Secretory immunoglobulin is normal in saliva. Methods for the study of antibodies in the blood. Immunity and immunoglobulins in children

Immunoglobulin A (IgA)- an indicator of humoral immunity. The main indications for use: assessment of local immunity, the course of infectious processes, diseases of the liver, kidneys, chronic inflammation.

Immunoglobulins (antibodies) involved in providing local immunity.

Serum IgA is a fraction of gamma globulins and accounts for 10-15% of the total amount of all soluble immunoglobulins. IgA are found mainly in the gastrointestinal tract and secretions (bronchial, cervical, etc.). In blood serum, IgA is mainly represented by monomeric molecules. The main amount of IgA (secretory IgA) is not in the serum, but on the surface of the mucous membranes, it is found in milk, colostrum, saliva, lacrimal, bronchial and gastrointestinal secretions, bile, urine. In the secretions of mucous membranes, IgA is present in the form of dimers of two monomeric units containing two heavy and two light chains, non-covalently linked by a secretory component. The secretory component, a small polypeptide, 60 kDa, is produced by epithelial cells of the mucous membranes and secretory glands, facilitates the transport of IgA through the epithelium and protects immunoglobulin molecules from being broken down by digestive enzymes. The half-life of antibodies of this class from the blood is 4-5 days.

Why is it important to take Immunoglobulin A (IgA)?

The main function of serum IgA is to provide local immunity, to protect the respiratory, urinary tract and gastrointestinal tract from infections. Secretory antibodies have a pronounced anti-adsorption effect: they prevent bacteria from attaching to the surface of epithelial cells, prevent adhesion, without which bacterial cell damage becomes impossible. Together with nonspecific factors of immunity, they protect the mucous membranes from microorganisms and viruses. IgA deficiency (congenital or acquired) can lead to repeated infections, autoimmune disorders, and allergies.

IgA does not pass through the placental barrier, its level in newborns is about 1% of the concentration in adults, by the first year of life this indicator is only 20% of the adult level. In the first days of life, secretory IgA enter the child's body with the mother's colostrum, protecting the child's respiratory tract and gastrointestinal tract. The age of 3 months is defined by many authors as a critical period; this period is especially important for the diagnosis of congenital or transient insufficiency of local immunity. A child reaches the IgA level characteristic of an adult by about 5 years of age.

Assessment of the course of diseases occurring with the activation of immunity

Acute and chronic infections of viral and bacterial etiology.
Bronchial asthma.
Oncological diseases of the lymphatic system (leukemia, myeloma).
Connective tissue diseases (systemic lupus erythematosus, rheumatoid arthritis and others).

For what diseases is Immunoglobulin A (IgA) done?

To check / improve the performance of which organs should Immunoglobulin A (IgA) be done?

Liver, stomach, intestines, lymphatic system.

How does Immunoglobulin A (IgA) work?

Blood sampling is performed in an empty test tube or with a gel (serum preparation).
For patients with low levels of immunoglobulins, especially IgG and IgM, it is important to follow measures to prevent bacterial infection. When caring for the patient, you should be careful about the symptoms of infection (fever, chills, skin rash and ulceration of the skin).
A patient with an elevated level of immunoglobulins and symptoms of monoclonal gammopathy should be warned to promptly report bone pain and bone tenderness. In such patients, the bone marrow contains many malignant plasma cells that produce antibodies and inhibit the process of hematopoiesis. You should be especially alert for signs of hypercalcemia, renal failure, and spontaneous fractures.
The venipuncture site is pressed with a cotton ball until the bleeding stops.
When a hematoma forms at the site of venipuncture, warming compresses are prescribed.
After taking blood, the patient can again switch to his usual diet and continue taking medications.

How to prepare for your Immunoglobulin A (IgA) test?

It should be explained to the patient that the analysis is necessary to determine the level of antibodies, and if he is receiving therapy aimed at increasing immunity, then also to monitor the effectiveness of therapy.
The patient should refrain from eating for 12-14 hours before the study, drinking water is allowed.
The patient should be warned that a blood sample will be required for the test and who will be performing venipuncture and when.
It should be warned about the possibility of discomfort during the application of a tourniquet on the arm and venipuncture.
You should find out if the patient is taking medications that may affect the test result.
It should be noted that the use of alcohol and drugs can affect the result of the analysis.

At Lab4U online laboratory, we want each of you to be able to take care of your health. To do this, we simply and clearly talk about the indicators of the body.

In the online laboratory Lab4U, serological tests are done to detect the pathogen antigens and specific antibodies to them - this is the most accurate method for diagnosing infectious diseases. "Why do you need to be tested for antibodies to diagnose infections?" Such a question may arise after a doctor's referral to the laboratory. Let's try to answer it.

Content

What are antibodies? And how to decipher the analysis results?

Antibodies are proteins that the immune system makes in response to an infection. In laboratory diagnostics, it is antibodies that serve as a marker of infection. The general rule for preparing for an antibody test is to donate blood from a vein on an empty stomach (at least four hours should pass after a meal). In a modern laboratory, blood serum is analyzed on an automatic analyzer using appropriate reagents. Sometimes serological antibody testing is the only way to diagnose infectious diseases.

Tests for infections can be qualitative (give an answer whether there is an infection in the blood) and quantitative (show the level of antibodies in the blood). The rate of antibodies for each infection is different (for some they should not be at all). Reference values (indicators of the norm) of antibodies can be obtained with the result of the analysis.
In the online laboratory Lab4U, you can take one time and

Various classes of antibodies IgG, IgM, IgA

The enzyme-linked immunosorbent assay detects antibodies of infections belonging to different classes of Ig (G, A, M). Antibodies to the virus, in the presence of infection, are determined at a very early stage, which ensures effective diagnosis and control of the course of diseases. The most common methods for diagnosing infections are tests for IgM antibodies (acute phase of infection) and IgG antibodies (resistant to infection). These antibodies are determined for most infections.

However, one of the most common tests does not differentiate the type of antibodies, since the presence of antibodies to the viruses of these infections automatically suggests a chronic course of the disease and is a contraindication, for example, for serious surgical interventions. Therefore, it is important to refute or confirm the diagnosis.

A detailed diagnosis of the type and amount of antibodies in a diagnosed disease can be done by passing an analysis for each specific infection and type of antibodies. Primary infection is detected when a diagnostically significant level of IgM antibodies is detected in a blood sample or a significant increase in the number of IgA or IgG antibodies in paired sera taken with an interval of 1-4 weeks.

Reinfection, or re-infection, is detected by a rapid rise in IgA or IgG antibody levels. IgA antibodies have a higher concentration in older patients and more accurately diagnose current infection in adults.

Past infection in the blood is defined as increased IgG antibodies without an increase in their concentration in paired samples taken with an interval of 2 weeks. At the same time, antibodies of the IgM and A classes are absent.

IgM antibodies

Their concentration rises soon after the disease. IgM antibodies are detected as early as 5 days after its onset and reach a peak in the interval from one to four weeks, then decline to diagnostically insignificant levels within a few months, even without treatment. However, for a complete diagnosis, it is not enough to determine only class M antibodies: the absence of this class of antibodies does not mean the absence of the disease. There is no acute form of the disease, but it can be chronic.

IgM antibodies are of great importance in the diagnosis of childhood infections (rubella, whooping cough, chickenpox), easily transmitted by airborne droplets, since it is important to identify the disease as early as possible and isolate the sick person.

IgG antibodies

The main role of IgG antibodies is the long-term protection of the body against most bacteria and viruses - although their production occurs more slowly, the response to an antigenic stimulus remains more stable than that of antibodies of the IgM class.

IgG antibody levels rise more slowly (15-20 days after the onset of the disease) than IgM, but remain elevated for longer, so they may show a long-standing infection in the absence of IgM antibodies. IgG levels can be low for many years, but with repeated exposure to the same antigen, IgG antibody levels rise rapidly.

For a complete diagnostic picture, it is necessary to determine IgA and IgG antibodies at the same time. If IgA result is unclear, confirmation is by IgM determination. In the case of a positive result and for an accurate diagnosis, a second test, made 8-14 days after the first, should be checked in parallel to determine the increase in IgG concentration. The results of the analysis should be interpreted in conjunction with the information obtained in other diagnostic procedures.

IgG antibodies, in particular, are used for diagnosis - one of the causes of ulcers and gastritis.

IgA antibodies

They appear in serum 10-14 days after the onset of the disease, and at first they can even be found in seminal and vaginal fluids. IgA antibody levels usually decline by 2-4 months after infection if treatment is successful. When reinfected, the IgA antibody level rises again. If the IgA level does not drop after treatment, then this is a sign of a chronic form of infection.

Antibody analysis in the diagnosis of TORCH infections

The abbreviation TORCH appeared in the 70s of the last century, and consists of capital letters of the Latin names of a group of infections, a distinctive feature of which is that, with relative safety for children and adults, TORCH infections during pregnancy are extremely dangerous.

Often, infection of a woman with infections of the TORCH complex during pregnancy (the presence of only IgM antibodies in the blood) is an indication for its termination.

Finally

Sometimes, having detected IgG antibodies in the test results, for example, toxoplasmosis or herpes, patients panic, not looking at the fact that IgM antibodies that indicate the presence of a current infection may not be present at all. In this case, the analysis speaks of a previous infection, to which immunity has developed.

In any case, it is better to entrust the interpretation of the analysis results to the doctor, and with him, if necessary, determine the treatment tactics. And you can entrust us with the tests.

Why is it faster, more convenient and more profitable to take tests in Lab4U?

You don't have to wait long at the reception

All registration and payment of the order takes place online in 2 minutes.

The way to the medical center will not take more than 20 minutes

Our network is the second largest in Moscow, and we are also located in 23 cities of Russia.

The amount of the check does not shock you

A permanent 50% discount applies to most of our analyzes.

You don't have to show up minute by minute or wait in line

The analysis takes place by appointment at a convenient period of time, for example, from 19 to 20.

You do not have to wait long for results or go to the laboratory for them

We will send them by email. mail at the moment of readiness.

Serum immunoglobulin A is one of the subtypes of blood globulins. These are secretory antibodies that are mainly responsible for the humoral protection of the mucous membranes and skin. Immunoglobulin a, increases sharply when viruses, microbes and infections appear in the body in the oral cavity, gastrointestinal tract, and in the respiratory tract. Group A antibodies bind all penetrated microbes and foreign substances, thereby preventing their further multiplication and spread to internal organs.

Answering the question, what is immunoglobulin a, a specific explanation can be given. It is one of the main factors in the body's primary immune response. However, these protective elements do not have an immunological memory, which means that with repeated infection, new antibodies will be produced. That is why, when the results of a blood, saliva or urine test fall into the hands of a doctor, where it is recorded that the immunoglobulin a is increased, the specialist has every reason to suspect that the patient is developing an acute inflammatory process in the body.

Let's talk in more detail about type A immunoglobulins, what should be the concentration of substances in a healthy person, and what level deviations may indicate?

Immunoglobulin A norm

IgA in the human body can exist in two configurations: secretory and serum. Secretory immunoglobulin a is found mainly in tears, saliva, sweat, breast milk, in the fluid produced in the bronchi and stomach, which are designed to protect mucous membranes from foreign agents. The serum same protective component is found in the circulating blood.

From birth, the child has a low immunoglobulin a, the component is produced in a very low amount, because the baby has not yet been in long-term contact with the environment. In the first 3-4 months. life, these antibodies mainly enter the body of the crumbs along with the mother's milk. Subsequently, immunoglobulin gr. And, it begins to form independently, up to 12 months, the level of the indicator is approximately 20% of the norm of an adult, and upon reaching the age of 5 it is practically equal to it.

So, the normative IgA values are as follows:

for newborn babies up to 3 months -
3-12 months - 0.02-0.5 g / l;
From one to 5 years - 0.08-0.9 g / l;
From 5 to 12 years old - 0.53-2.04 g / l;
12-16 years old - 0.58-2.49 g / l;
16-20 years old - 0.6-3.48 g / l;
More than 20 years - 0.9-4.5 g / l.

Immunoglobulin a is elevated, what does this mean?

If, according to the test results, an increased immunoglobulin a is detected, this may mean the development of certain diseases in a person, for example:

I would like to note some factors that can affect the result of the analysis, namely, overestimate the level of this immunoglobulin:

Taking certain medications (for example, chlorpromazine, medications with gold, taking estrogens or oral contraceptives, etc.);
Excessive physical loads on the eve of delivery;
"Immunization" in the next six months.

Immunoglobulin a lowered

When it comes to the deficiency of these antibodies, the reasons can also be pathological. When immunoglobulin a is significantly reduced, this may indicate the development of such diseases and conditions as:

Inflammation of the colon (after acute intestinal infections);
Hereditary / selective IgA deficiency;
Thymus hypoplasia;
HIV / AIDS and other immunodeficiency states;
Tumors in the lymphatic system;
Ataxia;
Nephrotic syndrome.

There are some internal and external factors due to which the IgA level may slightly decrease, these include:

Pregnancy period;
Extensive burns;
Renal failure;
The advent of radiation therapy.

Also, we must not forget that immunoglobulin a is lowered in a child up to 6 months in view of the physiological characteristics of the human body.

All test indicators must be assessed by a specialist, it is strictly forbidden to diagnose himself, and even more so to prescribe treatment.

Immunoglobulin A, unlike other immunoglobulins, is synthesized on the mucous membrane. He is responsible for the immunity of the lungs, reproductive system and gastrointestinal tract (gastrointestinal tract). It acts locally and protects against the effects of infections. Deviation of class A immunoglobulin from normal values indicates pathological processes in the body. Let's take a closer look at what this gamma globulin is.

Immunoglobulin A makes up 15% of the total immunoglobulin content.

There are two factions:

serum, responsible for local immunity;
secretory, which is contained in biological fluids (saliva, breast milk, intestinal secretions).

Together, class A immunoglobulins create mucosal immunity, protect against bacteria.

Up to 80% of the iga, consisting of the serum fraction, circulate in the blood.

Immunoglobulins are produced by plasma cells of the mucous membrane as a response to antigen exposure. The life cycle is up to 7 hours, but antibodies are completely removed within four days.

Antibodies protect mucous membranes and prevent microorganisms from penetrating deep into tissues and causing harm. With a sufficient level of iga, allergic reactions caused by a decrease in the body's defenses do not appear.

The functions of IgA immunoglobulin include:

Formation of humoral immunity.
Protection of body systems from infections (mainly respiratory, genitourinary and gastrointestinal tract).

Deficiency of immunoglobulin leads to autoimmune disorders, frequent infectious lesions, allergies and a tendency to anaphylactic shock during blood transfusion.

Since immunoglobulin A does not cross the placenta, the baby's level at birth is only 1% of the adult norm, which is why the baby is so vulnerable to infections and bacteria. But there is enough iga in breast milk for the formation of local immunity. It begins to be synthesized on the oral mucosa at two months, and at three months it is possible to conduct an examination to determine the level of iga. In a year, immunoglobulin A in a child reaches a quarter of the adult norm.

Class A immunoglobulin returns to normal only when the child reaches 12 years of age. The rate is considered from 0.4 to 2.5 g / l. In adults, serum A-immunoglobulins are contained in a concentration of 0.9 to 4.5 g / l.

Adequate iga level is necessary for the following diseases:

viral and bacterial infections that occur in acute or chronic form;
bronchial asthma;
leukemia, multiple myeloma and other tumor formations of the lymph;
autoimmune diseases;
connective tissue diseases.

If the level of immunoglobulins is insufficient, it is necessary to replenish immunoglobulin A. Let us consider why its level deviates from the norm.

Iga does not have memory, so when it is reinfected, the level of the substance increases dramatically. If a sharp jump in immunoglobulin is diagnosed, then this indicates an acute inflammatory process, and not a chronic one.

The reasons for exceeding the iga norm are as follows:

viral hepatitis or other acute liver disease;
cystic fibrosis;
alcoholism;
rheumatoid arthritis;
glomerulonephritis;
acute bronchitis or pneumonia;
autoimmune diseases;
purulent infections of the gastrointestinal tract;
myeloma and leukemia;
undergoing immunization.

Both an increase and a decrease in iga are undesirable for humans. Indeed, with a low content of immunoglobulin, neoplasms of the lymphatic system, skin diseases (chronic candidiasis, atopic dermatitis), anemia appear.

The level may decrease for the following reasons:

immunodeficiencies of various etiologies (for example, HIV);
the period after removal of the spleen;
chronic respiratory diseases, including tuberculosis;
condition after severe intestinal infections and poisoning;
giardiasis (infection with lamblia);
treatment with immunosuppressants;
pregnancy.

How do I know my iga level?

Lack of immunoglobulins is manifested by severe consequences in the form of allergic reactions to food, as well as autoimmune reactions. Diagnostics is carried out to determine the level of iga and adjust it to normal values in the event of an acute shortage.

Often the indications for undergoing diagnostics are the following violations:

selection of an effective treatment for myeloma;
anaphylactic reactions;
rheumatoid arthritis;
elucidation of the causes of persistent recurrent infections of viral and bacterial origin;
chronic diarrhea;
neoplasms;
cirrhosis of the liver;
blood diseases.

The analysis is also necessary to determine the effectiveness of therapy if the patient is undergoing a course of treatment aimed at increasing local immunity.

For examination, venous blood is taken.

In order to obtain reliable results, they are prepared for the examination in advance. They do not eat food 12 hours before donating blood, the analysis is carried out on an empty stomach, but it is allowed to drink water. Alcoholic drinks should not be consumed for several days.

If a person is taking any medication, a doctor must be warned. Medication can affect the quality of the diagnosis.

The analysis is carried out using an immunochemiluminescence study. The results are ready in two days.

If a hematoma has formed at the puncture site, then a warming compress must be applied.

The deciphering of the analyzes is done by an immunologist and prescribes therapy. It is impossible to diagnose on your own, such a step is fraught with unpleasant consequences.

The following factors can affect the reliability of the survey results:

Excessive physical activity.
Immunization (if it was carried out earlier within 6 months).
The use of medications (for example, hormonal drugs).

With reduced local immunity, as well as with congenital iga immunodeficiency, a person needs to increase it.

If the immunoglobulins are not brought back to normal, serious diseases develop:

Unfortunately, it is impossible to get rid of iga deficiency with drugs, since such drugs do not exist. Most often, therapy is aimed at treating serious illnesses that deplete the defenses of the immune system.
With iga deficiency, immunoglobulin is not prescribed, otherwise anaphylactic shock may occur, which is life-threatening.
Among the cardinal methods of forming immunity, blood transfusion is distinguished, but this procedure has a number of side effects.

People with low iga levels need to adhere to measures to prevent infectious diseases. If symptoms of an infectious or bacterial disease appear, namely, with an increase in body temperature, chills, fever or skin rash, you must immediately inform your doctor about this.

It is worth noting that immunoglobulin is lowered in most infants under 6 months of age. This is due to the physiological characteristics of the body. In adults, the reasons for the increase or decrease in iga are caused by pathological processes, therefore, such patients require mandatory examination.

Immunoglobulin A is an indicator of humoral immunity. It is determined to assess local immunity, the course of acute infectious processes, kidney and liver diseases, and chronic inflammation. In the Yusupov hospital, laboratory assistants use high-quality reagents to determine the level of immunoglobulins A. The results of the study are interpreted by professors and doctors of the highest category. Immunologists carry out therapy aimed at normalizing the concentration of immunoglobulins A. Therapists use effective drugs registered in the Russian Federation with minimal severity of side effects.

Immunoglobulins A are proteins that provide local immunity. They are represented in the human body by two fractions: serum, which provides local immunity, and secretory. The secretory fraction is contained in milk, respiratory and intestinal tract secretions, lacrimal fluid and saliva, which, together with nonspecific immunity factors, protect the mucous membranes from viruses and bacteria.

Immunoglobulin A functions

Serum immunoglobulin A is a fraction of gamma globulins. It makes up 10-15% of the total amount of all soluble immunoglobulins. In blood serum, immunoglobulin A is mainly represented by monomeric molecules. The main amount of immunoglobulin A is not in the blood serum, but on the surface of the mucous membranes. Secretory immunoglobulin facilitates the transport of immunoglobulin A across the epithelium. It protects immunoglobulin molecules from being broken down by enzymes in the digestive tract.

The main function of serum immunoglobulin A is to provide local immunity, to protect the genitourinary, respiratory tract and digestive organs from pathogens of infectious diseases. Secretory antibodies have a pronounced anti-adsorption effect: they prevent bacteria from attaching to the surface of epithelial cells, prevent the adhesion of microorganisms, without which bacterial cell damage becomes impossible. Also, immunoglobulins A, together with nonspecific factors of immunity, protect the mucous membranes from microorganisms. Congenital or acquired deficiency of IgA immunoglobulin can lead to allergies, autoimmune disorders, allergies, and repeated infections.

Immunoglobulin A does not cross the placental barrier. Its level in newborns is about 1% of the concentration in adults. By the first year of a child's life, this figure is 20% of the adult level. After the birth of the baby, secretory immunoglobulins enter his body with the mother's colostrum. They protect the baby's gastrointestinal tract and respiratory tract. Age 3 months is critical. During this period, doctors diagnose congenital or transient insufficiency of local immunity. By the age of five, the level of immunoglobulins A reaches the concentration characteristic of an adult.

The norm of immunoglobulin A in children depends on their age. In children from 3 to 12 months, it is 0.02-0.05 g / l, from 12 to 16 years old it is in the range of 0.6-3.48 g / l. In adults over 20 years of age, normal immunoglobulin A levels range from 0.9 to 4.5 g / L.

Indications for the study of immunoglobulin A

With the help of immunoglobulins A, doctors assess the course of diseases that occur with the activation of immunity:

acute and chronic infections of bacterial and viral origin; bronchial asthma;
oncological diseases of the lymphatic system (leukemia, myeloma);
connective tissue diseases (systemic lupus erythematosus, rheumatoid arthritis).

Immunoglobulin IgA is determined in the presence of the following diseases:

recurrent bacterial respiratory infections (sinusitis, pneumonia), as well as otitis media and meningitis, bronchial asthma;
chronic diarrhea, malabsorption syndrome;
anaphylactic post-transfusion reactions;
Louis-Bar syndrome (ataxia - telangiectasia);
tumor diseases of the lymphoid system (myeloma, leukemia, reticulosarcoma, lymphoma).
chronic hepatitis, liver cirrhosis.

With the help of an IgA immunoglobulin test, doctors at the Yusupov Hospital check the functioning of the liver, stomach, intestines, and lymphatic system.

Biomaterial sampling for research

In order to determine the level of immunoglobulin A, venous blood is taken into an empty tube or with a gel (to obtain serum). Patients with a low level of immunoglobulins on the eve of the study should observe preventive measures for bacterial infection. The venipuncture site is pressed with a cotton ball until the bleeding stops. If a hematoma has formed at the puncture site of the vein. Apply a warming compress.

The patient is advised to refrain from eating for 12-14 hours before the study. He can drink clean, still water. Doctors are discontinuing medications that could interfere with the test results. The patient should stop drinking alcohol 3 days before blood sampling. Analysis results can be obtained in 4 hours.

The reasons for the increase in immunoglobulin A in adults

Immunoglobulins A bind to microorganisms and delay their attachment to the cell surface. A decrease in the content of immunoglobulins A indicates a lack of local and general immunity. Their concentration increases with the following diseases:

The level of immunoglobulins A decreases in patients suffering from diseases that deplete the immune system. Immunoglobulin A may be lowered in a child with a viral infection

Decrease in the level of immunoglobulin A

Immunoglobulin A is lowered in patients with neoplasms of the lymphatic system, lymphoproliferative diseases, malignant anemias, hemoglobinopathies. The content of immunoglobulin A decreases after splenectomy, in case of protein loss in enteropathies and nephropathies. Treatment with immunosuppressants, cytostatics, exposure to ionizing radiation can also reduce the level of IgA immunoglobulin.

Long-term exposure to benzene, toluene, xylene, taking medications: dextran, estrogens, methylprednisolone, carbamazepine, gold preparations, valproic acid can lower the level of immunoglobulin A. Get a consultation with an immunologist by making an appointment by phone at the Yusupov Hospital. The doctor will conduct an examination, prescribe a study of the level of immunoglobulin A.