What does an immunoglobulin G test show? Total immunoglobulins G (IgG) in serum

Immunity is the body’s main guard against the entry of foreign microorganisms, which include harmful bacteria, viruses, allergens and fungi. It is a complex device that functions by binding antigens to cells immune system- glycoproteins, each of which has a specific role. Depending on their purpose, immune cells - immunoglobulins are divided into five classes: A, E, D, G, M. Immunoglobulin G has important functions and differs in structural features, and in quantity it significantly prevails over other proteins of the immune system.

What is IgG

Functions assigned to IgG immunoglobulins:

• Stimulation of phagocytosis.
• Instant formation of complement, that is, a complex of protective proteins aimed at destroying antigens.
• A unique opportunity to penetrate through the placenta from the pregnant woman to the fetus, providing intrauterine protection and immunity in the first six months of the child’s life.

IgG molecules are produced by mature group B lymphocytes, and this process occurs in the central hematopoietic organ. The structure of immunoglobulin G includes four polypeptide chains: two heavy (H), containing 440 amino acids each, and a pair of light (L), combining 220 amino acid fragments. All four chains are interconnected by numerous specific bonds, for this reason these antibodies are classified as monomers.

Immunoglobulin IgG is responsible for humoral long-term immunity, which guarantees protection from re-entry pathogenic microorganisms for a long time. Protection from a previous disease, the so-called immunological memory, can last a lifetime. An increase in IgG immunoglobulin is especially observed with autoimmune pathologies, that is, when the disease progresses to chronic form and recurs from time to time. For example, if one day you get sick with diseases such as rubella, measles, chicken pox, Epstein-Barr virus, cytomegalovirus or some other infections. It is precisely immunoglobulin G that will be entrusted with the task of preserving the “medical history” in order to prevent the entry of similar bacteria and viruses in the future.

IgG diagnostics

A complete blood test for immunoglobulin G is performed by collecting a small amount venous blood. It is studied using the immunoturbodimetric method. The study allows you to determine whether there is an infection in the body and the quantitative value of glycoproteins. To the most preferred methods Diagnosis of infection refers linked immunosorbent assay for IgM antibodies (an indicator of the acute phase of the disease) and immunoglobulin IgG class(stable immunity coefficient).

Positive CMV (cytomegalovirus) is diagnosed from the first days of infection by titers IgM antibodies, later immunoglobulin IgG joins. Approximately the same development of the clinical picture applies to Epstein-Barr virus. Due to a sharp reaction from the immune system, cytomegalovirus and Epstein-Barr disease flow without bright severe symptoms. It is necessary to take into account the fact that even after recovery, the immunoglobulin M and G indices may long time stay tall.

At the slightest suspicion of infection with infections such as cytomegalovirus and Epstein-Barr, you need to be prepared that repeated testing will be required, since you will need to make sure at what stage, current disease or past, the patient’s condition is.

The increasing effect of glycoprotein G can be observed in allergies, especially if an indicator such as immunoglobulin G4 is simultaneously increased. Exceeding the norm may occur during recovery from the first infection. Or in case of re-infection with the same antigen.

A low level of class G antibodies indicates a congenital or acquired deficiency. Among the diseases characterized by a decrease in immunoglobulin G, the most common ones can be identified.

Immunoglobulin G is reduced if present:

• Deviation in work lymphatic system.
• Serious allergic conditions.
• Exposure to radiation.
• Consequences of taking certain specific medications.
• HIV infection and other acute and chronic ailments.

Immunoglobulins IgG and M with great accuracy indicate the presence of any pathology. The only difference between them is the timing of detection of foreign cells. IgM antibodies show the presence of antigens after just five days. IgG molecules detect pathogens after 15–20 days, but unlike immunoglobulin M, they remain elevated for a longer time, so they can detect chronic infections when other indicators are normal.

Normal IgG level

If a person’s immunoglobulin is normal IgG, IgA, IgM in all respects, then this indicates the absence of infection, but only if it is not traceable clinical picture. In circumstances where even vague and especially pronounced signs of the disease are present. Then the diagnosis should be repeated, since perhaps there was no proper preparation to analysis.

Immunoglobulin IgG normal:

An enzyme immunoassay must be carried out according to the rules, since this analysis is intended to determine serious illnesses or their absence. Physical and emotional stress may affect the reliability of the readings. In addition, before the examination, you must stop taking medications and you will need to abstain from eating for at least 4-6 hours.

Immunity is a unique system of the body. Without it, a person is not able to resist microorganisms foreign to him. Despite the perfectly coordinated interaction of all organs and systems, nevertheless, we can say with confidence that the human body functions thanks to immunoglobulins G, M, A, D, E - the components of immunity. And, in the event of a breakdown in this system, researchers in the field of medicine have not found anything better than to create immunoglobulin gamma, therapeutic and prophylactic drug, based on a concentrated globulin fraction of glycoproteins.

In contact with

Immunoglobulins are special proteins of the immune system related to glycoproteins. Common immunoglobulins human body can be divided into 5 types, which differ from each other in their structure and the functions they perform. All immunoglobulins are produced by blood plasma cells after contact with a foreign substance that has entered the body. foreign protein. Upon initial contact with such a stranger, the antigens only recognize him and develop a special line of behavior towards him - in this case they say that the person develops immunity. Indeed, the immune system remembers the signs of the pathogenic microorganism with which it had to come into contact and in the case of subsequent contacts it reacts much faster, producing large quantities immunoglobulin necessary to neutralize and suppress a harmful foreigner.

Immunoglobulin G (IgG) occupies the largest share in this system - about 80%. Its functions include providing long-term protection and preventing re-infection. This type immunoglobulins neutralize pathological viruses, bacteria and toxins that have entered the body, activate the production of necessary antigens and activate the classical pathway of the complement system.

Immunoglobulin G (IgG) has two unique abilities: firstly, it can act not only in the blood vessels, but also between them, directly in tissues, protecting even intercellular space. This kind of immunity is usually called humoral. And secondly, this is the only one of the five types of immunoglobulins that overcomes the placental barrier during pregnancy and is transmitted to the fetus from the mother, protecting it, and also acting for about six months after the birth of the baby.

Normal immunoglobulin G (IgG) in the blood. Explanation of the result (table)

A blood test for immunoglobulin G (IgG) is prescribed if an immune deficiency is suspected - immunodeficiency state, and also in order to assess the state in which the patient’s humoral immunity resides. Also, an immunoglobulin G (IgG) test should be performed in the presence of autoimmune diseases or if the patient is susceptible to regularly recurring infectious diseases. The level of immunoglobulin G (IgG) is determined in the presence of neoplasms in the body, diseases of the hematopoietic system and to monitor treatment carried out with immunoglobulin preparations.

Blood is drawn from a vein, in the morning, on an empty stomach.

Normal immunoglobulin G (IgG) in the blood ordinary people and pregnant women.

If immunoglobulin G (IgG) is elevated, what does this mean?

An increase in the concentration of immunoglobulin G (IgG) may indicate the following: pathological conditions:

• inflammatory processes of an infectious nature, acute or chronic in genitourinary system, respiratory organs or intestines,
• relapse of infectious disease acute phase,
• recovery period after an acute infectious disease,
• various pathological processes in the liver, acute or chronic - hepatitis, alcohol impairment, cirrhosis of the liver,
• autoimmune diseases– systemic lupus erythematosus, rheumatoid arthritis, acute rheumatic fever, etc.
• chronic lymphocytic leukemia,
• cystic fibrosis,
• sarcoidosis,
• Waldenström's disease
• sarcoidosis,
• multiple sclerosis,
• lymphomas,
• neurosyphilis,
• multiple myeloma,
• Infectious mononucleosis,
• monoclonal gammopathy of unknown origin.

An increase in immunoglobulin G (IgG) levels is not always a sign of a disease. The same effect can be caused by overexertion, both physical and moral, as well as taking certain medications, including drugs based on estrogens, chlorpromazine, methylprednisolone, carbamazeline, dextran, penicillamine, valproic acid, phenytoin. After appropriate immunization increased level immunoglobulin G (IgG) can persist for six months.

If immunoglobulin G (IgG) is low, what does this mean?

Immunoglobulin G (IgG) deficiency can be either congenital or acquired. Genetic diseases, causing deficiency in the body of this immunoglobulin are agammaglobulinemia (Bruton's disease) and Wiskott-Aldrich syndrome.

Acquired immunoglobulin G (IgG) deficiency can occur in the following diseases:

• tumor diseases lymphatic system,
• leukemia,
• splenectomy,
• allergic diseases of different nature, including - atopic dermatitis,
• acquired immunodeficiency syndrome,
• transient hypogammaglobulinemia in infants,
• enteropathy,
• inflammatory processes in the large intestine:
• common variable immunodeficiency.

Taking certain drugs can also cause the level of immunoglobulin G (IgG) in the blood to decrease medical supplies– methylprednisolone, dextran, gold-based drugs. A natural decrease in the level of immunoglobulin G (IgG) occurs in the second and third trimester of pregnancy, which is not a pathology and should not worry the expectant mother.

The human body is a very complex matter. It contains so many substances, systems, organs, the work of which is interconnected, that it is sometimes difficult for an unprepared person to understand what we are talking about. There are special substances in the body that are responsible for protecting the body from external invasion by various bacteria, viruses, and fungi. Immunoglobulins are cells that are found in the human blood and are responsible for immunity; they are the ones that protect against microscopic enemies. These cells come in several types, and each of them has its own function.

IgG test

The role of immunoglobulins

Thanks to the presence of many mechanisms, protection against infection is achieved. Every day we encounter viruses, bacteria, fungi, and the immune system protects the body. Without such mechanisms, we would get sick every day. Immunoglobulins are divided into 5 classes; they are classified as glycoprotein substances.

This class of substances is also called antibodies. The following antibodies exist: IgG, IgA, IgM, IgE, IgD. They differ in structure and functions.

Between 70 and 80 percent of all immunoglobulins in the blood are IgG. Its production begins a few days after the body is infected. But globulin M is produced earlier. IgG antibodies remain in the body for a long time. They neutralize harmful particles:

• viruses
• helminths, protozoa
• fungal cultures
• bacteria
• toxins

This is the only type of antibody that crosses the placental barrier. Thus, immunity to diseases is transmitted from mother to child. All other globulins do not have this property.

IgG - molecule

IgG is also involved in the process of phagocytosis - that is, the capture of foreign cells by phagocytes. It also participates in the formation of the antigen-antibody complex.

In what cases is the IgG content elevated?

Like many other cells that provide immunity, globulins of this type have different levels in the blood for each age. Indicators differ for children and adults. But also in children normal values change with age. The norm for an adult is from seven to sixteen grams/liter. For the study, blood is taken from a vein, the collection is carried out in the morning, on an empty stomach. IN certain cases relative to the norm. This happens in the following situations:

• For oncology
• If immune system diseases or HIV infection are diagnosed
• Chronic liver pathologies
• Flu, ARVI
• Bronchitis, pneumonia
• Allergies
• Autoimmune diseases
• Helminthiases of various types
• Acute course of the disease after re-infection
• Chronic lymphocytic leukemia
• Sarcoidosis and others

Connected increased content with the fact that immunoglobulin G is produced in excess. This is a protective effect of the body on infectious process. And if the infection is repeated, the immune mechanisms develop a large number of this globulin.

"Important!" In order to correctly interpret test results, it is recommended to jointly determine the levels of other globulins.

When is a globulin G test prescribed?

Such a study is carried out in the following cases:

• Immunodeficiency states.
• When examining those who have frequent relapses of infections, including intestinal ones.
• For neoplasms.
• For the treatment of myeloma.
• Before use pharmaceuticals immunoglobulins.

When examining a patient to obtain a complete and reliable picture of the disease, it is necessary to simultaneously take tests not only for other globulins, but also for ESR, general analysis blood, Central Election Commission, protein fractions in serum and others. An IgG test can be prescribed by a rheumatologist, oncologist, immunologist, infectious disease specialist, or hematologist.

IgG functions

How to prepare for analysis

For diagnosis, blood is taken from a vein. To get the most correct analysis result you need to:

• Avoid eating two hours before visiting the laboratory.
• Half an hour before the analysis, do not overexert yourself physically and emotionally.
• Avoid smoking 3 hours before blood sampling.

It should be remembered that both stress and excessive stress increase the level of this globulin. physical exercise. It must be taken into account that high level globulins M and G may be present for some time after recovery.

"Important!" An analysis for IgM antibodies allows doctors to judge the acute phase of the disease, and an analysis for IgG - about stable immunity.

IgG drug

The human body with all its components, including the immune system, is a unique system. It is thanks to her that confrontation is possible foreign organisms. Globulin E, M, A, D, G are components of the immune system that allow the body to exist. If a failure occurs, globulin substitutes are used.

The immunoglobulin fraction is active substance normal human globulin. This substance is isolated from donor plasma. It contains neither antibodies to hepatitis C viruses nor immunodeficiency viruses, nor antibiotics. Such medications should only be used as prescribed by a doctor. Like all drugs from donated blood and plasma, they are quite expensive.

Reasons for decreased IgG

Normal level

Multiple units of measurement are used to represent results. Sometimes it's micromoles per liter. You just need to know the conversion factor. One micromole is equal to 6.67 grams per liter. But the most commonly used unit is grams per liter.

By the age of two years, the normative concentration of protective substances is achieved. In children under one year of age, the norm is considered to be from 2.30 to 14.11 g/liter. From one year to three years – from four and a half to 9.2 grams per liter. From four to sixteen years of age – from 5.50 to 15.84 g/l. A specialist, such as an immunologist or hematologist, must interpret the test results.

Thank you

Immunoglobulins(antibodies, gamma globulins) are special compounds produced by cells of the immune system that protect humans from bacteria, viruses and other foreign substances (antigens).

Properties of immunoglobulins

The human immune system and its functions

Humoral immunity is that part of the immune system that carries out its function in liquid media. human body. Those. Antibodies perform their work in the blood, interstitial fluids and on the surface of mucous membranes.

There is also cellular immunity carried out by a number of specialized cells (such as macrophages). However, it has nothing to do with immunoglobulins and is a separate element of protection.

The immune response may be:
1. Specific.
2. Non-specific.

Immunoglobulin carries out a specific immune response, finding and neutralizing foreign microorganisms and substances. Against each bacterium, virus or other agent, their own are formed, monoclonal antibodies(i.e. capable of interacting with only one antigen). For example, antistaphylococcal immunoglobulin will not help against diseases caused by other microorganisms.

Acquired immunity can be:
1. Active:

• is formed due to antibodies formed after an illness;
• occurs after preventive vaccination(introduction of weakened or killed microorganisms, or their modified toxins, in order to form an immune response).

• immunity in the fetus and newborn child, to whom maternal antibodies were transferred in utero, or during breastfeeding;
• occurs after ready-made immunoglobulins have been vaccinated against a specific disease.

Human immunoglobulin and its functions

• "recognizes" foreign substance(microorganism or its toxin);
• binds to antigen, forming an immune complex;
• participates in the removal or destruction of formed immune complexes;
• immunoglobulin against past diseases remains in the body for a long time (sometimes for life), which protects a person from re-infection.

Antibodies are actively used in medicines. Currently, you can buy immunoglobulin in almost any pharmacy.

Immunity and immunoglobulins in children

• In utero, the child does not encounter microorganisms, so his own immune system is practically inactive;
• during pregnancy, only class G immunoglobulins can pass from mother to child, easily penetrating the placenta due to their small size;
• detection of class M immunoglobulins in the blood serum of a fetus or newborn child indicates an intrauterine infection. It is often caused by cytomegalovirus (symptoms of the disease: runny nose, fever, enlarged lymph nodes, damage to the liver and spleen, and others);
• immunoglobulins acquired from the mother in the blood of an infant remain for about 6 months, protecting him from various diseases, therefore, in the absence of pathology of the immune system at this time, children practically do not get sick.

The final formation of the child’s immune system is completed only by the age of 7 years. Distinctive Features children's immunity are:
1. Insufficient ability for phagocytosis (absorption and destruction of cells pathogens human phagocytes).
2. Low production of interferons (proteins that carry out nonspecific protection against viruses).
3. A decrease in the amount of immunoglobulins of all classes (for example, for immunoglobulin E, the norm in children is lower than in adults).

Therefore, it is natural that during the development of the body’s immune system, the child often gets sick. To help him properly form immunity, increasing it should be achieved by such means as hardening, swimming and other sports activities, and staying in the fresh air.

Immunoglobulins during pregnancy: Rh conflict

The mechanism of development of this pathology is associated with the fact that when a pregnant woman Rh negative- immunoglobulin may begin to be produced against fetal red blood cells. This usually happens on later pregnancy. The threat of Rh conflict increases with pregnancy pathologies: inflammatory processes, threat of interruption, increased tone uterus and others.

Rh conflict can lead to severe hemolysis (destruction of red blood cells) in the fetus and newborn child. The consequences of this condition may be:

• severe hypoxia (oxygen starvation) of the fetus;
• violation metabolic processes, intrauterine growth retardation;
• the appearance of edema, fetal hydrops;
• miscarriages and premature births, fetal death.

Anti-Rhesus immunoglobulin during pregnancy

2. Prevention of the formation of “harmful” immunoglobulins during abortion or other manipulations that can lead to fetal serum entering the mother’s blood.

The price for anti-Rhesus immunoglobulin is quite high, but when we're talking about about the health of a pregnant woman and her child, you should not save. Lower cost distinguishes domestic analogues drugs. Therefore, you can buy anti-Rhesus immunoglobulin Russian production, especially since there are no differences in the mechanism of action of the agents.

Self-medication with medications containing antibodies is contraindicated. During pregnancy, other drugs, with the exception of anti-Rhesus immunoglobulin, are not used.

Determining the level of antibodies in the blood

Blood diseases and hypovitaminosis can also cause immunodeficiency. The most common of them is iron deficiency anemia, characterized by low hemoglobin content in red blood cells and a decrease in the amount of iron in the blood serum. This condition leads to oxygen starvation tissues and, as a result, decreased immunity. Therefore, when hemoglobin is reduced, infectious diseases often occur. This is especially true for children, pregnant women or elderly patients.

Antibody affinity and avidity

The avidity of antibodies allows us to identify the severity of the disease. For example, acute or recent (1-1.5 months ago) cytomegalovirus infection in children is confirmed by detecting highly avid IgM antibodies, while their low concentrations can persist for up to two years.

Affinity refers to the strength of interaction between antigens and antibodies. The higher the indicator, the better the antigens bind to antibodies. Therefore, high affinity indicates a good immune response when this disease occurs.

When is an immunoglobulin test prescribed?

• atopic dermatitis;
• food, drug allergies;
• some other conditions.

A blood test for immunoglobulin G is indicated in the following cases:

• diagnosis of immunodeficiency conditions;
• determining the presence of antibodies against a specific disease;
• monitoring the effectiveness of therapy with drugs containing immunoglobulin.

Analysis of fractions for the determination of class M antibodies is used to identify acute infectious diseases. It is often prescribed to determine cytomegalovirus infection, Epstein-Barr virus, Helicobacter pylori bacteria, which causes gastritis and stomach ulcers, and other infections. Fine total IgM – up to 10% of all immunoglobulins.

A blood test for immunoglobulin A is indicated for recurrent infectious diseases of the mucous membranes. Normal quantity IgA – 10-15% of total number immunoglobulins.

Blood is also donated for immunoglobulin for various autoimmune diseases. Specific antibodies and their complexes with antigens are determined in pathologies such as systemic lupus erythematosus, rheumatoid arthritis, autoimmune thyroiditis, myasthenia gravis and others.

Human immunoglobulin: application

• immunodeficiency states;
• autoimmune diseases;
• severe viral, bacterial, fungal infections;
• prevention of diseases in people at risk (for example, in children born very prematurely).

For severe allergic diseases, your doctor may recommend purchasing antiallergic immunoglobulin. This drug is effective means from atopic reactions. Indications for use will be:

• allergic dermatitis, neurodermatitis, urticaria, Quincke's edema;
• atopic bronchial asthma;
• hay fever

The importance of antibodies in vaccinations

Antibodies obtained from animals or human immunoglobulin can be used to produce preparations for passive immunization.
Immunoglobulin is part of preventive vaccinations against the following diseases:

• mumps (mumps);
• other.

A separate variant of immunoglobulins is toxoid. It is an antibody whose action is directed not at the causative agent of the disease, but against the toxic substances produced by it. For example, toxoids are used against tetanus and diphtheria.

There are also tools for emergency prevention containing human immunoglobulin. Their price will be an order of magnitude higher, but they are indispensable when there is a need to travel to another country that is an endemic zone of some kind. dangerous infection(For example, yellow fever). Immunity after the introduction of these drugs will be shorter (up to 1 month), but is formed within a day.

However, it should be remembered that the administration of immunoglobulin is not an alternative to full preventive vaccination in accordance with the vaccination calendar, since the emerging immunity is shorter lasting and not as strong.

Immunoglobulin preparations

Human normal immunoglobulin is available in bottles containing powder for preparing an injection solution or a ready-made solution (Immunoglobulin 25 ml). It contains IgG antibodies obtained from the plasma of healthy donors, as well as small quantities IgM and IgA.

Normal human immunoglobulin is contained in the following medications: Octagam, Pentaglobin, Antirotavirus immunoglobulin, Antistaphylococcal immunoglobulin, Normal human immunoglobulin, Complex immunoglobulin preparation (CIP), Antirhesus immunoglobulin, Antiallergic immunoglobulin, Cytotect and many others.

Immunoglobulin injections are prescribed intramuscularly or intravenously only by a qualified doctor. The dose of the drug and duration of treatment are selected individually, taking into account the patient’s age and weight, as well as the severity of the disease.

Treatment with immunoglobulins

• severe allergic reactions;
• flu-like symptoms (chills

  Where can I buy?

  You can purchase the drug at any large pharmacy or on the Internet. Medicines containing immunoglobulin must be accompanied by instructions. However, using them without a doctor’s prescription is strictly prohibited, since the drugs have a large number of contraindications. For example, during pregnancy and breastfeeding, immunoglobulin administration is prohibited.

  The price of immunoglobulin preparations can vary greatly, and depends on the specificity of the antibodies, the manufacturer medicine, release form and other characteristics.

  Any medications containing normal human immunoglobulin must be stored in the refrigerator (at a temperature of +2 - +8 o C).

  Before use, you should consult a specialist.

Description

Determination method Immunoturbidimetric.

Material under study Blood serum

The main type of serum immunoglobulins involved in the immune response.

Make up about 75 - 80% of all serum immunoglobulins and 10 - 20% total protein serum. Synthesized by B lymphocytes (plasmocytes). The molecule consists of 2 heavy and 2 light chains. The half-life is about 23 - 25 days.

IgG antibodies play a fundamental role in ensuring long-term humoral immunity for infectious diseases.

IgG deficiency weakens resistance to infections. IgG synthesis and serum levels increase in response to chronic or recurrent infection or autoimmune disease (many clinically important autoantibodies are of the IgG class).

The main function of IgG is the formation of the antigen-antibody complex. They contribute to the neutralization of bacterial exotoxins, phagocytosis, complement fixation, and can participate in allergic reactions. Antibodies of this class appear some time after contact with the antigen.

Immunoglobulins G have a small molecular weight and therefore can (the only one of all immunoglobulins) penetrate the placenta from mother to fetus. Thus, passive immunity of the newborn child is ensured to certain infectious diseases, for example, measles. The blood of the fetus and newborn contains only maternal IgG. They disappear very early, no later than 9 months after birth, when the synthesis of their own IgG begins.

Preparation

It is preferable to take blood in the morning on an empty stomach, after 8-14 hours of overnight fasting (you can drink water), it is acceptable in the afternoon 4 hours after easy reception food.

On the eve of the study, it is necessary to exclude increased psycho-emotional and physical stress ( sports training), drinking alcohol.

Indications for use

• Recurrent bacterial respiratory infections(sinusitis, pneumonia), as well as otitis and meningitis, sepsis.
• Infectious diseases.
• Chronic viral and autoimmune hepatitis.
• Cirrhosis of the liver.
• Diffuse diseases connective tissue(rheumatoid arthritis, systemic lupus erythematosus, dermatomyositis).
• Multiple myeloma.
• HIV infection, AIDS.
• Oncopathology.
• Control replacement therapy immunodeficiencies with immunoglobulin.

Interpretation of results

Interpretation of research results contains information for the attending physician and is not a diagnosis. The information in this section should not be used for self-diagnosis or self-treatment. Accurate diagnosis is determined by the doctor, using both the results of this examination¤ and necessary information from other sources: medical history, results of other examinations, etc.

Units of measurement in the Independent Laboratory INVITRO: g/l. Alternative units: mg/100 ml; mg/l.

Conversion factor:

• mg/l x 0.001 ==> g/l
• mg/100 ml x 0.01 ==> g/l.

Reference values

Increased IgG levels:

chronic and recurrent purulent infections(infectious mononucleosis, tuberculosis, leprosy, etc.);

autoimmune diseases, especially systemic lupus erythematosus, rheumatoid arthritis;

chronic liver damage ( chronic hepatitis, cirrhosis), while the degree of increase in IgG levels correlates with the severity of the disease;