that there is one blood group, the owner of which can be considered a universal donor. It contains no agglutinogens that can promote blood clotting, so theoretically it can be transfused to any patient. It is designated as the first (I) or (0).

However, a person with such a blood group is a “bad” recipient, since it contains antibodies that make blood transfusion from a donor with a group different from his own impossible.

People with the first blood group make up the largest category of inhabitants of the Earth - they are about 50%.

Let's list the compatibility for the remaining groups:

The second (II) or (A) contains agglutinogen A. For this reason, it can be transfused to those who have it - these are the owners of II (A) and IV (AB).
The third (III) or (B) is suitable for those who have agglutinogen B - III (B) and IV (AB).
The fourth (IV) can only be transferred to someone who has the same one - since they contain both antigens A and B. For the same reason, a person with this group is an ideal recipient, that is, he can accept blood from any donor.

Blood group determination

The process takes place in laboratory conditions, and consists in determining the presence or absence of red blood cell agglutination. A few drops of blood are added to serums that contain α, β, α and β antibodies. Then the reaction of red blood cell clumping is assessed:

if there is no reaction, then this is group I (0);
if clumping is present in sera that contain α and α+β, – II (A);
if agglutination is observed in sera with antibodies β and α+β, – III (B);
red blood cells stuck together in all three sera - this is IV (AB).

Rh factor compatibility

In addition, there is a division based on the Rh factor (RH) (referred to as D antigen). If it is on the surface of red blood cells, then they say that the person is Rh positive (RH+), and approximately 85% of the world's population are its owners. When the antigen is absent, the person is a carrier negative rhesus(RH-), and the remaining 15% of the population are its carriers.

If a person has RH-, blood transfusions with RH+ are contraindicated. Otherwise, a conflict will arise that threatens post-transfusion shock with fatal. At the same time, a negative Rh factor does not cause any harm to a recipient with a positive RH. Thus, group I (0) with RH- is universal.

However, in modern medical practice, it is customary to use blood that matches the group and Rh for transfusion in order to avoid complications. The first group is used only in extreme cases when the lack of blood transfusion will lead to the death of the patient. The same goes for RH – in emergency conditions Transfusion from a Rh negative donor is allowed.

Compatibility Determination

Before blood transfusion, tests are performed to determine group and rhesus compatibility:

The recipient's blood serum is mixed with a drop of donor blood. After 5 minutes, the presence or absence of agglutination is assessed. If it is missing, such blood can be used.
The Rh factor is determined in a similar way, but is added Chemical substance, in the presence of which a reaction is possible. Evaluation is also carried out by the presence or absence of red blood cell clumping.

Because other secondary group systems exist, the risk of transfusion complications remains. In order to minimize them, a biological test is carried out. The recipient receives 10–15 ml donated blood, after which the patient is monitored. This procedure is carried out three times. If a person begins to experience lower back pain, increased heart rate, shortness of breath, or fever, a transfusion is not performed.

Why know your blood type

This is important for several reasons:

when emergency situation, when a transfusion is required, and determining the group on site is difficult;
in the same case when a person acts as a donor;
during pregnancy, when there may be a conflict in the group or Rhesus of the mother and fetus, which threatens miscarriages, stillbirth, hemolytic disease newborns.

Emergency transfusion does not cancel the compatibility tests between the recipient's serum and donor blood, which were described above.

As a conclusion, it is worth noting that knowing the answer to the question which group is suitable for all people has practical significance in medical practice - in case of emergency blood transfusion. This includes the first, or according to the AB0 system - zero blood group. A prerequisite also must be a negative Rh factor, which, when transfused, does not cause red blood cells to stick together in the blood of people with a positive Rh factor.

In the case of a planned procedure, the condition of blood group and Rh compatibility must be met. In accordance with medical protocols, laboratory tests are always performed to eliminate the risk of complications.