IN medical practice There are cases when the 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:

1. 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).
2. The third (III) or (B) is suitable for those who have agglutinogen B - III (B) and IV (AB).
3. 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 occurs in laboratory conditions and consists of 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 Rh negative (RH-), and the remaining 15% of the population are 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 applies to 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:

• in case of an emergency when a transfusion is required, and identifying a 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 is of practical importance in medical practice - in the case of emergency blood transfusion. This includes the first, or according to the AB0 system - zero blood group. Required condition there must also be a negative Rh factor, which, when transfused, does not cause red blood cells to clump together in the blood of people with positive RH.

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.

Blood type (AB0): essence, definition in a child, compatibility, what does it affect?

Some life situations (upcoming surgery, pregnancy, desire to become a donor, etc.) require an analysis, which we are accustomed to simply calling “blood type.” Meanwhile, in the broad understanding of this term, there is some inaccuracy here, since most of us mean the well-known erythrocyte AB0 system, described in 1901 by Landsteiner, but do not know about it and therefore say “blood test for group”, thus separating another important system.

Karl Landsteiner, awarded for this discovery Nobel Prize, throughout his life he continued to work on the search for other antigens located on the surface of red blood cells, and in 1940 the world learned about the existence of the Rhesus system, which ranks second in importance. In addition, scientists in 1927 found protein substances isolated in the erythrocyte systems - MNs and Pp. At that time, this was a huge breakthrough in medicine, because people suspected that it could lead to the death of the body, and that someone else’s blood could save a life, so they attempted to transfuse it from animals to humans and from humans to humans. Unfortunately, success did not always come, but science has confidently moved forward to the present day We only talk about blood group out of habit, meaning the AB0 system.

What is a blood type and how did it become known?

Determination of blood group is based on the classification of genetically determined individually specific proteins of all tissues human body. These organ-specific protein structures are called antigens(alloantigens, isoantigens), but they should not be confused with antigens specific to certain pathological formations(tumors) or proteins that cause infections entering the body from the outside.

The antigenic set of tissues (and blood, of course), given from birth, determines the biological individuality of a particular individual, which can be a person, any animal, or a microorganism, that is, isoantigens characterize group-specific characteristics that make it possible to distinguish these individuals within their species.

The alloantigenic properties of our tissues began to be studied by Karl Landsteiner, who mixed the blood (erythrocytes) of people with the sera of other people and noticed that in some cases, red blood cells stick together (agglutination), while in others the color remains homogeneous. True, at first the scientist found 3 groups (A, B, C), the 4th blood group (AB) was discovered later by the Czech Jan Jansky. In 1915, the first standard sera containing specific antibodies (agglutinins) that determine group affiliation were already obtained in England and America. In Russia, the blood group according to the AB0 system began to be determined in 1919, but digital designations (1, 2, 3, 4) were introduced into practice in 1921, and a little later they began to use alphanumeric nomenclature, where antigens were designated with Latin letters(A and B), and antibodies - Greek (α and β).

It turns out there are so many of them...

To date, immunohematology has been replenished with more than 250 antigens located on erythrocytes. The main erythrocyte antigen systems include:

These systems, in addition to transfusiology (blood transfusion), where the main role still belongs to AB0 and Rh, most often remind of themselves in obstetric practice(miscarriages, stillbirths, birth of children with severe hemolytic disease), however, it is not always possible to determine erythrocyte antigens of many systems (except AB0, Rh), which is due to the lack of typing sera, the obtaining of which requires large material and labor costs. Thus, when we talk about blood groups 1, 2, 3, 4, we mean the main antigenic system of erythrocytes, called the AB0 system.

Table: possible combinations of AB0 and Rh (blood groups and Rh factors)

In addition, approximately from the middle of the last century, antigens began to be discovered one after another:

1. Platelets, which in most cases repeated the antigenic determinants of erythrocytes, but with a lesser degree of severity, which makes it difficult to determine the blood group on platelets;
2. Nuclear cells, primarily lymphocytes (HLA - histocompatibility system), which have opened up wide opportunities for organ and tissue transplantation and solving some genetic problems (hereditary predisposition to a certain pathology);
3. Plasma proteins (the number of described genetic systems has already exceeded a dozen).

The discoveries of many genetically determined structures (antigens) made it possible not only to take a different approach to determining the blood group, but also to strengthen the position of clinical immunohematology in terms of fight against various pathological processes, made possible safe, as well as organ and tissue transplantation.

Main system dividing people into 4 groups

The group affiliation of erythrocytes depends on group-specific antigens A and B (agglutinogens):

• Containing protein and polysaccharides;
• Closely associated with the stroma of red blood cells;
• Not related to hemoglobin, which is not involved in any way in the agglutination reaction.

By the way, agglutinogens can be found on other blood cells (platelets, leukocytes) or in tissues and body fluids (saliva, tears, amniotic fluid), where they are detected in much smaller quantities.

Thus, antigens A and B can be found on the stroma of a particular person’s red blood cells(together or separately, but always forming a pair, for example, AB, AA, A0 or BB, B0) or they cannot be found there at all (00).

In addition, globulin fractions (agglutinins α and β) float in the blood plasma. compatible with the antigen (A with β, B with α), called natural antibodies.

Obviously, in the first group, which does not contain antigens, both types of group antibodies will be present - α and β. In the fourth group, normally there should not be any natural globulin fractions, because if this is allowed, antigens and antibodies will begin to stick together: α will agglutinate (glue) A, and β, respectively, B.

Depending on combinations of options and the presence of certain antigens and antibodies, the group affiliation of human blood can be represented in the following form:

• Blood group 1 0αβ(I): antigens – 00(I), antibodies – α and β;
• Blood group 2 Aβ(II): antigens – AA or A0(II), antibodies – β;
• Blood group 3 Bα(III): antigens – BB or B0(III), antibodies – α
• 4 blood group AB0(IV): antigens only A and B, no antibodies.

The reader may be surprised to learn that there is a blood type that does not fit this classification . It was discovered in 1952 by a Bombay resident, which is why it is called “Bombay”. Antigenic-serological variant of red blood cells type « Bombay» does not contain antigens of the AB0 system, and in the serum of such people, along with natural antibodies α and β, anti-H are detected(antibodies directed at substance H, differentiating antigens A and B and preventing their presence on the stroma of red blood cells). Subsequently, “Bombay” and other rare types of group affiliation were found in different parts of the planet. Of course, you cannot envy such people, because in the event of massive blood loss, they need to look for a life-saving environment all over the globe.

Ignorance of the laws of genetics can cause tragedy in the family

The blood group of each person according to the AB0 system is the result of inheriting one antigen from the mother and another from the father. Receiving hereditary information from both parents, a person in his phenotype has half of each of them, that is, the blood group of the parents and the child is a combination of two characteristics, and therefore may not coincide with the blood group of the father or mother.

Discrepancies between the blood groups of parents and the child give rise to doubts and suspicions of their spouse’s infidelity in the minds of some men. This happens due to the lack of basic knowledge of the laws of nature and genetics, therefore, in order to avoid tragic mistakes on the part of the male sex, whose ignorance often breaks happy family relationships, we consider it necessary to once again explain where a child’s blood type according to the ABO system comes from and give examples of the expected results.

Option 1. If both parents have blood type O: 00(I) x 00(I), then the child will only have the first 0(I) group, all others are excluded. This happens because the genes that synthesize antigens of the first blood group are recessive, they can only manifest themselves in homozygous a state when no other gene (dominant) is suppressed.

Option 2. Both parents have the second group A (II). However, it can be either homozygous, when two characteristics are the same and dominant (AA), or heterozygous, represented by a dominant and recessive variant (A0), so the following combinations are possible here:

• AA(II) x AA(II) → AA(II);
• AA(II) x A0(II) → AA(II);
• A0(II) x A0(II) → AA(II), A0(II), 00(I), that is, with such a combination of parental phenotypes, both the first and second groups are probable, third and fourth are excluded.

Option 3. One of the parents has the first group 0(I), the other has the second:

• AA(II) x 00(I) → A0(II);
• A0(II) x 00(I) → A0 (II), 00(I).

Possible groups for a child are A(II) and 0(I), excluded - B(III) and AB(IV).

Option 4. In the case of a combination of two third groups inheritance will go according to option 2: possible membership will be the third or first group, whereas the second and fourth will be excluded.

Option 5. When one of the parents has the first group, and the second the third, inheritance is similar option 3– the child has possible B(III) and 0(I), but excluded A(II) and AB(IV) .

Option 6. Parent groups A(II) and B(III ) when inherited, they can give any group affiliation of the AB0 system(1, 2, 3, 4). The emergence of 4 blood groups is an example codominant inheritance when both antigens are equal in the phenotype and equally manifest themselves as a new trait (A + B = AB):

• AA(II) x BB(III) → AB(IV);
• A0(II) x B0(III) → AB(IV), 00(I), A0(II), B0(III);
• A0(II) x BB(III) → AB(IV), B0(III);
• B0(III) x AA(II) → AB(IV), A0(II).

Option 7. When combining the second and fourth groups possible for parents second, third and fourth groups in a child, the first one is excluded:

• AA(II) x AB(IV) → AA(II), AB(IV);
• A0(II) x AB(IV) → AA(II), A0(II), B0(III), AB(IV).

Option 8. A similar situation arises in the case of a combination of the third and fourth groups: A(II), B(III) and AB(IV) will be possible, and the first is excluded.

• BB (III) x AB (IV) → BB (III), AB (IV);
• B0(III) x AB(IV) → A0(II), ВB(III), B0(III), AB(IV).

Option 9 - most interesting. Parents have blood groups 1 and 4 as a result, the child develops a second or third blood group, but never – first and fourth:

• AB(IV) x 00(I);
• A + 0 = A0(II);
• B + 0 = B0 (III).

Table: child’s blood type based on parents’ blood groups

Obviously, the statement that parents and children have the same group membership is a fallacy, because genetics obeys its own laws. As for determining the child’s blood type based on the group affiliation of the parents, this is only possible if the parents have the first group, that is, in in this case the appearance of A(II) or B(III) will exclude biological paternity or maternity. The combination of the fourth and first groups will lead to the emergence of new phenotypic characteristics (group 2 or 3), while the old ones will be lost.

Boy, girl, group compatibility

If in the old days, for the birth of an heir in the family, the reins were placed under the pillow, but now everything is put on an almost scientific basis. Trying to deceive nature and “order” the gender of the child in advance, future parents perform simple arithmetic operations: divide the father’s age by 4, and the mother’s by 3, whoever has the larger remainder wins. Sometimes this coincides, and sometimes it disappoints, so what is the probability of getting the desired gender using calculations - official medicine does not comment, so it is up to everyone to calculate or not, but the method is painless and absolutely harmless. You can try, what if you get lucky?

for reference: what really affects the gender of the child is the combination of X and Y chromosomes

But the compatibility of the parents’ blood type is a completely different matter, not in terms of the child’s gender, but in the sense of whether he will be born at all. The formation of immune antibodies (anti-A and anti-B), although rare, can interfere normal flow pregnancy (IgG) and even breastfeeding (IgA). Fortunately, the AB0 system does not interfere with reproduction processes so often, which cannot be said about the Rh factor. It can cause miscarriage or the birth of babies with, the best consequence which is deafness, and in the worst case, the child cannot be saved at all.

Group affiliation and pregnancy

Determination of blood group according to the AB0 and Rhesus (Rh) systems is mandatory procedure when registering for pregnancy.

When negative Rh factor the expectant mother and the same result for the future father of the child, you don’t have to worry, since the baby will also have a negative Rh factor.

A “negative” woman should not immediately panic when first(abortions and miscarriages are also considered) pregnancy. Unlike the AB0 (α, β) system, the Rhesus system does not have natural antibodies, so the body only recognizes “foreign”, but does not react to it in any way. Immunization will occur during childbirth, therefore, so that the woman’s body does not “remember” the presence of foreign antigens (Rh factor is positive), a special anti-Rhesus serum is administered to the postpartum woman on the first day after birth, protecting subsequent pregnancies. In the case of strong immunization of a “negative” woman with a “positive” antigen (Rh+), compatibility for conception is in big question, therefore, without looking at long-term treatment, the woman is haunted by failures (miscarriages). A woman’s body, which has a negative Rhesus, having once “remembered” someone else’s protein (“memory cell”), will respond with the active production of immune antibodies during subsequent meetings (pregnancy) and will in every possible way reject it, that is, its own desired and long-awaited child, if it turns out to be positive Rh factor.

Compatibility for conception should sometimes be kept in mind in relation to other systems. By the way, AB0 is quite loyal to the presence of strangers and rarely gives immunization. However, there are known cases of the emergence of immune antibodies in women during ABO-incompatible pregnancy, when a damaged placenta allows fetal red blood cells to enter the mother’s blood. It is generally accepted that women are most likely to be isoimmunized by vaccinations (DTP), which contain group-specific substances of animal origin. First of all, this feature was noticed in substance A.

Probably, second place after the Rhesus system in this regard can be given to the histocompatibility system (HLA), and then - Kell. In general, each of them is capable of sometimes presenting a surprise. This happens because the body of a woman who has a close relationship with a certain man, even without pregnancy, reacts to his antigens and produces antibodies. This process is called sensitization. The only question is to what level sensitization will reach, which depends on the concentration of immunoglobulins and the formation of antigen-antibody complexes. With a high titer of immune antibodies, compatibility for conception is in great doubt. Rather, we will be talking about incompatibility, which requires enormous efforts of doctors (immunologists, gynecologists), unfortunately, often in vain. A decrease in titer over time is also of little reassurance; the “memory cell” knows its task...

Video: pregnancy, blood type and Rh conflict

Compatible blood transfusion

In addition to compatibility for conception, no less important It has transfusion compatible, where the ABO system plays a dominant role (transfusion of blood that is incompatible with the ABO system is very dangerous and can lead to death!). Often a person believes that the 1st (2, 3, 4) blood group of him and his neighbor must necessarily be the same, that the first will always suit the first, the second - the second, and so on, and in case of certain circumstances they (neighbors) can help each other to a friend. It would seem that a recipient with blood group 2 should accept a donor of the same group, but this is not always the case. The thing is that antigens A and B have their own varieties. For example, antigen A has the most allospecific variants (A 1, A 2, A 3, A 4, A 0, A X, etc.), but B is slightly inferior (B 1, B X, B 3, B weak, etc. .), that is, it turns out that these options may simply not be compatible, even though when testing blood for group the result will be A (II) or B (III). Thus, taking into account such heterogeneity, one can imagine how many varieties a 4th blood group can have, containing both A and B antigens?

The statement that blood type 1 is the best, as it suits everyone without exception, and blood type 4 can accept anyone, is also outdated. For example, some people with blood type 1 are for some reason called “dangerous” universal donors. And the danger lies in the fact that without having antigens A and B on their erythrocytes, the plasma of these people contains a large titer of natural antibodies α and β, which, entering the bloodstream of the recipient of other groups (except the first), begin to agglutinate the antigens located there (A and/or IN).

compatibility of blood groups during transfusion

Currently, transfusions of mixed blood groups are not practiced, with the exception of only some cases of transfusions that require special selection. Then the first Rh-negative blood group is considered universal, the red blood cells of which are washed 3 or 5 times to avoid immunological reactions. The first blood group with positive Rh can be universal only in relation to Rh(+) red blood cells, that is, after determining for compatibility and washing of red blood cells can be transfused to a Rh-positive recipient with any group of the AB0 system.

The most common group in the European territory of the Russian Federation is considered to be the second - A (II), Rh (+), the rarest is blood group 4 with negative Rh. In blood banks, the attitude towards the latter is especially reverent, because a person with a similar antigenic composition should not die just because, if necessary, they will not find the required amount of red blood cells or plasma. By the way, plasmaAB(IV) Rh(-) is suitable for absolutely everyone, since it contains nothing (0), but this question is never considered due to the rare occurrence of blood group 4 with negative Rhesus.

How is blood type determined?

Blood group determination according to the AB0 system can be done by taking a drop from your finger. By the way, every health worker who has a diploma of higher or secondary medical education should be able to do this, regardless of their profile. As for other systems (Rh, HLA, Kell), a blood test for the group is taken from a vein and, following the procedure, the affiliation is determined. Such studies are already within the competence of the doctor. laboratory diagnostics, and immunological typing of organs and tissues (HLA) generally requires special preparation.

A blood group test is done using standard serums , manufactured in special laboratories and meeting certain requirements (specificity, titer, activity), or using zoliclones, obtained in the factory. In this way, the group affiliation of red blood cells is determined ( direct method). To eliminate errors and gain complete confidence in the reliability of the results obtained, the blood type is determined at blood transfusion stations or in the laboratories of surgical and, especially, obstetric hospitals cross method , where serum is used as the test sample, and specially selected standard red blood cells go as a reagent. By the way, In newborns, it is very difficult to determine group affiliation using a cross-sectional method; although agglutinins α and β are called natural antibodies (given from birth), they begin to be synthesized only from six months and accumulate by 6-8 years.

Blood type and character

Does blood type affect character and is it possible to predict in advance what can be expected from a one-year-old pink-cheeked toddler in the future? Official medicine considers group affiliation from such a perspective with little or no attention paid to these issues. A person has many genes, as well as group systems, so one can hardly expect the fulfillment of all the predictions of astrologers and determine the character of a person in advance. However, some coincidences cannot be ruled out, because some predictions do come true.

prevalence of blood groups in the world and the characters attributed to them

So, astrology says that:

1. Carriers of the first blood group are brave, strong, purposeful people. Leaders by nature, possessing irrepressible energy, they not only achieve great heights themselves, but also carry others along with them, that is, they are wonderful organizers. At the same time, their character is not devoid negative traits: They can suddenly flare up and show aggression in a fit of anger.
2. People with the second blood group are patient, balanced, calm, slightly shy, empathetic and taking everything to heart. They are distinguished by homeliness, thriftiness, the desire for comfort and coziness, however, stubbornness, self-criticism and conservatism interfere with solving many professional and everyday problems.
3. The third blood group suggests a search for the unknown, a creative impulse, harmonious development, communication skills. With such a character, he could move mountains, but bad luck - poor tolerance of routine and monotony does not allow this. Holders of group B (III) quickly change their mood, show inconsistency in their views, judgments, and actions, and dream a lot, which prevents them from achieving their intended goal. And their goals change quickly...
4. With regard to individuals with the fourth blood group, astrologers do not support the version of some psychiatrists who claim that among its owners there are the most maniacs. People who study the stars agree that the 4th group has collected the best features of the previous ones, and therefore has a particularly good character. Leaders, organizers, with enviable intuition and communication skills, representatives of group AB (IV), at the same time, are indecisive, contradictory and original, their mind leads constant struggle with heart, but which side will win is a big question mark.

Of course, the reader understands that all this is very approximate, because people are so different. Even identical twins show some kind of individuality, at least in character.

Nutrition and diet by blood types

The concept of the blood type diet owes its appearance to the American Peter D’Adamo, who at the end of the last century (1996) published a book with recommendations proper nutrition depending on group affiliation according to the AB0 system. At the same time, this fashion trend penetrated into Russia and was classified as alternative.

According to the vast majority of doctors who have medical education, this direction is anti-scientific and contradicts established ideas based on numerous studies. The author shares the view official medicine, so the reader has the right to choose who to believe.

• The statement that at first all people had only the first group, its owners “hunters living in a cave”, are obligatory meat eaters having healthy digestive tract, you can safely question it. Group substances A and B were identified in preserved tissues of mummies (Egypt, America), which are more than 5000 years old. Proponents of the concept of “Eat Right for Your Type” (the title of D’Adamo’s book) do not point out that the presence of O(I) antigens is considered a risk factor for diseases of the stomach and intestines (peptic ulcer), in addition, carriers of this group more often than others have problems with blood pressure ( ).
• Holders of the second group were recognized as clean by Mr. D’Adamo vegetarians. Considering that this group affiliation is prevalent in Europe and in some areas reaches 70%, one can imagine the outcome of mass vegetarianism. Probably, mental hospitals will be overcrowded, because modern man- an established predator.

Unfortunately, the blood group A(II) diet does not draw the attention of those interested to the fact that people with this antigenic composition of erythrocytes make up the majority of patients , . It happens to them more often than others. So maybe a person should work in this direction? Or at least keep in mind the risk of such problems?

Food for thought

An interesting question: when should a person switch to the recommended blood type diet? From birth? During puberty? In the golden years of youth? Or when old age comes knocking? Here you have the right to choose, we just want to remind you that children and adolescents cannot be deprived of essential microelements and vitamins, you cannot prefer one and ignore the other.

Young people like some things and don’t like others, but if healthy man is ready, only after reaching adulthood, to follow all nutritional recommendations in accordance with group affiliation, then this is his right. I would just like to note that, in addition to the antigens of the AB0 system, there are other antigenic phenotypes that exist in parallel, but also contribute to the life of the human body. Ignore them or keep them in mind? Then diets also need to be developed for them, and it is not a fact that they will coincide with current trends promoting healthy eating for certain categories of people with one or another group affiliation. For example, the leukocyte HLA system is more associated with various diseases, it can be used to calculate in advance a hereditary predisposition to a particular pathology. So why not engage in just such, more realistic prevention immediately with the help of food?

Video: the secrets of human blood groups

There are frequent cases when large blood loss the patient needs to undergo a transfusion of liquid connective tissue from a donor. In practice, it is customary to use biological material that matches the group and Rh factor. However, some people's blood is considered universal, and in a critical situation, its transfusion can save the patient's life. There are also individuals who can be transfused with liquid connective tissue of any group. They are considered universal recipients.

Why is blood group compatibility important?

Transfusion of fluid connective tissue is a serious medical procedure. It must be carried out in accordance with certain conditions. As a rule, blood transfusion is indicated for seriously ill patients, people who have complications after surgical intervention etc.

Before carrying out a transfusion, it is important to select a donor whose blood is compatible with the recipient’s biomaterial group. There are four of them: I (O), II (A), III (B) and IV (AB). Each of them also has a negative or positive Rh factor. If the compatibility conditions are not met during blood transfusion, an agglutination reaction occurs. It involves the gluing of red blood cells with their subsequent destruction.

The consequences of such a transfusion are extremely dangerous:

• hematopoietic function is impaired;
• malfunctions occur in the functioning of most organs and systems;
• metabolic processes slow down.

The natural result is post-transfusion shock (manifested by fever, vomiting, shortness of breath, rapid pulse), which can be fatal.

Rh factor compatibility. Its meaning during transfusion

During transfusion, not only the blood type, but also the Rh factor should be taken into account. It is a protein present on the membranes of red blood cells. The overwhelming majority of the Earth's inhabitants (85%) have it, the remaining 15% do not. Accordingly, the former have a positive Rh factor, the latter - negative. When giving blood transfusions, they should not be mixed.

Thus, a patient who has a negative Rh factor should not receive liquid connective tissue whose red blood cells contain this protein. If this rule do not comply, the recipient's immune system will begin powerful fight With foreign substances. As a result, the Rh factor will be destroyed. If the situation repeats, the red blood cells will begin to stick together, thereby causing serious complications.

The Rh factor remains unchanged throughout life. In this regard, people who do not have it need to pay special attention during blood transfusion. Women who have a negative Rh factor should notify their doctor and obstetrician-gynecologist about this upon pregnancy. A note containing this information is entered into the outpatient card.

Universal recipient

Give your blood, i.e. Anyone can be a donor for people in need. But when transfusing, it is important to consider the compatibility of the biomaterial.

At the beginning of the 19th century, a scientist from Austria suggested, and soon proved, that the process of gluing red blood cells (agglutination) is a sign of activity immune system, caused by the presence in the blood of 2 reacting substances (agglutinogens) and 2 that can interact with them (agglutinins). The first were given the designations A and B, the second - a and b. Blood is incompatible if substances of the same name come into contact: A and a, B and b. Thus, the liquid connective tissue of each person must contain agglutinogens that do not stick together with agglutinins.

Each blood group has its own characteristics. Special attention deserves IV (AB). The red blood cells contained in it contain both A and B agglutinogens, but plasma does not contain agglutinins, which contribute to the gluing of red blood cells during donor blood transfusion. People with group IV are considered universal recipients. The transfusion process rarely causes complications in them.

A universal recipient is a person who can receive a blood transfusion from any donor. In this case, an agglutination reaction will not occur. But meanwhile, blood of group IV is allowed to be transfused only to people with it.

Universal donor

In practice, doctors select a donor who best suits the recipient. Blood transfusions are of the same type. But this is not always possible. In a critical situation, the patient may be transfused with group I blood. Its peculiarity is the absence of agglutinogens, but at the same time there are a and b in the plasma, making its owner a universal donor. During transfusion, red blood cells will also not stick together.

This feature is taken into account when transfusion of a small amount of connective tissue. If a large volume needs to be transfused, only the same group is taken, just as a universal recipient cannot accept a lot of donor blood from a different group.

Finally

Blood transfusion is medical procedure that can save lives seriously ill patients. Some people are universal blood recipients or donors. In the first case, they can take liquid connective tissue any group. In the second, their blood is transfused to all people. Thus, universal donors and recipients have special groups of connective tissue.

In medical practice, cases quite often occur 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. Need to pick up the right donor so that their blood is compatible. In case of complications, violation of this rule often leads to death. At the 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 antigenic properties available red blood cells in humans. 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 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 experiences severe and profuse blood loss. In this case, there is a need for transfusion (transfusion) from another person. Before the procedure, many tests are carried out to determine the possibility of matching the group and Rh factor. Transfusion of incompatible blood in complicated cases can be fatal. It is generally accepted that those with the first blood group are universal donors. Many modern doctors argue that this compatibility is conditional and there is no blood suitable for everyone.

Blood group refers to a description of the individual antigenic characteristics of red blood cells. This classification was first made by an Austrian scientist at the beginning of the 20th century, and at the same time the concept was voiced - incompatibility. Thanks to this discovery, many lives were saved, because transfusion unsuitable material leads to disastrous consequences. In practice, there are 4 blood groups:

• 0 (I) first (zero) – it does not contain antigens, but contains α and β antibodies. Due to the absence of foreign particles (antigens), this group Suitable for transfusion to all people. A donor with group 0 (I) is considered to be universal;
• A (II) second - contains antigen A and antibodies to agglutinogen B. This blood it is permissible to transfuse to patients with a group that does not contain antigen B (I and II);
• In (III) the third - has antigen B and antibodies to agglutinogen A. This blood can be used for recipients (recipient) with groups I and III, that is, not containing antigen A;
• AB (IV) fourth - has antigens A and B, but does not have antibodies. Holders of this group can serve as a donor only for patients with similar blood. Recipients with the fourth blood group are universal, since they do not have antibodies.

If antigens of incompatible groups enter the body during transfusion, the process of gluing of foreign red blood cells is activated. As a result, the blood circulation process is disrupted. Oxygen ceases to flow in the required volume to organs and tissues, and subsequently blood clotting occurs. Such a violation could lead to serious complications, even death. In this regard, it is very important to take into account the compatibility of the blood of the donor and recipient.

Also, when transfusing, the Rh factor must be taken into account - a special protein located on the membrane of red blood cells. The term is applied to the Rhesus factor D antigen. The designation Rh+ is used for positive Rh factor(antigen D present), Rh- for negative Rh factor (not possessing antigen D) and is indicated after the blood type designation. The difference between blood group and Rh factor is that immunization against Rh is relevant only in case of transfusion or placental exposure during pregnancy.

Universal donors and recipients

In the case of transfusion of red blood cells (the main component of the material for transfusion), people with group 0 and negative Rh D are considered universal donors. Representatives of AB (IV) and positive Rhesus D are recognized as universal recipients. These statements are true only in terms of the interaction of foreign particles of the recipient A and B for transfusion of red blood cells and reactive sensitivity to foreign Rhesus cells D. People with the HH system (Bombay phenotype) are an exception; it is permissible for them to receive material for transfusion only from HH donors, since they have antibodies against the H antigen present in red blood cells.

People with antigens A and B or atypical antibodies are excluded from the list of donors. Antibody A and B reactions are not always taken into account. The reason is that a small amount of plasma containing foreign particles is transfused. For example, when transfusion of 0 and D Rh- blood to a recipient with A and D Rh+, immune reactions will not occur between the recipient's B antibodies and red blood cells.

It is worth noting that a small volume of plasma in the donor material used for transfusion has antibodies A, which can react with foreign particles on the membrane of red cells, but a dangerous reaction will not occur, since the effect will be weakened.

Surface antigen erythrocytes, with the exception of A, B and Rhesus D, are capable of provoking harmful effects if they begin to interact with the corresponding antibodies to activate a protective reaction. The transfusion process is complicated by the fact that platelets and leukocytes have independent systems of surface foreign particles and sensitization may occur after transfusion ( increased sensitivity) to foreign cells. Plasma of group 0, with antibodies A and B, can only be used for recipients of group 0, since antibodies react aggressively to antigens of the contacted group. AB plasma transfusion can be performed in patients of any AB0 group.

In conditions modern medicine the recipient is transfused with blood strictly compatible with his group and Rh factor. The use of a universal one is resorted to only in cases where the risk is justified. The cause may be an emergency situation and the risk of death. If there is no blood available the desired group and Rh factor, then doctors use a universal one.