The main function of the immune system is to protect the human body from any foreign information. It is immunity that ensures the integrity and normal functioning of the human body. The first to study the protective properties of the human immunological system was the French microbiologist and chemist Louis Pasteur.
The cells of the immune system are lymphocytes (B-lymphocytes, T-lymphocytes). They are the “guardians” on the way of foreign organisms that are trying to break into the human body. These “protectors” are formed by the bone marrow and thymus. These organs are called the central organs of the immune system.
There are 2 types of immunity : cellular and humoral. B lymphocytes, which produce immunoglobulins or antibodies, are responsible for humoral immunity. The main function of humoral immunity is the fight against various types of bacteria. With reduced humoral immunity, a person often suffers from colds and infectious diseases, furunculosis.
Cellular immunity in the human body is provided by T-lymphocytes, which are produced by the thymus. The main task of cellular immunity is to protect the body from intracellular antigens: viruses, tumors, fungi.
An immunological blood test is a laboratory research method that allows you to assess the state of a person’s immune system and identify the presence of antibodies in his blood. An immunological test may be prescribed when the patient has chronic infectious diseases, allergic reactions, or develops cancer. This analysis will allow the doctor to assess the general state of the patient’s immunity, its ability to withstand the negative effects of various irritants on human health.
Indications for analysis
Immunological tests are prescribed in different cases: to identify immunity and secretive transmission of infectious diseases, to determine blood type, the nature of the tumor, the presence of foreign pathogens in the body, as well as to confirm or refute a possible pregnancy.
An immunological examination is prescribed for:
- Long-term immunodeficiency states.
- Aggravated allergic anamnesis.
- Sluggish autoimmune diseases.
- Chronic, acute infectious conditions.
- Preparation for organ donation and recipient.
- Preparation for surgical interventions.
- Detection of pregnancy.
- Oncological examinations.
- Analysis of prescribed treatment, the chemical components of which affect immunity.
Immunological studies require significant labor and a long time to carry out the necessary biochemical reactions and correctly interpret the results obtained. Therefore, in the case of a hyperacute or severe acute course of the disease, an immunoserological study can only be a secondary and collateral method of laboratory diagnosis, because waiting for the results of an immunochemical blood test is fraught with loss of time, which should be spent on alleviating the patient’s condition.
An immunological blood test is prescribed to identify the following diseases:
- anatomical and physiological changes in the myocardium and pericardium;
- rheumatoid arthritis and arthrosis;
- bone osteomyelitis;
- diabetes mellitus and diabetes insipidus;
- erysipelas;
- bronchial asthma, chronic obstructive pulmonary disease;
- candidiasis and vaginitis;
- echinococcosis;
- thyroiditis, Graves' disease, hypothyroidism;
- tonsillitis, sore throat, pneumonia;
- infectious mononucleosis, Epstein-Barr virus;
- scarlet fever, tularemia, borreliosis, brucellosis, tuberculosis, toxoplasmosis;
- miscarriages and abortions;
- infertility;
- AIDS and HIV;
- urticaria, psoriasis, eczema;
- animal bites.
Immunological blood tests are not performed in all laboratories; many clinics do not have the necessary equipment to conduct such studies, so if such immunochemistry is necessary, the patient may be sent to donate blood to another medical institution.
Diseases for which a doctor may prescribe immunological tests
Osteomyelitis of the thigh
Osteomyelitis is characterized by an increase in the concentration of antistreptolysin-O, a marker of the presence of streptococcal infection in the body.
Osteomyelitis of the leg bones
Osteomyelitis is characterized by an increase in the concentration of antistreptolysin-O, a marker of the presence of streptococcal infection in the body.
Osteomyelitis of the calcaneal tuberosity
Osteomyelitis is characterized by an increase in the concentration of antistreptolysin-O, a marker of the presence of streptococcal infection in the body.
Erysipelas
Erysipelas is characterized by an increase in the concentration of antistreptolysin-O, a marker of the presence of streptococcal infection in the body.
Bronchial asthma
Bronchial asthma is characterized by an increase in the content of immunoglobulin E (IgE).
Multiple myeloma
Multiple myeloma is characterized by an increase in the content of immunoglobulin A (IgA) and immunoglobulin G (IgG).
Oral candidiasis
Candidiasis is characterized by an increase in the content of immunoglobulin M (IgM).
Acute glomerulonephritis
Acute glomerulonephritis is characterized by an increase in the content of immunoglobulin A (IgA), an increase in the concentration of antistreptolysin-O, a marker of the presence of streptococcal infection in the body.
Liver echinococcosis
Parasitic infestations (including echinococcus) are characterized by an increase in the content of immunoglobulin E (IgE).
Autoimmune thyroiditis
Autoimmune thyroiditis is characterized by an increase in the concentration of antibodies to thyroglobulin (AT-TG) and to thyroid peroxidase (AT-TPO).
Acute tonsillitis
With angina, it is possible to increase the concentration of antistreptolysin-O, a marker of the presence of streptococcal infection in the body.
Vasomotor and allergic rhinitis
Allergic rhinitis is characterized by an increase in the content of immunoglobulin E (IgE).
Chronic tonsillitis
Chronic tonsillitis is characterized by an increase in the concentration of antistreptolysin-O, a marker of the presence of streptococcal infection in the body.
Diffuse toxic goiter
Diffuse toxic goiter is characterized by an increase in the concentration of antibodies to thyroglobulin (AT-TG) and to thyroid peroxidase (AT-TPO).
Pulmonary candidiasis
Candidiasis is characterized by an increase in the content of immunoglobulin M (IgM).
Subacute thyroiditis
Subacute thyroiditis is characterized by an increase in the concentration of antibodies to thyroid peroxidase (AT-TPO).
Scarlet fever
Scarlet fever is characterized by an increase in the concentration of antistreptolysin-O, a marker of the presence of streptococcal infection in the body.
Infectious mononucleosis
Infectious mononucleosis is characterized by an increase in the content of immunoglobulin G (IgG).
Urogenital candidiasis
Candidiasis is characterized by an increase in the content of immunoglobulin M (IgM).
Chronic glomerulonephritis
An increase in the content of immunoglobulin A (IgA) is possible with glomerulonephritis.
Chronic hepatitis
With hepatitis of the liver, an increase in the content of immunoglobulin M (IgM) is possible. Antinuclear factor is increased in chronic hepatitis.
Cirrhosis of the liver
Decreased levels of immunoglobulin A (IgA) and immunoglobulin G (IgG); An increase in the content of immunoglobulin M (IgM) is possible with liver cirrhosis.
Allergic urticaria
An increase in the content of immunoglobulin E (IgE) is possible with urticaria.
Candidiasis of the skin and nails
Candidiasis is characterized by an increase in the content of immunoglobulin M (IgM).
Pyoderma
The concentration of antistreptolysin-O, a marker of the presence of streptococcal infection in the body, is increased in pyoderma.
Toxoplasmosis
An increase in the content of immunoglobulin E (IgE) is possible with parasitic invasion - toxoplasma.
Candidiasis of a newborn
Candidiasis is characterized by an increase in the content of immunoglobulin M (IgM).
AIDS
An increase in immunoglobulin G (IgG) levels is possible with HIV.
Goodpasture's syndrome
The indirect IF method detects serum anti-GBM antibodies.
Sjögren's syndrome
Noting an increase in the levels of immunoglobulins IgG and IgM; the presence of antibodies to DNA, LE cells, antibodies to the epithelium of exocrine glands, an increase in the number of B lymphocytes, a decrease in the number of T lymphocytes.
Systemic lupus erythematosus
An increase in the content of immunoglobulin A (IgA), immunoglobulin G (IgG), immunoglobulin M (IgM) is possible with systemic lupus erythematosus. Antinuclear factor, when determined together with antibodies to DNA, is a diagnostic criterion for systemic lupus erythematosus, in which it is elevated.
Scleroderma
Autoantibodies specific to scleroderma are detected.
Autoimmune chronic gastritis
With autoimmune chronic gastritis, there is a decrease in IgA and IgG, an increase in the level of B-lymphocytes and T-helpers by more than 6 times, and the appearance of autoantibodies to parietal cells and gastromucoprotein.
Primary biliary cirrhosis of the liver
In primary biliary cirrhosis, an immunological study detects antimitochondrial antibodies (AMA) - a highly specific marker of PBC, in a titer above 1:40, increased levels of IgM and IgG.
Principle of analysis
Serum blood tests are based on the principle of conflict between the body's antibodies produced by lymphocytes and antigens - foreign substances. Antibodies and immunoglobulins are special proteins that are released into the internal environment of the body as a result of an immune response - the body’s reaction to hostile substances entering it. The presence or absence of certain proteins can tell a lot about the body - what diseases were suffered in the past, their duration and severity, current pathological processes, hormonal changes, the fact of tumor growth.
Note! Doctors isolate and examine 5 types of immunoglobulins - A, B, D, G, M.
Flagella, shell, capsid, nucleus, cytoplasm and other parts of bacteria, viruses, contain foreign particles to which our body reacts. Depending on the type of immunoglobulin (Ig), only complementary proteins are released. After the infection or fungal infection subsides, antigens gradually disappear from the blood, but antibodies remain. They determine all the ins and outs of immunity.
After blood is collected, serum is isolated from it, which is centrifuged and settled. Blood plasma devoid of fibrinogen is examined for dry residue, which includes all the formed elements, vitamins, minerals, hormones, and by-products.
There are several methods and methods of immunological analysis: enzyme immunoassay, immunochemical, immunohematological, radioimmunoassay, chemiluminescence. These methods differ in laboratory conditions and equipment, method of recording results and the range of diseases studied.
How does the body's defense work?
Foreign agents (viruses, bacteria, fungi, chemicals and toxic substances) that enter the human body are called antigens. The immune system reacts to their invasion by actively producing so-called antibodies - specific formations on the surface of lymphocytes aimed at binding to antigens and their further inactivation.
Maturation, differentiation and formation of immune cells occur in the following organs:
- bone marrow, located in large bones;
- thymus;
- tonsils;
- The lymph nodes.
Purification of the blood from foreign agents associated with blood cells occurs in the spleen. Lymphocytes are transported throughout the body and distributed to different areas with the flow of lymph through the lymphatic vessels. This is the peripheral part of the immune system.
Advantages and disadvantages
The advantages of the Ig method include the low cost of conducting the study, which results in potential mass coverage of the population - this allows, for example, to test all pregnant women for HIV when registering at a antenatal clinic. Also, most studies during clinical examination are carried out in this way - tumor markers for the most common malignant diseases (breast and pelvic cancer in women, prostate and lung cancer in men) are detected with high accuracy using the ELISA method.
The second positive point is the high dynamics of reference standards - that is, Ig can be effectively prescribed at different stages of the disease in order to assess the effectiveness of treatment, the course of the disease, and also to identify the approximate time of infection in a long-term chronic process.
Unlike punctures, taking blood for ELISA is painless for the patient, so in some cases Ig is prescribed first, and then, if necessary, functional diagnostics. Also, in case of focal epidemics and pandemics, immunological analysis is the only justified solution for fast, accurate, cheap and safe diagnosis of the entire population potentially exposed to danger.
The disadvantages of Ig include the fact that such research requires high-precision equipment, highly qualified personnel and special reagents.
Note! Carrying out radioimmunoassay in the field is completely impossible.
Few field laboratories have the necessary equipment to conduct serological tests. Most mobile systems test blood by fluorescence of dry blood matter. But this technique is more capable of producing false positive and false negative results than others.
When taking certain drugs (oral contraceptives, antiprotozoals, antihistamines and sedatives), unreliable results are possible. If immunoglobulins are not detected during the study, this does not mean that there is no inflammatory process. These pitfalls are taken into account when prescribing testing for serious diseases. So, if HIV is suspected, the first test is prescribed on the day of treatment, the next one 9 or 14 days later, then a month, three, six months, nine months, a year. The results will only be considered negative if the last step is negative. Therefore, another disadvantage of ELISA is the need for repeated studies.
In case of severe liver damage or other disorders in the functioning of internal organs, the body is not able to produce protein, so the analysis will be false negative. Very often this situation occurs among men with acute or chronic prostatitis. When the prostate is damaged, the glandular epithelium of the liver begins to degenerate into connective tissue, and silent cirrhosis occurs, which distorts the results.
When conducting parasitic studies, it is important to adhere to the rule - a positive result can only be given if helminths or their eggs are found. Therefore, when identifying parasites, you cannot rely only on a blood test.
Additional items
These blood tests involve determining the level of hormones and immunoglobulins that affect reproductive function. Sometimes the attending physician can refer the patient for a detailed study, which shows, in addition to the usual ones, additional elements of the body’s protective barrier, namely:
- Leukocytes.
- Phagocytes.
- Immunoglobulins classes A, M, G.
- Cells of the lymphocytic group.
- Circulating immune complexes.
- Complement components.
An immunogram is a very popular analysis today.
Conclusion
Analysis provides a very large amount of information. This modern method of blood testing helps to correctly assess the properties of the body’s defense system and the functioning of individual organs. Most often, a referral is given by a specialist when there are complaints about a deterioration in the patient’s general condition. However, you can test your immunity yourself by donating blood.
If the table with the results shows a deviation from the norm, then you must seek qualified help from a doctor. As a rule, therapy is aimed at eliminating the cause of decreased immunity and strengthening it.
Full picture
When the immunological blood test indicators are deciphered, the doctor receives a complete picture describing the patient’s condition. If they are lower or higher than normal, then additional examination may be prescribed, for example, magnetic resonance and computed tomography, ultrasound, angiography, etc.
The results obtained must also be compared with the symptoms and diseases in the patient’s medical history, as well as his immediate family. This is an informative immunological blood test.
Preparation for the procedure
To obtain objective results, it is necessary to act correctly before drawing blood. To do this, just follow these simple rules:
- It is better to undergo the examination in the morning, on an empty stomach. If this is not possible, it is permissible to donate blood at any other time after a 4-hour period of fasting;
- It is not recommended to drink alcohol, caffeine-containing drinks, or energy drinks for 3 hours before the test. Water and weak tea can be drunk without restrictions;
- Several hours before the procedure, you should not smoke or be in the presence of a person who smokes;
- Immediately before donating blood, significant physical activity (running, lifting weights, playing sports), contrasting water treatments, hypothermia/overheating of the body should be excluded;
- To obtain the most information, it is best to carry out an immunogram for a child and an adult during a period of complete health. During illness, the body will react to damage to its own tissues or to infection, so it is quite difficult to draw a conclusion about the blood picture.
general description
The study of the immune system includes determining the cellular composition of the blood and determining the presence of antigens and antibodies in the blood serum.
At the 1st stage, the cellular composition of the blood is considered:
- total number of lymphocytes;
- ratio of T-lymphocytes and B-lymphocytes;
- phagocytic activity of neutrophils;
- lymphocyte apoptosis;
- productivity of B-lymphocytes based on the total number of immunoglobulins.
This study allows you to determine the general condition and strength of the immune system.
At the 2nd stage, the humoral activity of immune cells is examined:
- the concentration of cytokinins is determined;
- the quantity and ratio of types of immunoglobulins are measured;
When diagnosing specific diseases, the presence of an antigen or antibodies to it in the blood serum is determined.
How do the Central Election Commissions behave under normal conditions, what are their objectives?
ICs are formed at each meeting of an antigen with an antibody with the participation of complement components, in order to soon be absorbed by phagocytes. In the constantly occurring physiological reaction of the occurrence of CEC, 2 mechanisms take part:
- Formation of the immune complex “antigen-antibody” due to specific contact;
- Delayed IC formation accelerated by nonspecific coupling using Fc fragments.
The complement system, also involved in the formation of complexes, causes secondary changes in them. Interaction with the C3 component inhibits the reaction between Fc structures, which prevents the development of the pathological process.
IKs that originate in the bloodstream bind to C3 receptors on cells that circulate in the bloodstream (for example, red blood cells) and are transferred to the cells of the phagocytic mononuclear cell system, which ensures their immediate destruction and removal from the body. In addition, the metabolism of immune complexes circulating in the blood also occurs in the liver parenchyma.
The task of the CEC is to neutralize and remove foreign antigens from the body using the mononuclear phagocytic system.
Immune complexes begin to play a pathogenetic role under some special conditions - then they are formed in larger quantities than necessary.
In general, circulating immune complexes are cleared by C receptors, but sometimes by some complement components they may not be very “viable” and will be easily broken down without having a significant pathogenic effect. For example, C3b, by its presence, encourages the formation of terminal ICs, which lose the ability to unite, which, in turn, leads to a decrease in their pathogenic properties.
