Hemoglobin(abbreviated Hb) is an iron-containing oxygen-carrying metalloprotein found in the red blood cells of vertebrates.

Hemoglobin is the main blood protein

Hemoglobin is a protein consisting of 4 heme-containing protein subunits. Protomers are connected to each other by hydrophobic, ionic, and hydrogen bonds according to the principle of complementarity. Moreover, they interact not arbitrarily, but with a certain area - the contact surface. This process is highly specific; contact occurs simultaneously at dozens of points according to the principle of complementarity. The interaction is carried out by oppositely charged groups, hydrophobic regions, and irregularities on the surface of the protein.

Protein subunits in normal hemoglobin can be represented by various types of polypeptide chains: α, β, γ, δ, ε, ξ (respectively, Greek - alpha, beta, gamma, delta, epsilon, xi). The hemoglobin molecule contains two chains of two different types.

Heme is connected to the protein subunit, firstly, through a histidine residue by an iron coordination bond, and secondly, through hydrophobic bonds of pyrrole rings and hydrophobic amino acids. Heme is located, as it were, “in a pocket” of its chain and a heme-containing protomer is formed.

Normal forms of hemoglobin

There are several normal variants of hemoglobin:

• HbP - primitive hemoglobin, contains 2 ξ- and 2 ε-chains, found in the embryo between 7-12 weeks of life;
• HbF - fetal hemoglobin, contains 2 α- and 2 γ-chains, appears after 12 weeks of intrauterine development and is the main one after 3 months;
• HbA - adult hemoglobin, the proportion is 98%, contains 2 α- and 2 β-chains, appears in the fetus after 3 months of life and by birth makes up 80% of all hemoglobin;
• HbA 2 - adult hemoglobin, the proportion is 2%, contains 2 α- and 2 δ-chains;
• HbO 2 - oxyhemoglobin, is formed when oxygen binds in the lungs; in the pulmonary veins it is 94-98% of the total amount of hemoglobin;
• HbCO 2 - carbohemoglobin, is formed by the binding of carbon dioxide in tissues; in venous blood it makes up 15-20% of the total amount of hemoglobin.

Pathological forms of hemoglobin

• HbS - sickle cell hemoglobin;
• MetHb is methemoglobin, a form of hemoglobin that includes a ferric ion instead of a ferrous one. This form is usually formed spontaneously; in this case, the enzymatic capacity of the cell is sufficient to restore it. When using sulfonamides, consuming sodium nitrite and nitrates in food products, and with insufficiency of ascorbic acid, the transition of Fe 2+ to Fe 3+ is accelerated. The resulting metHb is not able to bind oxygen and tissue hypoxia occurs. To restore iron ions, the clinic uses ascorbic acid and methylene blue;
• Hb-CO - carboxyhemoglobin, is formed in the presence of CO (carbon monoxide) in the inhaled air. It is constantly present in the blood in small concentrations, but its proportion can vary depending on conditions and lifestyle. Carbon monoxide is an active inhibitor of heme-containing enzymes, in particular cytochrome oxidase, the 4th complex of the respiratory chain;
• HbA 1C -

Hemoglobin (HB) is often talked about without even knowing, but only suspecting its importance in the human body. Anemia, popularly called anemia, or too thick blood, is usually associated with variations in the values ​​of the red blood pigment. Meanwhile, the range of tasks of hemoglobin is very wide and its fluctuations in one direction or another can cause serious health problems.

Most often, a drop in hemoglobin levels is associated with the development of iron deficiency anemia; it often occurs in adolescents, young girls, and during pregnancy, so the main emphasis in this article will be on what is most interesting and understandable to the patient, because the patient will not independently engage in any activities. any severe form of hemolytic anemia.

Four hemes + globin

The hemoglobin molecule is a complex protein (chromoprotein) consisting of four hemes and the globin protein. Heme, which has ferrous iron (Fe2+) at its center, is responsible for binding oxygen in the lungs. Combining with oxygen and turning into oxyhemoglobin (HHbO2), it immediately delivers the component necessary for respiration to the tissues, and from there it takes carbon dioxide, forming carbohemoglobin (HHbCO2), to transport it to the lungs. Oxyhemoglobin and carbohemoglobin are physiological hemoglobin compounds.

The functional responsibilities of the red blood pigment in the human body also include participation in the regulation of acid-base balance, because it is one of four buffer systems that maintain a constant pH of the internal environment at the level of 7.36 - 7.4.

In addition, being localized inside red blood cells, hemoglobin regulates blood viscosity, prevents the release of water from tissues and, thereby, reduces oncotic pressure, and also prevents unauthorized consumption of hemoglobin when blood passes through the kidneys.

Hemoglobin is synthesized in erythrocytes, or rather, in the bone marrow, when they are still in the nuclear stage (erythroblasts and normoblasts).

“Harmful” abilities of hemoglobin

Even better than with oxygen, hemoglobin binds with carbon monoxide (CO), transforming into carboxyhemoglobin (HHbCO), which is a very strong compound that significantly reduces the physiological abilities of red blood pigment. Everyone knows how dangerous it is for a person to stay in a room filled with carbon monoxide. It is enough to inhale only 0.1% CO with the air for 80% of Hb to combine with it and create a strong bond, leading to the death of the body. It should be noted that smokers are constantly at risk in this regard; the content of carboxyhemoglobin in their blood is 3 times higher than normal (N - up to 1%), and after a deep puff it is 10 times higher.

A very dangerous condition for the hemoglobin molecule is the replacement of divalent iron in heme (Fe2+) with trivalent iron (Fe3+) with the formation of a form dangerous to health - methemoglobin. Methemoglobin sharply inhibits the transfer of oxygen to organs, creating conditions that are unacceptable for normal life. Methemoglobinemia occurs as a result of poisoning with certain chemicals or is present as a hereditary pathology. It may be associated with the transmission of a defective dominant gene or due to recessive inheritance of a special form of enzymopathy (low activity of an enzyme capable of restoring metHb to normal hemoglobin).

Such a necessary and wonderful complex protein in all respects as hemoglobin, localized in red blood cells, can become a very dangerous substance if for some reason it is released into the plasma. Then it becomes very toxic, causing oxygen starvation of tissues (hypoxia) and poisoning the body with its breakdown products (bilirubin, iron). In addition, large Hb molecules, which are not destroyed and continue to circulate in the blood, enter the renal tubules, close them and thereby contribute to the development of acute kidney injury (acute renal failure).

Such phenomena, as a rule, accompany severe pathological conditions associated with disorders in the blood system:

• DIC syndrome;
• Hemorrhagic shock;
• Congenital and acquired hemolytic anemia; (sickle cell, thalassemia, autoimmune, toxic, Moshkovich disease, etc.);
• Transfusion of blood incompatible with group erythrocyte antigens (AB0, Rh).

Disturbances in the structural structure of hemoglobin are called hemoglobinopathies in medicine. This is a range of hereditary blood diseases that includes such well-known pathological conditions as, for example, sickle cell anemia and thalassemia.

Limits of normal values

Well, perhaps you don’t need to describe the hemoglobin norm. This is one of the indicators, the normal values ​​of which most people will name without hesitation. However, we would like to remind you that the norm in women is slightly different from that in men, which is understandable from a physiological point of view, because the female sex loses a certain amount of blood every month, and at the same time iron and protein.

In addition, the level of hemoglobin cannot remain unchanged during pregnancy, and although fetal tissue is mainly supplied with oxygen by fetal (HbF) hemoglobin, its level in the mother also decreases slightly (!). This happens because plasma volume increases during pregnancy and the blood thins (in proportion to the decrease in red blood cells). Meanwhile, such a phenomenon is considered a physiological condition, so there can be no talk of any significant drop in Hb levels as normal. Thus, the following values ​​are taken for normal hemoglobin, depending on gender and age:

1. In women from 115 to 145 g/l (during pregnancy from 110 g/l);
2. In men, from 130 to 160 g/l;
3. In children, the hemoglobin content is normal, as in adults: before birth, HbA begins to be synthesized, which by the year of life practically replaces the fetal hemoglobin that served the child during intrauterine development.

When considering hemoglobin, one cannot ignore other indicators that indicate whether hemoglobin sufficiently fills red blood cells, or whether they circulate lightly, without Hb.

The color index (CI), indicating the degree of saturation, can have the following values:

• 0.8 – 1.0 (red blood cells are normochromic – no problem);
• Less than 0.8 (hypochromic - anemia);
• More than 1.0 (Er hyperchromic, reason?).

In addition, the saturation of red blood cells with pigment can be indicated by such a criterion as SGE (average Hb content in 1 red blood cell, which when examined in an automatic analyzer is designated MCH), its norm is from 27 to 31 pg.

However, the hematology analyzer also calculates other parameters that reflect the state of red blood (hematocrit, average hemoglobin content in erythrocytes, average volume of erythrocytes, indicator of their heterogeneity, etc.).

Why does the hemoglobin level change?

Hemoglobin levels depend to some extent on:

1. Season (decreases in autumn, probably because people harvest and prefer plant foods),
2. Diet: vegetarians have lower Hb;
3. Climate and terrain (where there is little sun, anemia is more common, and in high mountain areas hemoglobin increases);
4. Lifestyle (active sports and intense physical work for a long time increase hemoglobin);
5. Oddly enough, both clean fresh air and smoking affect Hb levels to almost the same extent (they increase it). Most likely, for smokers this indicator includes hemoglobin modified by tobacco smoke, so those who like to relax with a cigarette seem to have no reason to be satisfied with the tests, but there is an opportunity to think: what does hemoglobin carry in the red blood cells of a smoker?

There is little hemoglobin

“I have low globin,” this is how a woman put it, having stayed too long in the maternity hospital and explaining the essence of the problem to curious neighbors. Low hemoglobin, unlike high hemoglobin, occurs quite often, everyone is actively fighting it, using not only medications containing iron and B vitamins, but also a wide range of folk remedies and products that increase hemoglobin.

Reduced or low hemoglobin together with a decrease in the number of red blood cells is called anemia (anemia); for men, anemia is considered to be a drop in the Hb level below 130 g/l; women are afraid of anemia if the hemoglobin content in red blood cells becomes less than 120 g/l.

In the diagnosis of anemia, hemoglobin plays a decisive role, since red blood cells do not always have time to decrease (in mild forms). It is appropriate to name the main forms of anemia, because this concept is not limited to iron deficiency anemia (IDA). Thus, 6 main groups are most often considered:

• Acute posthemorrhagic anemia, which occurs after massive blood loss. It is clear that the causes of low hemoglobin here will be injuries, wounds, and internal bleeding.
• Iron deficiency anemia is the most common, since a person does not know how to synthesize iron, but takes it from the outside with foods rich in this element. You may not know or know about IDA for a long time if you do not take a blood test for Hb, Er, CP, etc.
• Sideroachrestic anemia, associated with impaired utilization and synthesis of porphyrin and the accumulation of excess iron as a result. The cause of low hemoglobin in this case may be a hereditary factor (lack of an enzyme that includes iron in heme) or an acquired pathology resulting from lead intoxication, alcoholism, cutaneous porphyria, or as a consequence of treatment with anti-tuberculosis drugs (tubazid).
• Megaloblastic, B12 and/or folate deficiency (Addison-Biermer disease). This form was once called malignant anemia.
• Hemolytic anemia, united by a common feature - the accelerated breakdown of red blood cells, which instead of 3 months live only a month and a half.
• Anemia associated with inhibition of erythroid proliferation, for example, its displacement by tumors, aplastic anemia during treatment with cytostatics or exposure to high doses of radiation.

There are quite a few conditions that have the symptom of low hemoglobin, each of them has its own mechanism of development and prerequisites for its occurrence, but we will consider the most common causes and symptoms of this pathology.

Why does the color of blood fade?

The reasons for low hemoglobin, in addition to climate or pregnancy status, can arise from many circumstances:

Obviously, if you list the reasons for low hemoglobin for each form of anemia, and then add them up, there will be much more of them.

How does anemia manifest?

Symptoms indicating low hemoglobin, as well as the reasons: there are general ones, and there are purely specific ones. For example, the deposition of iron in places unusual for it in sideroachrestic anemia leads to the appearance of various pathologies: diabetes mellitus (Fe accumulates in the pancreas), cirrhosis of the liver, heart failure (in the heart), eunuchoidism (in the gonads), but this does not mean that such troubles will come out in other forms.

Meanwhile, low hemoglobin can be assumed based on some signs:

• Pale (sometimes with a yellowish tint), dry skin, scratches that heal poorly.
• Seizures in the corners of the mouth, cracks on the lips, painful tongue.
• Brittle nails, dull split ends.
• Muscle weakness, fatigue, drowsiness, lethargy, depression.
• Decreased concentration, flashing “flies” before the eyes, intolerance to stuffy rooms.
• Drooling at night, frequent urge to urinate.
• Decreased immunity, poor resistance to seasonal infections.
• Headaches, dizziness, possible fainting.
• Shortness of breath, attacks of rapid heartbeat.
• Enlarged liver and/or spleen (a sign that is not characteristic of all forms).

Clinical manifestations of anemia increase as the process develops and progresses.

Above normal

A high level of hemoglobin can be a sign of blood thickening and the risk of thromboembolism, a symptom of hematological diseases (polycythemia) and other pathologies:

1. Malignant neoplasms, the cells of which are in great need of oxygen;
2. Heart defects;
3. Bronchial asthma and cardiopulmonary failure;
4. A consequence of burn disease (poisoning by toxins released from dead cells);
5. Impaired protein synthesis in the liver, which could interfere with the release of water from the plasma (liver disease);
6. Fluid loss due to diseases of the intestinal tract (obstruction, poisoning, infections).

In addition to determining hemoglobin, which is an important indicator of a general blood test, in cases of diabetes mellitus, glycated hemoglobin is determined, which is a biochemical test.

Glycohemoglobin is considered a very important diagnostic criterion, based on the property of Hb to create a strong bond with glucose, so its increase may indicate an increase in blood sugar over a long period of time (approximately 3 months - this is the lifespan of red blood cells). The norm of glycated hemoglobin is in the range of 4 – 5.9%. Increased hemoglobin containing glucose indicates the development of complications of diabetes (retinopathy, nephropathy).

It is not recommended to deal with elevated hemoglobin levels (either with or without sugar) on your own. In the first case, you need to treat diabetes mellitus, and in the second you should look for the cause and try to eliminate it with the help of adequate therapeutic measures, because otherwise you can only worsen the situation.

Little secrets

In order to increase hemoglobin in the blood, you need to know the reason for its drop, just in case. You can consume foods that increase hemoglobin (iron, B vitamins) as much as you like, but if they are not properly absorbed in the gastrointestinal tract, then you may not achieve success. Most likely, first you will have to undergo a set of examinations, including the very scary and unloved FGDS (fibrogastroduodenoscopy) in order to exclude pathology of the stomach and duodenum.

As for products that increase hemoglobin, this also has its own nuances. Many plant sources are rich in iron (pomegranate, apples, mushrooms, seaweed, nuts, legumes, melons), but humans are naturally a carnivore and absorb Fe well with proteins, such as:

• Veal;
• Beef;
• Hot lamb;
• Lean pork (by the way, lard, whatever you season it with, will not add iron);
• Chicken is not very suitable, but goose and turkey can easily pass for foods that increase hemoglobin;
• Chicken eggs are low in iron, but contain a lot of vitamin B12 and folic acid;
• There is a lot of iron in the liver, but it is there in the form of hemosiderin, which is practically not absorbed (!), and we should not forget that the liver is a detoxification organ, so you probably shouldn’t get too carried away.

What can help the absorption of necessary substances? Here you really need to look carefully. So that the efforts and money spent on the diet are not in vain, and that home treatment yields good results, we must remember some features of dietary nutrition for anemia:

1. Ascorbic acid greatly promotes the absorption of iron from other foods, so citrus fruits (oranges, lemons) will complement the diet well and help raise hemoglobin at home.
2. Of the side dishes, buckwheat is the best way to increase Hb, millet porridge and oatmeal are good, but you don’t need to add butter and margarine, they still contain almost no iron.
3. It is not very useful to wash down lunch with strong tea, it inhibits the absorption of iron, but a rosehip drink, cocoa (without milk) or dark chocolate will complement an iron-enriched meal well.
4. Cheeses, cottage cheese, and milk should not be consumed simultaneously with foods that increase hemoglobin; they contain calcium, which interferes with the absorption of Fe.
5. Small (!) doses of dry red wine help to raise hemoglobin at home (this is prohibited in hospitals), but the main thing here is not to overdo it, because it will have the opposite effect, and even better, go to the pharmacy and buy hematogen, which is sold there in the form of toffee: both tasty and healthy.

Meat, buckwheat and rosehip decoction are, of course, wonderful, but only in cases of mild anemia (up to 90 g/l) and as an adjuvant for moderate anemia (up to 70 g/l), but if there is a pronounced form, then you definitely can’t do without the help of iron-containing drugs. Patients do not prescribe them to themselves, because, due to the development of complications and undesirable side effects (iron deposition in organs and tissues - secondary hemachromatosis), treatment requires constant laboratory monitoring and medical supervision.

Regarding other forms of anemia, it should be noted that it probably won’t be possible to increase hemoglobin at home with the help of foods and folk remedies; the underlying disease must be treated, and in this case it is better to trust a doctor.

Video: low hemoglobin - Dr. Komarovsky

The norm of hemoglobin in the blood and its functions

• The chemical "face" of hemoglobin
• Other properties and types of hemoglobin
• Glycated hemoglobin
• How is the norm calculated?
• How is the analysis carried out?
• What techniques are used in the laboratory
• Deviations from the norm
• Features during pregnancy

Hemoglobin in human blood performs important functions. The study showed a direct dependence of its content on the severity of anemia (anemia).
Determining hemoglobin in the blood is a simple test available to small outpatient clinics. Therefore, it is widely used in diagnostics.

The chemical "face" of hemoglobin

Chemically, this substance is a protein compound with iron. It is believed that histidine is the iron-retaining amino acid. The special role is confirmed by the fact that hemoglobin is contained only in red blood cells (90% of the mass of a healthy cell) and cannot be found anywhere else. It is born along with the red blood cell, gradually accumulates in concentration and reaches its maximum content in the mature cell.

Complex bonds allow hemoglobin to hold oxygen molecules and carbon dioxide. Constant changes occur in red blood cells:

• in the pulmonary capillaries, hemoglobin takes up oxygen and turns into oxyhemoglobin;
• carries oxygen to tissues, preventing hypoxia;
• then gives up an O2 molecule, turns into a reduced form and returns through the venous blood to the lungs.

These abilities presuppose the possibility, knowing the hemoglobin content in the blood, to judge the number of red blood cells, iron, and the degree of oxygen deficiency in the body.

Hemoglobin in the fetal blood changes its shape several times before birth until it adapts to the baby’s own breathing at the time of birth.

Other properties and types of hemoglobin

Hemoglobin can transform from “useful” physiological forms into pathological ones. It is able to combine with other gases dissolved in the blood, forming toxic compounds.

• When carbon monoxide appears in the air, half of the total amount of hemoglobin instantly binds and turns into carboxyhemoglobin.
• Methemoglobin is formed during poisoning with drugs (sulfonamides, phenacetin). These forms impair the ability to carry oxygen, so acute oxygen deficiency develops in the tissues of the entire body.
• Sulfhemoglobin can also be formed during drug poisoning. This form is more toxic. Even the accumulation of 10% in the blood leads to irreversible consequences: the destruction of red blood cells.

A less familiar function of hemoglobin is maintaining an optimal level of acid-base balance.

Glycated hemoglobin

A blood test for glycated hemoglobin determines the percentage of this substance associated with glucose. The indicator allows you to determine the average amount of glucose over three months.

This is important for monitoring compliance and dietary restrictions in diabetes mellitus.

Decoding indicates:

• normal if the level is below 5.7%;
• low risk of diabetes, if 5.7 – 6%;
• maximum risk at 6 – 6.4%;
• the presence of the disease with an indicator of more than 6.4%.

The indicator is very convenient in diagnosis, but is not carried out in all laboratories.

How is the norm calculated?

The norm of hemoglobin in the blood is established based on the determination in the body of practically healthy people of different sexes.

Normal level: for men – from 135 to 160 g/l, for women – from 120 to 140.
It has been established that the dependence of the analysis on the period of menstruation is important for the female body.

How the level of hemoglobin in the blood depends on the age of the child is presented in the table.

During the neonatal period, the hemoglobin level is at its maximum. It is called fetal, its properties are somewhat different from those of adults. By the first year, it is completely destroyed and changes to its normal appearance. Identification of this type in the older period indicates abnormal development and indicates a disease.
Determining hemoglobin in a baby is important for timely monitoring of proper nutrition and for the prevention of anemia.

How is the analysis carried out?

The hemoglobin test is included in a mandatory study when conducting any type of examination or medical examination of healthy individuals.

It is necessary to donate blood in the morning before meals, after a restful period of sleep. If you had to work a night shift, you need to warn your doctor; the readings may be unreliable.

In the laboratory, blood is taken from a finger. In the venous system, the amount of this substance is always less; the vein is usually analyzed for various biochemical tests. But sometimes, if blood from a vein has already been taken into a test tube, then hemoglobin can be determined, taking into account that the norm is somewhat lower.

What techniques are used in the laboratory

Various methods for determining hemoglobin have been proposed:

• colorimetry - involves measuring the color intensity of the reaction;
• gas metering - a blood sample is saturated with gas (the property of hemoglobin is used), then the volume of absorbed gas is measured;
• determination of iron - based on a certain correspondence of the amount of iron to dissolved hemoglobin.

The last two methods are considered the most accurate, but they are labor-intensive, so the first is used in medical institutions.

Deviations from the norm

Laboratory testing gives a conclusion about compliance with the standard, an increased level of hemoglobin or indicates a lack of it in the blood.

High hemoglobin is determined by:

• For mountaineer athletes who permanently live in high mountain areas. At high altitudes, blood oxygen saturation increases significantly because the oxygen pressure in the atmosphere is much higher than in flat areas.
• In cases of increased concentration of red blood cells with massive loss of fluid (prolonged vomiting, diarrhea, extensive burns).
• As an adaptive mechanism in the initial stages of heart and pulmonary failure, acute myocardial infarction. The body is trying to make a small reserve.
• With erythremia - cancer of the red blood cell.

Typical symptoms: facial flushing, headache, increased blood pressure, nosebleeds.

An indicator below normal is determined by anemia (anemia), at the same time the content of red blood cells and iron is reduced, and the ESR is sharply accelerated. WHO has determined the minimum hemoglobin level for the diagnosis of anemia for men - less than 130 g/l, for women - less than 120.

Anemia can be an independent disease or a symptom of blood loss or other diseases.

Abundant saturation of the body with fluid also leads to a relative decrease, since it dilutes the usual number of red blood cells in a larger volume of water.

Typical symptoms appear: dizziness, weakness, headaches, tachycardia, noise in the head, pallor and cyanosis of the skin.

Features during pregnancy

During pregnancy, hemoglobin testing is important for taking measures to prevent anemia. A woman accumulates a larger volume of blood to meet the needs of the fetus. This suggests a mechanism similar to red blood cell dilution.

It is allowed to reduce the rate in pregnant women to 110 g/l. Large deviations are taken as pathology and subject to treatment, because this means a risk of developing oxygen deficiency for the unborn baby and mother.

It is not difficult to undergo a test to determine hemoglobin. The analysis makes it possible to prevent pathology in a timely manner and is involved in differential diagnosis.

Major blood diseases

Blood diseases are a set of diseases that are caused by various causes and have different clinical presentations and courses. They are united by disturbances in the number, structure and activity of blood cells and plasma. The science of hematology studies blood diseases.

Types of pathologies

Classic blood diseases characterized by changes in the number of blood elements are anemia and erythremia. Diseases associated with malfunctions in the structure and functioning of blood cells include sickle cell anemia and lazy leukocyte syndrome. Pathologies that simultaneously change the number, structure and functions of cellular elements (hemoblastosis) are called blood cancer. A common disease with changes in plasma functions is myeloma.

Diseases of the blood system and blood diseases are medical synonyms. The first term is more comprehensive, since it includes not only diseases of blood cells and plasma, but also diseases of the hematopoietic organs. The origins of any hematological disease is a malfunction of one of these organs. Blood in the human body is very labile; it reacts to all external factors. It carries out a variety of biochemical, immune and metabolic processes.

When the disease is cured, blood parameters quickly return to normal. If there is a blood disease, special treatment is necessary, the purpose of which will be to bring all indicators closer to normal. To distinguish hematological diseases from other ailments, it is necessary to conduct additional examinations.

The main blood pathologies are included in ICD-10. It contains various types of anemia (iron deficiency, folate deficiency) and leukemia (myeloblastic, promyelocytic). Blood diseases are lymphosarcoma, histocytosis, lymphogranulomatosis, hemorrhagic disease of the newborn, coagulation factor deficiencies, deficiencies of plasma components, thrombasthenia.

This list consists of 100 different items and allows you to understand what types of blood diseases there are. Some blood pathologies are not included in this list because they are extremely rare diseases or various forms of a specific illness.

Principles of classification

All blood diseases in outpatient practice are conventionally divided into several broad groups (based on the blood elements that have undergone changes):

1. Anemia.
2. Hemorrhagic diathesis or pathologies of the homeostasis system.
3. Hemoblastosis: tumors of blood cells, bone marrow and lymph nodes.
4. Other ailments.

Diseases of the blood system that are included in these groups are divided into subgroups. Types of anemia (by reasons of occurrence):

• associated with impaired hemoglobin secretion or red blood cell production (aplastic, congenital);
• caused by the accelerated breakdown of hemoglobin and red blood cells (defective hemoglobin structure);
• provoked by blood loss (posthemorrhagic anemia).

The most common anemia is deficiency anemia, which is caused by a lack of substances essential for the secretion of hemoglobin and red blood cells by the hematopoietic organs. Severe chronic diseases of the circulatory system occupy the 2nd position in prevalence.

What are hemoblastoses?

Hemoblastoses are cancerous blood tumors that originate in the hematopoietic organs and lymph nodes. They are divided into 2 broad groups:

1. Lymphomas.

Leukemia causes primary damage to the hematopoietic organs (bone marrow) and the appearance of a significant number of pathogenic cells (blasts) in the blood. Lymphomas lead to lesions of lymphoid tissues, disruption of the structure and activity of lymphocytes. In this case, the appearance of malignant nodes and damage to the bone marrow occurs. Leukemias are divided into acute (lymphoblastic T- or B-cell) and chronic (lymphoproliferative, monocytoproliferative).

All types of acute and chronic leukemia occur due to pathological cell development. This occurs in the bone marrow at different stages. The acute form of leukemia is malignant, so it is less responsive to therapy and often has a poor prognosis.

Lymphomas can be Hodgkin's (lymphogranulomatosis) and non-Hodgkin's. The former can occur in different ways, having their own manifestations and indications for treatment. Types of non-Hodgkin's lymphomas:

• follicular;
• diffuse;
• peripheral.

Hemorrhagic diathesis leads to blood clotting disorders. These blood diseases, the list of which is very long, often provoke bleeding. Such pathologies include:

• thrombocytopenia;
• thrombocytopathy;
• failures of the kinin-kallikrein system (Fletcher and Williams defects);
• acquired and hereditary coagulopathies.

Symptoms of pathologies

Diseases of the blood and blood-forming organs have very different symptoms. This depends on the involvement of cells in pathological changes. Anemia manifests itself as symptoms of oxygen deficiency in the body, and hemorrhagic vasculitis causes bleeding. In this regard, there is no general clinical picture for all blood diseases.

Conventionally, manifestations of diseases of the blood and hematopoietic organs are distinguished, which to one degree or another are inherent in all of them. Most of these diseases cause general weakness, increased fatigue, dizziness, shortness of breath, tachycardia, and problems with appetite. There is a stable increase in body temperature, prolonged inflammation, itching, disruptions in the sense of taste and smell, bone pain, subcutaneous hemorrhages, bleeding of the mucous membranes of various organs, pain in the liver, and decreased performance. If the mentioned signs of a blood disease appear, a person should consult a specialist as soon as possible.

A stable set of symptoms is associated with the occurrence of various syndromes (anemic, hemorrhagic). Such symptoms in adults and children occur with various blood diseases. Anemic blood diseases have the following symptoms:

• paleness of the skin and mucous membranes;
• drying or waterlogging of the skin;
• bleeding;
• dizziness;
• problems with gait;
• loss of strength;
• tachycardia.

Laboratory diagnostics

To determine diseases of the blood and hematopoietic system, special laboratory tests are carried out. A general blood test allows you to determine the number of leukocytes, red blood cells and platelets. The parameters of ESR, leukocyte formula, and hemoglobin amount are calculated. The parameters of red blood cells are studied. To diagnose such diseases, the number of reticulocytes and platelets is counted.

Among other studies, a pinch test is performed and the duration of bleeding is calculated according to Duke. In this case, a coagulogram will be informative to determine the parameters of fibrinogen, prothrombin index, etc. The concentration of clotting factors is determined in the laboratory. Often it is necessary to resort to bone marrow puncture.

Diseases of the hematopoietic system include pathologies of an infectious nature (mononucleosis). Sometimes infectious diseases of the blood are mistakenly attributed to its reaction to the appearance of infection in other organs and systems of the body.

With a simple sore throat, certain changes begin in the blood as an adequate response to the inflammatory process. This state of affairs is absolutely normal and does not indicate a blood pathology. Sometimes people classify changes in its composition as infectious diseases of the blood, which are caused by the entry of a virus into the body.

Identification of chronic processes

The name chronic blood pathology mistakenly implies long-term changes in its parameters that are caused by other factors. This phenomenon can be triggered by the onset of a disease not related to blood. Hereditary blood diseases are less widespread in outpatient practice. They begin at birth and represent a large group of diseases.

The name systemic blood diseases often hides the possibility of leukemia. Doctors make this diagnosis when blood tests show significant deviations from the norm. This diagnosis is not entirely correct, since any blood pathologies are systemic. A specialist can only formulate a suspicion of a certain pathology. During autoimmune disorders, the human immune system eliminates its blood cells: autoimmune hemolytic anemia, drug-induced hemolysis, autoimmune neutropenia.

Sources of problems and their treatment

The causes of blood diseases are very different, sometimes they cannot be determined. Often the occurrence of the disease can be caused by a deficiency of certain substances and immune disorders. It is impossible to identify generalized causes of blood pathologies. There are also no universal methods for treating blood diseases. They are selected individually for each type of disease.

Their non-protein part is the heme - a structure that includes a porphyrin ring (consisting of 4 pyrrole rings) and an Fe 2+ ion. Iron binds to the porphyrin ring with two coordination and two covalent bonds.

The structure of hemoglobin

The structure of hemoglobin A

Protein subunits in normal hemoglobin can be represented by various types of polypeptide chains: α, β, γ, δ, ε, ξ (respectively, Greek - alpha, beta, gamma, delta, epsilon, xi). The hemoglobin molecule contains two chains of two different types.

Heme is connected to the protein subunit, firstly, through a histidine residue by an iron coordination bond, and secondly, through hydrophobic bonds of pyrrole rings and hydrophobic amino acids. Heme is located, as it were, “in a pocket” of its chain and a heme-containing protomer is formed.

Normal forms of hemoglobin

• HbР – primitive hemoglobin, contains 2ξ- and 2ε-chains, is found in the embryo between 7-12 weeks of life,
• HbF – fetal hemoglobin, contains 2α- and 2γ-chains, appears after 12 weeks of intrauterine development and is the main one after 3 months,
• HbA – adult hemoglobin, the proportion is 98%, contains 2α- and 2β-chains, appears in the fetus after 3 months of life and by birth makes up 80% of all hemoglobin,
• HbA 2 – hemoglobin of adults, the proportion is 2%, contains 2α- and 2δ-chains,
• HbO 2 - oxyhemoglobin, is formed when oxygen binds in the lungs; in the pulmonary veins it is 94-98% of the total amount of hemoglobin,
• HbCO 2 – carbohemoglobin, is formed by the binding of carbon dioxide in tissues; in venous blood it makes up 15-20% of the total amount of hemoglobin.

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Types of hemoglobin, diagnosis and interpretation of research results

Hemoglobin is a vital protein for the body that performs several functions, but the main one is the transfer of oxygen to tissues and cells. Hemoglobin deficiency can lead to serious consequences. It is this protein that gives blood its rich red color due to the iron content in it. Hemoglobin is found in red blood cells and consists of compounds of iron and globin (protein).

Hemoglobin - types and functions

The meaning and types of hemoglobin in the blood

Hemoglobin must be contained in a person’s blood in sufficient quantities so that the tissues receive the amount of oxygen they need. Each hemoglobin molecule contains iron atoms, which bind oxygen.

There are three main functions of hemoglobin:

1. Oxygen transport. The most famous function. A person inhales air, oxygen molecules enter the lungs, and from there they are transported to other cells and tissues. Hemoglobin binds oxygen molecules and transports them. If this function is disrupted, oxygen starvation begins, which is especially dangerous for the brain.
2. Transport of carbon dioxide. In addition to oxygen, hemoglobin can bind and transport carbon dioxide molecules, which is also important.
3. Maintaining pH level. Carbon dioxide, accumulating in the blood, causes its acidification. This cannot be allowed; carbon dioxide molecules must be constantly removed.

In human blood, the protein is present in several varieties. The following types of hemoglobin are distinguished:

• Oxyhemoglobin. This is hemoglobin with bound oxygen molecules. It is found in arterial blood, which is why it is bright scarlet.
• Carboxyhemoglobin. Hemoglobin with bound carbon dioxide molecules. They are transported to the lungs, where carbon dioxide is eliminated and hemoglobin is again saturated with oxygen. This type of protein is contained in the venous darker and thicker blood.
• Glycated hemoglobin. This is an inseparable combination of protein and glucose. This type of glucose can circulate in the blood for a long time, so it is used to determine blood sugar levels.
• Fetal hemoglobin. This hemoglobin can be found in the blood of a fetus or newborn baby in the first few weeks of life. This is hemoglobin, which is more active in terms of oxygen transfer, but is quickly destroyed under the influence of environmental factors.
• Methemoglobin. This is hemoglobin bound to various chemical agents. Its growth may indicate poisoning of the body. The bonds between the protein and the agents are quite strong. When the level of this type of hemoglobin increases, tissue oxygen saturation is disrupted.
• Sulfhemoglobin. This type of protein appears in the blood when taking various drugs. Its content usually does not exceed 10%.

Diagnosis of hemoglobin level

Hemoglobin level test: purpose, preparation and procedure

Hemoglobin is included in the clinical blood test. Therefore, most often a complete blood test is prescribed and all indicators are assessed as a whole, even if only hemoglobin is important.

If diabetes is suspected, a separate test for glycated hemoglobin is taken. In this case, the patient experiences increased thirst, frequent urination, gets tired quickly and often suffers from viral diseases.

In any case, blood is donated in the morning on an empty stomach. It is advisable that at least 8 hours pass after the last meal. On the eve of the analysis, it is not advisable to engage in physical activity, smoke, drink alcohol or take any medications. If some medications cannot be stopped, you should inform your doctor about their use. It is not necessary to adhere to a diet, but it is recommended to avoid fatty and fried foods, as the indicators may change. During pregnancy, a test for hemoglobin (and other indicators in general) is taken frequently, once every few weeks, if necessary every week.

A doctor may suspect a lack of hemoglobin and order a blood test to check if the patient experiences low blood pressure, fatigue, weakness, headaches and dizziness, fainting, as well as hair loss and brittle nails.

In different laboratories, blood testing for hemoglobin is carried out differently depending on the equipment available. Either the iron content in hemoglobin is measured, or the color saturation of the blood solution is assessed.

Useful video - Glycated hemoglobin is increased.

The most common method used to measure hemoglobin levels is hydrochloric acid. This method is called the Sali method. The resulting material is mixed with acid in a certain amount and then adjusted to a standard color using distilled water. The amount of hemoglobin is determined by relating the resulting volume to accepted standards. The Sali method has been used for a long time, it is somewhat lengthy and subjective, and largely depends on the human factor. However, modern medicine makes it possible to determine hemoglobin levels with more accurate and automated methods, using a device called a hemometer. This method is faster, but can also produce discrepancies of up to 3 grams per liter.

Analysis transcript

Hemoglobin: norm and reasons for deviation

Only a doctor should decipher the test result. Despite its apparent simplicity (just find out the norm and compare the result), there may be discrepancies. In addition, the doctor will evaluate other indicators and be able to determine what other examination needs to be performed.

• Men have a higher hemoglobin level than women. It is g/l, in women – g/l.
• During pregnancy, hemoglobin can drop to 90 g/l due to increased blood volume.
• In a small child the norm is even higher. If this is a newborn baby, its hemoglobin may exceed 200 g/l. With age, the level decreases due to the breakdown of fetal hemoglobin.

Glycated hemoglobin is determined depending on the level of total. Normally it is no more than 6.5%. In women, hemoglobin drops during menstruation, and this is considered normal due to a certain amount of blood loss. At this time, the hg/l indicator is not considered a deviation. When deciphering, the doctor must take into account factors affecting the patient’s hemoglobin level: these are operations, bleeding (menstrual, hemorrhoidal and even bleeding gums).

Hemoglobin below g/l is considered low.

If this mark reaches g/l, this is a critical decrease in hemoglobin, requiring hospitalization and observation. With such anemia, all organs and systems of the body suffer. The reasons for a decrease in hemoglobin levels can be not only various bleeding, but also pathologies of the reproductive system, infections, autoimmune and hereditary diseases, and cancer. Therefore, in case of chronically low hemoglobin, it is advisable to conduct additional examination.

An increased level of hemoglobin (more hemoglobin) is not at all a good sign and does not indicate a sufficient amount of oxygen in the tissues. This is only normal when working in conditions with insufficient oxygen levels, such as when working at high altitudes. An increased level of hemoglobin may indicate a malfunction of internal organs, cancer, bronchial asthma, serious heart and lung diseases, tuberculosis, etc.

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Pathological forms of hemoglobin

To date, more than 200 forms of pathological hemoglobins are known, differing from normal ones in the structure of the globin polypeptide chain, when one or more amino acids are replaced by others or are missing.

The most common hereditary disorder is hemoglobinopathy S (sickle cell anemia), which can be confirmed by sickling tests (see 3.3.2). Study of pathological hemoglobins Pathological derivatives of hemoglobin include:

Carboxyhemoglobin(HbCO)- is formed when hemoglobin combines with carbon monoxide (CO). This process is possible in 2-4% under normal conditions. CO is normally formed during the breakdown of hemoglobin, when verdoglobin is formed, during the cleavage of the methine bridge. The CH group (methine group) is not lost, but turns into CO. CO can activate guanylate cyclase, causing subsequent events in the target cell. Carboxyhemoglobin is a strong compound, weakly dissociating, unable to attach oxygen. In addition, in the presence of carboxyhemoglobin, deoxygenation of oxygenated hemoglobin is hindered (Holden effect). When the concentration of carbon monoxide in the inhaled air is about 0.1%, 50% of hemoglobin binds to it in 1/130 of a second (hemoglobin has a higher affinity for carbon monoxide than for oxygen). There are three degrees of carbon monoxide poisoning. The first is manifested by severe headaches, shortness of breath and nausea. The second, in addition to the manifestations of the first, is additionally characterized by muscle weakness and the presence of scarlet spots on the face. Third degree - coma (bright scarlet face, cyanosis of the extremities, temperature 38-40C, seizures). There are atypical forms - fulminant, when blood pressure drops sharply, pallor (white asphyxia). Chronic carbon monoxide poisoning is possible. If approximately 70% of hemoglobin is associated with carbon monoxide, the body dies from hypoxia. The blood has a lilac hue (“the color of lingonberry juice”). The absorption spectrum of carboxyhemoglobin is very similar to the absorption spectrum of oxyhemoglobin - two thin dark lines in the yellow-green part of the spectrum, but they are shifted somewhat towards the violet end. For more accurate recognition of oxyhemoglobin and carboxyhemoglobin, Stokes reagent (ammonia solution of tartaric iron) should be added to the test solution. Since this reagent is a strong reducing agent, when it is added to a solution of oxyhemoglobin, the latter is reduced to hemoglobin, the absorption spectrum of which is one dark line. The absorption spectrum of carboxyhemoglobin does not change when adding the Stokes reagent, because it has no effect on this connection. It is used in forensic practice to diagnose the difference between death from mechanical asphyxia (suffocation) and carbon monoxide poisoning.

Methemoglobin(HbOH)– can be formed under normal conditions (1-2%) during the utilization of nitric oxide. Under physiological conditions, methemoglobin is involved not only in the utilization of nitric oxide, but is also capable of binding cyanide, reactivating respiratory enzymes. Cyanides are constantly formed under physiological conditions (as a result of the interaction of aldehydes, ketones and alpha-hydroxy acids with cyanhydrin, as well as as a result of the metabolism of nitriles). The enzyme rhodonase (liver, kidneys and adrenal glands) also takes part in the disposal of cyanide. This enzyme catalyzes the addition of sulfur cyanides, which leads to the formation of thiocyanates - 200 times less toxic substances. Methemoglobin is capable of binding hydrogen sulfide, sodium azite, thiocyanates, sodium fluoride, formate, arsenous acid and other poisons. Methemoglobin is involved in the elimination of excess hydrogen peroxide, destroying it to water and atomic oxygen and converting it into oxyhemoglobin. Normally, methemoglobin does not accumulate in red blood cells, because they have a system for its recovery - enzymatic (NADP reductase, or diaphorase - 75%), non-enzymatic (vitamin C - 12-16% and reduced GLT - 9-12%).

It is labor-intensive and is carried out in specialized laboratories.

biochemical criteria for diagnosing anemia

They include: UAC (Nb, Er, Cv. p., reticul.), MSN, MCNS, serum. Fe, PVSS, LVSS, ferritin level. A blood test reveals a decrease in HB and a decrease in the concentration of HB in the Er. The number of Ers is reduced to a lesser extent.

Main hematological sign of IDA is its sharp hypochromic: color p.< 0,85 – 0,4-0,6. В N- цв. п. – 0,85-1,05. ЖДА always hypochromic although not all hypochromic anemia is Fe deficiency.

Microcytosis is detected (diameter Er< 6,8 мкм), анизо- и пойкилоцитоз. Количество ретикулоцитов, как правило нормальное, за исключением случаев кровопотери или на фоне лечения препаратами Fe.

With IDA it decreases average Hb concentration in erythrocyte(MCNS). This indicator reflects the degree of saturation of the erythrocyte with hemoglobin and in N is equal to 30-38%. This is the concentration of Hb in grams per 100 ml of blood.

Average Hb content in an erythrocyte(MSN) is an indicator reflecting the absolute content of HB in one erythrocyte (in N equal to picograms (pg)). This indicator is relatively stable and does not change significantly with IDA.

They are decisive in the diagnosis of IDA. These include: serum Fe level, THC, LVSS, transferrin saturation coefficient with iron. To study these indicators, blood is taken into special tubes, washed twice with distilled water. The patient should not receive Fe supplements 5 days before the study.

Serum Fe is the amount of non-heme Fe found in serum (iron transferrin, ferritin). In N – 40.6-62.5 µmol/l. LVSS is the difference between PVSS and the level of serum Fe (N should be at least 47 µmol/l).

Transferrin saturation coefficient reflects the specific gravity of serum Fe from THC. In N not less than 17%.

In patients with IDA, there is a decrease in the level of serum Fe, an increase in CVSS and LVSS, and a decrease in the coefficient of transferrin saturation with iron.

Since Fe reserves are depleted in IDA, there is a decrease in serum levels. ferritin (<мкг/л). Этот показатель является наиболее специфичным признаком дефицита Fe.

Fe reserves can also be estimated using desferalova samples. After intramuscular or intravenous administration of desferal, 0.6-1.3 mg/day of Fe is normally excreted in the urine, and with IDA, the amount of Fe excreted is reduced to 0.4-0.2 mg/day.

In the bone marrow, erythroid hyperplasia is observed with a decrease in the number of sideroblasts.

Hemoglobin. Hemoglobin content in the blood, level, hemoglobin measurement.

Hemoglobin is a respiratory pigment in the blood, involved in the transport of oxygen and carbon dioxide, performing buffer functions and maintaining pH. Contained in erythrocytes (red blood cells - every day the human body produces 200 billion red blood cells). It consists of a protein part - globin - and an iron-containing porphyrite part - heme. It is a protein with a quaternary structure formed by 4 subunits. Iron in heme is in divalent form.

The hemoglobin content in the blood of men is slightly higher than that of women. In children of the first year of life, a physiological decrease in hemoglobin concentration is observed. A decrease in hemoglobin content in the blood (anemia) may be a consequence of increased hemoglobin losses due to various types of bleeding or increased destruction (hemolysis) of red blood cells. The cause of anemia may be a lack of iron, necessary for the synthesis of hemoglobin, or vitamins involved in the formation of red blood cells (mainly B12, folic acid), as well as a violation of the formation of blood cells in specific hematological diseases. Anemia can occur secondary to various types of chronic non-hematological diseases.

Alternative units: g/l

Conversion factor: g/l x 0.1 ==> g/dal

Pathological forms of hemoglobin

Normal forms of hemoglobin

Hemoglobin is the main blood protein

Hemoglobin is part of the group of proteins hemoproteins, which themselves are a subtype of chromoproteins and are divided into non-enzymatic proteins (hemoglobin, myoglobin) and enzymes (cytochromes, catalase, peroxidase). Their non-protein part is the heme - a structure that includes a porphyrin ring (consisting of 4 pyrrole rings) and an Fe 2+ ion. Iron binds to the porphyrin ring with two coordination and two covalent bonds.

Hemoglobin is a protein consisting of 4 heme-containing protein subunits. Protomers are connected to each other by hydrophobic, ionic, and hydrogen bonds according to the principle of complementarity. Moreover, they interact not arbitrarily, but with a certain area - the contact surface. This process is highly specific; contact occurs simultaneously at dozens of points according to the principle of complementarity. The interaction is carried out by oppositely charged groups, hydrophobic regions, and irregularities on the surface of the protein.

Protein subunits in normal hemoglobin can be represented by various types of polypeptide chains: α, β, γ, δ, ε, ξ (respectively, Greek - alpha, beta, gamma, delta, epsilon, xi). The hemoglobin molecule contains two chains of two different types.

Heme is connected to the protein subunit, firstly, through a histidine residue by an iron coordination bond, and secondly, through hydrophobic bonds of pyrrole rings and hydrophobic amino acids. Heme is located, as it were, “in a pocket” of its chain and a heme-containing protomer is formed.

There are several normal variants of hemoglobin:

· HbР – primitive hemoglobin, contains 2ξ- and 2ε-chains, occurs in the embryo between 7-12 weeks of life,

· HbF – fetal hemoglobin, contains 2α- and 2γ-chains, appears after 12 weeks of intrauterine development and is the main one after 3 months,

· HbA – adult hemoglobin, the proportion is 98%, contains 2α- and 2β-chains, appears in the fetus after 3 months of life and by birth makes up 80% of all hemoglobin,

· HbA 2 – hemoglobin of adults, the proportion is 2%, contains 2α- and 2δ-chains,

· HbO 2 – oxyhemoglobin, formed by the binding of oxygen in the lungs, in the pulmonary veins it is 94-98% of the total amount of hemoglobin,

· HbCO 2 – carbohemoglobin, formed by the binding of carbon dioxide in tissues, in venous blood it makes up 15-20% of the total amount of hemoglobin.

HbS – sickle cell hemoglobin.

MetHb – methemoglobin, a form of hemoglobin that includes a ferric ion instead of a ferrous one. This form is usually formed spontaneously; in this case, the enzymatic capacity of the cell is sufficient to restore it. When using sulfonamides, consuming sodium nitrite and nitrates in food products, and with insufficiency of ascorbic acid, the transition of Fe 2+ to Fe 3+ is accelerated. The resulting metHb is not able to bind oxygen and tissue hypoxia occurs. To restore iron ions, the clinic uses ascorbic acid and methylene blue.

Hb-CO – carboxyhemoglobin, is formed in the presence of CO (carbon monoxide) in the inhaled air. It is constantly present in the blood in small concentrations, but its proportion can vary depending on conditions and lifestyle.

Carbon monoxide is an active inhibitor of heme-containing enzymes, in particular cytochrome oxidase 4 complex of the respiratory chain.

HbA 1C – glycosylated hemoglobin. Its concentration increases with chronic hyperglycemia and is a good screening indicator of blood glucose levels over a long period of time.

Myoglobin is also capable of binding oxygen

Myoglobin is a single polypeptide chain, consists of 153 amino acids with a molecular weight of 17 kDa and is structurally similar to the β-chain of hemoglobin. The protein is localized in muscle tissue. Myoglobin has a higher affinity for oxygen compared to hemoglobin. This property determines the function of myoglobin - deposition of oxygen in the muscle cell and its use only with a significant decrease in the partial pressure of O 2 in the muscle (up to 1-2 mm Hg).

Oxygen saturation curves show the differences between myoglobin and hemoglobin:

· the same 50% saturation is achieved at completely different oxygen concentrations - about 26 mm Hg. for hemoglobin and 5 mm Hg. for myoglobin,

· at a physiological partial pressure of oxygen from 26 to 40 mm Hg. hemoglobin is saturated by 50-80%, while myoglobin is almost 100%.

Thus, myoglobin remains oxygenated until the amount of oxygen in the cell decreases to extreme levels. Only after this does oxygen release for metabolic reactions begin.

Hemoglobin

Hemoglobin is a protein with a quaternary structure formed by four subunits. Iron in heme is in divalent form. There are the following physiological forms of hemoglobin:

Oxyhemoglobin (H b O 2) - a compound of hemoglobin with oxygen, is formed mainly in arterial blood and gives it a scarlet color (oxygen binds to the iron atom through a coordination bond);

Reduced hemoglobin, or deoxyhemoglobin (H b H), is hemoglobin that has given oxygen to tissues;

Carboxyhemoglobin (H bC O 2) - a compound of hemoglobin with carbon dioxide, is formed mainly in venous blood, as a result of which the blood acquires a dark cherry color.

Pathological forms of hemoglobin:

Carbohemoglobin (H bC O) is formed during carbon monoxide (CO) poisoning, while hemoglobin loses its ability to combine oxygen;

Methemoglobin is formed under the influence of nitrites, nitrates and some medications (ferrous iron undergoes a transition to ferric iron with the formation of methemoglobin - HbMet).

The standard cyanmethemoglobin method determines all forms of hemoglobin without their differentiation.

A decrease in hemoglobin content in the blood (anemia) occurs as a result of loss of hemoglobin during various types of bleeding or increased destruction (hemolysis) of red blood cells. The cause of anemia may be a lack of iron, necessary for the synthesis of hemoglobin, or vitamins involved in the formation of red blood cells (mainly B12 and folic acid), as well as a violation of the formation of blood cells in specific hematological diseases. Anemia can occur secondary to chronic somatic diseases.

Units of measurement: grams per liter (g/l).

Reference values: see table. 2-2.

Table 2-2. Normal values ​​for hemoglobin content

The hemoglobin content increases in diseases accompanied by an increase in the number of red blood cells (primary and secondary erythrocytosis), hemoconcentration, congenital heart defects, pulmonary heart failure, as well as for physiological reasons (in residents of high mountains, pilots after high-altitude flights, climbers after increased physical activity).

A reduced hemoglobin content is noted with anemia of various etiologies (the main symptom).

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Types of hemoglobin, its compounds, their physiological significance

There are three types of hemoglobin; Initially, the embryo has primitive hemoglobin (HbP) - up to 4-5 months. intrauterine life, then fetal hemoglobin (HbF) begins to appear, the amount of which increases until 6–7 months. intrauterine life. From this period there is an increase in hemoglobin A (adult), the maximum value of which reaches by 9 months. intrauterine life (90%). The amount of fetal hemoglobin at birth is one of the signs of full term: the higher the HbF, the less full-term the baby is. It should be noted that HbF in the presence of 2,3 diphosphoglycerate (DPG is a metabolic product of the erythrocyte membrane during oxygen deficiency) does not change its affinity for oxygen, unlike HbA, whose affinity for oxygen decreases.

Types of Hb differ from each other in the degree of chemical affinity for O2. Thus, HbF under physiological conditions has a higher affinity for O2 than HbA. This most important feature of HbF creates optimal conditions for O2 transport by fetal blood.

Hemoglobin is a blood pigment whose role is to transport oxygen to organs and tissues, transport carbon dioxide from tissues to the lungs, in addition, it is an intracellular buffer that maintains an optimal pH for metabolism. Hemoglobin is found in red blood cells and makes up 90% of their dry mass. Outside of red blood cells, hemoglobin is practically undetectable.

Chemically, hemoglobin belongs to the group of chromoproteins. Its prosthetic group, including iron, is called heme, and its protein component is called globin. The hemoglobin molecule contains 4 hemes and 1 globin.

Physiological hemoglobins include HbA (adult hemoglobin) and HbF (fetal hemoglobin, which makes up the bulk of fetal hemoglobin and disappears almost completely by the 2nd year of a child’s life). Modern electrophoretic studies have proven the existence of at least two varieties of normal hemoglobin A: A1 (main) and A2 (slow). The bulk of adult hemoglobin (96-99%) is HbAl, the content of other fractions (A2 F) does not exceed 1 - 4%. Each type of hemoglobin, or rather its globin part, is characterized by its own “polypeptide formula”. Thus, HbAl is designated as ά2 β2, that is, it consists of two ά-chains and two β-chains (a total of 574 amino acid residues arranged in a strictly defined order). Other types of normal hemoglobins - F, A2 - have a common β-peptide chain with HbAl, but differ in the structure of the second polypeptide chain (for example, the structural formula of HbF is ά2γ2).

In addition to physiological hemoglobins, there are several more pathological varieties of hemoglobin. Pathological hemoglobins arise as a result of a congenital, inherited defect in the formation of hemoglobin.

In the red blood cells of circulating blood, hemoglobin is in a state of continuous reversible reaction. He is

attaches an oxygen molecule (in the pulmonary capillaries), then releases it (in the tissue capillaries).

The main compounds of hemoglobin include: HHb - reduced hemoglobin and HbCO2 - a compound with carbon dioxide (carbohemoglobin). They are mainly found in venous blood and give it a dark cherry color.

HbO2 - oxyhemoglobin - is found mainly in arterial blood, giving it a scarlet color. HbO2 is an extremely unstable compound, its concentration is determined by the partial pressure of O2 (pO2): the higher the pO2, the more HbO2 is formed and vice versa. All of the above hemoglobin compounds are physiological.

Hemoglobin in venous blood with a low partial pressure of oxygen is bound to 1 molecule of water. Such hemoglobin is called reduced (reduced) hemoglobin. In arterial blood with a high partial pressure of oxygen, hemoglobin is combined with 1 molecule of oxygen and is called oxyhemoglobin. By continuously converting oxyhemoglobin into reduced hemoglobin and back, oxygen is transferred from the lungs to the tissues. The perception of carbon dioxide in tissue capillaries and its delivery to the lungs is also a function of hemoglobin. In tissues, oxyhemoglobin, giving up oxygen, turns into reduced hemoglobin. The acidic properties of reduced hemoglobin are 70 times weaker than the properties of oxyhemoglobin, so its free valencies bind carbon dioxide. Thus, carbon dioxide is delivered from tissues to the lungs using hemoglobin. In the lungs, the resulting oxyhemoglobin, due to its high acidic properties, comes into contact with the alkaline valences of carbohemoglobin, displacing carbon dioxide. Since the main function of hemoglobin is to provide tissues with oxygen, tissue hypoxia develops in all conditions accompanied by a decrease in the concentration of hemoglobin in the blood, or with qualitative changes in it.

However, there are also pathological forms of hemoglobin.

Hemoglobin has the ability to enter into dissociating compounds not only with oxygen and carbon dioxide, but also with other gases. As a result, carboxyhemoglobin, oxynitrogen hemoglobin and sulfhemoglobin are formed.

Carboxyhemoglobin (oxycarbon) dissociates several hundred times slower than oxyhemoglobin, so even a small concentration (0.07%) of carbon monoxide (CO) in the air, binding about 50% of the hemoglobin present in the body and depriving it of the ability to carry oxygen, is fatal. Carboxyhemoglobin (HbCO) is a very strong compound with carbon monoxide, due to the chemical properties of carbon monoxide in relation to Hb. It turned out that its affinity for Hb is several times greater than the affinity of O2 for Hb. Therefore, with a slight increase in CO concentration in the environment, a very large amount of HbCO is formed. If there is a lot of H2CO in the body, then oxygen starvation occurs. In fact, there is a lot of O2 in the blood, but tissue cells do not receive it, because HbCO is a strong compound with O2.

Methemoglobin is a more stable compound of hemoglobin with oxygen than oxyhemoglobin, resulting from poisoning with certain drugs - phenacetin, antipyrine, sulfonamides. In this case, divalent iron of the prosthetic group, oxidizing, turns into trivalent iron. Methemoglobin (MetHb) is an oxidized form of Hb that gives the blood a brown color. MetHb is formed when Hb is exposed to any oxidizing agents: nitrates, peroxides, potassium permanganate, red blood salt, etc. This is a stable compound because iron from the ferroform (Fe++) goes into the ferriform (Fe+++), which irreversibly binds O2. When large amounts of MetHb are formed in the body, oxygen deficiency (hypoxia) also occurs.

Sulfhemoglobin is sometimes found in the blood when using drugs (sulfonamides). The sulfhemoglobin content rarely exceeds 10%. Sulfhemoglobinemia is an irreversible process. Since the affected red blood cells

are destroyed in the same time frame as normal ones, hemolysis is not observed and sulfhemoglobin can remain in the blood for several months. The method for determining the residence time of normal red blood cells in peripheral blood is based on this property of sulfhemoglobin.

Physiological forms of hemoglobin. Pathological forms of hemoglobin. Hemoglobin content in the blood. Hemoglobin level in men, in women after childbirth, in children in the first year of life. Units of hemoglobin measurement.

Hemoglobin is a respiratory pigment in the blood, involved in the transport of oxygen and carbon dioxide, performing buffer functions and maintaining pH. Contained in erythrocytes (red blood cells - every day the human body produces 200 billion red blood cells). It consists of a protein part - globin - and an iron-containing porphyrite part - heme. It is a protein with a quaternary structure formed by 4 subunits. Iron in heme is in divalent form.

Physiological forms of hemoglobin: 1) oxyhemoglobin (HbO2) - the combination of hemoglobin with oxygen is formed mainly in arterial blood and gives it a scarlet color; oxygen binds to the iron atom through a coordination bond.2) reduced hemoglobin or deoxyhemoglobin (HbH) - hemoglobin that has given oxygen to tissues.3) carboxyhemoglobin (HbCO2) - a compound of hemoglobin with carbon dioxide; is formed mainly in venous blood, which as a result acquires a dark cherry color.

Pathological forms of hemoglobin: 1) carbhemoglobin (HbCO) - is formed during carbon monoxide (CO) poisoning, while hemoglobin loses the ability to attach oxygen.2) met hemoglobin - formed under the influence of nitrites, nitrates and some medications, the transition of ferrous iron to trivalent iron occurs with the formation of met hemoglobin - HbMet.

Hemoglobin content in blood slightly higher in men than in women. In children of the first year of life, a physiological decrease in hemoglobin concentration is observed. A decrease in hemoglobin content in the blood (anemia) may be a consequence of increased hemoglobin losses due to various types of bleeding or increased destruction (hemolysis) of red blood cells. The cause of anemia may be a lack of iron, necessary for the synthesis of hemoglobin, or vitamins involved in the formation of red blood cells (mainly B12, folic acid), as well as a violation of the formation of blood cells in specific hematological diseases. Anemia can occur secondary to various types of chronic non-hematological diseases.

Hemoglobin units in the Invitro laboratory - g/dal
Alternative units: g/l
Conversion factor: g/l x 0.1 ==> g/dal

Increased hemoglobin levels: Diseases accompanied by an increase in the number of red blood cells (primary and secondary erythrocytosis). Physiological causes in residents of high mountains, pilots after high-altitude flights, climbers, after increased physical activity.
Blood thickening;
Congenital heart defects;
Pulmonary heart failure;