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The blood changes during the flow. Can your blood type change? Dispelling myths! Rh factor in various conditions

A person is endowed with a certain blood type even when he is in the mother’s womb. This is the same genetically transmitted trait as skin color and eye color, which remains for life. But there are still opinions that changing the blood type is quite possible. Let's try to figure out whether the blood type can change, or is this just the result of an error when performing the analysis?

Blood group determination

The classification according to the ABO system is widespread in the world, within which there are four blood groups that are determined using analysis. To carry it out, four serums with antibodies are needed, to which blood is added. The laboratory assistant observes the reaction of red blood cells and the process of their connection. It is based on the results of agglutination that group affiliation is determined.

The ABO blood groups are the main ones and are used for transfusions. Associated antibodies A and B (immunoglobulins) are most often formed in the first years of life as a result of susceptibility to substances surrounding a person (food, viruses, bacteria).

Blood is a trait that a person is endowed with at birth, and has a certain composition of agglutinogens and agglutinins, genetically encoded. By all parameters, it would seem impossible to talk about a change in blood type. So, can blood type change? Let's figure it out. Still, such cases can occur for a number of specific reasons, which we will list below.

Error in analysis

It is possible that an erroneous analysis was performed to determine the patient’s blood type. Despite the simplicity of this procedure, the possibility of an incorrect result can never be excluded, so at some stage in life a person may think that he has a different blood type.

Pregnancy

Pregnancy may also affect the results. During this period, the production of red blood cells increases, and the concentration of agglutinogens decreases so much that the red blood cells containing them do not combine. Maybe because of this, many people wonder whether blood type changes in life.

Diseases

There are diseases during which the composition of red blood cells may also increase, as was the case in the previous case, and the blood type may change. In addition, certain pathogens and bacteria release enzymes that change the composition of type A agglutinogens so that they begin to resemble type B agglutinogens.

A blood test in this case will show the second group instead of the third, but transfusion of group B is impossible in any case, as it will cause incompatible reactions. Therefore, the change is temporary. Thus, thalassemia (Cooley's disease) can reduce the content of antigens. Cancerous tumors can also contribute to these changes.

Thus, under certain conditions, the results of analyzes may temporarily be different, but a change in group membership is in principle impossible. Therefore, the answer to the question of whether blood type can change will be negative.

Rh factor

In medicine, it is categorically stated that the Rh factor and blood group are permanent indicators, inherited properties received at conception and remaining until death. But sometimes events occur that cannot be explained rationally. There are also opinions about the possibility of changing blood group and rhesus. Let's find out whether the blood type and Rh factor change.

The Rh factor is a trait that is of genetic origin, and changing it under natural conditions is not feasible. To determine it, you need to check for the presence of Rh antigen on red blood cells. In 85% of humanity, this protein is detected, and Rh is positive. The rest, accordingly, have a negative indicator.

But there are antigens in the Rh system that are not so immunogenic. In some people with positive Rh, the ability to produce the opposite antibodies is revealed, and the expression of the standard Rh antigen is significantly reduced. In this case, positive patients are classified as a negative group. For example, when donor blood reaches a patient, an immune conflict may occur.

It is necessary to determine Rhesus in the process of pregnancy planning in order to promptly identify a possible immunological conflict between the fetus and mother, as a result of which the child may develop a hemolytic disease.

So does blood type change throughout life? There are exceptions to the rules. More on this later.

Unique case

A case of a change in the Rh factor was once recorded by Australian doctors in a girl after a liver transplant. Then all the properties of her immune system changed.

During transplantation, this phenomenon is very welcome, since most often the body tries to reject the new organ, which poses a threat to the patient’s life. To prevent such developments, the patient is prescribed long-term use of drugs that suppress the functioning of the immune system. To some extent, this is a non-standard answer to the question of whether the blood type changes in women.

Non-standard scenario

The case with the fifteen-year-old girl did not go according to the standard scenario. When the transplant was performed, the doctors did all the usual procedures, but after some time the patient developed a disease that rebuilt her immune system. After recovery, an analysis was carried out, as a result of which it turned out that the blood in some incomprehensible way became positive, although it was negative before the liver transplant. As a result, even the immunity readings became the same as those of the donor.

Doctors explain this case by transferring stem cells from a donor organ into the girl’s bone marrow. An additional reason could be her young age, due to which there was a low content of leukocytes in the blood. However, such a case is still isolated; no other similar phenomena have been recorded.

Therefore, when asked whether a person’s blood type changes, one must boldly answer: “No.” But the Rh factor may change.

Advanced teaching on rhesus change

Researchers at the Brazilian Institute in São João de Meriti, after many tests carried out on patients who had undergone spleen and liver transplants, concluded that the protein on red blood cells can change under certain conditions.

Studies show that almost 12% of transplant patients are at risk of changing the sign of the Rh factor, although the blood type is preserved.

Dr. Itar Minas argues that the functioning of the immune system after organ transplantation is significantly restructured, especially those that synthesize erythrocyte antigen. He explains this by the fact that during the engraftment of the organ, they are able to take over some of the hematopoietic functions of the bone marrow, and as a result, a change in the rhesus polarity is possible.

The ages of the donor and recipient are also significant. Young people have more potential for antigen rearrangement than older people. This group of scientists believes that the content of information about protein determinants, which are located in chromosomal alleles and loci (their exact number has not yet been established), also has an influence. It is assumed that some of them may allow the possibility of changing the Rh factor.

So we looked into the question of whether blood type can change

There is a lot of information about blood groups, and their varieties have long been well studied by scientists. However, many people often ask the following question: can blood type change? This option is, in fact, simply impossible, since a certain group has its own indicators, which were laid down at the genetic level during the mother’s time and therefore their change is impossible. But some claim that their group has changed throughout their lives. Why is this happening?

What is the definition of a group based on?

A blood group is a set of elements that make up a person's blood. These elements include:

  1. Leukocytes;
  2. Red blood cells.

This combination is determined by plasma proteins and antigens. There are now 300 different antigens known to exist in the blood, which can create different combinations. But during analyzes, specialists take into account the data of the Rh factor and antigens (agglutinogens) of red blood cells, since due to their activity they are easier to detect. It is because of them that some types of blood are incompatible with each other.

Human blood groups are characterized by their agglutinogens and antibodies (agglutins). As a rule, there are two types of agglutins: “alpha” and “beta”, which are present in the blood plasma, as well as two agglutinogens: A and B, which are found on red blood cells.

Antigens can be found in almost all human tissues, with the exception of brain tissue and on any red blood cells. But when analyzing blood, specialists only care about agglutinogens on the surface of red blood cells. Agglutins can only combine with such antigens, causing hemolysis and agglutination. The only exception is agglutinogen 0, with which these reactions are impossible. Antibodies are found in plasma, lymph, and exudate. They, producing different blood groups, combine with antigens A-, B-.

Blood groups - their varieties

Today, four blood groups will be distinguished, having a negative as well as a positive Rh factor. Blood type can be determined using the following compounds of agglutinogens and agglutins:

  • In the first group there are no antigens, but both agglutens are present;
  • In the second group there is agglutinogen A, beta antibodies, but there is no agglutinogen B;
  • The third group contains agglutin “alpha” and agglutinogen B;
  • The fourth group contains agglutinogens A and B, but no agglutins.

Every person needs to know information about the group. Thanks to this, during a blood transfusion, it is possible to determine compatibility or its absence with another group.

Determination of Rh factor

A protein found on red blood cells makes it possible to detect the Rh factor of the blood. There are two types of them: negative positive. If such a protein is present, the Rh factor is positive, otherwise negative. The number of people with positive Rh factor blood is about 85%.

Experts call the absence or presence of the Rh factor in a person immunological. This indicator does not change, and its transmission occurs at the genetic level.

You need to know that the Rh factor, whether positive or negative, is not a heredity error or any disease or deviation. This is simply a sign of individuality and a feature of the human body. This indicator can be compared with hair shade or skin color.

Rh factor conflict

In addition to belonging to a specific group, you also need to know the Rh factor. This is especially important for expectant mothers. When planning a child, women need to know not only their own Rh factor, but also that of their partner. With different Rh factors in a man and a woman, there is a risk of Rh conflicts in the fetus and woman.

It is impossible to determine the Rh factor before the birth of the child. We can only roughly guess the percentage of bad outcomes. So, for example, the probability that a woman with a negative Rh factor will give birth to a child with a positive Rh factor is approximately 8-9%. However, such mothers quite calmly give birth to children who have a positive Rh factor. Conflicts associated with differences in Rh factors are very dangerous, but occur quite rarely and account for approximately 1% of the total number of pregnancies. As a result, it is necessary to immediately undergo all tests at the first consultation and always follow the doctor’s recommendations so that there are no complications later.

Possible reasons for data changes

Due to the distinctive characteristics of the body in different people, it happens that the classical options for determining a specific blood group do not provide the opportunity to obtain comprehensive information. Because of this, information about membership in a particular group may change at different times. The result of this may be poorly expressed A-, B- antigens.

However, such signs can also be observed in people who have blood cancer or similar oncology. As a result of diseases, the content of antigens in the plasma decreases, as a result of which they are poorly expressed. Using standard tests, it is often not always possible to reliably determine the group, as well as the Rh factor. Using standard tests in such patients, determining the blood type is quite complicated, but this does not mean that the blood type, as well as its parameters, have changed.

To put it more intelligently, the indicators simply cannot be determined 100% accurately. Based on this fact that this can be encountered when taking blood tests from people who are susceptible to serious illnesses, doctors advise regular medical examinations.

The answer to the question: can blood type change is negative. In addition, the combination of antigens present at the very beginning of intrauterine development cannot change either after or during pregnancy.

If, after examining the analysis, the blood type has changed, it can be assumed that there is an error, or that the antigens in the blood are weak in nature. In this case, new studies are carried out using other reagents.

Video about blood type types

In this video you will learn why you need to know your blood type:

Quite often the question comes up: can the Rh factor change throughout life? In order to answer it reasonably, you need to understand what the Rh factor is from the point of view of modern hematology.

The concept of Rh factor

The Rh factor is an innate hematopoietic indicator that depends on the presence or absence of D-antigen protein molecules, which can be located on the plasma membranes of erythrocytes.

Approximately 84% of the white population has this immunogenic protein, so their blood is called Rh positive and is designated Rh+. 16% of white-skinned people do not produce such a D-antigen and their blood is considered Rh-negative - Rh-.

The table below shows the percentage of people with Rh+ and Rh- among other inhabitants of the globe.

The presence of the Rh factor system in humans was discovered and proven, in the period from 1937 to 1942, by outstanding scientists - the American immunologist and infectious disease specialist Karl Landsteiner, his student Alexander Wiener, as well as Philip Levin and John Mahoney. For their research in this area, they were awarded the Albert Lasker Award for Clinical Medical Research in 1946.

To date, the existence of 50 different antigens of the Rhesus system has been proven, which can be located on the plasma membranes of human red blood cells, together or separately.

The most significant among them are D, C, c, CW, E and e. The term Rh factor (negative or positive) applies only to the D antigen.

Rh factor analysis

Rh positive or negative is determined during a special laboratory test of venous blood. Such an analysis can be carried out on a glass plane or in a test tube using various techniques:

  • using a direct agglutination reaction in a special saline solution;
  • with direct agglutination with special high-molecular amplifiers;
  • with pre-treatment of red cells with protolytic enzymes;
  • using the indirect antiglobulin Coombs test.

It is not necessary to take an analysis for the Rh factor on an empty stomach, but 2 hours before taking the sample for testing, you must avoid eating, especially fatty foods, do not smoke or drink a lot of liquid, and also do not drink alcohol the day before, cancel physiotherapeutic procedures and reduce physical activity. loads.

Important! When first determining Rhesus status, the reliability of the analysis performed must be confirmed and a secondary study must be carried out, subject to the same conditions and in the same medical laboratory.

Clinical significance of Rh status

In a person’s normal life or during the time when he is sick, the congenital Rh indicator has no meaning. This factor takes on special meaning in the following cases:

  • in preparation for operations that may or will definitely require transfusion;
  • before the planned blood transfusion of both blood and its components;
  • during pregnancy - to establish the compatibility of the blood of mother and fetus;
  • immediately after birth - with a diagnosis of “Hemolytic disease of the newborn”.

Rh factor during transfusion

For a harmless blood transfusion, it is necessary to carry out an analysis for the Rh factor of both the person who donates blood (donor) and the person receiving it (recipient). A reasonable question arises - why?

The most dangerous of all antigens in the Rh system is the D antigen. If a person whose blood does not have such antigens is transfused with blood containing them, the reaction of destruction of red blood cells starts - they begin to stick together into coin columns, which without immediate correction can lead to the development of transfusion shock and end in death.

At the moment, in the vast majority of cases, transfusion is allowed only if both the blood type and its Rh factor are fully consistent.

The immunogenic danger of 5 other significant antigens (C, c, CW, E and e) is significantly lower. They are determined when multiple transfusions are necessary for a person who has detected immune antibodies, and he requires an individual selection of donor blood.

In addition, about 1% of white-skinned people are carriers of weak variants of the D-antigen, which are combined into the Du (Dweek) subgroup. A characteristic difference of this subgroup is that in such people the red blood cells are weakly expressed or never stick together in reactions during direct agglutination.

Therefore, today, the blood of absolutely all donors and recipients is required to undergo testing for the presence of Du. Donors with the Du antigen are classified as Rh positive.

If such blood is transfused into an Rh-negative recipient, severe transfusion consequences and an immune response are possible. But recipients with Du-antigens are considered Rh-negative, and accordingly they are transfused only with Rh-negative blood.

Here is one example that can mislead ordinary people and suggest a change in the Rh factor throughout life. In fact, the Rh factor does not change in people with the Du antigen.

Rhesus and pregnancy

Being Rh negative in a woman can significantly complicate the relationship between mother and fetus and affect the course of pregnancy. A dangerous situation or Rh conflict arises only when the expectant mother has a negative Rh factor, and the child inherited a positive Rh factor from the father at the time of conception. But this situation is not a disaster and depends on 2 points:

  1. What kind of pregnancy is there, how many abortions and miscarriages have there been before;
  2. Does a woman produce antibodies and which ones?

Hemolytic disease in the fetus is caused by certain classes of antibodies, which, due to their small size, can penetrate the placenta and harm the development of the child. Therefore, if antibodies are detected in a pregnant woman, she will definitely be prescribed nonspecific treatment. This does not mean that she will be prescribed any medications and the Rh factor will be able to change for a while. Basically, this will be a course of vitamin-mineral complexes and medications that help relieve allergic reactions.

In severe cases, the plasmapheresis procedure can be used to cleanse the pregnant woman’s blood of antibodies. In particularly rare cases and if the necessary equipment is available, intrauterine blood transfusion in the fetus is possible. But these blood transfusion procedures will not affect the Rh factor, and it will not be able to change in either the mother or the fetus.

With the development of hemolytic disease of the newborn, the child is usually prescribed nursing therapeutic measures, but in especially severe cases, an exchange transfusion may be used, which can also become erroneous evidence of the statement that the Rh factor changes throughout life. Why?

For example, a newborn child with a positive Rh factor is transfused with Rh-negative donor blood, since the mother’s Rh-negative blood began to destroy his own even before birth. Thus, the child lives for some time with a negative Rh factor. But this does not mean that the child’s Rh factor changes forever. When the blood is naturally renewed, Rh will become positive again.

Change in Rh factor

Like the blood group, the Rh factor refers to such hemolytic indicators, which are established at conception at the genetic level and do not change under any external or internal circumstances. Again why?

The production of D and other antigens, or lack thereof, is encoded at the DNA level, and will be produced or not produced throughout a person's life. A change in the Rh factor is always caused by mistakes made by laboratory technicians during the study.

With a large volume of lost blood, a patient’s life can often be saved only after a transfusion of blood and its components, in particular, red blood cells, which also has a group affiliation. In the vast majority of cases, single-group material is transfused. Of course, there can be no doubt that the blood type will remain the same.

However, in emergency cases, when the patient’s life is at risk and there is no time to wait for the right drug, doctors can try to transfuse the patient with blood of a different type. Thus, it is believed that group 1 is universal donors. On the surface of such red blood cells there are no proteins - agglutinogens, which can cause sticking and destruction of red blood cells. Therefore, when blood of any group enters, the introduced red blood cells will, of course, be attacked by agglutinins a and b contained in the plasma of people with group I (0). Some of the cells will be destroyed, but will perform their transport function, and will also saturate the body with iron, necessary for the production of new blood cells.

On the other hand, owners of blood type IV are considered universal recipients. On the surface of their red blood cells there are agglutinogens of both types - A and B. Blood of groups 1 - 3, entering the body of such a patient, will react by gluing agglutinins infused with plasma with the patient’s red blood cells, but this reaction will not have significant clinical significance .

The question arises: if a patient is transfused with type 1 blood, will his own blood group change? Or if a blood transfusion is given to a patient with group 4, will he still have it?

Blood type does not change during transfusion for several reasons:

  • this trait is inherited and determined by the gene set, which is not affected by transfused blood;
  • foreign red blood cells introduced into the patient’s body are quickly destroyed, and agglutinogens on their surface are utilized;
  • the amount of administered blood or red blood cells is always significantly less than the volume of the patient’s own circulating blood, therefore, even immediately after a blood transfusion, diluted donor material cannot affect the patient’s results.

There are four main exceptions to this rule:

  • initially or repeatedly when determining blood grouping;
  • the patient has a disease of the hematopoietic system, for example, aplastic anemia, and after treatment he may develop other antigenic properties of red blood cells, which were previously weakly expressed due to the disease;
  • a massive blood transfusion was performed, replacing a large volume of donor blood; in this case, for several days, until the injected red blood cells die, a different blood type can be determined;
  • the patient underwent a donor bone marrow transplant, before which all his own blood progenitor cells were destroyed by chemotherapy; after engraftment of the donor material, it can begin to produce cells with a different antigenic set; however, the likelihood of this is reduced to casuistry, since the donor is selected based on many parameters, including blood type. However, there are cases where after a bone marrow transplant, the blood type changes, as does the genetic structure of the blood cells. That is why the process of selecting a bone marrow donor with the closest antigenic characteristics is so important and so expensive.

You can calculate a child's blood type based on the blood groups of his parents.

Blood is unique biologically active liquid, which is formed during the formation of the embryo. Its uniqueness is determined by the presence of the group and the Rh factor, which, in turn, indicates the presence or absence of special protein molecules on the surface of red blood cells. Under normal conditions, blood cannot change during life, since its characteristics are fixed at the genetic level. Whether the blood type (BG) can change, and in what situations this happens, we will consider further.

There are only four GCs, which have their own distinctive characteristics. It is necessary to determine the group and Rh factor in order to eliminate the likelihood of complications and death if blood transfusion is necessary.

Under normal conditions, when a person is not stressed, does not get sick and does not have serious pathologies, BG does not change. This is due to the fact that it is DNA that determines the quantity and process of synthesis of protein molecules on the surface of red blood cells. It is impossible to influence in any way what was formed long before birth.

The exception is situations in which a person suffers from certain diseases that provoke changes in protein synthesis.

Does it change under abnormal conditions?

There are a number of diseases that may influence the process of determining blood group, inhibiting or accelerating the agglutination process. These include:

Malignant neoplasms - an oncological tumor developing in the body provokes activation of the immune system, which entails a change in the process of protein synthesis. In some cases, the quantitative and qualitative composition of the blood may change, but the blood type and Rh factor remain unchanged.

Blood diseases - especially leukemia and pathological anemia - can provoke the appearance of additional proteins in the blood that were previously undetectable. This phenomenon is temporary and disappears immediately after the disease is cured. In the case of oncology, there are known moments when a person’s Rh factor or individual protein molecules changed, but no external influence can be exerted on the blood group itself.

Error in group establishment - the use of low-quality reagents or stale blood can cause inaccurate results at the output.

However, the blood cannot completely change, therefore, to obtain reliable information, several tests can be carried out at once, which increases the chances of obtaining the most accurate result.

There are often cases when a person is sure that he has a certain blood type. Her analysis was taken at birth, therefore it is reliable and officially documented. But when undergoing medical examination or unscheduled examination, it turns out that the blood type has changed. Since this is impossible in practice, the only explanation for this remains an error in the initial determination of the blood group.

Video on changing blood type

Absence of ABO system antigens

In some situations absence of ABO antigens is diagnosed, which is quite simple to explain. The thing is that agglutinogens from carbohydrate particles form a certain chain, the formation of which is impossible without glycosyltransferase.

The last component is an enzyme that activates the process of creating agglutinogenic compounds on the surface of red blood cells.

Lack of synthesis of this enzyme formed in the presence of cancer, therefore, in the blood test of such patients, the absence of antigens often “slips through”. It is worth noting that this particular analysis helps to identify the presence of a neoplasm at the earliest stages, which is impossible even when examined using high-precision technology.

Thus, throughout life a person's blood type does not change. This is due to the influence of DNA on the process of blood formation, so no other factors can change what was laid down at the time of embryo development. Any inaccuracies and changes in the composition of the blood are explained by the presence of serious pathologies or errors in determining the blood group.