A person is surrounded by bacteria and microbes throughout his life. Many of them living outside do not cause any problems to human health, and some are even beneficial. However, along with harmless microbes, pathogenic microorganisms that provoke viral and infectious diseases can also enter the human body. The human body tries to fight them. And this is where immunoglobulins enter the arena.
Immunoglobulin is a special cell contained in a person’s blood that supports his immunity. When foreign cells, viruses or microorganisms are detected, these immune molecules begin to neutralize them.
What is immunoglobulin: features
Immunoglobulins are important tool immune system. They have a number of characteristic features:
- Specificity. It consists of neutralizing exclusively the causative agent of the disease itself. While most antimicrobial and antiviral drugs have a toxic effect not only on pathogens, but also on the body’s own cells.
- Harmless to the body.
- A minimum concentration is required to combat the antigen.
- Mobility. Immunoglobulins travel with the blood to the most distant parts and cells of the body to fight pests.
Functions of immune molecules
Immunoglobulin is a protein that copes with many biological functions, which are as follows:
- recognition of a foreign substance;
- subsequent binding to the antigen and formation of an immune complex;
- protection against re-infection;
- destruction of excess immunoglobulins by anti-idiotypic types of antibodies;
- rejection of tissues of another biological species, for example, transplanted organs.
Classification of immunoglobulins
Depending on the molecular weight, structure and functions performed, five groups of immunoglobulins are distinguished: G (lgG), M (lgM), A (lgA), E (lgE), D (lgD).
Immunoglobulin E (IgE) is found in blood plasma in very small quantities. Fixed on skin cells, mucous membranes and basophils. This group of immunoglobulins is responsible for causing an allergic reaction. Its attachment to an antigen leads to swelling, itching, burning and other allergic reactions.
If immunoglobulin E is elevated, this indicates the penetration of irritating substances into the body or the presence of an allergy to a large number histamines. To establish an accurate diagnosis, it is necessary to carry out additional tests blood to identify specific antibodies.
Immunoglobulin M (lgM) has an increased molecular weight, which is why it cannot penetrate the child’s blood during his or her intrauterine development. The fetus produces it on its own. The production of this group of immunoglobulins begins first after infection enters the body. Immunoglobulin M plays an important role in the process of removing the pathogen from the bloodstream. An increase in immunoglobulin M is an indicator of severe inflammatory process in organism. For example, an increased content of these titers indicates the occurrence of an intrauterine infection of the fetus, infection with rubella, syphilis or toxoplasmosis.
Makes up the bulk of immune cells in the blood. Production begins a few days after the infection enters the body and after the production of immunoglobulin M begins. It remains in the body for a long time. This is the only type of antibody that is transmitted from mother to child and creates passive immunity.
Immunoglobulin lgA is called secretory because it protects the respiratory, urinary tract And gastrointestinal tract from infections. It also reflects the attack of viruses on mucous membranes. What immunoglobulin D is, its quantity and functions are still not fully understood.
Prescribing an immunoglobulin test
A blood test to determine the amount of immunoglobulin E is prescribed if bronchial asthma, atopic dermatitis, food or drug allergies are detected. Recurrent pneumonia, skin abscesses, frequent fractures of the limbs, scoliosis and sinusitis indicate a genetic pathology expressed in an abnormally high concentration of group E immune proteins.
An immunoglobulin A test is done for recurrent meningitis, otitis media, sinusitis, myeloma, leukemia, lymphoma.
Deficit state
A deficiency of antibodies of any fraction indicates the presence of an immunodeficiency state. It can be either congenital, that is, primary, or secondary, acquired. This manifests itself in recurrent and chronic bacterial infections. The most common deficiency is immunoglobulin lgA. This is expressed in increased sensitivity to infections. The causes can be very diverse - from nutritional disorders to exposure to ionizing radiation.
Application of human immunoglobulin
Immunoglobulin is not only protein cells that perform a protective function, but also a substance that is actively used in medicine. Available in two forms:
- solution for intramuscular injection;
- powder for
Human immunoglobulin can be prescribed for replacement treatment:
- primary and secondary immunodeficiencies;
- severe viral and bacterial infections;
- various autoimmune diseases;
- AIDS in children;
- for the prevention of diseases in premature infants.
Anti-allergenic immunoglobulin can significantly improve the condition of a child with constantly recurring severe allergies. It can only be prescribed by a qualified attending physician.
Included preventive vaccinations human or animal immunoglobulin can also be found. Serum is used to form passive immunity. Included in vaccinations against influenza, rubella, mumps, and measles.
Treatment with immunoglobulins
Treatment using immune cells is carried out exclusively in a hospital, as there are a number of side effects:
- fever, chills, headaches;
- shortness of breath, dry cough;
- vomiting, diarrhea, stomach cramps;
- drowsiness, weakness, sensitivity to light;
- tachycardia, chest discomfort.
With strict medical supervision, the drug can be prescribed to pregnant women and during breastfeeding.
Where to buy drugs with immunoglobulin
Buy a medicine from immune cells possible at the pharmacy. It comes with instructions with detailed description, contraindications and dosage. But you should not buy and take the drug without a prescription. The price of intramuscular immunoglobulin for 10 ampoules averages 800-900 rubles. A 25mm bottle costs an average of 2,600 rubles. You can also purchase medications for emergency prevention, which include human immunoglobulin. Its price will be much higher, but they are simply necessary for a person caught in an epidemic outbreak.
Immunoglobulin is a character, the absence or deficiency of which seriously affects the condition of the human body. Isolated from blood plasma, it is present in most immunostimulating drugs.
Immunoglobulins (Ig) are a group of serum proteins, heterogeneous in a number of ways, most of them are located in the region of γ-globulins during electrophoresis, and some are located in the region of the beta-globulin fraction.
Immunoglobulins are heterogeneous in their physicochemical and biological properties and also have structural differences. The WHO Expert Committee has developed a classification of human immunoglobulins, according to which they are divided into classes A, D, E, G, M.
Immunoglobulins A
IgA is usually found in immune sera in low concentrations. In structure and properties they differ from IgG and IgM. This is a heterogeneous group of proteins, located during electrophoresis in the region of beta globulins. It consists of components that differ in mass, sedimentation constant -7S, 9S, 11S and 19S. The 7S IgA molecule contains two active centers, which have a greater affinity for the antigen than 7S IgG antibodies of the same specificity.
IgA contains light chains that are identical in immunochemical properties to the light chains of IgG and IgM of the same type. The H-chains of IgA differ significantly from those in IgG in their size and structure.
IgA makes up about 20% of the total number of immunoglobulins and is the main secretory immunoglobulin. Contained in colostrum, tear fluid, bile, intestinal juice, sputum. Secretory immunoglobulins A are important in protection against intestinal, respiratory infections, determine the severity of local immunity. The development of immunity in respiratory diseases is associated with this Ig class; impaired IgA synthesis is accompanied by the development of respiratory tract diseases.
In the mucous membrane of the digestive apparatus, plasma cells predominate, synthesizing secretory IgA, responsible for the human immune defense against intestinal invasion.
IgA of secreted fluids (bronchi, intestines, saliva) are identical to each other, but differ from IgA of blood serum by an additional chain (I).
Immunoglobulins D
These proteins differ from other classes of immunoglobulins in the structure of the H-chains and biological properties. Immunoglobulins D are present in biological fluids in very low concentrations and constitute about 1% of all Igs. Their molecular weight is about 180,000.
IgD does not have the property of fixing complement and does not pass through the placenta. Its role in the body is extremely insufficiently studied. IgDs are believed to be related to immunological memory.
Immunoglobulins E
The IgE group includes antibodies of the reagin type, responsible for the immediate type. They do not pass through the placenta, do not fix complement, and do not tolerate cutaneous passive anaphylaxis with blood serum. They are characterized by the ability to sensitize human skin, therefore one of the methods for their detection is the Prausnitz-Küstner passive transfer reaction. They also sensitize the mucous membranes of the nose, eyes, and respiratory apparatus. In healthy individuals their levels are very low. With allergies, the IgE level increases 4-30 times. They contain 20% light chains, 80% heavy chains (E-chains heavy chains). IgE 8S sedimentation constant. In an electric field they migrate with the y- and beta-fraction of serum globulins at pH 8.6.
Reagins are non-precipitating antibodies, which makes their detection difficult. There are a number of methods for determining IgE. The reagin-allergen complex is combined with a substrate, which is detected by radiological methods. Both the total total amount of IgE and the level of IgE against a particular allergen are detected (specific reagins). A number of other methods are also used (reaction of degranulation of basophilic granulocytes, degranulation of tissue basophils).
Reagins are bivalent. At one end they are connected by heavy chains (Fc) to the cell, and at the other (Fab) to the allergen. One allergen molecule combines with two reagin molecules.
Reagins can also connect with smooth muscle cells of organs (bronchi, intestines, uterus), connective tissue and blood (tissue basophils, basophilic granulocytes, lymphocytes), with capillary endothelial cells and other tissues. These cells have receptors for Fc IgE. IgE is formed only in humans, but can also be fixed by animal tissue cells. Reagins are also found in the secretions of the nasal mucosa of patients with hay fever; with reactions of the reagin type, eosinophilic granulocytes appear in the bronchial secretions.
Following the discovery of IgE as the antibody responsible for the immediate type of allergic reactions, for a long time believed that other types of Ig are not involved in the mechanisms of allergy, in particular in the pathogenesis of asthma. However, evidence has gradually accumulated that immunoglobulins of other classes play a significant role.
Immunoglobulins of various classes have significant physicochemical and structural differences that determine their biological properties.
All the variety of properties and biological functions antibodies are determined by the Fc and Fab fragments of immunoglobulins of various classes. The Fab fragment, the carrier of the active center, determines the avidity of antibodies, that is, the degree of their ability to bind to the antigen. Thus, immunoglobulin G and immunoglobulin M differ in their avidity depending on the type of antigen. For example, corpuscular antigens interact more strongly with IgM, which is explained by the polyvalency of this type of immunoglobulin. Antigens that are simpler in structure (protein, polysaccharide) bind more strongly to IgG, the active center of which is characterized by greater avidity.
Structural differences in the Fc fragments of different classes of immunoglobulins determine the unequal properties of antibodies to one antigen, their different abilities fix complement, neutralize toxins, permeability through biological membranes etc. For example, the ability to fix complement plays a very important role in both the implementation defensive reactions organism, and in the participation of complement-fixing antibodies in the formation of immunopathological processes.
The Fc fragment has a cytotropic region, due to which immunoglobulins attach to cells (antibody homocytotropy); this may cause the corresponding cells to react. This kind of cell reaction ends with the release of biologically active substances such as histamine, which occurs in immediate type allergies.
This homocytotropy is inherent in IgE, which mainly determines the pathogenesis of allergic diseases.
Antibodies belonging to different classes of immunoglobulins play different roles in the formation pathological process. The study of immunoglobulins is very important in assessing the state of immunological reactivity and especially in diagnosing diseases with impaired immune system.
An important point in the study of immunoglobulins was the creation of simple quantitative methods based on the use of monospecific sera. The most widely used method is radial diffusion.
Most studies usually use the definition of three classes of immunoglobulins - G, M, A. Immunoglobulins D, E are determined less frequently. IgE research is carried out using special techniques.
The normal ratio of immunoglobulins is: immunoglobulin G -85%, immunoglobulin A-10%, immunoglobulin M -5%, immunoglobulin D and immunoglobulin E - less than 1%. The level of IgG in newborns is 80% or more of the level in adults. In the elderly, on the contrary, an increase in the level of all classes of immunoglobulins is observed.
When assessing the humoral component of immunity, it is important not only to determine the amount of individual classes of immunoglobulins, but also to identify the content of antibodies to a specific antigen.
The concentration of immunoglobulins reflects the state of the immune organs, the strength of the antigenic stimulus, but there is no direct relationship between the content of immunoglobulins and the level of antibodies to a specific antigen.
Great importance is attached to the study of the ratio of immunoglobulins in bronchial asthma. At the same time, many authors note the presence of disimmunoglobulinemia, the severity of which depends to a certain extent on the form and severity of the disease. However, there is no clearly defined pattern in this regard.
Many researchers note an increase in the levels of immunoglobulins of all classes in infectious-allergic asthma. A number indicate significant fluctuations in the level of various classes of immunoglobulins. This heterogeneity is explained by the wide variety of patient populations examined, the variety of etiology and pathogenesis of the disease and its severity.
Data on IgE levels in asthmatics are of great interest. There is a sharp increase in the atopic form of asthma, less pronounced in the infectious-allergic form of the disease. are considering high content immunoglobulin E in the blood with a simultaneous decrease in IgA is a poor prognostic sign.
As for immunoglobulins in bronchial secretions, the literature information is very diverse. A higher level of IgA and IgG is indicated in the washings from the bronchi of patients with asthma compared to their content in patients with bronchitis. Allergists explain this by hypersecretion of Ig in bronchial asthma. Other authors, on the contrary, note a decrease in the content of immunoglobulins in bronchial secretions. It can be assumed that the fact of an increase in IgG levels with a decrease in IgM is explained by the duration of antigenic exposure.
Immunoglobulins G
The most studied class is IgG, which makes up the bulk of immunoglobulins in adults (0.8-68 g/l). IgG includes antibodies against many antigens, which determines their important protective value.
Using proteolytic degradation methods, doctors deciphered the structure of the IgG molecule. As it turned out, immunoglobulins G consist of 2 light (L-chain) and 2 heavy (H-chain) polypeptide chains connected by disulfide (-S-S-) bridges, as well as less strong covalet bonds. The L chains are identical in all classes of immunoglobulins; the main structural differences in Ig are localized in the H chains. More detailed studies of the H-chains made it possible to identify four subclasses and isotypes within IgG. IgG subclasses are divided according to their action and specificity. The sedimentation rate of IgG is 7S, molecular weight is 160,000, consists of 1330 amino acids. The immunoglobulin G molecule has two centers of the same structure, which are the working part of the molecule and are also called combining participants.
From IgG, using proteolytic enzymes, one section can be separated, including two parts of heavy chains that do not have an active center, the Fc fragment (Fragment constant). The rest of the molecule is divided into two Fab fragments (Fragment antigen binding), which can bind antigen and include one light chain and one part of the heavy chain. Each Fab fragment has one active center, which determines the specificity of antibodies. The active center, or otherwise combining region, is formed by a small number of amino acids (about 15) and gives the molecule specificity and unique variability. This active site is related to both chains.
The variability of the amino acid composition in the active site of the Fab fragment ensures the formation large number structural variants complementary to many natural and synthetic antigenic determinants. The constancy of another Fc fragment determines the uniformity of the effector function of a given class of immunoglobulins. IgG is the only immunoglobulin that can cross the placenta.
Immunoglobulin M
Proteins of this class make up 5-10% of serum immunoglobulins. They are macroglobulins, have a molecular weight of 900,000-1,000,000, and during electrophoresis they migrate in the zone of beta globulins. The immunoglobulin M molecule consists of five units, each corresponding to IgG, consisting of 2 heavy and 2 light chains. They are all connected by disulfide bridges. The amino acid composition and antigenic structure of the light chains are similar to those of IgG. IgM heavy chains differ from IgG H-chains in molecular weight, amino acid composition and antigenic structure.
Since the IgM molecule includes five subunits, similar to IgG, one would expect it to have ten active centers, but studies show that in each subunit one of the active centers is inaccessible to the antigen due to spatial difficulties.
IgG is formed during the early stages of immunization various antigens. When exposed to antigens of a protein nature, the synthesis of IgM is quickly replaced by the synthesis IgG antibodies; if the antigens are of a polysaccharide nature, IgM is synthesized simultaneously with IgG. IgM is not very specific, but in combination with an antigen it has a high activity of fixing complement, which contributes to the rapid destruction of the antigen. This feature is very important in the early stages of infection of the body.
Types of immunoglobulins by nature of action
In addition to assessing individual classes of immunoglobulins, determining the nature of the action of immunoglobulins is also important. In allergic diseases, in addition to reagins, other types of antibodies are also detected (precipitins, hemagglutinins, blockers). They can take part in various allergic processes - bronchial asthma, food allergies, drug allergy, hay fever.
Precipitating antibodies(usually immunoglobulin G), involved in allergic processes, are a component of immune complexes. The latter are localized, penetrating through vascular wall, in the bronchial alveoli. Activation of complement and release of leukotactic factors lead to the appearance of granulocytes and macrophages. The destruction of the latter releases enzymes and monokines that damage lung tissue and forms its fibrosis. An inflammatory reaction mediated by biologically active substances develops.
Complement-fixing antibodies participate in the pathogenesis of such allergies as reactions such as “reverse” anaphylaxis, cytotoxic anaphylactic shock, anaphylactic shock in bacterial allergies, tuberculin shock; They also occur in hay fever.
Blocking allergy antibodies are present in the blood of people recovering from allergies. They belong to immunoglobulins G, are heat stable, do not sensitize the skin, and do not cause the formation of precipitates. This type of antibody is formed after specific hyposensitization.
Hemagglutinating antibodies- antibodies that can specifically react with red blood cells connected to the allergen. It has not been conclusively established whether other types of antibodies (reagins or blocking) also have this agglutination property.
Allergic antibodies are specific, but for some types of allergens the specificity is relative, so-called cross-reactions may develop. Reactions between antigen (allergen) and antibody are diverse and lead to various clinical manifestations.
The article was prepared and edited by: surgeon– a group of primary immunodeficiency conditions that are caused by impaired synthesis or accelerated destruction of immunoglobulin molecules of this class. Symptoms of the disease include frequent bacterial infections (especially of the respiratory system and ENT organs), gastrointestinal disorders, allergies and autoimmune lesions. Diagnosis of immunoglobulin A deficiency is made by determining its amount in the blood serum; molecular genetic techniques are also used. Treatment is symptomatic and boils down to prevention and timely treatment of bacterial infections and other disorders. In some cases, immunoglobulin replacement therapy is performed.
General information
Immunoglobulin A deficiency is a polyetiological form of primary immunodeficiency, in which there is a deficiency of this class of immunoglobulins with normal levels of other classes (G, M). The deficit may be complete, with sharp decline all fractions of globulin A, and selective, with a deficiency of only certain subclasses of these molecules. Selective immunoglobulin A deficiency is a very common condition; according to some data, its incidence is 1:400-600. The phenomena of immunodeficiency with selective deficiency of the compound are quite blurred; in almost two thirds of patients the disease is not diagnosed, since they do not seek treatment medical care. Immunologists have found that immunoglobulin A deficiency can manifest itself not only as infectious symptoms; patients also often experience metabolic and autoimmune disorders. Taking into account this circumstance, it can be assumed that the incidence of this condition is even higher than previously thought. Modern geneticists believe that the disease occurs sporadically or is hereditary pathology, and the transmission mechanism can be either an autosomal dominant or an autosomal recessive mode of inheritance.
Causes of immunoglobulin A deficiency
The etiology and pathogenesis of both complete and selective immunoglobulin A deficiency has not yet been fully determined. So far, only genetic and molecular mechanisms have been established separate forms diseases. For example, selective deficiency immunoglobulin A type 2 is caused by mutations of the NFRSF13B gene, localized on chromosome 17 and encoding the protein of the same name. This protein is a transmembrane receptor on the surface of B lymphocytes and is responsible for recognizing tumor necrosis factor and some other immunocompetent molecules. The compound takes an active part in regulating the intensity of the immune response and the secretion of various classes of immunoglobulins. According to molecular studies, a genetic defect in the TNFRSF13B gene, leading to the development of an abnormal receptor, makes certain fractions of B lymphocytes functionally immature. Such cells, instead of producing optimal amounts of immunoglobulins A, secrete a mixture of classes A and D, which leads to a decrease in the concentration of class A.
Mutations of the TNFRSF13B gene are a common, but far from the only cause of the development of immunoglobulin A deficiency. In the absence of damage to this gene and in the presence of clinical manifestations immunodeficiency of this type the presence of mutations is assumed on chromosome 6, where the genes of the major histocompatibility complex (MHC) are located. In addition, a number of patients with immunoglobulin A deficiency have deletions of the short arm of chromosome 18, but it is not yet possible to unambiguously connect these two circumstances. Sometimes a deficiency of class A molecules is combined with a deficiency of immunoglobulins of other classes and impaired activity of T-lymphocytes, which forms clinical picture common variable immunodeficiency (CVID). Some geneticists suggest that immunoglobulin A deficiency and CVID are caused by very similar or identical genetic defects.
Immunoglobulin A differs from other related molecules in that it determines the very first stage of the body’s nonspecific immunological defense, since it is secreted as part of the secretion of the glands of the mucous membranes. With its deficiency, it becomes easier for pathogenic microorganisms to penetrate into the poorly protected delicate tissues of the mucous membranes of the respiratory tract, gastrointestinal tract and ENT organs. The mechanisms of autoimmune, metabolic and allergic disorders due to immunoglobulin A deficiency are still unknown. There is an assumption that its low concentration causes an imbalance in the entire immune system.
Symptoms of immunoglobulin A deficiency
All manifestations of immunoglobulin A deficiency in immunology are divided into infectious, metabolic (or gastrointestinal), autoimmune and allergic. Infectious symptoms consist in an increased frequency of bacterial respiratory tract infections - patients often experience laryngitis, tracheitis, bronchitis and pneumonia, which can take a severe course and be accompanied by the development of complications. In addition, immunoglobulin A deficiency is characterized by a rapid transition of acute inflammatory processes into chronic forms, which is especially indicative of lesions of the ENT organs - patients are often diagnosed with otitis, sinusitis and sinusitis. A fairly common combined deficiency of immunoglobulins A and G2 leads to severe obstructive pulmonary lesions.
To a lesser extent, infectious lesions affect the gastrointestinal tract. With a deficiency of immunoglobulin A, there is a slight increase in giardiasis, and gastritis and enteritis can be recorded. The most characteristic gastrointestinal symptoms of this immunodeficiency are lactose intolerance and celiac disease (immunity to the cereal protein gluten), which, in the absence of nutritional correction, can lead to intestinal villi atrophy and malabsorption syndrome. Among patients with immunoglobulin A deficiency, ulcerative colitis, biliary cirrhosis and chronic hepatitis of autoimmune origin are also often recorded. The listed diseases are accompanied by abdominal pain, frequent episodes of diarrhea, weight loss and hypovitaminosis (due to impaired absorption of nutrients due to malabsorption).
In addition to the diseases of the gastrointestinal tract described above, autoimmune and allergic lesions with immunoglobulin A deficiency are manifested by an increased incidence of systemic lupus erythematosus and rheumatoid arthritis. Thrombocytopenic purpura and autoimmune hemolytic anemia are also possible, often with a severe course. In more than half of patients, autoantibodies against their own immunoglobulin A are detected in the blood, which further aggravates the phenomenon of deficiency of this compound. Patients with immunoglobulin A deficiency are often diagnosed with urticaria, atopic dermatitis, bronchial asthma and other diseases of allergic origin.
Diagnosis of immunoglobulin A deficiency
Diagnosis of immunoglobulin A deficiency is made on the basis of the patient's medical history (frequent infections of the respiratory tract and ENT organs, gastrointestinal lesions), but the most accurate way to confirm the diagnosis is to determine the amount of serum immunoglobulins of different classes. In this case, an isolated decrease in the level of this component may be detected humoral immunity below 0.05 g/l, which indicates its deficiency. Against this background, the level of immunoglobulins G and M remains within normal limits; sometimes a decrease in the G2 fraction is detected. With partial deficiency of immunoglobulin A, its concentration remains in the range of 0.05-0.2 g/l. When evaluating the results of the analysis, it is important to remember age characteristics the amount of globulins in the blood plasma - for example, the concentration of fraction A 0.05-0.3 g/l in children under 5 years of age is called a transient deficiency and may disappear in the future.
Sometimes a partial deficiency of immunoglobulin A is detected, in which its amount in the plasma is reduced, but the concentration of the compound in the secretions of the mucous membranes is quite high. None clinical symptoms the disease is not detected in patients with partial deficiency. In the immunogram, attention should be paid to the number and functional activity of immunocompetent cells. With immunoglobulin A deficiency, the number of T and B lymphocytes is usually maintained at normal level, a decrease in the number of T-lymphocytes indicates the possible presence of common variable immunodeficiency. Among other diagnostic methods, a supporting role is played by the determination of antinuclear and other autoantibodies in plasma, automatic sequencing of the TNFRSF13B gene and allergy tests.
Treatment, prognosis and prevention of immunoglobulin A deficiency
There is no specific treatment for this immunodeficiency; in some cases, immunoglobulin replacement therapy is performed. Antibiotics are mainly used to treat bacterial infections, sometimes prophylactic courses are prescribed antibacterial agents. It is necessary to correct the diet (excluding dangerous foods) during development food allergies and celiac disease. In the latter case, cereal-based dishes are excluded. Bronchial asthma and other allergic pathologies are treated with conventional drugs - antihistamines and bronchodilators. For severe autoimmune disorders, immunosuppressive drugs are prescribed - corticosteroids and cytostatics.
The prognosis for immunoglobulin A deficiency is generally favorable. In many patients, the pathology is completely asymptomatic and does not require special treatment. With an increase in the frequency of bacterial infections, autoimmune lesions and malabsorption disorders (malabsorption syndrome), the prognosis may worsen according to the severity of symptoms. To prevent the development of the listed manifestations, it is necessary to use antibiotics at the first signs of an infectious process, adherence to rules regarding diet and diet composition, and regular observation by an immunologist and doctors of other specialties (depending on concomitant disorders). Caution should be exercised when transfusing whole blood or its components - in rare cases, patients experience an anaphylactic reaction due to the presence of autoantibodies to immunoglobulin A in the blood.
Immunoglobulin A (IgA) is a type of protein glycoprotein. In the body, immunoglobulin A plays the role of an antibody participating in local immune reactions. Immunoglobulin A is secreted on the mucous membranes of internal organs by group B lymphocytes when interacting with an antigen certain type. And although the normal level of immunoglobulin A in the human body is significantly lower than the normal level of other immunoglobulins, this is due to the fact that this immunoglobulin is actively removed from the body along with the antibodies it forms. At the same time, its production occurs much more actively.
Immunoglobulin A is also different in that it contains a special component that not only allows it to easily penetrate epithelial cells, but also protects it from digestion. Immunoglobulin A is normally found in secretions secreted by the bronchial glands and gastrointestinal tract; it can be found in tears and saliva, as well as in fluid secreted through the sweat glands.
When a pathogen enters the mucous membrane, the production of immunoglobulin A begins, which neutralizes the virus or bacteria and prevents them from penetrating the cells. The effect of immunoglobulin A is that it prevents bacteria from attaching to the mucous membrane and thus neutralizes it. In addition, immunoglobulin A protects the body from non-infectious allergens, thus protecting the body from an allergic reaction.
It must be said, however, that some bacteria and viruses have developed special systems, aimed specifically at blocking immunoglobulin A. In particular, these are pathogens of gonorrhea, pneumonia, and meningitis.
Immunoglobulin A is not able to cross the placental barrier, so it is practically not present in the blood of a fetus or newborn child. But the mother passes immunoglobulin A to the baby through breast milk. That's why it's so important breast-feeding, which protects the baby in the first months of life from all kinds of viruses and bacteria, until he develops his own defense mechanisms.
The normal level of immunoglobulin A (IgA) in the blood. Explanation of the result (table)
Immunoglobulin A deficiency leads to the development of allergic reactions, gastrointestinal intestinal infections, constant colds, and often – development autoimmune pathologies. Therefore, a test to determine the level of immunoglobulin A in the patient’s blood is often prescribed in order to determine the cause of relapses of one or another infectious disease, in order to find out the state of the immune system when autoimmune diseases occur, to monitor immunodeficiency conditions, and also to evaluate the effectiveness of the prescribed treatment.
A blood test for immunoglobulin A is also prescribed in the presence of tumor diseases of the hematopoietic and lymphatic systems.
Blood is drawn from a vein, usually in the morning and on an empty stomach. If blood needs to be taken at another time, the patient is recommended not to eat anything 2-3 hours before, only drink clean water without gas and do not smoke for the specified time.
Normal level of immunoglobulin A (IgA) in the blood ordinary people and pregnant women:
If immunoglobulin A (IgA) is elevated, what does this mean?
The following diseases can lead to increased levels of immunoglobulin A:
- infectious processes of an acute or chronic nature on the skin, intestines, genitourinary and respiratory organs,
- malignant and benign neoplasms,
- autoimmune diseases– systemic cranial lupus, vasculitis,
- hemorrhagic vasculitis,
- cystic fibrosis,
- liver diseases, in particular portal cirrhosis,
- lymphomas,
- multiple myeloma,
- Wiskott-Aldrich syndrome,
- monoclonal gammopathy.
An increase in Anya's immunoglobulin level always indicates the presence of a disease. Intense exercise can lead to the same result. physical exercise, as well as the use of certain medications - methylprednisolone, valproic acid, carbamiseline, penicylamine, as well as oral contraceptives based on estrogen.
If immunoglobulin A (IgA) is low, what does this mean?
A decrease in the level of immunoglobulin A indicates a deficiency of local immunity in the patient. Such a deficiency may be hereditary or acquired.
Some diseases leading to a decrease in immunoglobulin A levels:
- hereditary selective immunoglobulin A deficiency,
- agammaglobulemia,
- common variable immunodeficiency,
- hypogammaglobulinemia,
- hyper-IgM syndrome,
- acquired immunodeficiency syndrome,
- chronic diseases upper and lower respiratory tract,
- leukemia,
- inflammatory processes in the large intestine,
- nephrotic syndrome,
- splenectomy,
- extensive burns,
- irradiation, including malignant tumors:
- some other diseases.
It should be understood that if the level of immunoglobulin A (IgA) in the blood either increases or decreases, it does not always indicate the development of the disease. In particular, a similar effect is achieved by taking medical supplies based on cytostatics and immunosuppressants.
There is a natural decrease in the level of immunoglobulin A during pregnancy. This is not a pathology and should not worry the expectant mother.
Serum immunoglobulin A is one of the subtypes of globulins in the blood. 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 oral cavity, gastrointestinal tract, in respiratory tract. Group A antibodies bind all invading microbes and foreign substances, thereby preventing their further reproduction and spread to internal organs.
Answering the question of what immunoglobulin A is, we can give a specific explanation. This is one of the main factors in the body's primary immune response. However, these protective elements do not have immunological memory, which means that upon re-infection, new antibodies will be produced. That is why, when the doctor receives the results of a blood, saliva or urine test, where it is recorded that immunoglobulin A is elevated, 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 immunoglobulins type A, what should be the concentration of substances in healthy person, and what can level deviations indicate?
Normal immunoglobulin A
IgA in the human body can exist in two configurations: secretory and serum. Secretory immunoglobulin a is found primarily in tears, saliva, sweat, breast milk, and in the produced fluid in the bronchi and stomach, which are designed to protect the mucous membranes from foreign agents. The serum protective component is found in the circulating blood.
From birth, the child has low immunoglobulin a, the component is produced in very low quantities, because the baby has not yet been in long-term contact with environment. In the first 3-4 months. life, these antibodies mainly enter the baby’s body along with 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 adult norm, and upon reaching 5 years of age it is practically equal to it.
So, the standard IgA values look like this:
- 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 - 0.53-2.04 g/l;
- 12-16 years - 0.58-2.49 g/l;
- 16-20 years - 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 test results reveal elevated immunoglobulin a, this may mean that a person develops certain diseases, for example:
I would like to note some factors that may affect the result of the analysis, namely, increase the level of this immunoglobulin:
- Taking some medicines(eg chlorpromazine, drugs with gold, taking estrogens or oral contraceptives, etc.);
- Excessive physical loads on the eve of the test;
- “immunization” in the next six months.
Immunoglobulin a is reduced
When it comes to a deficiency of these antibodies, the reasons may also be pathological. When immunoglobulin a is significantly reduced, this may indicate the development of diseases and conditions such as:
- Inflammation of the colon (after acute intestinal infections);
- Hereditary/selective IgA deficiency;
- Hypoplasia of the thymus;
- HIV/AIDS and other immunodeficiency conditions;
- Tumors in the lymphatic system;
- Ataxia;
- Nephrotic syndrome.
There are some internal and external factors due to which the IgA level may decrease slightly, these include:
- Pregnancy period;
- Extensive burns;
- Kidney failure;
- Treatment of radiation-related therapy.
We also must not forget that immunoglobulin A is reduced in a child under 6 months due to the physiological characteristics of the human body.
All test indicators must be assessed by a specialist; diagnosing yourself, much less prescribing treatment, is strictly prohibited.
