Blood on ig g. IgG antibodies - what is it. Serological and immunological studies

Description

Method of determination Turbidimetric.

Material under study Serum

Home visit available

“Antibodies of anxiety”, which are the first to react to antigens that enter the body and trigger further immune defenses.

IgM is synthesized by plasma cells, accounting for 5-10% of the total amount of immunoglobulins in the blood serum. They circulate predominantly in the blood as a pentamer consisting of 5 monomeric IgM subunits. It is called macroglobulin due to its high molecular weight. IgM - antibodies formed in the early stages of the infectious process.

Their half-life is about 5 days. At the beginning of the immune response, antibodies of the IgM class are synthesized, and only after 5 days does the synthesis of antibodies of the IgG class begin.

IgM in blood serum agglutinates bacteria, neutralizes viruses, and activates complement. They play an important role in the elimination of the pathogen from the bloodstream, in the activation of phagocytosis. IgM appear in the fetus and are involved in anti-infective protection. Isohemagglutinins (anti-A, anti-B), rheumatoid factor (at an early stage of the disease), cold agglutinins also belong to the IgM class. During fetal development, they do not cross the placenta due to their high molecular weight.

A significant increase in the concentration of IgM in the blood is observed in a number of infections, both in adults and in newborns. An increased content of IgM in cord blood is a diagnostic criterion for intrauterine infection of the fetus, infection with pathogens of rubella, syphilis, toxoplasmosis, and cytomegaly.

Training

It is preferable to take blood in the morning on an empty stomach, after 8-14 hours of a night fasting period (you can drink water), it is permissible in the afternoon 4 hours after a light meal.

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

Indications for appointment

Recurrent or chronic bacterial infections of the respiratory tract (sinusitis, pneumonia), as well as purulent otitis and meningitis, sepsis.
Chronic diarrhea, malabsorption syndrome.
Suspicion of prenatal infections (test of blood from the umbilical cord).
Rheumatoid arthritis and autoimmune diseases.
Tumor diseases.
Chronic hepatitis, cirrhosis of the liver.
Waldenström's macroglobulinemia (treatment control).

Interpretation of results

The interpretation of test 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. An accurate diagnosis is made by the doctor, using both the results of this examination and the necessary information from other sources: history, results of other examinations, etc.

Units of measurement in the Independent laboratory INVITRO: g/l. Alternative units of measurement: 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 IgM level: An increase in IgM titers in the blood indicates an acute inflammatory process.

cytostatic and radiation therapy;
condition after splenectomy;
protein loss in gastroenteropathy, burns;
lymphoma.

congenital deficiency:

agammaglobulinemia (Bruton's disease);

monoclonal gammopathy (not IgM);

selective deficiency of IgM.

other reasons: taking dextran, gold preparations.

The presence of positive results in tests that detect cytomegalovirus IgG means that there are antibodies in the human body that block the activity of the virus. This means that this person acts as a carrier of the infection. The presence of immunity to this type of infection allows you not to be afraid of possible complications that threaten the life of the patient.

In this matter, an important role is occupied by the quality of the protective functions of the body and the physical health of the patient. Increased attention should be paid to a negative result of such a test carried out during pregnancy. This fact can threaten the health of the child, since there are no antibodies against this infection in the developing body.

Cytomegalovirus is one of the most common infections in the world

Cytomegalovirus IgG antibodies detected, what does this mean? To answer this question, it is necessary to consider the research procedure itself. During this procedure, the genetic material submitted for research is studied in order to search for specific antibodies to cytomegalovirus. The term Ig in this case is an abbreviation for the word "immunoglobulin". This trace element is a protective protein that is synthesized by the immune system to fight various viruses.

The immune system of the human body produces dozens of types of special antibodies, the purpose of which is to fight various types of infection. At the end of puberty, several dozen types of immunoglobulins are present in the internal environment of the body. With the help of the letter G in the combination under consideration, a class of antibodies is indicated that are responsible for fighting certain pathogens. Each of these classes is denoted by the letters of the Latin alphabet.

It should also be said that if a person has not previously encountered cytomegalovirus, then in the internal environment there are no antibodies necessary to fight the disease. Based on this, it can be said that a positive test result can act as evidence that this type of infection has already been present in the body. In addition, attention should be paid to the fact that immunoglobulins belonging to the same class, but having a different purpose, have noticeable differences. Based on this, testing for cytomegalovirus IgG allows you to get the most accurate results.

How analyzes are deciphered

A characteristic feature inherent in cytomegalovirus is that after penetrating into the internal environment of the human body, the infection remains in it forever. To date, medicine has no answer to the question of how to remove this strain of the virus completely from the body. This type of infection is in an inactive state and is stored in the secretions of the salivary glands, blood composition, and also in the cells of some organs. It should be noted here that some people are not even aware of the presence of the infection and that they are carriers.

The analysis of IgG for cytomegalovirus itself means the search for specific antibodies to the virus in various samples from the patient's body

Considering the question, positive cytomegalovirus IgG, what does this mean, we should make a small digression and consider some of the differences between classes of antibodies. The IgM class includes antibodies that are large in size. They are produced by the immune system in order to reduce the activity of a viral infection within a short period of time. This class of antibodies does not have the ability to create immunological memory. This means that after a certain period of time, the reproduced antibodies disappear, and the body's defenses are compromised.

Polymer chain reaction studies and a positive response to these studies indicate that there are antibodies to cytomegalovirus in the human body. If there are antibodies from the M group in the blood, one can judge the amount of time that has passed since the infection. The presence of these antibodies is a kind of evidence that this virus is at the peak of its activity and the body is actively fighting the infection. To get more detailed information, you should pay attention to additional data.

What to pay attention to

The polymer chain reaction test allows you to detect not only the presence of IgG to cytomegalovirus, but also a lot of other useful information. The attending physician is engaged in deciphering the data of the analyzes performed, however, knowledge of certain terms will allow you to independently familiarize yourself with the information provided. Below is a list of the most common terms:

"IgM positive, IgG negative"- means that the immune system actively produces antibodies, the action of which is aimed at fighting viruses. The presence of this result indicates that the infection has occurred recently, and the immune system has not yet had time to develop antibodies from the class "G".
"IgM negative, IgG positive"- the infection is in an inactive state. Infection with citalomegavirus took place a long time ago, and the immune system completely protects the body. When re-infected, the antibodies prevent the infection from spreading.
"IgM negative, IgM negative"- this result indicates that there are no antibodies in the internal environment of the body that suppress the activity of cytomegalovirus, since this strain of infection is not yet known to the body.
"IgM positive, IgG positive"- this status tells about the reactivation of the virus and the exacerbation of the disease.

The result of the analysis "Cytomegalovirus IgG positive" means that a patient with such results is immune to cytomegalovirus and is a carrier

Sometimes in such results the following line is found: "Anti CMV IgG is elevated." This means that the amount of antibodies needed to fight the citalomegavirus exceeds the norm. In order to understand what value indicates the norm, let's consider such an indicator as the antibody avidity index:

0 index- means the absence of infection in the body.
≤50% - This result is evidence of primary infection.
50-60% - undefined data. Upon receipt of this result, it is necessary to undergo a second examination procedure after fifteen days.
≥60% - indicates that the body has antibodies that protect a person from reactivation of the infection. However, this status may mean that the disease itself has acquired a chronic form.

In the presence of strong immunity and the absence of chronic diseases that affect the quality of the immune system, a positive test result for the presence of antibodies should not cause concern for one's own health. In most cases, exposure of the immune system to the virus results in asymptomatic disease. In more severe cases, cytomegalovirus with strong immunity can manifest itself in the form of symptoms such as:

sore throat;
slight increase in temperature;
decrease in performance.

Although there may be no signs of infection activity, an infected person during the acute period of the disease should be in isolation. Experts recommend visiting public places as little as possible and completely avoiding close contact with pregnant women and young children. Being in this stage of the disease, a person is an active source of infection, therefore, in order to shorten the period of the acute stage of infection, therapy should be started without delay.

Positive test result during pregnancy

With a positive test result for the presence of IgM antibodies, several conclusions can be drawn. This result may indicate both a primary infection with cytomegalovirus and a relapse of the disease. If this class of immunoglobulins is detected in the first trimester of pregnancy, treatment of the disease should be started immediately. Delay in taking the necessary measures can lead to the fact that the infection will have a teratogenic effect on the development of the fetus.

In a situation with a relapse of the disease during pregnancy, the risk of developing possible complications is significantly reduced. However, as in the previous case, the lack of therapy can cause a congenital infectious disease in a newborn. It is also necessary to take into account the risk of infection of the child during passage through the birth canal.

The therapy strategy is determined by the doctor accompanying the process of bearing the fetus.

Cytomegalovirus - a herpes virus with a latent course when it enters the body

In order to determine the nature of the infection, you should pay attention to the level of immunoglobulins belonging to the class "G". The presence of these bodies is a confirmation of immunity to secondary infection. Symptoms characteristic of cytomegalovirus, in this situation, indicate a decrease in the quality of the protective functions of the body. If the result of the PCR procedure is negative, the doctor should regard the damage to the body as primary and take all necessary measures to reduce the risk of complications for the fetus.

To prescribe a treatment regimen, it will be necessary to analyze the patient's medical history in detail. Along with this, various factors are taken into account, including existing chronic diseases. The presence of immunoglobulins from class M is a kind of sign of the danger of the disease. However, it should be noted that a result such as a negative Anti cmv IgM in the absence of antibodies from class G may pose a certain threat. In this situation, a pregnant woman needs to take all measures that will protect her body from primary infection.

Positive result in infants

The presence of antibodies from class G in a newborn child is a kind of evidence that the infection occurred during the intrauterine development of the embryo. In order to obtain unambiguous evidence, you will need to take several samples with an interval of one month. The presence of a congenital infection can be determined by microscopic examination of the composition of the blood.

In most cases, the development of cytomegalovirus infection proceeds latently. However, in such a situation, there is a risk of developing serious complications that pose a threat to the health of the baby. These complications include liver dysfunction, hepatitis, and pneumonia. In addition, there is a risk of developing chorioretinitis, which in the future can cause complete loss of vision.

If there is suspicion of cytomegalovirus activity in a newborn, treatment should be started immediately in order to avoid possible complications. In the first days after birth, an infected infant should be constantly cared for.

Treatment Method

In most cases, antibodies to cytomegalovirus independently eliminate the exacerbation of the disease. However, in some situations, the use of potent drugs is required to eliminate the infection. The use of such drugs without the need is highly undesirable, due to the high risk of developing side effects of drugs. Among the various drugs used in the treatment of cytomegaloviruses, drugs such as Ganciclovir, Foscarnet, Panavir should be distinguished. Despite possible side effects in the form of impaired functioning of the kidneys and organs of the gastrointestinal tract, these drugs eliminate the activity of the infection in a short time.

Human infection usually occurs before 12 years of age.

In addition, as part of complex treatment, drugs from the group of interferons are used, as well as immunoglobulins obtained from donors who are immune to infection. The use of the above medicines is allowed only after prior consultation with a specialist. These potent medicines have their own characteristics, which are known only to specialists in the field of medicine and pharmacology.

In conclusion, it must be said that a positive result of the PCR procedure for the presence of a cytomegalovirus infection indicates that there are antibodies in the human body that prevent the development of the disease. In order for the immune system to continue to protect the body, it is necessary to pay increased attention to the state of one's health.

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At the 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 Lab4U online laboratory, serological studies are made to detect pathogen antigens and specific antibodies to them - this is the most accurate method for diagnosing infectious diseases. "Why do I need to take an antibody test to diagnose infections?". Such a question may arise after the doctor's referral to the laboratory. Let's try to answer it.

Content

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

Antibodies are proteins that the immune system produces 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 must pass after eating). In a modern laboratory, blood serum is examined on an automatic analyzer using appropriate reagents. Sometimes serological testing for antibodies is the only way to diagnose infectious diseases.

Tests for infections can be qualitative (give an answer if 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 Lab4U online laboratory, you can pass at one time and

Various classes of antibodies IgG, IgM, IgA

ELISA detects infection antibodies belonging to different Ig classes (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 antibodies of the IgM class (acute phase of the course of infection) and antibodies of the IgG class (resistant immunity 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 testing for each specific infection and type of antibody. Primary infection is detected by the detection of a diagnostically significant level of IgM antibodies in a blood sample or by a significant increase in the number of IgA or IgG antibodies in paired sera taken at an interval of 1-4 weeks.

Reinfection, or re-infection, is detected by a rapid rise in the level of IgA or IgG antibodies. IgA antibodies are higher in older patients and are more accurate in diagnosing current infection in adults.

A past infection in the blood is defined as elevated IgG antibodies without an increase in their concentration in paired samples taken at an interval of 2 weeks. At the same time, there are no antibodies of the IgM and A classes.

IgM antibodies

Their concentration rises shortly 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 decrease to diagnostically insignificant levels within several 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), which are 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 is slower, the response to an antigenic stimulus remains more stable than that of IgM class antibodies.

IgG antibody levels rise more slowly (15-20 days after the onset of the disease) than IgM, but remain elevated longer, so they may show a long-term infection in the absence of IgM antibodies. IgG levels may 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 simultaneously. If the IgA result is unclear, confirmation is by IgM determination. In the case of a positive result and for an accurate diagnosis, a second test, taken 8-14 days after the first, should be checked in parallel to determine the increase in the concentration of IgG. The results of the analysis should be interpreted in conjunction with 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. The level of IgA antibodies usually decreases by 2-4 months after infection in case of successful treatment. With re-infection, the level of IgA antibodies again increases. If the level of IgA does not fall after the treatment, then this is a sign of a chronic form of infection.

Antibody testing 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 TORCH-complex infections during pregnancy (the presence of only IgM antibodies in the blood) is an indication for its termination.

Finally

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

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

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The question of the norm of the content of IgG immunoglobulins to cytomegalovirus in the blood serum worries the majority of women planning a pregnancy or already bearing a child, as well as many young mothers. The increased attention to the virus in recent years is explained by its wide prevalence in the human population and the negative impact on the development of the fetus when the expectant mother is infected during pregnancy. In addition, cytomegalovirus infection (CMVI) is often associated with the development of atypical pneumonia in children, delayed physical and mental development, and impaired vision and hearing.

CMVI is also of particular importance in organ transplantation and the treatment of immunocompromised patients.

Determining the level of IgG antibodies in the blood is the most common method for detecting cytomegalovirus infection and determining its status in the body. It is important to understand that the content of class G immunoglobulins in blood serum is expressed in relative units, which may vary depending on the location of the laboratory performing the analysis and the equipment used.

Accordingly, the numerical expression of the norm may look different. It is generally accepted that the very presence of IgG in the body of adults is normal, since more than 90% of the world's population are carriers of the virus. In this case, the production of antibodies indicates a normal reaction of the immune system to infection with a virus.

The detection of IgG antibodies in the blood of a patient has a certain diagnostic value: in itself, this is not an indication for the appointment of treatment, but only indicates the presence of immunity to infection. That is, the body once already encountered a virus and produces (for life) the corresponding antibodies.

What is the norm

The amount of antibodies to cytomegalovirus is usually expressed as a titer. The titer is the highest dilution of the patient's blood serum at which a positive reaction is observed. As a rule, in immunological studies, serum dilutions are prepared in multiples of two (1:2, 1:4, and so on). The titer does not reflect the exact number of immunoglobulin molecules in the blood, but gives an idea of their total activity. This greatly speeds up the delivery of analysis results.

There is no norm for the titer value, since the amount of antibodies synthesized by an individual human body can vary depending on the general condition of the body, lifestyle, immune system activity, the presence or absence of chronic infections, and metabolic characteristics.

To interpret the results of the analysis for antibodies to cytomegalovirus, the concept of "diagnostic titer" is used. This is a certain dilution of blood serum, a positive result in which is considered an indicator of the presence of a virus in the body. For cytomegalovirus infection, the diagnostic titer is a dilution of 1:100.

Currently, the arsenal of immunological laboratories has several dozen test systems for the detection of antibodies to cytomegalovirus. All of them have different sensitivity and consist of different components. General is only the principle of research - enzyme immunoassay (ELISA).

The results of ELISA are taken into account according to the degree of staining (optical density) of the solution to which the patient's serum is added. The optical density (OD) of the analyzed sample is compared with obviously positive and negative samples - controls.

As a rule, to speed up the study, each test system is configured to work with one dilution of blood serum specified in the instructions for the test system. This eliminates the need to prepare multiple dilutions, and the analysis procedure is reduced by several hours.

There is currently no single diagnostic titer for all laboratories. For each test system, the manufacturer specifies the so-called reference values at which the result is considered positive or negative.

That is why in the forms of the results of the analysis for antibodies to cytomegalovirus you can find the following: the norm is 0.3, the result is 0.8 (positive). In this case, the norm means the optical density of the control sample, which does not contain antibodies to the virus.

Learn more about IgG and IgM immunoglobulins

With the penetration of cytomegalovirus into the body, the nonspecific cellular link of immunity is initially activated - phagocytic cells (macrophages and neutrophils). They capture and neutralize the virus. The protein components of the virus envelope appear on the membranes of macrophages. This serves as a signal for a special group of T-lymphocytes - helpers, which secrete specific stimulators of B-lymphocytes. Under the influence of a stimulator, B-lymphocytes begin an active synthesis of immunoglobulins.

Immunoglobulins (antibodies) are soluble proteins that circulate in the blood and interstitial tissue fluid, and are also present on the surface of B-lymphocytes. They provide the most effective and rapid protection against the multiplication of infectious agents in the body, are responsible for lifelong immunity to certain infections and are involved in the development of protective inflammatory and allergic reactions.

There are five classes of antibodies - IgA, IgM, IgG, IgD, IgE. They differ from each other in structure, molecular weight, strength of binding to antigens and types of immune responses in which they take part. In antiviral protection in CMVI, immunoglobulins of classes M and G are of the greatest importance.

IgM is the first to be synthesized when the body is infected with a virus.. They appear in the blood within 1-2 weeks after the initial infection and persist from 8 to 20 weeks. The presence of these antibodies in the blood serum usually indicates a recent infection. Class M immunoglobulins can also appear during reactivation of a long-standing infection, but in much smaller quantities. In this case, it is possible to distinguish the primary infection from the reactivated one by determining the avidity of antibodies, that is, the strength of their binding to viral particles.

Immunoglobulins IgG appear in the blood serum about a month after infection with cytomegalovirus. At the beginning of the immune response, they have low avidity. 12-20 weeks after the onset of infection, avidity becomes high. IgG persist in the body for life and allow the immune system to quickly respond to increased virus activity.

The amount of synthesized immunoglobulins depends on the individual characteristics of the organism, therefore, there are no normal values \u200b\u200bfor this indicator. In most people with normal immune system activity, the amount of IgG to cytomegalovirus rapidly increases during the first 4-6 weeks after the initial infection or reactivation of the infection, then gradually decreases and remains at a constant level.

Deciphering the results of the analysis

In order to independently decipher the results of the analysis for cytomegalovirus, it is necessary to compare the obtained data with the reference values \u200b\u200bspecified in the answer form. These indicators can be expressed in arbitrary units (c.u., IU), optical units (r.u.), optical density indicators (OD), units per milliliter or as a titer. Examples of results and their interpretation are given in the table.

Possible options for the results of determining IgG in blood serum and their interpretation:

Reference values (norm)	Patient serum	Result
		No virus
		There is a virus
Negative index 1.0		There is a virus
Positive Control >1.2		There is a virus
		There is a virus
OD syv: 0.5 - negative 0.5-1 - doubtful >1 - positive		Doubtful
		There is a virus

If the form does not contain reference values or normal indicators, the laboratory must provide a transcript. Otherwise, the attending physician will not be able to determine the presence or absence of infection.

High titers of IgG do not indicate a danger to the body. Determination of only class G immunoglobulins gives an idea of the possible contact of the organism with cytomegalovirus in the past, but does not allow to establish the activity of the virus. Thus, if IgG is detected in the patient's blood serum, this only indicates the carriage of the virus.

To determine the stage of infection, the level of IgG avidity should be assessed. Low avid antibodies always indicate a fresh primary infection, high avid antibodies circulate in the blood of carriers of the virus all their lives. When reactivating a long-standing chronic infection, highly avid IgGs are also detected.

A complete picture of the picture can be obtained by a combination of immunological and molecular biological diagnostic methods: ELISA for antibodies of classes M and G to cytomegalovirus, IgG avidity, polymerase chain reaction (PCR) for the presence of virus DNA in blood, saliva and urine.

Norm of IgG antibodies to cytomegalovirus in pregnant women

Analysis for the presence of IgG to cytomegalovirus is mandatory when examining pregnant women. It has been proven that the primary infection of a future mother can lead to spontaneous abortion, the development of severe congenital anomalies in the fetus, or long-term complications of the infection.

In this regard, one should not neglect the mandatory analyzes and take them on time. It is advisable to take an analysis for cytomegalovirus before 10-12 weeks of pregnancy. If a re-examination is recommended, it must be completed strictly within the specified time frame.

The ideal option is to determine antibodies to cytomegalovirus when planning pregnancy and in each of its trimesters. This allows you to exclude or detect in time the primary infection or reactivation of a long-standing infection during pregnancy.

If before pregnancy a woman did not have antibodies to cytomegalovirus, she is at risk. When infected with the virus during pregnancy, the probability of intrauterine infection of the fetus reaches 50%. It is recommended to limit contact with children under the age of 6 and carefully observe the rules of personal hygiene.

If class G antibodies with low avidity and / or IgM are detected before pregnancy, the diagnosis is “recent primary infection”. It is recommended to postpone conception for 2-3 months due to the high probability of infection of the fetus.

If antibodies to cytomegalovirus were not detected in a woman before pregnancy, and IgG was detected in the blood during pregnancy, this also indicates a primary infection. It is recommended to consult an infectious disease specialist and carefully monitor the health of the newborn, since the possibility of a congenital infection is not excluded.

In practice, they are most often limited to a single determination of IgG and IgM in the first trimester of pregnancy, when the risk to the fetus is maximum. Analysis of immunoglobulins M is necessary to establish the timing of infection. In the absence of the possibility of its implementation, the determination of IgG avidity is required.

Identification of only class G immunoglobulins does not give a complete picture of the duration of infection and the activity of the infectious process. The most accurate results can be obtained by setting up all three analysis options: the determination of IgG, IgM and IgG avidity.

Interpretation of the results of the analysis for the determination of antibodies to cytomegalovirus in pregnant women and the prognosis for the child:

		Avidity IgG		Fetal risk
			Recent primary infection	High chance of infection

		Not defined	Indefined Possible long-standing latent infection or late stage of recent primary infection
not defined		Not defined		See above and/or IgM definition
			Reactivation of latent infection
	+ (increase in titer during a double examination)		Reactivation of latent infection	Low chance of infection
	+ (no increase in titer during a double examination)		A long-standing latent infection	Virtually absent
			No previous exposure to the virus or sampling within 7-14 days of initial infection	Indefined Re-examination required in 2-3 weeks

When obtaining questionable results or in the case of immunodeficiency conditions, confirmation of the diagnosis by PCR (polymerase chain reaction) is recommended.

The possibility of superinfection in the presence of class G immunoglobulins in the blood

As a rule, the immune system of adults and children over 5-6 years of age effectively suppresses the activity of cytomegalovirus in the body, and the infection proceeds without clinical manifestations.

However, this virus is characterized by great genetic variability, which leads to frequent changes in the structure of its proteins. The human immune system has a high specificity, that is, in response to the introduction of the virus, antibodies are formed that have an affinity for a certain structure of its components. With a significant modification of viral proteins, the strength of the immune response decreases, therefore, in rare cases, carriers of cytomegalovirus may have a primary infection caused by an altered version of the virus.

It should be remembered that with a positive result for cytomegalovirus, you should not immediately sound the alarm. Asymptomatic infection does not pose a threat to the adult body and does not require treatment. Pregnant women and women planning a pregnancy, as well as persons with clinical manifestations of CMVI, should consult an infectious disease specialist.

Doctor's explanations about IgG and IgM to cytomegalovirus

General information about the study

The first immunoglobulins produced at the beginning of the immune response to the entry of a foreign antigen into the body are antibodies of the IgM class. Their formation does not require additional participation of T-helper lymphocytes, which are responsible for switching synthesis to other classes of immunoglobulins, which allows you to quickly start the humoral immune defense mechanisms of the body.

IgM predominantly circulate in the bloodstream and make up 5-10% of all blood immunoglobulins. IgM is a pentamer - consists of five subunits, each of which has two antigen-binding centers. The half-life of IgM in the body is 5 days. These antibodies bind to antigens, opsonize and enhance their phagocytosis, and activate the complement system in the classical way. IgM, due to its large molecular weight, is not able to cross the placenta from mother to fetus, so their increased amount to a certain antigen indicates intrauterine infection of the fetus. IgM includes blood group isohemagglutinins (antiA and antiB), heterophile antibodies, and early rheumatoid factor.

Specific IgMs are produced in response to exposure to a particular antigen. They begin to be synthesized upon initial contact with an infectious agent or foreign substance, several days earlier than the first IgG antibodies appear. The amount of IgM increases during the first weeks after infection and gradually decreases until it disappears completely. IgM are replaced by IgG, which provide long-term protection against infections.

Overproduction of immunoglobulin M may be associated with hyperstimulation of all clones of plasma cells or a single clone of IgM-producing B cells. This may accompany an active infectious process or some types of immunoproliferative diseases (eg, multiple myeloma, Waldenström's macroglobulinemia).

IgM deficiency can be primary (congenital), which is rare, or secondary (acquired), due to various factors that deplete humoral immunity.

What is research used for?

To assess humoral immunity.
For the diagnosis of immunodeficiency states.
For the differential diagnosis of acute and chronic infections (with simultaneous determination of the level of IgG).
For the diagnosis of intrauterine infections.
For the diagnosis of Waldenström's macroglobulinemia.
To assess the immune system in autoimmune pathologies, blood diseases and neoplasms.
To evaluate the effectiveness of immunoglobulin preparations.

When is the study scheduled?