Complete blood count with leukocyte formula and ESR. General (Clinical) blood test with a leukocyte formula: what is it, decoding Formula of a clinical blood test decoding

To determine the exact diagnosis and evaluate the effectiveness of treatment, the doctor usually prescribes a blood test, in which the leukocyte formula is examined. Let's figure out what this concept means, what indicators are considered normal, and what these or those deviations may indicate?

Functions of leukocytes

So, what is the leukocyte formula, and how can it be determined? The leukocyte blood formula shows the percentage of various types of leukocytes in human blood plasma. Each of the existing types of cells reacts in a certain way to the penetration of viruses or pathogenic bacteria into the body, the development of diseases. Therefore, deciphering the leukocyte formula, showing the composition of the blood, allows the doctor to diagnose the type of disease, judge its severity, and control the course of treatment of the disease.

The leukocyte blood formula considers the composition in the blood of two main groups of leukocytes:

• Granulocytes, which in turn are divided into:
  • Eosinophils.
  • Basophils.
  • Neutrophils.
• Agranulocytes, which include:
  • Monocytes.
  • Lymphocytes of various types.

Granulocytes have a large granular structure divided into segments by the nucleus.

Their varieties are divided according to the ability to stain with certain types of dyes.

Eosinophils, when tested in the laboratory, are able to absorb the acidic dye eosin, which is the reason for their name. Basophils are stained with alkaline dyes. Neutrophils are able to perceive both alkaline and acidic compounds.

A clinical blood test with a leukocyte formula can be prescribed by a doctor in the following cases:

• to determine the cause of the disease,
• to determine the severity of the disease, the presence of complications,
• to monitor the course of the disease and evaluate the effectiveness of treatment,
• to evaluate further forecasts,
• when conducting preventive examinations or planning pregnancy to identify existing pathologies.

In order for the decoding to not contain distorted indicators when analyzing the leukocyte blood count, you should properly prepare for the study. To do this, follow these recommendations:

• 24 hours before the test, do not drink alcohol-containing drinks and drugs,
• donate blood for analysis on an empty stomach, not earlier than 6-8 hours after eating,
• do not smoke for at least 30 minutes before taking a sample for research,
• avoid strong physical or emotional stress 30-40 minutes before blood sampling.

To determine the leukocyte formula, venous or capillary blood is taken. It is treated with special reagents that stain the cells in one color or another, which allows you to count their number.

Cell counting is carried out by a laboratory assistant using a microscope or an automatic analyzer.

A modern leukocyte blood count counter significantly increases the reliability of the results obtained, since it makes it possible to analyze more than 2 thousand cells. In comparison, examination under a microscope allows assessment of the types of approximately 200 cells.

The following factors may affect the reliability of the result:

• sex and age, race of the patient,
• the use of medicines,
• pregnancy.

For this reason, the results obtained should be interpreted taking into account the individual characteristics of the patient. If there are deviations from the norm of the leukocyte formula, a re-analysis should be done. Sometimes an incorrect count of the leukocyte formula is caused by errors in blood sampling, improper preparation of a smear, the quality of reagents, and other factors.

Norms

The correct interpretation of the leukocyte blood count can only be done by a qualified specialist. Since, for making a diagnosis, one should pay attention not only to the relative content of leukocytes, but also their absolute indicators, as well as the levels of other blood parameters.

For adults, the following norms of leukocytes are accepted:

Deviations

A shift in the leukocyte formula is a change in the ratios of different types of these cells in the blood. There are shifts to the left or to the right.

Shift left

It is curious that the vast majority of all leukocytes are represented by mature neutrophils. Their number, as already mentioned, reaches 70-72%. But young neutrophils with a rod-shaped nucleus make up no more than 5% of the total number of leukocytes.

The reason for this is that immature cells are in the blood for a very short period of time, since they mature quite quickly and turn into mature neutrophils with a segmented nucleus.

Segmented particles are the main fighters against infections and viruses. Therefore, when the body is attacked by any pathogens, a command is given to the bone marrow to produce new cells. In other words, the disease is a stimulus for the intensive reproduction of new (young) neutrophils. Accordingly, a sharp change in their number above the normative 5% may be a sign of the following pathologies:

• acute diseases - pyelonephritis, prostatitis,
• necrosis, purulent infections,
• acidosis,
• heavy bleeding,
• severe intoxication,
• leukemia,
• malignant neoplasms,
• significant physical activity.

shift right

In the case when a blood test shows the presence of exclusively mature neutrophils. At the same time, young cells with a rod-shaped nucleus are reduced or absent altogether. In this situation, we are talking about shifting the formula to the right. Such insufficient reproduction of new blood cells is characteristic of the following pathologies:

• diseases of the liver and kidneys,
• radiation sickness,
• megaloblastic anemia,
• conditions after blood transfusion,
• vitamin B12 deficiency or folic acid deficiency.

The degree of formula shift determines the leukocyte index, which reflects the ratio of young and young neutrophils counted together to the number of mature cells with a segmented nucleus. Permissible norms for such an index are in the range of 0.05-0.1.

In addition to neutrophils, in deciphering the analysis, deviations from the norm can also be observed for other leukocytes.

The reason for the increased number of lymphocytes may be:

• Infectious mononucleosis,
• various viral infections, such as rubella, chickenpox, hepatitis,
• severe bacterial diseases such as tuberculosis, brucellosis, toxoplasmosis, syphilis, whooping cough,
• chronic lymphocytic leukemia, lymphosarcoma, in which the number of lymphocytes can reach 50-100 Gg / l,
• hyperthyroidism,
• some types of anemia.

A decrease in the level of lymphocytes is typical for:

• lymphogranulomatosis,
• kidney failure,
• autoimmune diseases,
• acute infections,
• radiation sickness,
• taking corticosteroid drugs.

Relatively rare is an increase in the number of eosinophils in excess of standard values. This situation usually occurs when:

A decrease in the level of these cells is typical for:

• conditions after severe stress,
• taking adenocorticotropic hormonal drugs,
• Cushing's syndrome.

ESR

Often, for diagnosis, the doctor prescribes a general blood test with a leukocyte formula and ESR. Such a KLA is often used as a screening study for:

• infectious diseases,
• rheumatic diseases,
• renal pathology,
• the presence of malignant neoplasms.

The principle of this study is that the erythrocyte has a density somewhat greater than the density of blood plasma. Because of this, such cells with a certain speed settle to the bottom of the test tube with a blood sample, deprived of the possibility of coagulation.

Under the influence of various processes, for example, when tumor cells appear, infection penetrates, lymphocytes begin to intensively produce certain protein compounds. Under their influence, the aggregation of erythrocytes (sticking together) increases, which leads to an increase in their density and accelerates the sedimentation of particles to the bottom of the tube.

The normal level of ESR for men is 1-10 mm/hour, for women it is slightly higher and is in the range of 2-15 mm/hour.

The erythrocyte sedimentation rate increases significantly in the case of inflammatory processes, infectious and autoimmune diseases, in the presence of anemia, tumors, rheumatism and other pathologies. A qualified specialist should decipher the results of the analysis, taking into account the presence of clinical symptoms and data from other examinations.

The study of the ratio of leukocytes contained in the blood is a very important element in diagnosing diseases and monitoring the effectiveness of treatment. The leukocyte balance determined during the study will allow the doctor to timely identify hidden pathologies, assess the prognosis of the course of the disease and prescribe the correct therapy.

In contact with

It is used to diagnose and control the treatment of many diseases.

Russian synonyms

General blood test, KLA.

SynonymsEnglish

Complete blood count (CBC) with differential, Erythrocyte Sedimentation Rate (ESR), KLA

Research method

SLS (sodium lauryl sulfate) method + capillary photometry method (venous blood).

Units

*10^9/l - 10 per st. 9/l;

*10^12/l - 10 per st. 12/l;

g/l - grams per liter;

fL, femtoliter;

pg – picogram;

% - percent;

mm/h - millimeter per hour.

What biomaterial can be used for research?

Venous, capillary blood.

How to properly prepare for research?

• Eliminate alcohol from the diet 24 hours before the study.
• Do not eat for 8 hours before the study, you can drink clean non-carbonated water.
• Eliminate physical and emotional overstrain for 30 minutes before the study.
• Do not smoke for 30 minutes prior to the study.

General information about the study

Clinical blood test: general analysis, leukocyte formula, ESR (with microscopy of a blood smear when pathological changes are detected) is one of the most frequently performed tests in medical practice. Today, this study is automated and allows you to get detailed information about the quantity and quality of blood cells: erythrocytes, leukocytes and platelets. From a practical point of view, the doctor should first of all focus on the following indicators of this analysis:

1. Hb (hemoglobin) - hemoglobin;
2. MCV (mean corpuscular volume) - the average volume of an erythrocyte;
3. RDW (RBC distribution width) - distribution of erythrocytes by volume;
4. The total number of red blood cells;
5. The total number of platelets;
6. The total number of leukocytes;
7. Leukocyte formula - the percentage of different leukocytes: neutrophils, lymphocytes, monocytes, eosinophils and basophils;
8. Erythrocyte sedimentation rate, ESR. The ESR indicator depends on the ratio of protein fractions of the blood and the number of red blood cells.

Determination of indicators of a clinical blood test allows diagnosing conditions such as /polycythemia, thrombocytopenia/ and leukopenia/leukocytosis, which can either be symptoms of a disease or act as independent pathologies.

When interpreting the analysis, the following features should be considered:

• In 5% of healthy people, blood test values ​​deviate from the accepted reference values ​​(normal limits). On the other hand, the patient may have a significant deviation from his usual indicators, which at the same time remain within the accepted norms. For this reason, test results must be interpreted in the context of each individual's individual routine.
• Blood counts vary by race and gender. Thus, in women, the quantity and quality characteristics of erythrocytes are lower, and the number of platelets is higher than in men. For comparison: norms for men - Hb 12.7-17.0 g / dl, erythrocytes 4.0-5.6 × 10 12 / l, platelets 143-332 × 10 9 / l, norms for women - Hb 11, 6-15.6 g/dl, erythrocytes 3.8-5.2×10 12 /l, platelets 169-358×10 9 /l. In addition, neutrophils and platelets are lower in black people than in white people.

What is research used for?

• To diagnose and control the treatment of many diseases.

When is the study scheduled?

• During a preventive examination;
• if the patient has complaints or symptoms of any disease.

What do the results mean?

Deciphering the results of the analysis: norm tables for children and adults (r reference values)

Leukocytes

red blood cells

Hemoglobin

Hematocrit

Mean erythrocyte volume (MCV)

Mean erythrocyte hemoglobin (MCH)

Mean erythrocyte hemoglobin concentration (MCHC)

platelets

RDW-SD (RBC volume distribution, standard deviation): 37 - 54.

RDW-CV (RBC volume distribution, coefficient of variation)

Lymphocytes (LY)

Monocytes (MO)

Eosinophils (EO)

Basophils (BA): 0 - 0.08 *10^9/l.

Neutrophils, % (NE %)

Lymphocytes, % (LY %)

Monocytes, % (MO %)

Eosinophils, % (EO %)

Basophils, % (BA%): 0-1.2%.

Erythrocyte sedimentation rate (photometry)

Analysis interpretation:

1. Anemia

A decrease in hemoglobin and / or red blood cells indicates the presence of anemia. Using the MCV indicator, you can conduct a primary differential diagnosis of anemia:

1. MCV less than 80 fl (microcytic anemia). The reasons:
   1. Iron-deficiency anemia,
   ,
2. drugs (hydroxyurea, zidovudine),
3. deficiency of vitamin B 12 and folic acid.

Severe macrocytosis (MCV greater than 110 fl) usually indicates primary bone marrow disease.

With anemia, regardless of its type, ESR is usually increased.

2. Thrombocytopenia

• thrombocytopenic purpura / hemolytic uremic syndrome;
• DIC (disseminated intravascular coagulation);
• drug thrombocytopenia (co-trimoxazole, procainamide, thiazide diuretics, heparin);
• hypersplenism;
• idiopathic thrombocytopenic purpura.

It should be remembered that in pregnant women, normal platelets can decrease to 75-150×10 9 /l.

3. Leukopenia

For the differential diagnosis of leukopenia, both the absolute number of each of the 5 main sprouts of leukocytes and their percentage (leukocyte formula) matter.

Neutropenia. Decrease in neutrophils less than 0.5×10 9 /l - severe neutropenia. The reasons:

• Congenital agranulocytosis (Kostmann's syndrome);
• Drug neutropenia (carbamazepine, penicillins, clozapine and others);
• Infections (sepsis, viral infection);
• Autoimmune neutropenia (SLE, Felty's syndrome).

Lymphopenia. The reasons:

• Congenital lymphopenia (Bruton's agammaglobulinemia, severe combined immunodeficiency, diGeorge's syndrome);
• Acquired variable immunodeficiency;
• Drug-induced lymphopenia (glucocorticosteroids, monoclonal antibodies);
• Viral infection ();
• Autoimmune lymphopenia (SLE, rheumatoid arthritis, sarcoidosis);
• Tuberculosis.

4. Polycythemia

An increase in the concentration of Hb and / or Ht and / or the number of red blood cells can be observed with:

• Polycythemia vera is a myeloproliferative disease. In the blood test, in addition to erythrocytosis, thrombocytosis and leukocytosis are observed.
• Relative polycythemia (compensatory bone marrow response to hypoxia in COPD or CAD; excess erythropoietin in renal cell carcinoma).

For the differential diagnosis of polycythemia, a study of the level of erythropoietin is recommended.

1. thrombocytosis

• Primary thrombocytosis (malignant disease of the myeloid germ of the bone marrow, including essential thrombocytosis and chronic myelogenous leukemia);
• Secondary thrombocytosis after removal of the spleen, with an infectious process, iron deficiency anemia, hemolysis, trauma and malignant diseases (reactive thrombocytosis).

An increase in Hb, MCV, or total leukocyte count is indicative of primary thrombocytosis.

1. Leukocytosis

The first step in interpreting leukocytosis is to evaluate the leukocyte count. Leukocytosis may be due to an excess of immature leukocytes (blasts) in acute leukemia or mature, differentiated leukocytes (granulocytosis, monocytosis, lymphocytosis).

Granulocytosis - neutrophilia. The reasons:

• Leukemoid reaction (reactive neutrophilia in the presence of infection, inflammation, the use of certain drugs);
• Myeloproliferative disease (eg, chronic myelogenous leukemia).

An increase in stab neutrophils of more than 6% indicates the presence of infection, but can also be observed in chronic myelogenous leukemia and other myeloproliferative diseases.

Also, an indirect sign of the infectious process is an increase in ESR, which, however, can also be observed in many malignant diseases.

Granulocytosis - eosinophilia. The reasons:

Granulocytosis - basophilia. The reasons:

• Chronic basophilic leukemia.

Monocytosis. The reasons:

• Myeloproliferative disease, such as CML;
• Reactive monocytosis (chronic infections, granulomatous inflammation, radiation therapy, lymphoma).

Lymphocytosis. The reasons:

• Reactive lymphocytosis (viral infection). Virus-specific laboratory tests are recommended.
• Lymphocytic leukemia (acute and chronic).

Clinical blood test: general analysis, leukocyte formula, ESR (with microscopy of a blood smear when pathological changes are detected) is a screening method with which many diseases can be suspected or excluded. This analysis, however, does not always allow to establish the cause of the changes, the identification of which, as a rule, requires additional laboratory, including pathomorphological and histochemical studies. The most accurate information can be obtained by dynamic observation of changes in blood parameters.

What can influence the result?

• age;
• race;
• the presence of concomitant diseases;
• the use of medicines.

Important Notes

• Test results must be interpreted in the context of each individual's individual routine;
• the most accurate information can be obtained by dynamic observation of changes in blood parameters;
• test results should be interpreted taking into account all anamnestic, clinical and other laboratory data.

• Clinical and biochemical blood test - main indicators

Who orders the study?

Therapist, surgeon, gynecologist, pediatrician, general practitioner.

Literature

• Jolobe OM. How to interpret and pursue an abnormal complete blood cell count in adults. Mayo Clinic Proc. 2005 Oct;80(10):1389-90; author reply 1390, 1392.
• McPhee S.J., Papadakis M. CURRENT Medical Diagnosis and Treatment / S. J. McPhee, M. Papadakis; 49 ed. – McGraw-Hill Medical, 2009.

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.

Blood indicators characterize the state of human health and can greatly facilitate diagnosis. By determining the leukocyte formula, one can assume the type of disease, judge its course, the presence of complications, and even predict its outcome. And to understand the changes taking place in the body will help deciphering the leukogram.

What does the leukocyte blood formula show?

The leukocyte blood formula is the ratio of different types of leukocytes, usually expressed as a percentage. The study is carried out as part of a general blood test.

Leukocytes are white blood cells that represent the body's immune system. Their main functions are:

• protection against microorganisms that can cause health problems;
• participation in the processes that occur in the body when exposed to various pathogenic factors and cause disturbances in normal life (various diseases, exposure to harmful substances, stress).

The following types of leukocytes are distinguished:

Deciphering the indicators of LYM (lymphocytes) in a blood test:

Plasma cells (plasmocytes) are involved in the formation of antibodies and are normally present in a very low amount only in the blood of children, in adults they are absent and can appear only in the case of pathologies.

The study of the qualitative and quantitative characteristics of leukocytes can help in making a diagnosis, since with any changes in the body, the percentage of some types of blood cells increases or decreases due to an increase or decrease in varying degrees of others.

The doctor prescribes this analysis in order to:

• get an idea of ​​the severity of the patient's condition, judge the course of the disease or pathological process, learn about the presence of complications;
• establish the cause of the disease;
• evaluate the effectiveness of the prescribed treatment;
• predict the outcome of the disease;
• in some cases, assess the clinical diagnosis.

Technique, calculation and interpretation of the analysis

To calculate the leukocyte formula with a blood smear, certain manipulations are performed, dried, treated with special dyes and examined under a microscope. The laboratory assistant notes those blood cells that fall into his field of vision, and does this until a total of 100 (sometimes 200) cells are accumulated.

The distribution of leukocytes over the surface of the smear is uneven: the heavier ones (eosinophils, basophils and monocytes) are located closer to the edges, and the lighter ones (lymphocytes) are closer to the center.

There are 2 ways to calculate:

• Schilling method. It consists in determining the number of leukocytes in four areas of the smear.
• Filipchenko method. In this case, the smear is mentally divided into 3 parts and counted along a straight transverse line from one edge to the other.

On a sheet of paper in the appropriate columns, the quantity is noted. After that, each type of leukocyte is counted - how many of which cells were found.

It should be borne in mind that counting cells in a blood smear when determining the leukocyte formula is a very inaccurate method, since there are many hard-to-remove factors that introduce errors: errors in blood sampling, smear preparation and staining, human subjectivity in interpreting cells. A feature of some types of cells (monocytes, basophils, eosinophils) is that they are unevenly distributed in the smear.

If necessary, leukocyte indices are calculated, which are the ratio of various forms of leukocytes contained in the patient's blood, and sometimes the ESR indicator (erythrocyte sedimentation rate) is also used in the formula.

The norms of the leukocyte formula depend on the age of the person. In women, the difference also lies in the fact that the indicators can change during the period of ovulation, after or during menstruation, during pregnancy, after childbirth. That is why in cases of deviations, a gynecologist should be consulted.

Possible deviations from the norm in the leukogram

An increase or decrease in the level of certain types of leukocytes indicates pathological changes occurring in the body.

Causes of changes in the number of leukocytes in the blood - table

Shift of the leukocyte formula

In medicine, there are concepts of a shift in the leukocyte formula, indicating deviations in the health status of patients.

Shift of the leukocyte formula to the left and right - table

To obtain data on the patient's condition, based on the results of the leukocyte formula, the shift index is taken into account. It is determined by the formula: IP \u003d M (myelocytes) + MM (metamyelocytes) + P (stab neutrophils) / C (segmented neutrophils). The norm of the shift index of the leukocyte formula in an adult is 0.06.

In some cases, there may be such a phenomenon as a significant content of young cells in the blood - metamyelocytes, myelocytes, promyelocytes, myeloblasts, erythroblasts. This usually indicates diseases of a tumor nature, oncology and metastasis (the formation of secondary tumor foci).

Crossover of the leukocyte formula

The cross of the leukocyte formula is a concept that arises when analyzing the blood of a child. If in an adult, changes in the blood are caused by diseases or a significant impact on the body of harmful factors, then in young children, changes occur in connection with the formation of the immune system. This phenomenon is not a pathology, but is considered absolutely normal. The non-standard numbers are due only to the formation of immunity.

The first crossover of the leukocyte formula usually occurs towards the end of the first week of a baby's life. At this time, the number of neutrophils and lymphocytes in the blood is equalized (they become approximately 45% each), after which the number of lymphocytes continues to grow, and neutrophils decrease. This is considered a normal physiological process.

The second crossover of the leukocyte formula occurs at the age of 5-6 years, and only by the age of ten, blood counts approach the norm of an adult.

How to determine the nature of the inflammatory process by a blood test - video

The leukocyte formula is able to give many answers in case of difficulties in diagnosing the disease and prescribing therapy, as well as characterize the patient's condition. However, it is better to entrust the interpretation of a blood test to an experienced specialist. The doctor can give detailed explanations and adjust the treatment.

One of the components of a blood test is a leukocyte formula. Doctors recommend its definition for any pathology, as it is sensitive to many pathologies. In the article, we will analyze all possible changes in the number of leukocytes and what they mean.

Varieties of leukocytes

A general blood test consists of several indicators. All of them are reflected in their own units of measurement, with designations in Latin letters.

Therefore, when receiving a blood test (leukogram) on hand, decoding the values ​​\u200b\u200bis useful to any person:

Separately recorded leukocyte formula. It reflects the ratio of white blood cells to each other. This is important for clinical diagnosis, as all white blood cells are not the same.

There are several varieties of them, which differ in their functions in the human body:

• Neutrophils;
• Lymphocytes;
• Monocytes;
• eosinophils;
• Basophils.

Neutrophils

One of the most versatile cells. They are activated by any inflammation, no matter if it is bacterial or viral. Neutrophils destroy any substances foreign to the body, releasing chemical components that attract other inflammatory cells. Therefore, any inflammatory reaction is essentially triggered by neutrophils.

Neutrophil cells are also divided according to their degree of maturity:

• Myelocytes and metamyelocytes- very young, young cells that do not perform any functions. A healthy person does not have them in the blood.
• stab- maturing cells that are always found in the blood. Their number increases sharply during the onset of infection.
• Segmented- the most mature, mature cells. They perform all the functions of protecting the body inherent in neutrophils. Segmented neutrophils are the latest stage in the development of myelocytes.

Lymphocytes

These are the cells that carry out the second stage of the immune response. They come to the site of inflammation, reacting to chemicals released by neutrophils.

There are several types of lymphocytes:

• B-lymphocytes- create antibodies to viral and bacterial infections.
• T-lymphocytes helpers and killers- start the work of B-lymphocytes and independently destroy viral cells.
• natural killers- able to destroy cells that have been infected by the virus or that have undergone tumor changes.

Monocytes

Similar in function to neutrophils. The main work of monocytes– destroy foreign material. They perform their task with the help of phagocytosis.

This is the process of engulfment by a monocyte of a bacterium, virus, or any other pathogen. Inside the cell, this element dies, giving monocytes information about its structure. In the future, this will help B-lymphocytes to develop antibodies specifically to this pathogen.

Eosinophils and basophils

These are the cells involved in allergic reactions. Their number increases sharply if an allergy to any substance develops in the human body.

It is due to the chemical elements that eosinophils secrete that a person develops symptoms of an acute allergic reaction:

• Swelling of the face;
• Cough or runny nose;
• The skin turns red;
• A rash occurs.

Functions of leukocytes

It is not in vain that the leukoformula consists of several components. Each of these cells is important in providing the body with a healthy immune system. It all starts with the entry of a bacterium or virus into the human body. The pathogenic microbe is absorbed by the neutrophil, which digests it - phagocytosis.

After phagocytosis, the neutrophil retains the microbe particle, showing it to lymphocytes. T-lymphocytes and B-lymphocytes together organize an attack on the pathogen. B cells create a mass of antibodies that are ideally suited to this bacterium. Only such joint actions provide an immune response to any infection. Therefore, the ratio of leukogram cells is so important.

Normal leukogram values

In each laboratory, different values ​​​​can be taken as normal, depending on the technology and the reagent used by the laboratory. Therefore, analysis in dynamic observation should be performed in one laboratory. This will keep the correctness of the values ​​and clearly trace the dynamics.

But there are average criteria that can be used if the laboratory has not provided its data.

The norm of the number of cells strongly depends on the sex and age of the person.

How is the analysis carried out

Blood for determining the number of leukocytes can be taken in two ways:

• capillary- from a finger.
• Venous from a peripheral vein.

Analysis indicators taken in different ways can differ even in one person. But usually these changes do not exceed normal values. Viewing blood under a microscope has always been used as a counting technique. It is carried out by a laboratory assistant, counting the number of cells in the fields of view under a microscope.

The calculation is carried out for 100 cells, so it is convenient to set the final result as a percentage. Before counting neutrophils or other cells, the field of view is mentally divided into 3 sections from one edge to the other.

Today, many laboratories use an automatic analyzer. This is an apparatus that counts all the possible cells that it has encountered.

When using a hematology analyzer, more cells can be viewed in a short time. But in controversial cases, preference is given to viewing under a microscope by a laboratory assistant. A person can determine slight differences in the appearance of cells, which can indicate pathology.

Why determine the leukoformula

A large number of indicators of the leukoformula allows it to respond to many diseases. A well-calculated analysis in normal and pathological conditions will be of great help to the doctor.

When a doctor directs to determine the number of leukocytes, he has several goals:

• Assistance in making a diagnosis;
• Determining the severity or activity of the process;
• The dynamics of recovery;
• Reaction or lack thereof to drugs;
• Early detection of complications.

Change in the amount and ratio in the leukogram

When calculating the percentage of neutrophilic cells, the ratio of mature and young forms of leukocytes is necessarily displayed. This allows you to understand the severity of the process and its severity.

With an increase in the number of stab and young cells in the analysis, they speak of a shift in the leukocyte formula to the left, since these cells are located on the left in the form. This speaks for an active immune response. In some cases, the appearance of the most immature cells in the peripheral blood may indicate an oncological disease.

Table of the ratio of neutrophil forms as a percentage of the total number of white blood cells.

In controversial cases or when conducting clinical trials, the determination of the leukocyte intoxication index (LII) can be used. This is the ratio of immature forms of neutrophils that appear during acute inflammation to other cells - lymphocytes, monocytes, eosinophils.

Index values ​​are calculated depending on age and gender. The approximate index number is 0.6.

Causes of an increase or decrease in leukocytes

An increase in the number of neutrophils occurs when:

• bacterial infections- angina, pyelonephritis, pneumonia;
• Intoxications of any nature;
• Taking glucocorticosteroids- prednisolone;
• burn disease;
• Gangrene, heart attack.

A decrease in the number of neutrophils accompanies:

• severe bacterial infections- brucellosis, tuberculosis;
• Viral infections- measles, rubella;
• The effect of toxins on the bone marrow;
• Radiation sickness;
• Autoimmune diseases.

The main reason for the change in the number of lymphocyte cells- different kinds of infections. B-lymphocytes mature in the bone marrow, and T-lymphocytes in the thymus. This difference emphasizes that their functions are different. But in the analyzes it does not matter which of the fractions is increased. The laboratory examines the total number of lymphocytes.

Lymphocytosis or an increased number of lymphocytes occurs when:

• Chronic bacterial infections- tuberculosis, syphilis, brucellosis;
• Acute viral diseases- influenza, chickenpox, measles;
• Tumors of the blood system- lymphomas;
• Hormonal dysfunctions- hypothyroidism;
• Macrocytic anemias- folic acid deficiency;
• Autoimmune pathologies- systemic lupus erythematosus.

A reduced number of lymphocytes or lymphocypenia accompanies:

• Primary immunodeficiencies- DiGeorge syndrome;
• Secondary immunodeficiencies- HIV infection;
• Taking glucocorticosteroids- prednisolone;
• Acute bacterial infections- streptococcal pneumonia;
• Toxic effects on the bone marrow- Irradiation, heavy metals.

Monocytes are of little or no clinical significance when considered individually. Therefore, usually their changes are evaluated in combination with other leukocyte parameters.

Monocytes usually increase with:

A decrease in the number of monocytes practically does not occur without general leukocytopenia. Therefore, it has no diagnostic value. It is worth mentioning infectious mononucleosis. This is a viral infection, the main criterion of which is the detection of mononuclear cells in the blood.

These are cells similar to monocytes, but are pathological. In a healthy person, the detection of mononuclear cells in the blood is unacceptable.

Eosinophils and basophils are a criterion for allergic reactions and some infectious diseases. Estimation of their number is also highly dependent on the total number of leukocytes in the blood test.

Low eosinophils accompany:

• Taking corticosteroid medications;
• Some severe infections such as typhoid.

Video: Deciphering a blood test