Total IgE. Blood test for IgE total

The human immune system is quite diverse in its structure. It includes some organs (eg, spleen, thymus, lymph nodes), and cells (leukocytes, lymphocytes). The main role is played mainly by cells, which synthesize special substances - immunoglobulins. They are responsible for the development of immune and allergic reactions.

In the development of allergies, a special role is played by immunoglobulin E.

What is this substance?

Immunoglobulin E is a special molecule that is located in the submucosa of many tissues and organs. Has a high affinity for many cells, because of what in the body is mainly in a bound state. In plasma of blood in a free form is practically not determined.

In the human body, this fraction of immunoglobulins is responsible for the development of an allergic reaction (hypersensitivity reactions of type 1).

The time for which half of the immunoglobulin present in the serum dissolves - 3 days. Much more time it is on the membranes of cells (mostly obese, extensively located on the surface of the mucous membrane of the bronchi) - about two weeks.

The level of this substance varies throughout life. Normally, in adults, the total IgE is about 20-100 kE / l. In children, the concentration is much less - in newborns it is not (norm 0-3); As you grow up, the concentration gradually increases.

Causes of an increase in the level of allergic immunoglobulin

Like any indicator, the level of a given molecule can fluctuate depending on the conditions of the internal environment of the body.

IgE is generally elevated in general for such diseases as bronchial asthma, atopic dermatitis and allergic rhinitis. These diseases begin to appear already from childhood and are often preserved in adults. Increasing the level of immunoglobulin suggests that the body is sensitized (has a high sensitivity and the risk of allergies) to many allergens (substances that can cause an allergic reaction).

IgE children are generally elevated in many diseases, and not only with the above. Such diseases include allergic aspergillosis, helminthiosis, Joba syndrome, Wiskott-Aldrich, etc.

Increasing the concentration of immunoglobulin in newborns indicates a high risk of atopic diseases from the first days of life.

Low level of immune substances

A decrease in the level of all immunoglobulins can be observed in many diseases accompanied by either a thymus lesion (in childhood) or systemic immunodeficiency, the cause of which can be many.

The defeat of the bone marrow and liver (in children) leads to the fact that not only the total IgE decreases, but also other immunoglobulin fractions. This is due to the fact that the main cells responsible for the synthesis of these substances - B-limophytes are affected.

The main function of B-lymphocytes is the synthesis of active substances involved in the destruction of foreign agents.

With lesions (hepatitis, radiation, tumor process, massive injuries of the musculoskeletal system), damage occurs to the B-cell sprout, which, as a result, reduces the level of all immunoglobulins. The common IgE is also an exception.

One of the common reasons for reducing the level of immunoglobulins of class E is a disease, such as ataxia-telangiectasia.

The mechanism of development of an allergic reaction

How does the development of an allergic reaction caused by this class of immunoglobulins occur? If the total IgE is increased, the following pattern can be observed (the most striking example of an allergic reaction of the first type is asthma).

Initially, the sensitization of the body occurs, i.e. in response to ingestion of a specific antigen, the production of immunoglobulin data occurs. They are transported with blood flow to the vessels of the respiratory system (mainly bronchi) and settle in the mucous membrane. With the re-entry of the antigen, immunoglobulins that have already "populated" the mucous membrane cause the activation of specific cells (obese and goblet). They, in turn, produce mediators of inflammation - histamine, serotonin, heparin, which have a constrictive effect (cause the contraction of smooth muscle cells of the mucous membrane). This reduces the clearance of the bronchus, which leads to a significant difficulty in exhaling. Thus, asthma develops.

Analysis for immunoglobulins

When you have the first symptoms of the development of allergies, you should definitely make an immunogram. It is a so-called list of all the immunoglobulins contained in the blood, indicating their concentration.

Venous blood is needed for the analysis. Testing is usually administered in the morning, on an empty stomach, because as a result of food intake it is possible to provoke an allergy-like reaction and to receive unreliable results of the study.

The collected blood can be stored for up to 8 days, subject to certain conditions.

With the help of a special analyzer, the level of all immunoglobulins is determined, and already on the basis of a change in their number, a diagnosis is made.

When an increased level of immunoglobulins is detected (especially common IgE in a child), one should suspect the presence of an allergy to an antigen, for which it is necessary to carry out skin tests. A decrease in the level may indicate a weakened immunity.

Features of immunoglobulins in children

In the fetal body, immunoglobulins E begin to be produced at the time of 11 weeks. However, they are so large that they do not pass through the placenta and remain in the body of the child. The total IgE in a child gradually begins to grow over a period of up to 15 years, with growth quite rapid. At the age of 15 years, the amount of the E-fraction of immunoglobulins is about 200 kE / l, and up to 18 years, its concentration decreases to 100, which is normal in an adult.

When there is a high amount of immunoglobulins in the umbilical cord , the possibility of developing atopic dermatitis or asthma should be suspected.

Based on the foregoing, it is clear that the most dangerous age for the development of allergies in children is the period from 10 to 15 years. The total IgE in a child is quite sensitive to various antigens, and during the "teenage" age, against the background of a change in the hormonal background, the sensitivity rises at times.

Change in the level of immunoglobulins in various diseases

The concentration of immunoglobulins may vary depending on the nature of the disease.

• Many atopic diseases usually occur with a significant increase in the amount of immunoglobulin E, although cases of the development of diseases with a normal level of these molecules are known.
• Bronchial asthma can occur without increasing the level of molecules, if there is a sensitivity to only one allergen.
• The total IgE in a child may increase in the case of the development of helminthiases. In parallel, there is an increase in the level of eosinophils.
• One of the most serious diseases is hyper-IgE-syndrome. With it, it is possible to increase the level of this molecule more than 2000 (up to 50 000 kE / l). The disease is accompanied by severe allergic manifestations, hives, an allergy to most substances. This condition requires mandatory testing, and the delivery of tests should be conducted as early as possible.

The danger of high concentration of immunoglobulin E

As it was said, high concentrations of this molecule already presuppose the development of allergies. The most dangerous is the presence of sensitivity to most allergens, since in this case an allergy can develop on almost any substance.

An excessively high number of these molecules in the mucosa suggests the development of such a dangerous condition as angioedema (Quincke's edema). For its timely diagnosis (since the condition refers to life-threatening), a blood test must be performed. IgE (general) in it can not be detected, but it can be suspected of its development in the case of a high concentration of lymphocytes.

In severe allergies, mucosal necrosis may develop. The condition is dangerous because it is possible to develop intoxication of the body, as well as the formation of fistulas between the bronchi and pulmonary tissue, the development of pneumothorax and pneumoperitoneum.

Cumulative samples

When determining the high concentration of these molecules in the serum, it is necessary to conduct skin tests. They allow you to determine the sensitivity to specific allergens and prevent the development of allergies in the future.

The main indication for carrying out these samples is the immunological analysis - IgE common in it will be increased. In addition, there must be at least one allergic attack in the history (although a diagnostic study is also possible for the risk of allergy, even if there were no clinical manifestations).

The sample is carried out using weak solutions of allergens (diagnosticums - suspensions of allergens - quite a lot, which allows to find out the exact allergen that can provoke the development of an immune response). Be sure to take blood for IgE before carrying out the test, as well as conduct a general blood test. Be sure to prepare a set of emergency preparations before the analysis in case there is an unforeseen complication of the procedure.

Necessity of research

Why is this immunoglobulin so important in time to determine?

Usually it is the main indicator that the immune system has started to give an allergic reaction (in the event that its concentration has increased), therefore it is necessary to take the necessary measures to protect the body from all sorts of complications.

If the blood is recorded (IgE total) rate, you should not immediately rejoice. As it was said, normal indices can be observed in some diseases, so it is necessary to conduct skin tests to exclude allergic diagnoses (if there is an appropriate clinic).

With a reduced immunoglobulin, the danger is that the immune system may not respond to the antigen present, which can lead to a more serious illness, which will lead to irreversible consequences.

Precisely because of all that has been said, it is necessary to take into account the importance of this molecule and not to neglect its definition.