Clinical blood test: general analysis, leukocyte formula, ESR (with microscopy of a blood smear when pathological changes are detected). Deciphering the leukocyte blood formula What does plus mean on a blood test

When we come to see a doctor, Dr. Aibolit always recommends going through a whole list of laboratory tests for diagnostic purposes. And the first on this list is a general blood test - UAC.

It would seem that a familiar and often prescribed examination, and therefore many patients do not attach much importance to it. But don't underestimate him. After all, for all its accessibility and seemingly simplicity, it is important and contains a lot of information about the human body.

The attending physician may prescribe:

General blood test with leukocyte formula.
Complete blood count without leukocyte formula.

But most often a clinical blood test with a leukocyte formula is prescribed. It includes the study of blood cells together with the determination of the erythrocyte sedimentation rate - ESR.

We often take a general blood test and ESR during the examination. According to him, the doctor can judge whether there is or is not a pathological process.

But first, some information about the blood itself. Its volume is 5-5.5 liters in an adult and a one-time loss in the amount of 1-1.5 liters very often threatens with irreparable consequences. It supplies all organs with oxygen and nutrients. It also takes away carbon dioxide and metabolic products, which it leaves in the lungs, liver and kidneys. Thus, the whole process takes place day and night non-stop.

Blood is a kind of service of a person's own security, which instantly reacts to the slightest threat to the human body. In its structure it contains 2 large mobile units - plasma and a whole army of shaped elements.

Plasma is a warehouse in which all proteins, minerals and vitamins necessary for a person are stored, as well as pathogenic microorganisms and waste products of the latter in the form of poisons and toxins are dissolved in it. With a significant decrease in its volume, blood thickens and blood circulation slows down, which is often the cause of headaches and heart pain, up to heart attacks and strokes.

But let's talk about shaped elements separately, because they perform such important functions as transport, protection and regulation.

Blood parameters

A clinical blood test examines the indicators:

Hemoglobin.
Erythrocytes.
platelets.
Leukocytes.

At the same time, their level remains stable in full health and changes with any pathological process or in a state of physical or emotional stress.

And finally, more about each of these parameters and the interpretation of their indicators. There is no doubt how necessary the correct interpretation of the results of the examination by a specialist is for the general clinical determination of the course of a particular disease.

It is always necessary to properly prepare the patient for a general blood test. The last meal should be 8-9 hours before the test. It is given in the morning before meals.

For research, a portion of blood is taken from a finger or vein.

Hemoglobin

It is the carrier of all nutrients. It is protein-linked iron that enters the body from the outside with food. The daily norm of its consumption is about 20 mg, which are contained in:

100 gr. red meat,
pork and beef liver,
buckwheat,
dried apricots,
blackcurrant,
apricots.

Normal indicators for men: 120-160 g / l, and for women 120-140 g / l. The decrease occurs when:

Acute post-traumatic bleeding or that occurred during surgical interventions.
Prolonged uterine, gastrointestinal bleeding.
Hematopoietic disorders.

red blood cells

These are red blood cells of a biconcave shape, normal values in men are 4-5 * 10¹² per liter, and in women - 3-4 * 10¹² per liter.

An erythrocyte containing hemoglobin has an important transport and nutritional role. An increase in the number of red blood cells can be reactive in hot weather, when a person loses about 1 liter of fluid with sweat or while drinking alcohol. And also when taking certain medications, such as diuretics - diuretics.

A decrease in the number of red blood cells indicates anemia.

platelets

Their functions include stopping bleeding, nourishing and restoring broken communications - the walls of blood vessels in case they are damaged. An increase in the level of platelets is called thrombocytosis. It provokes an increase in blood viscosity, which becomes one of the causes of frequent vascular accidents, especially against the background of atherosclerosis in the elderly and even middle-aged.

Leukocytes

Shield and sword of our body. Normally, adults should have from 4 to 9x10x9.

Their number always increases with:

any inflammatory and infectious processes,
poisoning,
injuries,
leukemias of various forms

And it decreases with problems in the immune status. The leuko formula reflects the true situation in the service of its own security. In it, as in a mirror, the state of the body's immunity is reflected. For a correct assessment of the clinic and the stage of the disease, deciphering this part of the analysis is extremely important.

The leukocyte formula will include:

eosinophils,
lymphocytes,
basophils,
monocytes,
Stab and segmented cells.

Eosinophils

A reduced amount occurs when:

intoxication with salts of heavy metals,
extensive or generalized purulent processes, such as sepsis,
at the very beginning of the inflammatory processes.

Lymphocytes

Normally, the amount ranges from 19-38%. They remember the enemy in the face and quickly react to his reappearance. There are 3 types of lymphocytes: T-helpers, suppressors and killers.

So, when foreign agents invade, they initiate the production of specific hormones, which in turn stimulate the growth of all 3 types of lymphocytes. It is they who take the "enemy" into a tight ring and "destroy" him.

An increase in their level is noted with:

viral infections,
diseases of the hematopoietic system,
poisoning with salts of heavy metals, such as lead or poisons such as arsenic,
leukemia.

The decrease is noted when:

AKI - acute renal failure,
CRF - chronic renal failure,
Malignant neoplasms in the final stage,
AIDS
Chemo- and radiation therapy,
The use of certain hormonal drugs.

Basophils

This is the smallest group, it may not be determined at all, or their number does not exceed 1%. They are involved in all allergic reactions of the body.

However, their level can also increase with:

Some blood diseases, such as myeloid leukemia or hemolytic anemia;
Hypothyroidism - decreased thyroid function
Allergization of the body
Hormone therapy.

Reduction is often observed in the case of removal of the spleen.

Monocytes

The largest immune cells in the body, their normal level in the blood is in the range of 3-11%. This is a kind of sentinel point for the identification of all foreign substances, giving a command for their destruction to eosinophils and lymphocytes. Outside the bloodstream, they migrate in the form of macrophages to the lesion, completely clearing it of decay products.

Their number grows with:

Infectious processes caused by fungi, viruses or protozoa.
Specific diseases, such as: tuberculosis of various localization, syphilis and brucellosis.
Connective tissue diseases, the so-called collagenoses: SLE - systemic lupus erythematosus, RA - rheumatoid arthritis, periarteritis nodosa.
Damage to the normal function of the hematopoietic system.

The decrease is observed when:

Aplastic anemia - the complete absence of the production of blood cells in the bone marrow.
Extensive purulent lesions.
postoperative conditions.
Long-term use of steroid hormonal drugs.

Sometimes a specialist who gives a transcript of the leukocyte formula registers a "shift to the left or right." “Shift to the left” signals the appearance of immature forms of neutrophils, which, in full health, are found only in the bone marrow.

Their appearance in large quantities is evidence of extensive infectious lesions and some malignant diseases of the hematopoietic system. But the “shift to the right” indicates the release of “old” segmented neutrophils into the bloodstream. It is often observed in diseases of the liver and kidneys, or can be observed in healthy people living in an area with a high radioactive background, such as Chernobyl.

ESR

Sedimentation rate of erythrocytes. Normal in women is from 2-15mm/hour, in men - 1-10mm/hour. Their increase occurs in any oncological and inflammatory processes. In women, it may increase during menstruation. Its high rates at low values of leukocytes, this effect is called "scissors", a very alarming indicator, which is recorded in the almost complete absence of immunity.

Many of these parameters are determined using the latest category 5 diff hematology analyzer. It measures the number of red blood cells, white blood cells, platelets, platelet mass, hemoglobin concentration and its distribution in red blood cells. Its throughput is 50 tests/hour and it determines a total of 22 indicators.

In conclusion, I would like to note that a competent decoding of a clinical blood test and interpretation of its data plays the most important role in the correct diagnosis and treatment of the patient. So in obtaining a positive result of all medical and diagnostic measures. After all, their ultimate goal is the recovery of the patient!

It was and remains the most common and frequently prescribed diagnostic method. It is taken many times throughout life and with any diagnosis. This analysis allows you to evaluate the work of all systems and organs in the body.

It includes a qualitative and quantitative description of the formed elements, their ratio to the liquid part of the blood (plasma). Making a diagnosis based on a complete blood count alone is difficult, but this procedure allows you to determine the direction for further examination.

Blood consists of formed elements and plasma. The number of these elements, their ratio, concentration and quality indicators form the basis of a blood test. With such a diagnosis, the amount is estimated, as well as the level and (erythrocyte sedimentation rate).

The standard is a general blood test with a formula, the decoding of which implies the presence, that is, the ratio of various types of leukocytes (neutrophils, monocytes, basophils,). These are standard indicators, but they may not be in the brief analysis, so the necessary items are noted when assigning.

The positive aspects of such an examination are simplicity and accessibility, a quick result (within 1-2 days), a small price (it is free of charge if there is a referral), as well as high information content.

But it should be borne in mind that blood counts largely depend on various factors: nutrition, ecology, gender, age, and even race.

Prevention. As a preventive measure, you can donate blood every six months or a year. Even in the case when nothing bothers, the diagnosis will not be superfluous. It helps to suspect diseases at the earliest stages, when symptoms have not yet manifested. This greatly increases the effectiveness of the treatment.
Diagnosis of diseases. When diagnosing any diseases (heart, kidney, liver and other organs), as well as any infections, it is recommended to donate blood for analysis.
Suspicion of blood diseases. The analysis allows you to determine whether there are abnormalities in the composition of the blood, deviations in the quantity and quality of formed elements, which can lead to suspicion of a bone marrow disease.
Pregnancy. During pregnancy, a woman donates blood for examination constantly. The closer to childbirth, the more often the examination is carried out. In the early stages, especially with toxicosis, a general blood test is also necessary. Particularly important are the number of platelets (a tendency to thrombosis or bleeding) and the level of hemoglobin (risk of oxygen starvation of the fetus).

Preparation and procedure

The blood sampling procedure is familiar and understandable to everyone. The nurse takes venous (capillary) blood, numbers it, draws it up, and then the material is delivered to the laboratory, where it is examined during the day.

All that is required of the patient is to come to the laboratory at the appointed time with a ticket and a referral. Before giving a referral, the doctor will tell you the necessary preparation rules. They should not be neglected.

The composition of the blood tends to change and react to everything that happens to the body. For the result to be reliable, you need to follow some rules. Many believe that the only rule is to fast for 8-10 hours before visiting the laboratory.

But other factors can also affect the result of the analysis:

Food. Even if the patient came to the laboratory with an empty stomach, what he ate the day before may affect the result. For example, an abundance of protein or fatty foods eaten during the day before analysis can cause the blood serum to be cloudy and unsuitable for examination.
Preparations. Taking medications has a direct effect on the composition and. All medications taken (including oral contraceptives, vitamins and dietary supplements) should be reported to the doctor. He will advise which of them need to be canceled and for how long.
Physical exercise. Before passing the analysis, it is not recommended to engage in physical exercises, even for those who are used to it. Physical activity can cause hormonal changes and affect the result.
Emotional condition. Stress also has an effect on the body. Strong emotional stress negatively affects the work of all systems and organs, the result of the analysis may be poor.
Bad habits. Smoking and alcohol affect metabolism. In general, it is advisable to give up alcohol 3 days before visiting the laboratory, and smoking - at least on the day of blood sampling.
Times of Day. The analysis is prescribed precisely in the morning, not only because it is easier to observe hunger. The body has certain daily rhythms. During the day, blood counts can change depending on environmental factors. In order to standardize the reference values, it is recommended to donate blood only in the morning, except in emergency cases.

Indicators and their norm

A detailed blood test includes a large number of indicators. Each indicator has its own reference values, the limits of the norm. An increase or decrease in indicators, going beyond the boundaries of this norm may be a sign of any pathology.

The main indicators of a general blood test include the following:

Even with knowledge of the reference values, it is quite difficult to interpret the result of the analysis on your own. You need to take into account all the indicators in the aggregate. In addition, the deviation from the norm of one or another indicator can be interpreted differently depending on gender, age, cycle time (in women) and other factors.

Very often, with any violations, a deviation from the norm is observed in several indicators at once. It is problematic to make an accurate diagnosis on the basis of a blood test alone, so the doctor identifies certain disorders and directs them for further examination.

With the help of blood indicators, the following conditions and diseases can be detected:

. Anemia has many types and forms. Most often, it is observed with a decrease in hemoglobin levels, when all organs and tissues experience oxygen starvation. Anemia is usually said to occur when the hemoglobin level falls below 90-100 g/l. The causes of anemia can be physiological (heavy exercise, dehydration) or pathological. Leukocytosis. The reasons for the increase in the level of leukocytes can be different. Among the physiological reasons, pregnancy and childbirth, a large amount of protein food, great physical activity, PMS are noted. Among the pathological causes, inflammatory processes of microbial and non-microbial origin, leukemia, oncological diseases, burns and prolonged bleeding can be distinguished.
Thrombocytosis. A high level of platelets is dangerous because it can lead to the formation of blood clots and blockage of blood vessels and arteries. The number of platelets in the blood increases dramatically with anemia with iron deficiency, with certain infections and heavy bleeding, oncology.

You can learn more about the leukocyte formula from the video:

Each of these states can be interpreted in different ways. For example, leukocytosis can be caused by a wide variety of infections. You cannot prescribe treatment based on a blood test.

The diagnostic value of a blood test cannot be overestimated. With the help of this study, one can assess the state of human health, determine the development of inflammatory processes, infectious diseases, and blood diseases.

Most often, patients are prescribed a clinical (general) blood test. In some cases, the doctor directs for a general blood test with a leukocyte formula. Consider what this study is, what are the values \u200b\u200bof the norm indicators in deciphering a blood test.

Complete blood count with leukocyte formula

Leukocyte formula - percentage determination of the relative number of different types of leukocytes. In total, five types of leukocytes are determined - lymphocytes, neutrophils, monocytes, basophils, eosinophils.

The determination of the leukocyte formula is used in the diagnosis of inflammatory, infectious, hematological diseases. In addition, it is used to assess the severity of the course of the disease, control the effectiveness of the therapy.

It is impossible to talk about the specificity of changes in the leukocyte formula. Changes in its parameters often have a similar character in different pathologies. At the same time, with the same disease in different patients, there may be dissimilar changes in the indicators of the leukocyte formula.

When deciphering a blood test with a formula, age-related features are taken into account, which is especially important in diagnosing diseases in children.

Only a specialist can professionally decipher a blood test. No free interpretation of a blood test online can replace a competent interpretation of the results of the study by a doctor. But each person can compare the values of the main characteristics of the blood of his analysis with the norm of decoding a blood test. To do this, we will give the normal indicators of a blood test with a leukocyte formula and determine what their deviations may indicate.

Clinical blood test- a laboratory study that allows you to assess the general state of human health. Any changes in the blood picture may indicate the development of a pathological process. Clinical blood test includes: complete blood count, leukocyte formula and erythrocyte sedimentation rate (ESR).

Blood consists of formed elements - blood cells and a liquid part - blood plasma. The formed elements of the blood are composed of 3 main types of cells: white blood cells (leukocytes), red blood cells (erythrocytes) and platelets. Mature cells are formed in the bone marrow and enter the blood as needed.

The ratio of the volume of all blood cells to plasma is called hematocrit. However, hematocrit is often also understood as the ratio of only the volume of erythrocytes to the volume of blood plasma. This indicator evaluates the degree of "thinning" or "thickening" of the blood.

Red blood cells are responsible for transporting oxygen to tissues. They contain hemoglobin, a protein that carries oxygen from the lungs to organs and tissues and carbon dioxide on the way back. Red blood cells are usually homogeneous with minimal changes in size and shape. A decrease in the number of red blood cells is observed with blood loss, anemia, pregnancy. Less commonly, erythrocytosis occurs - an excess of red blood cells in the blood, which can interfere with the flow of blood through small veins and arteries. Erythrocytosis develops with malignant tumors, Cushing's disease and syndrome, as well as taking corticosteroids and a number of other pathological conditions.

In the KLA, erythrocyte indices are also determined, which include MCV, MCH, MCHC. These indicators reflect the volume of red blood cells, the content and concentration of hemoglobin in them.

Leukocytes are key components of the immune system. The body uses them to fight infections and foreign microorganisms. There are five types of white blood cells: neutrophils, lymphocytes, basophils, eosinophils, and monocytes. They are present in the blood in relatively stable numbers. With an infectious process, the number of neutrophils increases significantly, with an allergic one - eosinophils, and with a viral one - lymphocytes. A decrease in the number of leukocytes - leukopenia - is characteristic of diseases of the bone marrow, radiation sickness, leukemia, and other diseases.

The leukocyte formula reflects the ratio of types of leukocytes, expressed as a percentage.

Platelets play a vital role in the blood clotting process. A decrease in platelet count can cause bleeding and bruising of the skin, while an increase leads to the formation of blood clots.

ESR or erythrocyte sedimentation rate shows the ratio of protein fractions of the blood and is a marker of the inflammatory process.

This analysis allows you to determine the number of blood cells, as well as determine the percentage of various forms of leukocytes (leukocyte formula) and the erythrocyte sedimentation rate (ESR). The analysis helps to assess the general condition of the body.

Complete blood count (Complete Blood Count)

Routine screening blood test, which includes determining the concentration of total hemoglobin, the number of erythrocytes, leukocytes and platelets per unit volume, hematocrit and erythrocyte indices (MCV, MCH, MCHC).

Hemoglobin (Hb, Hemoglobin)

The respiratory pigment of the blood, which is contained in erythrocytes and is involved in the transport of oxygen and carbon dioxide.

It consists of a protein part - globin - and an iron-containing part - heme. Hemoglobin is a quaternary protein made up of four polypeptide chains. The iron in heme is in the divalent form. The content of hemoglobin in the blood in men is slightly higher than in women. In children of the first year of life, a physiological decrease in hemoglobin concentration is observed. An increase in hemoglobin concentration is observed when the blood thickens or is the result of an increase in the formation of red blood cells. A pathological decrease in the content of hemoglobin in the blood (anemia) may be the result of increased losses of hemoglobin during various bleedings, the result of accelerated destruction (hemolysis) of red blood cells, a violation of the formation of red blood cells, or other causes. Anemia can be both an independent disease and a symptom of a general chronic disease (anemia of chronic diseases). As an independent disease, anemia develops with a lack of iron necessary for the synthesis of hemoglobin, with a deficiency of vitamins involved in the formation of red blood cells (mainly vitamin B12, folic acid), due to increased destruction of red blood cells in the peripheral bloodstream (hemolytic anemia) or impaired formation of blood cells in the bone marrow with specific hematological diseases.

Hematocrit (Ht, Hematocrit)

Proportion (%), which is made up of all formed elements of the total blood volume.

This indicator, along with hemoglobin and erythrocytes, is used to monitor the state of the erythrocyte system. Hematocrit reflects the volume of all formed elements of the blood - mainly erythrocytes - and not their number. Changes in hematocrit do not always correlate with changes in total red blood cells. For example, in patients in shock due to blood clotting, hematocrit may be normal or even high, although due to blood loss, the total number of red blood cells may be significantly reduced. Therefore, the value of hematocrit is not indicative in assessing the degree of anemia immediately after blood loss or blood transfusion.

Erythrocytes (Red Blood Cells, RBC)

Highly specialized non-nuclear blood cells containing hemoglobin, the main function of which is the transport of oxygen from the lungs to tissues and carbon dioxide from tissues to the lungs.

Red blood cells are formed in the red bone marrow from stem cells. For the normal development of red blood cells, vitamin B 12 , folic acid and a sufficient supply of iron are essential. The formation of red blood cells is stimulated by erythropoietin, which is produced in the kidneys. The level of erythropoietin increases with tissue hypoxia. The average life span of erythrocytes in the vascular bed is 120 days. Old cells are destroyed in the reticuloendothelial system and spleen, and hemoglobin iron is used to form new red blood cells. About 1% of red blood cells are renewed in one day. An increase in the number of red blood cells above normal levels is called erythrocytosis, a decrease in the number of red blood cells (and hemoglobin) is called anemia,

For the differential diagnosis of anemia, in addition to determining the number of red blood cells, an assessment of their morphological characteristics is used. Normally, the diameter of erythrocytes is 7.2-7.5 microns, the volume is 80-100 fl. Erythrocytes with a diameter of less than 6.7 microns and a volume of less than 80 fl are called microcytes; erythrocytes with a diameter of more than 7.7 microns and a volume of more than 100 fl - macrocytes; erythrocytes more than 9.5 microns in diameter - megalocytes. Anisocytosis is the presence of red blood cells of different sizes in the blood. Depending on the predominance of certain forms of erythrocytes, there are: macrocytosis - a condition when 50% or more of the total number of erythrocytes are macrocytes (noted with B 12 and folate deficiency anemia, liver diseases); microcytosis - a condition in which 30-50% are microcytes (observed with iron deficiency anemia, microspherocytosis, heterozygous thalassemia, lead intoxication).

A more detailed description of the morphology of erythrocytes: changes in the shape of cells - poikilocytosis (the presence of ovalocytes, schizocytes, spherocytes, target erythrocytes, etc.); the presence of inclusions in erythrocytes; the content in the peripheral blood of nuclear forms of the erythroid series; cell color changes, etc. - if necessary, it is done by a hematologist when viewing a blood smear under a microscope. This information is reflected in the comments to the analysis.

Erythrocyte indices (MCV, MCH, MCHC)

Indices that allow to quantify the main morphological characteristics of erythrocytes.

MCV - Mean Cell Volume

A quantitative indicator of the volume of red blood cells, a more accurate parameter than a visual assessment of the size of red blood cells when viewing a smear under a microscope. However, it should be borne in mind that this parameter is an average value, and in case of severe anisocytosis, as well as in the presence of a large number of erythrocytes with a changed shape, it does not sufficiently reflect the true size of the cells. Based on the MCV value, microcytic, normocytic and macrocytic anemias are distinguished. Microcytosis is characteristic of iron deficiency anemia, heterozygous thalassemia; macrocytosis - for B 12 - and folate deficiency anemia. Aplastic anemia can be normo- and macrocytic.

MCH - the average content of hemoglobin in an erythrocyte (Mean Cell Hemoglobin)

Calculated in absolute units, calculated by dividing the hemoglobin concentration by the number of erythrocytes per unit volume. This parameter determines the average content of hemoglobin in a single erythrocyte and is similar in clinical value to the color index. Based on this index, anemia can be divided into normo-, hypo- and hyperchromic.

MCHC - the average concentration of hemoglobin in erythrocytes (Mean Cell Hemoglobin Concentration)

It is calculated by the ratio of blood hemoglobin to hematocrit and reflects the saturation of red blood cells with hemoglobin. This is a concentration index that does not depend on cell volume, unlike MCH. MCHC is a sensitive indicator of changes in hemoglobin formation, in particular, with iron deficiency anemia, thalassemia, and some hemoglobinopathies (decrease in MCHC).

Leukocytes (White Blood Cells, WBC)

Blood cells that provide recognition and neutralization of foreign components, elimination of altered and decaying cells of one's own body, effectors of immune and inflammatory reactions, the basis of the body's antimicrobial defense.

The formation of leukocytes (leukopoiesis) takes place in the bone marrow and organs of the lymphatic system. This is a group of cells heterogeneous in origin, structure and properties. There are 5 main types of leukocytes: neutrophils, eosinophils, basophils, lymphocytes, monocytes, which perform different functions. A differential count of the content of these forms is carried out when prescribing a leukocyte formula test. The total number of leukocytes can change under the influence of various factors. A physiological increase in the level of leukocytes occurs after eating, after physical activity, due to various kinds of stress. Reactive physiological leukocytosis is provided by the redistribution of parietal and circulating neutrophils, the mobilization of mature leukocytes from the bone marrow. In women, a physiological increase in the number of leukocytes can be observed in the premenstrual period. The number of leukocytes normally increases in the second half of pregnancy and during childbirth.

A pathological increase in the number of leukocytes in the blood is observed when exposed to various infectious agents, poisons, under the influence of inflammation and tissue necrosis factors, endogenous toxins. These factors stimulate the formation of leukocytes, which is a protective reaction of the body.

With some viral infections, under the influence of cytotoxic drugs, leukopenia, a decrease in the level of blood leukocytes, can develop. Significant changes in the number of leukocytes are observed in specific hematological diseases, which can manifest as a significant increase in the content of leukocytes, or a sharp decrease in their number. Important diagnostic information in these cases is provided by the definition of a differential leukocyte formula with a view of a blood smear under a microscope.

Platelets (Platelet count)

Formed elements of the blood involved in hemostasis. Platelets - small non-nuclear cells, oval or rounded; their diameter is 2-4 microns. Platelets are formed in the bone marrow from megakaryocytes. At rest (in the bloodstream), platelets are disc-shaped. When activated, platelets acquire a spherical shape and form special outgrowths (pseudopodia). With the help of such outgrowths, platelets can connect with each other (aggregate) and adhere to the damaged vascular wall (adhesion ability).

Platelets have the ability to eject the contents of their granules upon stimulation, which contain coagulation factors, the enzyme peroxidase, serotonin, calcium ions - Ca 2 *, adenosine diphosphate (ADP), von Willebrand factor, platelet fibrinogen, platelet growth factor. Some clotting factors, anticoagulants, and other substances can be carried by platelets on their surface. The properties of platelets that interact with the components of the walls of blood vessels allow the formation of a temporary clot and stop bleeding in small vessels (platelet-vascular hemostasis). A temporary increase in platelet count can be seen after intense exercise. A slight physiological decrease in the level of platelets is observed in women during menstruation. A moderate decrease in the number of platelets can sometimes be observed in apparently healthy pregnant women.

Clinical signs of a decrease in the number of platelets - thrombocytopenia (increased tendency to intradermal hemorrhages, bleeding gums, menorrhagia, etc.) - usually occur only when the number of platelets decreases below 50x10 3 cells / μl.

A pathological decrease in the number of platelets occurs due to their insufficient formation in a number of diseases of the blood system, as well as with increased consumption or destruction of platelets (autoimmune processes). After massive bleeding followed by intravenous infusions of plasma substitutes, the platelet count may decrease to 20-25% of the initial value due to dilution.

An increase in the number of platelets (thrombocytosis) can be reactive, accompanying certain pathological conditions (as a result of the production of immunomodulators that stimulate the formation of platelets) or primary (due to defects in the hematopoietic system).

Neutrophils (Neutrophils)

They make up 50-75% of all leukocytes. In the peripheral blood, two morphological types of these cells are normally found: stab (younger) and segmented (mature) neutrophils. Less mature cells of the granulocytic series - young (metamyelocytes), myelocytes, promyelocytes - are normally located in the bone marrow and appear in the peripheral blood only in case of pathology. The appearance of the latter in the peripheral circulation indicates either stimulation of the formation of granulocytes in the bone marrow (reactive changes) or the presence of hemoblastosis. Mature neutrophils circulate in the blood for 8-10 hours, then enter the tissues. The life span of a neutrophilic granulocyte in tissues is 2-3 days. The number of neutrophils, if necessary, can rapidly increase due to the mobilization of mature cells from the parietal pool of the vascular bed or the bone marrow reserve, or an increase in hematopoiesis. The main function of neutrophils is to participate in the fight against microorganisms by their phagocytosis. The contents of the granules can destroy almost any microbes. Neutrophils contain numerous enzymes that cause bacteriolysis and digestion of microorganisms.

Variants of change (shift) of the leukocyte formula.

Neutrophilia (an increase in the number of neutrophils) may be reactive (associated with infection, inflammation, tumor, or endocrine disorders) or associated with primary disorders of hematopoiesis (hemoblastoma).

Neutropenia (absolute neutrophil count less than 1800/mcL) may be caused by depletion of the neutrophil reserve (eg, due to septicemia), autoimmune disorders (agranulocytosis, sometimes drug-induced), circulatory disorders, and other pathological conditions.

"Shift to the left": ("rejuvenation" of neutrophils): an increased number of stab neutrophils is present in the blood, the appearance of metamyelocytes (young), myelocytes is possible.

Eosinophils (Eosinophils)

Eosinophils make up 0.5-5% of all blood leukocytes, are in circulation for about 30 minutes, after which they enter the tissues, where they stay for about 12 days. The change in the content of eosinophils in the peripheral blood is the result of a balance in the production of cells in the bone marrow, their migration into tissues and destruction.

Evaluation of the dynamics of changes in the number of eosinophils during the inflammatory process has a certain prognostic value.

Eosinopenia (a decrease in the number of eosinophils in the blood less than 0.2x10 "/l) is often observed at the onset of inflammation. An increase in the number of eosinophils (> 5%) accompanies the onset of recovery. However, a number of infectious and other diseases with a high level of IgE are characterized by eosinophilia even after the end of the inflammatory process, which indicates the incompleteness of the immune response.At the same time, a decrease in the number of eosinophils in the active phase of the disease often indicates the severity of the process and is an unfavorable sign.

Basophils (Basophils)

The smallest population of leukocytes. Basophils account for an average of only 0.5% of the total number of blood leukocytes. Mature baeophils enter the bloodstream, where they circulate for about 6 hours. Then they migrate to the tissues, where they die within 1-2 days after performing their function. These are cells related to tissue mast cells. Basophils are capable of phagocytosis. Their granules contain sulfated or carboxylated acidic proteins, such as heparin, which turn blue when stained according to Giemsa, and other biologically active substances.

Basophils are involved in allergic reactions, including lgE-dependent mechanisms, initiate the development of an immediate anaphylactic hypersensitivity reaction.

Basophilia (basophil content> 0.15x10 "/l) may be associated with allergic reactions, viral diseases, chronic infections, inflammatory processes, and oncological diseases.

Lymphocytes

Lymphocytes have the ability to synthesize and secrete into the blood various protein regulators - cytokines, through which they coordinate and regulate the immune response. An increase in the content of lymphocytes is observed as a reaction to acute viral infections, chronic infections (tuberculosis and syphilis), this may also be a consequence of specific hematological diseases.

It should be borne in mind that the leukocyte formula reflects the relative (percentage) content of leukocytes of various types, and an increase or decrease in the percentage of lymphocytes can be both absolute and relative. So, a high percentage of lymphocytes in the formula may be the result of true (absolute) lymphocytosis, when the content of blood lymphocytes exceeds 3000 / μl, or a decrease in the absolute number of leukocytes of other types (usually neutrophils) - in this case, lymphocytosis is relative. Lymphopenia (decrease in the number of lymphocytes) can also be absolute, when the number of cells falls below 1000 / μl, or relative - be the result of an increase in the number of granulocytes.

Monocytes

Monocytes - the largest cells among leukocytes, make up 2-10% of all leukocytes, belong to agranulocytes. In the peripheral blood, monocytes make up 80-600x10 "/L. Monocytes circulate in the blood from 36 to 104 hours, then leave the vascular bed. In tissues, monocytes differentiate into organ- and tissue-specific macrophages. The life expectancy of tissue macrophages (histiocytes) is calculated in months and years. Macrophages are involved in the formation and regulation of the immune response, performing the function of antigen presentation to lymphocytes and being a source of biologically active substances (including regulatory cytokines, interleukins, interferons, complement components).

Monocytes/macrophages capable of amoeboid movement exhibit pronounced phagocytic and bactericidal activity. One macrophage is able to absorb up to 100 microorganisms, while a neutrophil is only 20-30. They appear in the focus of inflammation after neutrophils and show maximum activity in an acidic environment, in which neutrophils lose their activity. In the focus of inflammation, macrophages phagocytize microorganisms, as well as dead leukocytes, damaged cells of inflamed tissue, clearing the focus of inflammation and preparing it for regeneration. Macrophages are more efficient than neutrophils in phagocytosis of mycobacteria, fungi and macromolecules. In the spleen, macrophages ensure the utilization of sensitized and aging erythrocytes. Monocytosis (an increase in the absolute number of monocytes over 10xNU/l) is observed in patients with chronic infections or inflammatory processes.

ESR (Erythrocyte Sedimentation Rate, ESR)

Nonspecific indicator of inflammation.

ESR is an indicator of the rate of separation of blood stabilized by an anticoagulant in a capillary into two layers: upper (transparent blood plasma) and lower (settled erythrocytes and other blood cells). ESR is estimated by the height of the formed layer of blood plasma (in mm) for 1 hour. The specific gravity of erythrocytes is higher than the specific gravity of plasma, therefore, under the influence of gravity, erythrocytes settle to the bottom. The process of sedimentation (sedimentation) of erythrocytes can be divided into 3 phases, which occur at different rates. At first, red blood cells slowly settle into individual cells. Then they form aggregates - "coin columns", and settling occurs faster. In the third phase, a lot of erythrocyte aggregates are formed, their sedimentation first slows down, and then gradually stops. The main factor influencing the formation of "coin columns" and the erythrocyte sedimentation rate is the protein composition of blood plasma. Proteins of the acute phase of inflammation, being adsorbed on the surface of erythrocytes, reduce their charge and repulsion from each other, contribute to the formation of "coin columns" and accelerated erythrocyte sedimentation. An increase in the content of acute phase proteins, for example, C-reactive protein, haptoglobin, alpha-1 antitrypsin, in acute inflammation leads to an increase in ESR. In acute inflammatory and infectious processes, a change in the erythrocyte sedimentation rate is noted 24 hours after an increase in temperature and an increase in the number of leukocytes. In chronic inflammation, an increase in ESR is due to an increase in the concentration of fibrinogen and immunoglobulins. A decrease in the content of erythrocytes in the blood (anemia) leads to an acceleration of ESR, and, conversely, an increase in the content of erythrocytes in the blood slows down the rate of their sedimentation. The determination of ESR is used in screening examinations, as well as in monitoring the course and monitoring the effectiveness of the treatment of inflammatory and infectious diseases, usually in combination with a general blood test.

The level of ESR varies depending on many physiological factors. The values of ESR in women are slightly higher than in men. Changes in the protein composition of the blood during pregnancy lead to an increase in ESR. During the day, fluctuations in values are possible, the maximum level is noted in the daytime.