Blood of Bombay. Bombay phenomenon - what is it? Increased hematocrit number
A person with a blood type known as the Bombay phenomenon is a universal donor: his blood can be transfused to people with any blood type. However, people with this rare blood type cannot accept blood of any other type. Why?
There are four blood groups (first, second, third and fourth): the classification of blood groups is based on the presence or absence of an antigenic substance that appears on the surface of blood cells. Both parents influence and determine the child's blood type.
Knowing the blood type, a couple can predict the blood type of their unborn child using the Punnett grid. For example, if the mother has the third blood group, and the father has the first blood group, then most likely their child will have the first blood group.
However, there are rare cases when a couple gives birth to a child with the first blood group, even if they do not have the genes for the first blood group. If this occurs, the child most likely has Bombay phenomenon, which was first discovered in three people in Bombay (now Mumbai) in India in 1952 by Dr. Bhende and his colleagues. The main characteristic of red blood cells in the Bombay phenomenon is the absence of h-antigen in them.
Rare blood type
The h-antigen is located on the surface of red blood cells and is the precursor of antigens A and B. The A-allele is necessary for the production of transferase enzymes, which convert the h-antigen into the A-antigen. In the same way, the B allele is necessary for the production of transferase enzymes for the transition of h-antigen to B-antigen. In blood type O, the h-antigen cannot be converted because transferase enzymes are not produced. It is worth noting that antigen conversion occurs by adding complex carbohydrates produced by transferase enzymes to the h-antigen.
Bombay phenomenon
A person with Bombay phenomenon inherits a recessive allele for the h antigen from each parent. He carries the homozygous recessive genotype (hh) instead of the homozygous dominant (HH) and heterozygous (Hh) genotypes found in all four blood types. As a result, the h-antigen does not appear on the surface of blood cells, so antigens A and B are not formed. The h-allele is the result of a mutation in the H-gene (FUT1), which affects the manifestation of the h-antigen in erythrocytes. Scientists have found that people with Bombay phenomenon are homozygous (hh) for the T725G mutation (leucine 242 changes to arginine) in the FUT1 coding region. This mutation produces an inactivated enzyme that is unable to form the h-antigen.
Antibody production
People with Bombay phenomenon produce protective antibodies against H, A, and B antigens. Because their blood produces antibodies against H, A, and B antigens, they can only receive blood from donors with the same phenomenon. Transfusion of blood from the other four groups can be fatal. There have been cases in the past where patients with supposedly O blood group died during transfusion because doctors did not test for the Bombay phenomenon.
Since the Bombay phenomenon is , it is very difficult for patients with this blood type to find donors. The probability of having a donor with the Bombay phenomenon is 1 in 250,000 people. India has the highest number of people with the Bombay phenomenon: 1 case in 7,600 people. Geneticists are convinced that the large number of people with the Bombay phenomenon in India is associated with consanguineous marriages between members of the same caste. Consanguineous marriage in the upper caste allows you to maintain your position in society and protect your wealth.
August 15th, 2017
Who doesn’t know that people have four main blood groups. The first, second and third are quite common, the fourth is not so widespread. This classification is based on the content of so-called agglutinogens in the blood - antigens responsible for the formation of antibodies.
Blood type is most often determined by heredity, for example, if the parents have the second and third groups, the child can have any of the four, if the father and mother have the first group, their children will also have the first, and if, say, the parents have the fourth and the first, the child will have either the second or the third.
However, in some cases, children are born with a blood type that, according to the rules of inheritance, they cannot have - this phenomenon is called the Bombay phenomenon, or Bombay blood.
Within the ABO/Rhesus blood group systems that are used to classify most blood types, there are several rare blood types. The rarest is AB-, this blood type is observed in less than one percent of the world's population. Types B- and O- are also very rare, each accounting for less than 5% of the world's population. However, in addition to these two main ones, there are more than 30 generally accepted blood typing systems, including many rare types, some of which are observed in a very small group of people.
There are three types of genes responsible for blood group - A, B, and 0 (three alleles).
Every person has two blood type genes - one received from the mother (A, B, or 0), and one received from the father (A, B, or 0).
There are 6 possible combinations:
| genes | group |
| 00 | 1 |
| 0A | 2 |
| AA | |
| 0V | 3 |
| BB | |
| AB | 4 |
On the surface of our red blood cells there are carbohydrates - “H antigens”, also known as “0 antigens”. (On the surface of red blood cells there are glycoproteins that have antigenic properties. They are called agglutinogens.)
| genes | letter designation of the group | ||
| 00 | - | 1 | 0 |
| A0 | A | 2 | A |
| AA | |||
| B0 | IN | 3 | IN |
| BB | |||
| AB | A and B | 4 | AB |
Bombay phenomenon
H - gene encoding antigen H
h - recessive gene, H antigen is not formed
This mutation was first discovered in Bombay, hence the name. In India, it occurs in one person in 10,000, in Taiwan - in one in 8,000. In Europe, hh is very rare - in one person in two hundred thousand (0.0005%).
An example of the Bombay phenomenon No. 1: if one parent has the first blood group, and the other has the second, then the child cannot have the fourth group, because neither of the parents has the B gene necessary for group 4.
And now the Bombay phenomenon:
| Parent AB (4 group) |
Parent AB (group 4) | |
| A | IN | |
| A | AA (2nd group) |
AB (4 group) |
| IN | AB (4 group) |
BB (3rd group) |
And now the Bombay phenomenon
| Parent ABHh (4 group) |
Parent ABHh (4th group) | |||
| AH | Ah | B.H. | Bh | |
| A.H. | AAHH (2nd group) |
AAHh (2nd group) |
ABHH (4 group) |
ABHh (4 group) |
| Ah | AAHH (2nd group) |
Ahh (1 group) |
ABHh (4 group) |
АBhh (1 group) |
| B.H. | ABHH (4 group) |
ABHh (4 group) |
BBHH (3rd group) |
BBHh (3rd group) |
| Bh | ABHh (4 group) |
ABhh (1 group) |
ABHh (4 group) |
BBhh (1 group) |
Cis position A and B
In a person with blood type 4, during crossing over, an error (chromosomal mutation) may occur when both genes A and B appear on one chromosome, but nothing on the other chromosome. Accordingly, the gametes of such an AB will turn out strange: one will contain AB, and the other will have nothing.
| Mutant parent | ||
| AB | - | |
| 0 | AB0 (4 group) |
0- (1 group) |
| A | AAV (4 group) |
A- (2nd group) |
| IN | ABB (4 group) |
IN- (3rd group) |
And now the mutation:
| Parent 00 (1 group) | AB mutant parent (4 group) |
|||
| AB | - | A | IN | |
| 0 | AB0 (4 group) |
0- (1 group) |
A0 (2nd group) |
B0 (3rd group) |
The probability of having children shaded in gray is, of course, less - 0.001%, as agreed, and the remaining 99.999% falls on groups 2 and 3. But still, these fractions of a percent “should be taken into account during genetic counseling and forensic medical examination.”
How do they live with unusual blood?
The everyday life of a person with unique blood does not differ from its other classifications, with the exception of several factors:
· a serious problem is transfusion; only the same blood can be used for these purposes, while it is a universal donor and is suitable for everyone;
· impossibility of establishing paternity; if it happens that DNA testing is necessary, it will not give results, since the child does not have the antigens that his parents have.
Interesting fact! In the USA, Massachusetts, there lives a family where two children have the Bombay phenomenon, only they also have an A-H type, such blood was diagnosed once in the Czech Republic in 1961. They cannot be donors for each other, since they have different rhesus. factor, and transfusion of any other group is naturally impossible. The eldest child reached adulthood and became a donor for himself as a last resort, the same fate awaits his younger sister when she turns 18
And something else interesting on medical topics: I talked about it in detail here and here. Or maybe someone is interested or, for example, well-known to everyone
As you know, there are four main blood groups in humans. The first, second and third are quite common, the fourth is not so widespread. This classification is based on the content of so-called agglutinogens in the blood - antigens responsible for the formation of antibodies. The second blood group contains antigen A, the third contains antigen B, the fourth contains both of these antigens, and the first contains no antigens A and B, but there is a “primary” antigen H, which, among other things, serves as a “building material” for the production of antigens contained in the second, third and fourth blood groups.
Blood type is most often determined by heredity, for example, if the parents have the second and third groups, the child can have any of the four, if the father and mother have the first group, their children will also have the first, and if, say, the parents have the fourth and the first, the child will have either the second or the third. However, in some cases, children are born with a blood type that, according to the rules of inheritance, they cannot have - this phenomenon is called the Bombay phenomenon, or Bombay blood.
By the way, the Japanese often ask what their blood type is when they first meet a person. This is somewhat surprising to foreigners, but the Japanese ask this question for a reason, but because they want to determine the main character traits of this person.
Let's understand blood groups and check character according to this parameter
In truth, there are no special statistics or scientific grounds to consider such a definition of character reliable. However, since it is often talked about on TV and many books are sold, the number of people interested in it is increasing in Japan, Korea and Vietnam.
In the Japanese “horoscope” for the owner of each blood group - A, B, O and AB, there is a description of character.
Now this phenomenon has gained extraordinary popularity; publishing books and websites on this topic can make a good business.
A (II) They are honest, capable of working in a group, very diligent, hide their thoughts and feelings; worry about what others think of them, think clearly, don't like to lose, worry about little things, rely on facts rather than emotions; patient, prone to pessimism;
B (III) Active, self-centered, completely immersed in work, hobbies, favorite things; not interested in fame and power, have a keen sense of justice, are emotional, have a good sense of humor, their mood often changes, they do not pay attention to the rules, they do not pay attention to other people;
O (I) Cheerful, loved by people, romantic, often complain, easily moved, stubborn, often help people, if something unpleasant happens, the mood quickly deteriorates; do not hide their feelings, love people with a character different from theirs; optimistic;
AB (IV) Serious, delicate, inquisitive, expressing one’s own feelings causes difficulties, pure, manic, have a keen sense of justice, mysterious, often doubt people, take promises seriously, have a very complex character.
*************************************************
Within the ABO/Rhesus blood group systems that are used to classify most blood types, there are several rare blood types. The rarest is AB-, this blood type is observed in less than one percent of the world's population. Types B- and O- are also very rare, each accounting for less than 5% of the world's population. However, in addition to these two main ones, there are more than 30 generally accepted blood typing systems, including many rare types, some of which are observed in a very small group of people.
Blood type is determined by the presence of certain antigens in the blood. Antigens A and B are very common, making it easier to classify people based on which antigen they have, whereas people with type O blood have neither antigen. A positive or negative sign after the group means the presence or absence of the Rh factor. At the same time, in addition to antigens A and B, other antigens may be present, and these antigens may react with the blood of certain donors. For example, someone may have type A+ blood and not have another antigen in their blood, indicating the likelihood of an adverse reaction with type A+ donated blood containing that antigen.
Bombay blood does not have antigens A and B, so it is often confused with the first group, but it also does not contain antigen H, which can become a problem, for example, when determining paternity - after all, the child does not have a single antigen in his blood that he has. him from his parents.
A rare blood type does not cause its owner any problems, except for one thing - if he suddenly needs a blood transfusion, then only the same Bombay blood can be used, and this blood can be transfused to a person with any group without any consequences.
The first information about this phenomenon appeared in 1952, when the Indian doctor Vhend, conducting blood tests in a family of patients, received an unexpected result: the father had blood group 1, the mother had blood group II, and the son had blood group III. He described this case in the largest medical journal, The Lancet. Subsequently, some doctors encountered similar cases, but could not explain them. And only at the end of the 20th century the answer was found: it turned out that in such cases the body of one of the parents mimics (fake) one blood group, while in fact it has another; two genes are involved in the formation of the blood group: one determines the group blood, the second encodes the production of an enzyme that allows this group to be realized. For most people this scheme works, but in rare cases the second gene is missing, and therefore the enzyme is missing. Then the following picture is observed: a person has, for example. Blood group III, but it cannot be realized, and the analysis reveals II. Such a parent passes on his genes to the child - hence the child’s “inexplicable” blood type. There are few carriers of such mimicry - less than 1% of the Earth's population.
The Bombay phenomenon was discovered in India, where, according to statistics, 0.01% of the population have “special” blood; in Europe, Bombay blood is even less common - approximately 0.0001% of the population.
And now a little more detail:
There are three types of genes responsible for blood group - A, B, and 0 (three alleles).
Every person has two blood type genes - one received from the mother (A, B, or 0), and one received from the father (A, B, or 0).
There are 6 possible combinations:
| genes | group |
| 00 | 1 |
| 0A | 2 |
| AA | |
| 0V | 3 |
| BB | |
| AB | 4 |
How it works (from the point of view of cell biochemistry)
On the surface of our red blood cells there are carbohydrates - “H antigens”, also known as “0 antigens”. (On the surface of red blood cells there are glycoproteins that have antigenic properties. They are called agglutinogens.)
Gene A encodes an enzyme that converts some of the H antigens into A antigens. (Gene A encodes a specific glycosyltransferase that adds an N-acetyl-D-galactosamine residue to an agglutinogen, resulting in agglutinogen A).
Gene B encodes an enzyme that converts some of the H antigens into B antigens (Gene B encodes a specific glycosyltransferase that adds a D-galactose residue to the agglutinogen, resulting in agglutinogen B).
Gene 0 does not code for any enzyme.
Depending on the genotype, carbohydrate vegetation on the surface of red blood cells will look like this:
| genes | specific antigens on the surface of red blood cells | blood type | letter designation of the group |
| 00 | - | 1 | 0 |
| A0 | A | 2 | A |
| AA | |||
| B0 | IN | 3 | IN |
| BB | |||
| AB | A and B | 4 | AB |
For example, let’s cross parents with groups 1 and 4 and see why they cannot have a child with group 1.
(Because a child with type 1 (00) should receive a 0 from each parent, but a parent with blood type 4 (AB) does not have a 0.)
Bombay phenomenon
It occurs when a person does not produce the “original” antigen H on his red blood cells. In this case, the person will have neither antigens A nor antigens B, even if the necessary enzymes are present. Well, great and powerful enzymes will come to convert H into A... oops! but there’s nothing to transform, there’s no one!
The original H antigen is encoded by a gene, which is unsurprisingly designated H.
H – gene encoding antigen H
h – recessive gene, H antigen is not formed
Example: a person with the AA genotype must have blood group 2. But if he is AAHh, then his blood type will be the first, because there is nothing to make antigen A from.
This mutation was first discovered in Bombay, hence the name. In India, it occurs in one person in 10,000, in Taiwan - in one in 8,000. In Europe, hh is very rare - in one person in two hundred thousand (0.0005%).
An example of the Bombay phenomenon No. 1: if one parent has the first blood group, and the other has the second, then the child cannot have the fourth group, because neither parent has the B gene necessary for group 4.
And now the Bombay phenomenon:
The trick is that the first parent, despite its BB genes, does not have B antigens, because there is nothing to make them from. Therefore, despite the genetic third group, from the point of view of blood transfusion he has the first group.
An example of the Bombay phenomenon No. 2. If both parents have group 4, then they cannot have a child of group 1.
| Parent AB (4 group) |
Parent AB (group 4) | |
| A | IN | |
| A | AA (2nd group) |
AB (4 group) |
| IN | AB (4 group) |
BB (3rd group) |
And now the Bombay phenomenon
| Parent ABHh (4 group) |
Parent ABHh (4th group) | |||
| AH | Ah | B.H. | Bh | |
| A.H. | AAHH (2nd group) |
AAHh (2nd group) |
ABHH (4 group) |
ABHh (4 group) |
| Ah | AAHH (2nd group) |
Ahh (1 group) |
ABHh (4 group) |
АBhh (1 group) |
| B.H. | ABHH (4 group) |
ABHh (4 group) |
BBHH (3rd group) |
BBHh (3rd group) |
| Bh | ABHh (4 group) |
ABhh (1 group) |
ABHh (4 group) |
BBhh (1 group) |
As we see, with the Bombay phenomenon, parents with group 4 can still get a child with group 1.
Cis position A and B
In a person with blood type 4, during crossing over, an error (chromosomal mutation) may occur, when both genes A and B will appear on one chromosome, and there will be nothing on the other chromosome. Accordingly, the gametes of such an AB will turn out strange: one will contain AB, and the other will have nothing.
| What other parents have to offer | Mutant parent | |
| AB | - | |
| 0 | AB0 (4 group) |
0- (1 group) |
| A | AAV (4 group) |
A- (2nd group) |
| IN | ABB (4 group) |
IN- (3rd group) |
Of course, chromosomes containing AB and chromosomes containing nothing at all will be rejected by natural selection, because they will have difficulty conjugating with normal, non-mutant chromosomes. In addition, AAV and ABB children may experience a gene imbalance (impaired viability, death of the embryo). The probability of encountering a cis-AB mutation is estimated at approximately 0.001% (0.012% cis-AB relative to all AB).
Example of cis-AV. If one parent has group 4, and the other has group 1, then they cannot have children of either group 1 or 4.
And now the mutation:
| Parent 00 (1 group) | AB mutant parent (4 group) |
|||
| AB | - | A | IN | |
| 0 | AB0 (4 group) |
0- (1 group) |
A0 (2nd group) |
B0 (3rd group) |
The probability of having children shaded in gray is, of course, less - 0.001%, as agreed, and the remaining 99.999% falls on groups 2 and 3. But still, these fractions of a percent “should be taken into account during genetic counseling and forensic medical examination.”
In medicine, four blood groups are described in detail. They all differ in the location of agglutinins on the surface of red blood cells. This property is encoded genetically using proteins A, B and H. Bombay syndrome is very rarely recorded in people. This anomaly is characterized by the presence of the fifth blood group. Patients with the phenomenon lack proteins that are normally detected. The peculiarity is formed at the stage of intrauterine development, that is, it is of a genetic nature. This characteristic of the main body fluid is rare and does not exceed one in ten million cases.
5 blood group or the history of the Bombay phenomenon
This feature was discovered and described not so long ago, in 1952. The first cases of lack of antigens A, B and H in humans were registered in India. It is here that the percentage of the population with the anomaly is the highest and amounts to 1 case in 7600. The discovery of Bombay syndrome, that is, a rare blood type, occurred as a result of studying fluid samples using mass spectrometry. Tests were carried out due to an epidemic in the country of a disease such as malaria. The defect was named after an Indian city.
Theories of the origin of Bombay blood
Presumably, the anomaly formed against the background of frequent consanguineous marriages. They are common in India due to social customs. Incest not only led to an increase in the prevalence of genetic diseases, but to the emergence of Bombay syndrome. This feature is currently found in only 0.0001% of the planet's population. A rare characteristic of the main fluid in the human body may remain unrecognized due to the imperfections of modern diagnostic methods.
Development mechanism
In total, four blood groups are described in detail in medicine. This division is based on the location of agglutinins on the surface of red blood cells. Outwardly, these characteristics do not appear in any way. However, they need to be known in order to carry out blood transfusion from one person to another. If the groups do not match, reactions occur that can lead to the death of the patient.
This phenomenon is completely determined by the chromosomal set of the parents, that is, it is hereditary. The laying occurs even at the stage of intrauterine development. For example, if the father has the first blood group, and the mother has the fourth, then the child will have the second or third. This characteristic is due to combinations of antigens A, B and H. Bombay syndrome occurs against the background of recessive epistasis - non-allelic interaction. This is what causes the absence of blood proteins.
Features of life and problems with paternity
The presence of this anomaly does not affect human health in any way. A child or adult may not be aware of the presence of a unique feature of the organism. Difficulties arise only if the patient needs a blood transfusion. Such people are universal donors. This means that their liquid is suitable for everyone. However, when determining Bombay syndrome, the patient will need the same unique group. Otherwise, the patient will face incompatibility, which will mean a threat to life and health.
Another problem is confirming paternity. The procedure is difficult for people with this blood type. Determination of family relationships is based on the detection of corresponding proteins that are not detected when the patient has Bombay syndrome. Therefore, in doubtful situations, more difficult genetic tests will be required.
Modern medicine has not described any pathologies associated with a rare blood group. Perhaps this feature is caused by the low prevalence of Bombay syndrome. It is assumed that many patients with the phenomenon are unaware of its presence. However, a case of detection of a rare hemolytic disease in a newborn baby, whose mother had the fifth blood group, is described. The diagnosis was confirmed based on the results of antibody screening, lectin studies and determination of the location of agglutinins on the surface of the red blood cells of the mother and child.
The pathology diagnosed in the patient is accompanied by life-threatening processes. These features are associated with incompatibility between the blood of the parent and the fetus. In this case, two patients suffer from the disease at once. In the described case, the mother's hematocrit was only 11%, which did not allow her to become a donor for the child.
A big problem in such cases is the lack of this rare type of physiological fluid in blood banks. This is primarily due to the low prevalence of Bombay syndrome. Another difficulty is the fact that patients may not be aware of the feature. Moreover, according to available data, many people with the fifth group willingly agree to be donors because they realize the importance of creating a blood bank. In case of hemolytic disease of newborns against the background of diagnosis of Bombay syndrome in the mother, cases of which are rare, there is also the possibility of conservative treatment without the use of blood transfusion. The effectiveness of such therapy depends on the severity of pathological changes in the body of the mother and child.
The significance of unique blood
The anomaly is considered poorly understood. Therefore, it is too early to talk about the impact of this feature on the health of the planet’s population and medicine. It is undeniable that the occurrence of Bombay syndrome complicates the already difficult procedure of blood transfusion. The presence of blood group 5 in a person puts life and health at risk when the need for transfusion arises. At the same time, a number of scientists are inclined to believe that such an evolutionary event may have a beneficial effect in the future, since this structure of biological fluid is considered perfect in comparison with other common options.
From school we know that there are four main blood types. The first three are common, but the fourth is rare. The groups are classified according to the content of agglutinogens in the blood, which form antibodies. However, few people know that there is also a fifth group, called the “Bombay phenomenon”.
To understand what we are talking about, you should remember the content of antigens in the blood. So, the second group contains antigen A, the third contains antigen B, the fourth contains antigens A and B, and the first group does not contain these elements, but it contains antigen H - this is a substance that takes part in the construction of other antigens. In the fifth group there is neither A, nor B, nor H.
Inheritance
Blood type determines heredity. If parents have the third and second groups, then their children can be born with any of the four groups, if the parents have the first group, then the children will only have blood of the first group. However, there are cases when parents give birth to children with an unusual, fifth group or Bombay phenomenon. This blood does not contain antigens A and B, which is why it is often confused with the first group. But in Bombay blood there is no antigen H, contained in the first group. If a child turns out to have the Bombay phenomenon, then it will not be possible to accurately determine paternity, since there is not a single antigen in the blood that his parents have.
History of discovery
The discovery of an unusual blood type was made in 1952, in India, in the Bombay area. During malaria, massive blood tests were carried out. During the examinations, several people were identified whose blood did not belong to any of the four known groups, since it did not contain antigens. These cases were called the "Bombay phenomenon". Later, information about such blood began to appear all over the world, and in the world, for every 250,000 people, one has a fifth type. In India, this figure is higher - one per 7,600 people.
According to scientists, the emergence of a new group in India is due to the fact that consanguineous marriages are allowed in this country. According to Indian laws, procreation within a caste allows one to preserve one’s position in society and family wealth.
What's next
After the discovery of the Bombay phenomenon, scientists at the University of Vermont made a statement that there are other rare blood types. The latest discoveries are named Langereis and Junior. These species contain completely unknown proteins responsible for blood type.
The uniqueness of the 5th group
The most common and oldest is the first group. It arose during the time of the Neanderthals - it is more than 40 thousand years old. Almost half of the world's population has the first blood group.
The second group appeared about 15 thousand years ago. It is also not considered rare, but according to various sources, about 35% of people are carriers of it. Most often, the second group is found in Japan and Western Europe.
The third group is less common. Its carriers are about 15% of the population. Most people with this group are found in Eastern Europe.
Until recently, the fourth group was considered the newest group. About five thousand years have passed since its appearance. It occurs in 5% of the world's population.
The Bombay phenomenon (blood group V) is considered the newest, as it was discovered several decades ago. There are only 0.001% of people on the entire planet with such a group.
Formation of the phenomenon
The classification of blood groups is based on the content of antigens. This information applies to blood transfusions. It is believed that the H antigen contained in the first group is the “progenitor” of all existing groups, since it is a kind of building material from which antigens A and B emerged.
The formation of the chemical composition of blood occurs in utero and depends on the blood groups of the parents. And here geneticists can tell which possible groups a baby may be born with by carrying out simple calculations. Sometimes deviations from the usual norm do occur, and then children are born who exhibit recessive epistasis (Bombay phenomenon). Their blood does not contain antigens A, B, H. This is the uniqueness of the fifth blood group.
People with the fifth group
These people live the same way as millions of others, with other groups. Although there are some difficulties for them:
- It's difficult to find a donor. If a blood transfusion is necessary, only the fifth group can be used. However, Bombay blood can be used for all groups without exception, and there are no consequences.
- Paternity cannot be established. If you need to do a DNA paternity test, it will not give any results, since the child will not have the antigens that his parents have.
There is a family in the USA in which two children were born with the Bombay phenomenon, and also with the A-H type. Such blood was detected once in the Czech Republic in 1961. There are no donors for children in the world, and transfusions from other groups are fatal for them. Because of this feature, the eldest child became his own donor, and the same thing awaits his sister.
Biochemistry
It is generally accepted that there are three types of genes responsible for blood groups: A, B and 0. Each person has two genes - one gets from the mother, and the second from the father. Based on this, there are six gene variations that determine blood type:
- The first group is characterized by the presence of 00 genes.
- For the second group - AA and A0.
- The third contains antigens 0B and BB.
- In the fourth - AB.
Carbohydrates are located on the surface of red blood cells, they are also antigens 0 or antigens H. Under the influence of certain enzymes, antigen H is encoded into A. The same thing happens when antigen H is encoded into B. Gene 0 does not produce any encoding of the enzyme. When there is no synthesis of agglutinogens on the surface of erythrocytes, i.e., there is no original H antigen on the surface, then this blood is considered Bombay. Its peculiarity is that in the absence of the H antigen, or “source code,” there is nothing to convert into other antigens. In other cases, various antigens are found on the surface of red blood cells: the first group is characterized by the absence of antigens, but the presence of H, the second - A, the third - B, the fourth - AB. People with the fifth group do not have any genes on the surface of their red blood cells, and they don’t even have H, which is responsible for coding, even if there are enzymes that are encoded - it is impossible to convert H into another gene, because this source H does not exist.
The original H antigen is encoded by a gene called H. It looks like this: H is the gene that encodes the H antigen, h is a recessive gene in which the H antigen is not formed. As a result, when conducting a genetic analysis of the possible inheritance of blood groups, parents may have children with different groups. For example, parents with the fourth group cannot have children with the first group, but if one of the parents has the Bombay phenomenon, then they can have children with any group, even with the first.
Conclusion
Over many millions of years, evolution has been taking place, and not only of our planet. All living beings change. Evolution has not abandoned blood either. This liquid not only allows us to live, but also protects us from the negative effects of the environment, viruses and infections, neutralizing them and preventing them from penetrating vital systems and organs. Similar discoveries made by scientists decades ago in the form of the Bombay phenomenon, as well as other types of blood groups, remain a mystery. And it is unknown how many secrets that have not yet been revealed by scientists are kept in the blood of people around the world. Maybe after some time it will become known about another phenomenal discovery of a new group, which will be very new, unique, and the people with it will have incredible abilities.
Who doesn’t know that people have four main blood groups. The first, second and third are quite common, the fourth is not so widespread. This classification is based on the content of so-called agglutinogens in the blood - antigens responsible for the formation of antibodies.
Blood type is most often determined by heredity, for example, if the parents have the second and third groups, the child can have any of the four, if the father and mother have the first group, their children will also have the first, and if, say, the parents have the fourth and the first, the child will have either the second or the third.
However, in some cases, children are born with a blood type that, according to the rules of inheritance, they cannot have - this phenomenon is called the Bombay phenomenon, or Bombay blood.
Within the ABO/Rhesus blood group systems that are used to classify most blood types, there are several rare blood types. The rarest is AB-, this blood type is observed in less than one percent of the world's population. Types B- and O- are also very rare, each accounting for less than 5% of the world's population. However, in addition to these two main ones, there are more than 30 generally accepted blood typing systems, including many rare types, some of which are observed in a very small group of people.
Blood type is determined by the presence of certain antigens in the blood. Antigens A and B are very common, making it easier to classify people based on which antigen they have, whereas people with type O blood have neither antigen. A positive or negative sign after the group means the presence or absence of the Rh factor. At the same time, in addition to antigens A and B, other antigens may be present, and these antigens may react with the blood of certain donors. For example, someone may have type A+ blood and not have another antigen in their blood, indicating the likelihood of an adverse reaction with type A+ donated blood containing that antigen.
Bombay blood does not have antigens A and B, so it is often confused with the first group, but it also does not contain antigen H, which can become a problem, for example, when determining paternity - after all, the child does not have a single antigen in his blood that he has. him from his parents.
A rare blood type does not cause its owner any problems, except for one thing - if he suddenly needs a blood transfusion, then only the same Bombay blood can be used, and this blood can be transfused to a person with any group without any consequences.
The first information about this phenomenon appeared in 1952, when the Indian doctor Vhend, conducting blood tests in a family of patients, received an unexpected result: the father had blood group 1, the mother had blood group II, and the son had blood group III. He described this case in the largest medical journal, The Lancet. Subsequently, some doctors encountered similar cases, but could not explain them. And only at the end of the 20th century the answer was found: it turned out that in such cases the body of one of the parents mimics (fake) one blood group, while in fact it has another; two genes are involved in the formation of the blood group: one determines the group blood, the second encodes the production of an enzyme that allows this group to be realized. For most people this scheme works, but in rare cases the second gene is missing, and therefore the enzyme is missing. Then the following picture is observed: a person has, for example. Blood group III, but it cannot be realized, and the analysis reveals II. Such a parent passes on his genes to the child - hence the “inexplicable” blood type in the child. There are few carriers of such mimicry - less than 1% of the Earth's population.
The Bombay phenomenon was discovered in India, where, according to statistics, 0.01% of the population have “special” blood; in Europe, Bombay blood is even less common - approximately 0.0001% of the population.
And now a little more detail:
There are three types of genes responsible for blood group - A, B, and 0 (three alleles).
Every person has two blood type genes - one received from the mother (A, B, or 0), and one received from the father (A, B, or 0).
There are 6 possible combinations:
| genes | group |
| 00 | 1 |
| 0A | 2 |
| AA | |
| 0V | 3 |
| BB | |
| AB | 4 |
How it works (from the point of view of cell biochemistry)
On the surface of our red blood cells there are carbohydrates - “H antigens”, also known as “0 antigens”. (On the surface of red blood cells there are glycoproteins that have antigenic properties. They are called agglutinogens.)
Gene A encodes an enzyme that converts some of the H antigens into A antigens. (Gene A encodes a specific glycosyltransferase that adds an N-acetyl-D-galactosamine residue to an agglutinogen, resulting in agglutinogen A).
Gene B encodes an enzyme that converts some of the H antigens into B antigens (Gene B encodes a specific glycosyltransferase that adds a D-galactose residue to the agglutinogen, resulting in agglutinogen B).
Gene 0 does not code for any enzyme.
Depending on the genotype, carbohydrate vegetation on the surface of red blood cells will look like this:
| genes | specific antigens on the surface of red blood cells | letter designation of the group | |
| 00 | - | 1 | 0 |
| A0 | A | 2 | A |
| AA | |||
| B0 | IN | 3 | IN |
| BB | |||
| AB | A and B | 4 | AB |
For example, let’s cross parents with groups 1 and 4 and see why they cannot have a child with group 1.
(Because a child with type 1 (00) should receive a 0 from each parent, but a parent with blood type 4 (AB) does not have a 0.)
Bombay phenomenon
It occurs when a person does not produce the “original” antigen H on his red blood cells. In this case, the person will have neither antigens A nor antigens B, even if the necessary enzymes are present. Well, great and powerful enzymes will come to convert H into A... oops! but there’s nothing to transform, there’s no one!
The original H antigen is encoded by a gene, which is unsurprisingly designated H.
H - gene encoding antigen H
h - recessive gene, H antigen is not formed
Example: a person with the AA genotype must have blood group 2. But if he is AAHh, then his blood type will be the first, because there is nothing to make antigen A from.
This mutation was first discovered in Bombay, hence the name. In India, it occurs in one person in 10,000, in Taiwan - in one in 8,000. In Europe, hh is very rare - in one person in two hundred thousand (0.0005%).
An example of the Bombay phenomenon No. 1: if one parent has the first blood group, and the other has the second, then the child cannot have the fourth group, because neither of the parents has the B gene necessary for group 4.
And now the Bombay phenomenon:
The trick is that the first parent, despite its BB genes, does not have B antigens, because there is nothing to make them from. Therefore, despite the genetic third group, from the point of view of blood transfusion he has the first group.
An example of the Bombay phenomenon No. 2. If both parents have group 4, then they cannot have a child of group 1.
| Parent AB (4 group) |
Parent AB (group 4) | |
| A | IN | |
| A | AA (2nd group) |
AB (4 group) |
| IN | AB (4 group) |
BB (3rd group) |
And now the Bombay phenomenon
| Parent ABHh (4 group) |
Parent ABHh (4th group) | |||
| AH | Ah | B.H. | Bh | |
| A.H. | AAHH (2nd group) |
AAHh (2nd group) |
ABHH (4 group) |
ABHh (4 group) |
| Ah | AAHH (2nd group) |
Ahh (1 group) |
ABHh (4 group) |
АBhh (1 group) |
| B.H. | ABHH (4 group) |
ABHh (4 group) |
BBHH (3rd group) |
BBHh (3rd group) |
| Bh | ABHh (4 group) |
ABhh (1 group) |
ABHh (4 group) |
BBhh (1 group) |
As we see, with the Bombay phenomenon, parents with group 4 can still get a child with group 1.
Cis position A and B
In a person with blood type 4, during crossing over, an error (chromosomal mutation) may occur when both genes A and B appear on one chromosome, but nothing on the other chromosome. Accordingly, the gametes of such an AB will turn out strange: one will contain AB, and the other will have nothing.
| What other parents have to offer | Mutant parent | |
| AB | - | |
| 0 | AB0 (4 group) |
0- (1 group) |
| A | AAV (4 group) |
A- (2nd group) |
| IN | ABB (4 group) |
IN- (3rd group) |
Of course, chromosomes containing AB and chromosomes containing nothing at all will be rejected by natural selection, because they will have difficulty conjugating with normal, non-mutant chromosomes. In addition, AAV and ABB children may experience a gene imbalance (impaired viability, death of the embryo). The probability of encountering a cis-AB mutation is estimated at approximately 0.001% (0.012% cis-AB relative to all AB).
Example of cis-AV. If one parent has group 4, and the other has group 1, then they cannot have children of either group 1 or 4.
And now the mutation:
| Parent 00 (1 group) | AB mutant parent (4 group) |
|||
| AB | - | A | IN | |
| 0 | AB0 (4 group) |
0- (1 group) |
A0 (2nd group) |
B0 (3rd group) |
The probability of having children shaded in gray is, of course, less - 0.001%, as agreed, and the remaining 99.999% falls on groups 2 and 3. But still, these fractions of a percent “should be taken into account during genetic counseling and forensic medical examination.”
How do they live with unusual blood?
The everyday life of a person with unique blood does not differ from its other classifications, with the exception of several factors:
· a serious problem is transfusion; only the same blood can be used for these purposes, while it is a universal donor and is suitable for everyone;
· impossibility of establishing paternity; if it happens that DNA testing is necessary, it will not give results, since the child does not have the antigens that his parents have.
Interesting fact! In the USA, Massachusetts, there lives a family where two children have the Bombay phenomenon, only they also have an A-H type, such blood was diagnosed once in the Czech Republic in 1961. They cannot be donors for each other, since they have different rhesus. factor, and transfusion of any other group is naturally impossible. The eldest child reached adulthood and became a donor for himself as a last resort, the same fate awaits his younger sister when she turns 18
Today, every person is aware of the existing division of known blood groups according to the ABO system. In biology lessons they talk in some detail about the principles, compatibility, and prevalence of each type among the population. Thus, it is generally accepted that the rarest blood group is fourth, and the rarest Rh factor is negative. In fact, such information is not true.
Genetic principles
Based on data obtained in the field of archeology and paleontology, geneticists were able to determine that the first division into occurred more than 40 thousand years ago. It was then, according to scientists, that it arose. Subsequently, over the course of thousands of years, as a result of certain mutational changes, the rest of its types known today arose.
The blood group of a person according to the AB0 system is determined by the presence or absence of unique compounds on the membranes of red blood cells - agglutinogens (antigens) A and B.
Blood type is inherited according to the laws of genetics and is determined by two genes, one of which is passed on to the child by the mother, and the second by the father. Each of these genes is programmed at the DNA level to transmit only one of these agglutinogens or not to contain (and, accordingly, not to transmit in generations) any information (0):
- first 0(I) -00;
- A(II) – A0 or AA;
- B(III) – B0 or BB;
- AB(IV) – AB.
, can be clearly represented in the following examples:
- If parents have groups zero and four, their offspring can inherit only the second or third: AB + 00 = B0 or A0.
- If both parents have group zero, then no other blood group can appear in the offspring: 00 + 00 = 00.
- For parents whose blood types are second and third, children have an equal chance of being born with any of the possible groups: AA/A0 + BB/B0 = AB, A0, B0, 00.
Currently, the existence of the so-called Bombay phenomenon, discovered by scientists in 1952, is known. Its essence lies in the fact that a person’s blood group is determined, which according to the laws of genetics is impossible, what is its explanation and the cause of the effect. That is, there is an agglutinogen on the membranes of his red blood cells, which neither of the parents has.
An example of the Bombay phenomenon, the rarest blood type:
- For parents with group zero, the child is born with group three: 00 + 00 = B0.
- For parents whose groups are zero and , the child is born with the fourth or second: 00 + B0/BB = AB, A0.
After numerous studies, an explanation for the Bombay phenomenon was obtained. The answer is that in extremely rare cases, when blood grouping is determined by standard methods (according to the AB0 system) as zero 0 (I), in fact it is not such. In fact, one of the agglutinogens, either A or B, is present on the membranes of her red blood cells, but under the influence of specific factors they are suppressed and when determining the blood group, the blood behaves as 0 (I). But when a suppressed agglutinogen is inherited in children, it manifests itself. As a result, parents have doubts about the existence of a relationship between them and the child.
How often do such cases occur?
The prevalence of people with the Bombay blood phenomenon in the world does not exceed 0.0004% of all people on the globe. The exception is the Indian city of Mumbai, where the frequency percentage increases to 0.01%. It was by the name of this city that this phenomenon was named (the old name was Bombay).
One of the theories that studies the causes and factors influencing the manifestation of this phenomenon in the population states that among Hindus, a higher frequency of manifestation of this blood type is due to religious characteristics, in particular, the prohibition of eating beef.
In Europe, such a ban does not exist and the frequency of manifestation of Bombay blood in humans here is several times lower. This led geneticists to the idea that beef contains specific antigens that suppress the manifestation of agglutinogens.
Specificity of people's lives
In reality, people with rare Bombay blood are no different from the rest. The only difficulty they may encounter is... Due to the uniqueness of the blood type, they cannot be transfused with any foreign blood, since Bombay blood in humans is incompatible with all other groups. Therefore, people who exhibit this phenomenon are forced to create their own blood bank, which will be used in case of emergency.
In the USA, in the state of Massachusetts, there are currently living a brother and sister who have the manifestation and essence of the Bombay phenomenon. Their blood type is the same, but they cannot donate to each other because their Rh factors are different.
Problems of establishing paternity
When a child is born with manifestations of the Bombay phenomenon, it is impossible to prove its presence without the use of special methods for studying group affiliation. Therefore, the presence of Bombay blood in at least one of the family members (even the most distant relatives) should definitely be taken into account when the father has a desire to establish. Then specialists will conduct a test for genetic matches much more carefully and in a more extensive manner; in the process of studying samples of the genetic material of the father and child, the antigenic composition of the blood and the structure of the membranes of red blood cells will be studied.
Confirming the manifestation of the Bombay phenomenon in a child is possible only through the use of certain genetic tests that make it possible to establish the type of inheritance of blood group. For this reason, if a child is born with an unexpected blood type, first of all, one should suspect the manifestation of this unusual phenomenon in him, and not suspect the spouse of infidelity. This is the rarest blood group that can occur in humans, but it is extremely rare.
This article discusses the choice of medication to treat hypertension in elderly patients. Older people suffering from hypertension are a category of patients to which doctors have a special attitude. Practice has shown that drug-based lowering of blood pressure in older people has its own characteristics, and below you will find out what they are.
The standard approach, which is used for patients aged 30 to 60 years, may not be effective for people of retirement age. However, this in no way means that elderly hypertensive patients should give up on themselves and refuse all medical help. Effective treatment of hypertension in older people is real! For this, the competent actions of the doctor, the love of life of the patient himself, as well as the support that his relatives can provide are important.
- The best way to recover from hypertension (quickly, easily, healthy, without “chemical” drugs and dietary supplements)
- Hypertension - a popular way to cure it at stages 1 and 2
- Causes of hypertension and how to eliminate them. Tests for hypertension
- Effective treatment of hypertension without drugs
If an older person with hypertension has no complications, it is recommended to start treatment with a thiazide diuretic, which is also prescribed for younger people with a similar condition. However, an elderly person should start taking the drug at half the normal dose. For most older people, the optimal dosage is 12.5 mg dichlorothiazide. It is necessary to increase the dosage to 50 mg in extremely rare cases. If 12.5 mg tablets are not available, break the 25 mg tablet into two halves.
The activity of pharmacological agents in lowering blood pressure varies depending on the age of the patients. This was confirmed in a 1991 study. In particular, it was possible to show that the effectiveness of thiazide diuretics is higher in people 55 years of age and older than in younger patients. Therefore, diuretics in low doses are especially indicated for the treatment of elderly patients suffering from hypertension. Although older people often have high levels of cholesterol and other harmful fats in the blood (such as triglycerides), this does not necessarily prevent them from taking small doses of a thiazide diuretic (which raises blood cholesterol in high doses). It appears that taking a thiazide diuretic in low doses will have little effect on cholesterol levels.
If your body has low potassium or sodium levels, or high calcium levels, a thiazide diuretic can be taken in combination with a potassium-sparing drug. It is not recommended for older people to take extra potassium because it causes two problems at their age: they have difficulty taking pills, and their kidneys cannot remove the extra potassium from the body.
Calcium antagonists for the treatment of hypertension in the elderly
Calcium antagonists from the dihydropyridine subclass (nifedipine and its analogues), together with thiazide diuretics, are very suitable medications for hypertension in elderly patients. Dihydropyridine calcium antagonists have a moderate diuretic effect, which does not lead to a further decrease in the volume of circulating blood plasma, which is generally characteristic of old people and is usually enhanced by diuretics. Calcium antagonists are active in the low-renin form of hypertension and support renal and cerebral blood flow. There are also indications that drugs from this class can improve the properties of the aortic elastic chamber of the heart, thereby helping to lower systolic pressure, which is especially important for elderly patients.
Another study in 1998 confirmed the effectiveness of calcium antagonists in patients with isolated systolic hypertension. Patients were prescribed nitrendipine as monotherapy or in combination with enalapril or hypothiazide (12.5-25 mg per day). This made it possible to clearly reduce the risk of cardiovascular complications: sudden death by 26%, the incidence of strokes by 44%, and overall mortality by 42%. There is no doubt that diuretics, as well as calcium antagonists, improve the prognosis for patients with isolated systolic hypertension. Calcium antagonists are not only blood pressure medications, but also effective treatments for angina. True, patients whose hypertension is combined with coronary heart disease should take these drugs not for too long and preferably with breaks (pauses).
We would like to draw the attention of readers of this article (this is for doctors, patients - do not self-medicate!) to the fairly high effectiveness of the calcium antagonist diltiazem in elderly patients with hypertension. Particularly good results can be obtained by combining diltiazem with perindopril. It is appropriate to consider another important issue. It has been suggested that calcium antagonists contribute to the development of cancer in patients over 65 years of age. In a large-scale study that lasted 3 years, these assumptions were not confirmed.
Treatment of hypertension in elderly patients with beta blockers
If the patient cannot take a thiazide diuretic or for some reason the drug is not suitable for the patient, it is recommended to take a beta blocker. Beta blockers are less effective than thiazide diuretics, and they also have more side effects.
Beta blockers are less effective in treating older people with heart failure, asthma, chronic lung disease, or obstructive blood vessel disease. However, if a person has previously taken a thiazide diuretic, but the blood pressure has not normalized, taking an additional beta blocker will often help normalize the blood pressure.
Other drugs for the treatment of hypertension in elderly patients
ACE inhibitors and angiotensin II receptor blockers are not as effective as thiazide diuretics or beta blockers, but they can be used in cases where thiazide diuretics or beta blockers are not suitable for any reason (for example, in case of allergies to medications ). According to the results of the American study VACS (Veterans Affairs Study), the activity of captopril in patients 60 years of age and older did not exceed 54.5%. ACE inhibitors are more indicated for treatment in patients with diabetes. The problem with ACE inhibitors and angiotensin II receptor blockers is that while they all lower blood pressure, they are less effective at preventing hypertension-related illnesses and deaths.
Taking an ACE inhibitor and a diuretic together may cause an excessive decrease in blood pressure. A few days before starting an ACE inhibitor, you should stop taking the diuretic. The dose of an ACE inhibitor for an elderly person should be reduced. The usual daily dose is 10 mg, but an older person should reduce it to 5 mg.
Other drugs that act on the brain include medications such as methyldopa, clonidine (clonidine) and guanabenz, as well as alpha-adrenergic blockers. These are powerful medications that cause drowsiness and depression, as well as a decrease in blood pressure when standing. They are prescribed to older people with caution. Alpha-1-blockers (doxazazine, etc.) remain the drugs of choice for the treatment of hypertension in patients suffering from benign prostatic hyperplasia (adenoma). Agonists of central alpha-2-adrenergic receptors (clonidine) cause weakness, drowsiness, and mental depression in elderly patients with hypertension. In addition, when treated with clonidine (clonidine), “rebound” hypertension often occurs and, apparently, there is no reversal of left ventricular hypertrophy of the heart.
Special cases
- The use of beta blockers is advisable in cases where an elderly hypertensive person also experiences chest pain caused by coronary atherosclerosis.
- ACE inhibitors tend to prolong life in people with congestive heart failure, which is why these drugs are worth prescribing for people with heart attacks and hypertension.
- ACE inhibitors and angiotensin II receptor blockers are especially useful in older adults with high blood pressure and kidney problems often associated with diabetes.
What medications for hypertension should be used in elderly patients, depending on the presence of concomitant diseases
This information is provided for doctors! Patients - please do not prescribe hypertension pills on your own! Contact a qualified doctor!
- How can an elderly person take medications for hypertension correctly?
- Isolated systolic hypertension in the elderly
- Pseudohypertension in elderly patients
- Postural hypertension in the elderly
Hematocrit is increased or decreased: what does it mean and why does it happen?
Norm in children and adult men and women
You can find out about hematocrit indicators after taking a general blood test (displayed as a percentage by the NST indicator). The healthy state of the body depends on the patient’s age and gender.
Age group - children:
- newborns - 35-65
- up to 12 months - 32-40
- from one to eleven years - 32-41
Teenagers (12-17 years):
- girls - 35-45
- boys - 34-44
Age group - adults:
- women from 18 to 45 - 39-50
- men from 18 to 45 years old - 34-45
- age of a man over 45 - 40-50
- woman's age over 45 - 35-46
Hematocrit concentration variations in adults between 30% and 35% will require observation in the clinic and recommendations for dietary changes to increase the intake of meat, liver, fruits and leafy vegetables.
29% and 24% - a pre-painful condition, eliminated by taking medications with iron, vitamin B and folic acid.
Increased hematocrit number
High hematocrit concentrations result in thicker blood, which increases the risk of thrombosis. An increase in hematocrit in the blood can occur due to an incorrect lifestyle and for other reasons:
- Dehydration. Drinking less fluid than normal leads to moisture deficiency, and correspondingly reduced plasma concentrations change blood parameters. Active dehydration occurs after diarrhea, bouts of vomiting, overheating, or too active physical activity that provokes profuse sweating.
- Hypoxia. Chronic lack of oxygen leads to the active appearance of new blood cells - red blood cells, which serve to transport oxygen to the tissues of various organs. Hypoxia is typical for people who spend a long time in stuffy spaces, smokers and patients with diabetes.
- Mountain conditions. Directly related to hypoxia caused by being in mountainous areas. Low oxygen content in rarefied air leads to an unpleasant effect - increased production of red blood cells. Climbers and people forced by profession to be at heights are recommended to take oxygen tanks with them.
Indicator in the diagnosis of cardiovascular diseases
Bringing the number of red blood cells in the blood to normal is extremely important for heart patients.
Blockage of the lumen of blood vessels, the formation of blood clots in small and large arteries impede arterial flow, dangerously loading the heart muscle. A weak heart begins to work harder, which leads to an increased risk of myocardial infarction.
The resulting arterial thrombosis (due to an increase in the number of platelets) initially leads to the appearance of the ischemic stage, followed by the process of tissue death through induced oxygen starvation.
Heart failure, which results in fluid accumulation, also results in identical test results. The critical hematocrit content is considered to be more than 50-55% (hospitalization required).
Significance of high level in determining other diseases
Kidney problems, primarily hydronephrosis and polycystic disease, lead to an increase in the quantitative value of red blood cells. A similar effect is achieved by uncontrolled (long-term) use of corticosteroid and diuretic drugs that stimulate the removal of fluid from the body.
Other states:
- suffered stress;
- skin injuries (over 10%);
- gastrointestinal diseases;
- erythrocytosis;
- bone marrow diseases.
Pulmonary diseases - bronchial asthma, obstructive bronchitis - make it difficult to supply oxygen to the lungs, so the process of hematopoiesis intensifies.
During pregnancy, late toxicosis disrupts the functioning of the kidneys, which increases the content of red blood cells in the blood. Blood thickening is observed closer to childbirth - in the second half of pregnancy: this is how nature prepares a woman for childbirth, which is often associated with heavy blood loss.
Reduced content
Red blood cells participate in the construction of the body, feeding it with amino acids and carrying out gas exchange. A decrease in the number of blood cells can lead to various dysfunctions and problematic conditions. A lower level should alert you. Let's consider the possible reasons for the decrease in hematocrit in the blood.
Heart pathologies
Any heart defects are more difficult to treat if the number of red blood cells is low, since cardiac problems are aggravated by a difficult supply of oxygen to the tissues of the heart. Unlike an increased hematocrit, a decreased red blood cell count does not have such a detrimental effect on the heart.
Red blood cell to hemoglobin ratio:
- initial stage - 3.9-3/110-89
- average - 3-2.5/89-50
- severe - less than 1.5/less than 40
These indicators also determine the degree of anemia.
Low percentage for other reasons
A low number of red blood cells is often associated with general malaise, a constant desire to lie down to rest, and a general loss of strength. The most common disease when the hematocrit in the blood is reduced is anemia caused by a decrease in the amount of iron.
Reasons for the decrease in red blood cells:
- blood loss;
- overhydration;
- primary tumors;
- dysbacteriosis;
- smoking and alcohol.
Long-term use of medications can also cause blood thinning; for example, frequent use of aspirin leads to exactly this consequence.
An unfavorable factor is prolonged bed rest, as well as high water consumption (also caused by renal failure and intravenous infusions).
Past infectious diseases and chronic inflammatory processes equally have a lowering effect on the number of red elements in the blood. Not only visible bleeding - caused by fractures and injuries - is dangerous, but also hidden bleeding, primarily internal.
Liver cirrhosis, tumor disintegration, uterine fibroma, varicose veins of the esophagus, thallasemia are frequent companions of invisible blood loss.
Children's tests - what to prepare for
Newborns often exhibit hyperprolactinemia, indicating an increase in protein in the blood plasma. It is caused by feeding the child milk from a goat or cow (situation: the mother is not able to breastfeed) with a high protein content. To increase the tendency for blood to thicken, you should buy milk with less protein.
Over the age of 3 years, there is a decrease in mental abilities, fatigue, shortness of breath, pale skin color and rapid heartbeat. Among the diseases in children, there are all the diseases characteristic of this group, however, unpleasant conditions are also caused by trivial vitamin deficiency.
Helminthic infection, which is more typical for children and adolescents than for adults, can be eliminated by taking anthelmintic drugs, after a course of which the tests return to normal.
Changes in blood during pregnancy
A woman who is pregnant experiences a natural increase in the amount of blood, due to which the hematocrit decreases slightly.
After birth, all indicators return to normal; otherwise, unsatisfactory test results are corrected by taking iron-containing medications.
Extremely low levels lead to malaise and the likelihood of developing anemia. Red blood cell concentrations of less than 30% are dangerous for the unborn baby, since the fetus begins to experience oxygen starvation.
Let's sum it up
Now you know what this means and what the situation leads to when the hematocrit is higher or lower than normal. There are a few basic facts to remember:
- In children, changes in the number of red blood cells are a common physiological norm.
- In newborns, the ratio of elements in the blood is significantly higher than in adults.
- Men have a higher hematocrit value than women.
- A prolonged decrease in red blood cells requires consultation with a hematologist.
- A hematocrit of less than 13% requires urgent hospitalization.
Be attentive to your health! More interesting information on the topic is described in the video:
10.04.2015 13.10.2015
Blood is a unique liquid in the human body; it continuously circulates through the vessels, supplying oxygen and necessary components to the internal organs. Everyone knows that there are four of its groups, I, II, III, IV, but not everyone knows about the existence of another, extremely rare, exceptional group called the Bombay phenomenon.
Undiscovered Blood, a Discovery Story
The discovery of the phenomenon occurred in 1952, in India (the city of Mumbai, formerly Bombay, where the name originated), by the scientist Bhende. The discovery was made during research into mass malaria, after three people lacked the necessary antigens that determine which type the blood belongs to. Cases of occurrence are unique, the number of people with the Bombay phenomenon in the world is one per two hundred and fifty thousand population, only in India this figure is higher, amounting to 1 case per 7,600 people.
Interesting fact! Scientists believe that the emergence of unknown blood in India is associated with frequent marriages with members of one’s own family. According to the laws of the country, procreation within the circle of one, higher caste allows you to preserve wealth and your position in society.
Recently, a sensational statement was made by employees of the University of Vermont that there are also types of rare blood, their names are Junior and Langereis. They were discovered by mass spectrometry, as a result of which two completely new proteins were identified. Previously, science knew about 30 proteins responsible for blood group, and now there are 32 of them, which allowed scientists to announce their discovery. Experts believe that this discovery is a new step in the fight against cancer and will allow the development of a new technology for treating oncology.
What is unique?
· The first group is considered the most widespread, it arose during the time of the Neanderthals and has been known for more than 40 thousand years, almost half of its carriers on earth;
· The second has been known for more than 15 thousand years, it is also not rare, according to various sources, its carriers are about 35%, the most people with this type in Japan and Western Europe;
· the third, slightly less common than the first two, approximately the same amount is known about it as about the second, the largest concentration of people with this species is found in Eastern Europe, its total carriers are about 15%;
· the fourth, the newest, no more than a thousand years have passed since its formation, it arose as a result of the merger of I and III, only 5%, and according to some data, even 3% of the world's population have this important red liquid flowing through their vessels.
Now imagine, if group IV is considered young and rare, what can we say about the Bombay group, which is just over 60 years old from its discovery and is found in 0.001% of people on the planet; of course, its uniqueness is undeniable.
How is the phenomenon formed?
Classification into groups is based on the content of antigens, for example, the second contains antigen A, the third contains antigen B, the fourth contains both of them, and in the first they are absent, but there is an initial antigen H and all the others arise from it, it is considered a kind of “building material” for A and B.
The formation of the chemical composition of a child’s blood occurs in utero and depends on what kind of blood it is in the parents; it is heredity that becomes the fundamental factor. But there are rare exceptions to the rules that cannot be explained genetically. This is the emergence of the Bombay phenomenon, it lies in the fact that born children have a type of blood that a priori they cannot have. It does not have antigens A and B, so it can be confused with the first group, but it also does not have the H component, this is its uniqueness.
How do they live with unusual blood?
The everyday life of a person with unique blood does not differ from its other classifications, with the exception of several factors:
· a serious problem is transfusion; only the same blood can be used for these purposes, while it is a universal donor and is suitable for everyone;
· impossibility of establishing paternity; if it happens that DNA testing is necessary, it will not give results, since the child does not have the antigens that his parents have.
Interesting fact! In the USA, Massachusetts, there lives a family where two children have the Bombay phenomenon, only they also have an A-H type, such blood was diagnosed once in the Czech Republic in 1961. They cannot be donors for each other, since they have different rhesus. factor, and transfusion of any other group is naturally impossible. The eldest child reached adulthood and became a donor for himself as a last resort, the same fate awaits his younger sister when she turns 18.
· In the body of an average adult man, the blood volume is 5-6 liters;
· June fourteenth is considered world donor day, it is dedicated to the birthday of Karl Landsteiner, he was the first to classify blood into groups;
· it is believed that if the icon begins to bleed, there will be trouble; there are people who claim to have observed this process before the terrorist attack of September 11, 2001 and the beginning of World War II. Also, written sources speak of a bleeding icon before St. Bartholomew's Night;
· in the middle of the 20th century, a relationship was established between the tendency to certain diseases and blood type, for example, those with the second group are more susceptible to leukemia and malaria, those with the first group are more susceptible to ruptures of ligaments, tendons and peptic ulcers;
· the diagnosis of cancer is heard more often than others in the third group, less often than others in the first;
· there is a person who lives without a pulse, his uniqueness lies in the fact that instead of the heart that was removed, he has a device installed for blood circulation, it continues to function fully, but there is no pulse even when an ECG is performed;
· in Japan they are sure that the character and fate of a person depends on what type of blood he was born with.
The liquid, which has evolved over millions of years in order to give us the opportunity to live, contains many mysteries and secrets. It protects us from environmental influences, from various viruses and infections, neutralizing them, preventing them from penetrating vital organs. But how many more secrets, in addition to the Bombay phenomenon, as well as the Junior and Langereis groups, remain to be revealed to scientists and told to the whole world.
