Diagnosis, analysis and treatment of CMV. Treatment of cytomegalovirus (CMV, CMV) IgG positive, how to treat

Patients are wondering if antibodies are detected with cytomegalovirus igg, what does this mean? Nowadays, there are a number of diseases that do not manifest themselves in any way, and their presence in the body is detected only using laboratory methods, sometimes completely by accident. One such infection is cytomegalovirus. What does it mean if cytomegalovirus iG antibodies are detected?

What are antibodies to cytomegalovirus?

Testing for IgG antibodies to cytomegalovirus allows one to detect the presence of this infection.

Cytomegalovirus (abbreviated CMV) is a member of the herpesvirus family that causes cytomegaly in humans. Cytomegaly is a viral disease that is transmitted from person to person. It is characterized by the fact that the virus attaches to healthy cells of human tissues, changes their internal structure, and as a result, huge cells, the so-called cytomegales, are formed in the tissues.

This virus has the peculiarity of living in the human body for many years and not showing itself in any way. When the immune balance in the body is disturbed, the virus is activated, and the disease begins to progress very quickly. As a rule, cytomegalovirus is localized in the salivary glands, since its structure is close to this type of tissue.

in the human body are excreted independently. According to official data, antibodies to this virus are found in adolescent children in 10–15% of cases, and in adults in 40%.

Cytomegalovirus is spread:

by airborne droplets, for example, through saliva;
transplacental, i.e. from mother to fetus through the placenta, as well as during the passage of the child through the birth canal;
nutritional, i.e. through the mouth when eating or drinking, as well as through dirty hands;
sexually - in contact, for example, with the mucous membrane of the vagina, contact of mucous membranes with sperm;
during blood transfusion;
during lactation through mother's milk.

The incubation period of CMV lasts from 20 to 60 days, the acute period of the disease passes within 2–6 weeks. In the acute phase of the disease, a person experiences the following manifestations:

After the acute stage of the disease has passed, the immune system is activated and antibodies are produced. If the immune system is weak due to previous diseases and poor lifestyle, the disease enters the chronic stage and affects the tissues, and often the internal organs of a person.

For example, CMV provokes the development of wet macular degeneration, i.e., a disease of the eye cells responsible for transmitting nerve impulses from the organ of vision to the brain.

The disease manifests itself as:

ARVI, in some cases pneumonia;
generalized form, namely, damage to internal organs, for example, inflammation of the liver, pancreas and other glands, as well as tissues of the intestinal walls;
problems with the organs of the genitourinary system, manifested in the form of recurrent inflammation.

You need to be especially concerned if a pregnant woman becomes infected with cytomegalovirus. In this case, fetal pathology develops when viruses in the mother’s blood are transmitted to it through the placenta. Pregnancy ends in miscarriage, or the child’s brain is damaged, as a result of which he suffers from diseases of both a physical and mental nature.

It is necessary to pay great attention to the diagnosis of the disease in utero form. It is especially important to establish how the pregnant woman became infected. If before conception the body has already suffered from a disease, and during pregnancy a second infection occurs, this fact means a higher chance of having a healthy baby. Cytomegalovirus provokes diseases that have a high risk of severe complications for life.

How is the disease diagnosed? The methods used in diagnosing CMV are as follows:

immunofluorescence method, which allows to detect the virus in biological fluids of the body;
chemiluminescence immunoassay (CHLA) method, based on an immunoassay;
polymerase chain reaction (PCR) is a molecular biology method that allows you to detect viral DNA in human biological fluids;
cell culture seeding;
enzyme-linked immunosorbent assay (ELISA), which determines whether there are antibodies to CMV in the blood.

What does it mean if Anti-CMV IgG is detected?

The listed types of tests are aimed at identifying specific antibodies called immunoglobulins. This in turn makes it possible to determine at what stage of development the disease is. The most effective and frequently used of them are ELISA and CLLA tests.

There are 2 classes of immunoglobulins that appear in CMV. The analysis reveals their quantitative indicator, which goes beyond the reference values, i.e., exceeds the norm.

Immunoglobulins M, which quickly respond to viral infections. These antibodies have the international abbreviation ANTI-CMV IgM, which stands for antibodies generated against class M cytomegalovirus.

These antibodies do not form immune memory and are destroyed in the body within six months.

With an increased amount of cytomegalovirus IgM, the acute stage of the disease is diagnosed.

Immunoglobulins G, which are formed throughout life and are activated after the infection is suppressed. ANTI-CMV IgG is the abbreviated name for these antibodies, according to the international classification, which means class G antibodies. IgG antibodies to cytomegalovirus indicate that the virus is developing in the body. Laboratory tests can determine the approximate time of infection. This is indicated by an indicator called titer. For example, a titer of cytomegalovirus igg 250 indicates that the infection has entered the body over several months. The lower the indicator, the longer the duration of infection.

When assessing the likelihood of infection, an analysis of the ratio of antibodies of the IgG class and the IgM class is used. The interpretation of the relationship is:

It is especially important to conduct these studies in women of reproductive age. If a positive result for cytomegalovirus IgG is obtained with a negative IgM before conception, this means that during pregnancy there will be no primary infection (the most dangerous for the fetus).

If IgM is positive, pregnancy should be postponed and consult with your doctor. And if the result for cytomegalovirus IgG and IgM is negative, then there is no virus in the body, and there is a possibility of primary infection.

What should I do if I test positive for IgG antibodies?

Treatment for CMV is usually aimed at strengthening the immune system in order to bring the cytomegalovirus into a latent form that can be controlled by the human immune system.

Therapy is also based on taking antiviral drugs with antiherpes action. Concomitant diseases that develop along with CMV are treated with antibiotics.

To prevent CMV, a special vaccine has been developed, aimed primarily at protecting pregnant women. According to studies, the vaccine currently has an effectiveness rate of approximately 50%.

The results revealing a positive cytomegalovirus iGG should not be taken as a death sentence. The CMV virus is present in the body of the vast majority of people. Timely analysis, prevention and adequate treatment can minimize the risks of the disease provoked by this infection.

If the cytomegalovirus IgG test is positive, many people become concerned. They believe that this indicates a hidden serious illness that needs to be treated immediately. However, the presence of IgG antibodies in the blood is not a sign of developing pathology. The vast majority of people become infected with cytomegalovirus in childhood and do not even notice it. Therefore, a positive test result for antibodies (AT) to cytomegalovirus is a surprise for them.

What is cytomegalovirus infection?

The causative agent is herpes virus type 5 - cytomegalovirus (CMV). The name "herpes" is derived from the Latin word "herpes", which means "creeping". It reflects the nature of diseases caused by herpes viruses. CMV, like their other representatives, are weak antigens (the so-called microorganisms that bear the imprint of foreign genetic information).

Recognition and neutralization of antigens is the main function of the immune system. Weak are those that do not cause a pronounced immune response. Therefore, the primary often occurs unnoticed. The symptoms of the disease are mild and resemble the symptoms of a common cold.

Transmission and spread of infection:

In childhood, the infection is transmitted by airborne droplets.
Adults become infected mainly through sexual contact.
After the initial invasion, herpes viruses settle permanently in the body. It is impossible to get rid of them.
The infected person becomes a carrier of cytomegalovirus.

If a person’s immunity is strong, CMV hides and does not manifest itself in any way. If the body's defenses are weakened, microorganisms are activated. They can cause the development of serious diseases. In immunodeficiency states, various human organs and systems are affected. CMV causes pneumonia, enterocolitis, encephalitis and inflammatory processes in various parts of the reproductive system. With multiple lesions, death can occur.

Cytomegalovirus is especially dangerous for a developing fetus. If a woman is first infected during pregnancy, the pathogen is likely to cause serious developmental defects in her baby. If infection occurs in the 1st trimester of pregnancy, the virus often causes fetal death.

A recurrence of cytomegalovirus infection poses a significantly less threat to the embryo. In this case, the risk of developmental defects in the child does not exceed 1–4%. Antibodies present in a woman’s blood weaken pathogens and prevent them from attacking fetal tissue.

It is very difficult to determine the activity of cytomegalovirus infection only by external manifestations. Therefore, the presence of a pathological process in the body is detected using laboratory tests.

How the body reacts to the activation of viruses

In response to the invasion of viruses, they form in the body. They have the ability to combine with antigens according to the “key to lock” principle, linking them into an immune complex (antigen-antibody reaction). In this form, viruses become vulnerable to cells of the immune system, which cause their death.

At different stages of CMV activity, different antibodies are formed. They belong to different classes. Immediately after the penetration or activation of “dormant” pathogens, class M antibodies begin to appear. They are designated IgM, where Ig is an immunoglobulin. IgM antibodies are an indicator of humoral immunity that protects the intercellular space. They allow you to capture and remove viruses from the bloodstream.

The concentration of IgM is highest at the beginning of the acute infectious process. If the activity of the viruses has been successfully suppressed, the IgM antibodies disappear. Cytomegalovirus IgM is detected in the blood for 5–6 weeks after infection. In the chronic form of the pathology, the amount of IgM antibodies decreases, but does not completely disappear. A small concentration of immunoglobulins can be detected in the blood for a long time until the process subsides.

After class M immunoglobulins, IgG antibodies are formed in the body. They help destroy pathogens. When the infection is completely defeated, immunoglobulins G remain in the bloodstream to prevent re-infection. During secondary infection, IgG antibodies quickly destroy pathogenic microorganisms, preventing the development of a pathological process.

In response to the invasion of a viral infection, class A immunoglobulins are also formed. They are found in various biological fluids (saliva, urine, bile, lacrimal, bronchial and gastrointestinal secretions) and protect the mucous membranes. IgA antibodies have a pronounced anti-adsorption effect. They prevent viruses from attaching to the surface of cells. IgA antibodies disappear from the bloodstream 2–8 weeks after the destruction of infectious agents.

The concentration of immunoglobulins of different classes makes it possible to determine the presence of an active process and evaluate its stage. An enzyme-linked immunosorbent assay (ELISA) is used to study the amount of antibodies.

Linked immunosorbent assay

The ELISA method is based on searching for the formed immune complex. The antigen-antibody reaction is detected using a special tag enzyme. After combining the antigen with the enzyme-labeled immune serum, a special substrate is added to the mixture. It is broken down by an enzyme and causes a color change in the reaction product. The intensity of the color is used to judge the number of bound antigen and antibody molecules. Features of ELISA diagnostics:

The results are assessed automatically using special equipment.
This minimizes the influence of the human factor and ensures error-free diagnosis.
ELISA is characterized by high sensitivity. It allows detection of antibodies even if their concentration in the sample is extremely low.

ELISA allows you to diagnose the disease already in the first days of development. It makes it possible to detect infection before the first symptoms appear.

How to decipher ELISA results

The presence of antibodies to CMV IgM in the blood indicates the activity of cytomegalovirus infection. If the amount of IgG antibodies is insignificant (negative result), primary infection has occurred. The normal cmv IgG is 0.5 IU/ml. If fewer immunoglobulins are detected, the result is considered negative.

In cases where, simultaneously with a high concentration of IgM antibodies, a significant amount of IgG is detected, an exacerbation of the disease is observed, and the process actively develops. These results indicate that the primary infection occurred a long time ago.

If IgG appears positive in the absence of IgM and IgA antibodies, there is no need to worry. The infection happened a long time ago, and a stable immunity to cytomegalovirus has developed. Therefore, re-infection will not cause serious pathology.

When the analysis shows negative indicators of all antibodies, the body is not familiar with cytomegalovirus and has not developed protection against it. In this case, a pregnant woman needs to be especially careful. The infection is very dangerous for her fetus. According to statistics, primary infection occurs in 0.7–4% of all pregnant women. Important points:

the simultaneous presence of two types of antibodies (IgM and IgA) is a sign of the height of the acute stage;
the absence or presence of IgG helps distinguish primary infection from relapse.

If IgA antibodies are detected, and class M immunoglobulins are absent, the process has become chronic. It may be accompanied by symptoms or occur hidden.

For a more accurate assessment of the dynamics of the pathological process, ELISA tests are performed 2 or more times every 1–2 weeks. If the amount of class M immunoglobulins decreases, the body successfully suppresses the viral infection. If the concentration of antibodies increases, the disease progresses.

It is also defined. Many people don't understand what this means. Avidity characterizes the strength of the binding of antibodies to antigens. The higher its percentage, the stronger the connection. At the initial stage of infection, weak bonds are formed. As the immune response develops, they become stronger. The high avidity of IgG antibodies allows one to completely exclude primary infection.

Features of evaluating ELISA results

When assessing test results, you need to pay attention to their quantitative significance. It is expressed in assessments: negative, weakly positive, positive or strongly positive.

Detection of antibodies to CMV class M and G can be interpreted as a sign of recent primary infection (no more than 3 months ago). Their low indicators will indicate the attenuation of the process. However, some strains of CMV are capable of causing a specific immune response, in which class M immunoglobulins can circulate in the blood for up to 1–2 years or longer.

An increase in the titer (number) of IgG to cytomegalovirus several times indicates a relapse. Therefore, before pregnancy, it is necessary to do a blood test to determine the level of immunoglobulins G in the latent (dormant) state of the infectious process. This indicator is important, since when the process is reactivated, in approximately 10% of cases IgM antibodies are not released. The absence of class M immunoglobulins is due to the formation of a secondary immune response, characterized by overproduction of specific IgG antibodies.

If the number of immunoglobulins G has increased before conception, there is a high probability of exacerbation of cytomegalovirus infection during pregnancy. In this case, you need to consult an infectious disease doctor to reduce the risk of relapse.

According to statistics, recurrent infection (reactivation) occurs in 13% of pregnant women. Sometimes secondary infection with other strains of CMV is observed.

If IgG is positive in a newborn, it follows that the baby was infected during fetal development, during childbirth, or immediately after birth. The presence of IgG antibodies can be passed on to the child from the mother. The greatest risk to the health and life of the baby is intrauterine infection.

The active stage of cytomegalovirus infection will be indicated by a several-fold increase in IgG titer in the results of 2 tests done at an interval of a month. If you start treating the disease during the first 3-4 months of a child’s life, the likelihood of developing serious pathologies will be significantly reduced.

Other methods for detecting CMV

In sick people with immunodeficiency, antibodies are not always detected. The absence of immunoglobulins is due to the weakness of the immune system, which is unable to form antibodies. Newborns, especially premature babies, are at risk.

For people with immunodeficiency conditions, cytomegalovirus infection is especially dangerous. To detect it in them, the polymerase chain reaction (PCR) method is used. It is based on the properties of special enzymes that detect the DNA of pathogens and repeatedly copy its fragments. Due to a significant increase in the concentration of DNA fragments, visual detection becomes possible. The method allows you to detect cytomegalovirus, even if only a few molecules of this infection are present in the collected material.

To determine the degree of activity of the pathological process, a quantitative PCR reaction is performed.

Cytomegalovirus can remain in an inactive state in various organs (in the cervix, on the mucous membrane of the throat, in the kidneys, salivary glands). If the analysis of a smear or scraping using the PCR method shows a positive result, it will not indicate the presence of an active process.

If it is detected in the blood, this means that the process is active or has recently stopped.

To make an accurate diagnosis, two methods are used simultaneously: ELISA and PCR.

A cytological examination of saliva and urine sediments may also be prescribed. The collected material is studied under a microscope to identify cells characteristic of cytomegalovirus infection.

During infection by the virus, they increase many times over. This reaction to infection gave another name to cytomegalovirus infection - cytomegaly. The altered cells look like an owl's eye. The enlarged core contains a round or oval inclusion with a strip-shaped light zone.

Warning signs

In order to detect cytomegalovirus infection in time, you need to pay attention to the presence of its characteristic symptoms.

The acute form of cytomegalovirus infection is accompanied by pain and sore throat in children and adults. The lymph nodes in the neck area become enlarged. A sick person becomes lethargic and drowsy, and loses ability to work. He develops a headache and cough. Body temperature may rise and the liver and spleen may enlarge. Sometimes a rash appears on the skin in the form of small red spots.

Infants with a congenital form of cytomegaly have an enlarged liver and spleen. Hydrocephalus, hemolytic anemia, or pneumonia may be present. If cytomegalovirus hepatitis develops, the child develops jaundice. His urine becomes dark and his stool becomes discolored. Sometimes the only sign of cytomegalovirus infection in a newborn is petechiae. They are round dotted spots of a rich red-purple color. Their size ranges from a dot to a pea. Petechiae cannot be felt because they do not protrude above the surface of the skin.

Disorders of the acts of swallowing and sucking appear. They are born with low body weight. Strabismus and muscle hypotonia are often detected, followed by increased muscle tone.

If such signs are observed against the background of a positive test result for IgG antibodies, you should immediately consult a doctor.

Type 5, which causes carriage in 99% of the world's population. For a healthy person, persistent infection does not have a negative effect on the body. Infection is dangerous for people with immunodeficiencies and poses a risk to fetal development. Serological laboratory diagnostics makes it possible to detect infection in the early stages of development and prevent the progression of the disease. Cytomegalovirus IgG is positive - one of the possible test results.

After the virus enters the body, the infection goes into a dormant (latent) state, in other words, carriage. The virus remains in the tissues of a recovering person throughout life and can be activated when the immune system is suppressed. Carriage does not cause harm to health - the vital activity of the virus occurs in a “sleeping” mode, virions do not multiply, do not release toxins, and do not destroy host cells.

During primary infection, the immune system produces specific antibodies that recognize foreign CMV antigens and destroy them. This is a protective reaction of the body aimed at maintaining homeostasis and fighting infection. Antibodies are called immunoglobulins. They come in different classes, which differ in the production time after infection and functional features.

Immunity in CMV

For the diagnosis of CMV, antibodies of class M and G are important, which are usually designated IgM and IgG, respectively. IgM are fast antibodies that are produced in the first days after infection enters the body. They bind to virus antigens and neutralize them. IgG is synthesized on days 10-14 of the disease, when the activity of the infectious process is suppressed by rapid antibodies. They perform the function of immunological memory; detection of IgG antibodies in the blood indicates the development of stable immunity against CMV.

To determine antibodies in peripheral blood, a serological laboratory test method is used - ELISA (enzyme-linked immunosorbent assay for short). Diagnostics allows you to obtain a quantitative and qualitative indicator of specific immunoglobulins, as well as determine the titer of the increase in antibodies in paired sera. The antibody titer is detected over time with an interval of biomaterial collection of 3-4 weeks. Using serology, the avidity of IgG is determined - the ability to bind to the virus. The avidity index indicates the time of infection. This information is especially important when diagnosing intrauterine infection of the fetus.

Blood is often used for analysis, but in some cases other biological fluids of the body (sputum, saliva, urine, cerebrospinal fluid) or scrapings (cervical canal, vagina, bronchi) are taken. Blood is taken on an empty stomach after abstaining from food for 6-8 hours. Before the examination, you must refrain from physical and mental stress, consuming fatty foods and alcoholic beverages. One hour before the procedure you should not smoke.

Indications for ELISA to assess IgG levels:

pregnancy planning;
high risk of intrauterine infection of the fetus;
signs of cytomegalovirus infection in newborns;
acquired and congenital immunodeficiency conditions (HIV/AIDS, taking cytostatics, chemotherapy, radiation therapy);
atypical pneumonia;
increased liver transaminases with a negative result for markers of viral hepatitis;
recurrent miscarriage, stillbirth;
prolonged low-grade fever;
enlarged spleen, liver;
clinical picture of infectious mononucleosis, not confirmed by the detection of the Epstein-Barr virus.

The qualitative result of the analysis can be “positive” or “negative”. The quantitative result contains the titer of IgG and IgM antibodies.

Possible ELISA result options

The ELISA results provide the attending physician with information about the stage of the disease, acquired immunity, the time of primary infection or exacerbation of the disease. According to the data received, the specialist makes decisions on the tactics of pregnancy and childbirth and selects the optimal course of therapy. In most clinical cases, infection or activation of infection does not require special treatment.

If IgG antibodies to cytomegalovirus are detected, what does this mean? This examination result is the most optimal for healthy people, pregnant women and patients with immunosuppression. It means that the body has strong immunity against infection and CMV is under control. However, there may be several options, and they all require an individual medical approach, especially for the risk group.

Option 1

IgM negative,IgG negative– the body does not have specific immunity to CMV, the immune system is not familiar with the virus. For women planning to conceive, pregnant women, and patients with immunodeficiencies, this result means the need for preventive measures to prevent primary infection. For healthy people there are no restrictions or dangers.

Option 2

IgM positive,IgG negative– primary infection with CMV. This condition poses a risk of intrauterine infection of the fetus if a woman is infected in the first trimester of pregnancy. During immunosuppressive therapy with cytostatics, chemotherapy, and radiation, primary infection worsens the prognosis of therapy for the underlying disease and can cause death.

Option 3

IgM positive,IgG positive– primary infection at the height of the disease or relapse of infection. In this case, there remains a danger both for the pregnant woman and for patients with immunosuppression. To clarify the stage of the infection and the time of infection (relapse), the antibody titer and avidity index are determined. The antibody titer is tested over time - ELISA analysis is prescribed at intervals of 3-4 weeks. If the titer is high or increasing, then the infection is in the acute phase. If the titer decreases over time, then the disease is in the recovery stage. IgG antibodies circulate in small quantities in the peripheral blood throughout life.

Option 4

IgM negative,IgG positive– persistent immunity to infection, latent course of CMV, carriage. The vast majority of people by the age of 40-50 will have such results recorded in serological tests.

IgG is positive for cytomegalovirus, but IgM antibodies are also detected, and avidity determination of class G immunoglobulins is prescribed. Based on the avidity level, the time of primary CMV infection can be calculated. This is important in the case of the formation of developmental defects.

The avidity indicator is high (more than 60%) – indicating infection more than 20 weeks ago. For a pregnant woman, this is a comforting result; intrauterine infection of the fetus either has not occurred or will not cause the formation of severe malformations or stillbirth.
The avidity indicator is average (40-60%) - a questionable result; it requires determining the antibody titer over time and monitoring the woman’s health.
The avidity indicator is low (less than 40%) - indicates a high risk of intrauterine infection of the fetus; due to infection in the first 12 weeks of pregnancy, spontaneous miscarriages are possible, the formation of defects of internal organs; infection in the 2nd and 3rd trimester is associated with the risk of deafness, blindness, and delay in the child mental development.

Intrauterine infection of the fetus does not always cause severe illness in the child. With normal function of the mother’s immune system, antibodies suppress the activity of the virus and prevent the formation of severe consequences.

When is treatment prescribed for CMV?

Detection of IgG to cytomegalovirus is not a reason to worry and prescribe antiviral treatment. To prevent exacerbation of infection, it is necessary to strengthen the immune system, lead a healthy lifestyle, and promptly treat chronic diseases. These measures are enough to keep the virus under control. In healthy people, primary infection or relapse of CMV is either asymptomatic, or the clinical picture is similar to acute respiratory infections.

Treatment of the disease is carried out in severe cases of infection, when the virus spreads throughout the body and affects internal organs: heart, liver, lungs, kidneys, brain. This is a generalized form of infection that occurs when the body’s defenses are suppressed. At risk are patients with congenital and acquired (HIV/AIDS) immunodeficiencies, as well as those taking immunosuppressants (cytostatics, radiation, chemotherapy).

Treatment is given to pregnant women with a high risk of intrauterine infection of the fetus, as well as infants with congenital cytomegalovirus infection. The course of therapy is determined by the attending physician according to the severity of the disease and the degree of immune suppression.

CMV therapy includes:

antiviral drugs (cidofovir, ginciclovir, forscanet) – suppress the reproduction of viruses, destroy virions, prevent the negative effect of infection on the body;
medications based on interferons (cycloferon, viferon, anaferon) - normalize the functioning of the immune system;
immunoglobulins (cytotect, megalotect) - antibodies that are obtained from the blood of people who have recovered from CMV, help inactivate the virus, improve the immune response to the introduction of infection into the body.

To eliminate the symptoms of the disease, antipyretic, painkillers, and anti-inflammatory drugs are prescribed.

The detection of a positive IgG result for cytomegalovirus infection in laboratory tests should not cause concern. On the contrary, this indicator indicates strong immunity to the virus. The immune system has coped with the infection and, despite its constant presence in the body, keeps it under control.

How to donate blood for CMV and the norms of IgG antibodies in healthy people and people with HIV

The presence of antibodies can only be detected through a blood test for CMV (serological techniques).

The essence of the methods is to examine the blood and search for antibodies in it.

The most common and informative method is ELISA.

When testing blood for CMV, a portion of the material being tested is treated with an already known enzyme.

Options for IgG tests in blood serum and their interpretation

In addition to simply a positive cytomegalovirus IgG, the results of a blood test for CMV may contain other data.

A qualified specialist can decipher it:

Anti-CMV IgM+, Anti-CMV IgG- signals the presence of specific antibodies and that the course of the disease is acute. It is possible that the infection occurred relatively recently.
Anti-CMV IgM-, Anti-CMV IgG+ indicates an inactive form of the pathology. The infection occurred a long time ago, the body has already developed a stable immunity.
Anti-CMV IgM-, Anti-CMV IgG- indicates a lack of immunity to CMV. The pathogen has never penetrated before.
Anti-CMV IgM+, Anti-CMV IgG+ indicates reactivation of the virus, exacerbation of the infectious process.
An avidity value not exceeding 50% indicates a primary infection.
An avidity value of more than 60% indicates immunity to the virus, carriage, or latent form of infection.
An avidity of 50-60 indicates an ambiguous result. That is why the blood is tested for CMV again.
An avidity value of 0 indicates excellent health.

Norm of antibodies to CMV

As previously mentioned, the amount of antibodies to CMV is expressed in titers. There is no standard, as such, for the titer value, since the concentration of antibodies may vary. The variation in their concentration is due to the state of the immune system, metabolism, lifestyle, and the presence of chronic diseases. To date, many laboratory methods for DNA research have been developed to facilitate the detection of antibodies to CMV.

If you have a strong immune system and test positive for CMV, relax. In completely healthy people, a positive result is, in principle, normal. Whatever the form of the disease, with a strong immune system it will be asymptomatic. The maximum that can occur is a sore throat, weakness and a slight increase in temperature.

Antibody norms in HIV patients

The virus is most dangerous for people suffering from immunodeficiency. In people with HIV, IgG+ may indicate damage to various organs and the development of serious complications of infection: jaundice, hepatitis, pneumonia, gastrointestinal pathologies (inflammation, exacerbation of ulcers, enteritis), encephalitis, retinitis. It is worth recalling that HIV infection can occur through any biological fluid: vaginal discharge, blood, urine, saliva. Often infection occurs through sexual contact. It is also possible to become infected during a blood transfusion.

Antibodies to cytomegalovirus IgG positive in pregnancy and children

Antibodies to cytomegalovirus IgG positive in women carrying a fetus, detected at the very beginning, signal that the fetus is not at risk of infection. In addition, the baby will be completely protected for some period.

But a similar result in the third trimester requires evaluation in combination with other antibodies. So, for example, antibodies to cytomegalovirus IgG positive and IgM+ signal an advanced primary infection. The risk of infection of the fetus, as well as the appearance of disturbances in the formation of organs and systems in this case, is high. A positive result of antibodies to CMV IgG and IgM is negative, indicating that CMV has been overcome and the body has already developed immunity.

The baby is not in danger of developing the disease. You should know that research (PCR - polymerase chain reaction and ELISA - enzyme-linked immunosorbent assay) is necessary in the first weeks of gestation. Such diagnostics will be of high quality; you can find out the exact avidity index and markers of infection. In addition, the doctor will have the opportunity to select treatment tactics and monitor dynamics.

As for the positive result of antibodies to cytomegalovirus IgG in children, it indicates a strong, stable immunity to this virus. It is likely that some minor disease was the primary CMV infection. You should be afraid only when the baby is undergoing therapy associated with the suppression of the body's defenses. In this case, reactivation of the infection with the development of serious consequences is possible. Doctors who are preparing a child for serious therapy take this into account.

Viruses of the herpes group accompany a person throughout his life. The degree of their danger is directly related to the level of immunity - depending on this indicator, the infection can remain dormant or provoke serious diseases. All this fully applies to cytomegalovirus (CMV). If a blood test shows the presence of IgG antibodies to a given pathogen, this is not a reason to panic, but important information for maintaining health in the future.

Cytomegalovirus belongs to the herpesvirus family, otherwise known as human herpes virus type 5. Once it enters the body, it remains in it forever - there is currently no way to get rid of infectious pathogens of this group without a trace.

It is transmitted through body fluids - saliva, blood, semen, vaginal secretions, so infection is possible:

by airborne droplets;
when kissing;
sexual contact;
using shared utensils and hygiene items.

In addition, the virus is transmitted from mother to child during gestation (then we can talk about a congenital form of cytomegalovirus infection), during childbirth or through breast milk.

The disease is widespread - according to research, by the age of 50 years, 90-100% of people are carriers of cytomegalovirus. Primary infection, as a rule, is asymptomatic, but with a sharp weakening of the immune system, the infection becomes more active and can cause pathologies of varying severity.

Once in the cells of the human body, cytomegalovirus disrupts their division processes, leading to the formation of cytomegaloviruses - huge cells. The disease can affect various organs and systems, manifesting itself in the form of atypical pneumonia, cystitis and urethritis, inflammation of the retina, and diseases of the digestive system. Most often, the external symptoms of infection or relapse resemble seasonal colds - acute respiratory infections or acute respiratory viral infections (accompanied by fever, muscle pain, runny nose).

Primary contact with is considered the most dangerous. This can lead to intrauterine infection of the fetus and provoke pronounced deviations in its development.

Cytomegalovirus: pathogen, transmission routes, carriage, re-infection

Diagnostics

Most carriers of cytomegalovirus are not aware of its presence in the body. But if it is not possible to identify the cause of a disease, and treatment does not produce results, tests for CMV are prescribed (antibodies in the blood, DNA in a smear, cytology, etc.). Testing for cytomegalovirus infection is mandatory for pregnant women or women planning to conceive, and for people with immunodeficiency conditions. For them, the virus poses a serious danger.

There are several research methods that are successfully used to diagnose CMV infection. For a more accurate result, it is advisable to use them in combination. Since the pathogen is contained in body fluids, blood, saliva, urine, vaginal secretions and even breast milk can be used as biological material.

Cytomegalovirus in a smear is detected using PCR analysis - polymerase chain reaction. The method makes it possible to detect the DNA of an infectious agent in any biomaterial. A smear for CMV does not necessarily include discharge from the genital organs, it can be a sample of sputum, discharge from the nasopharynx, or saliva. If cytomegalovirus is detected in a smear, this may indicate either a latent or an active form of the disease. In addition, the PCR method does not make it possible to determine whether the infection is primary or whether it is a recurrent infection.

If cytomegalovirus DNA is detected in samples, additional tests may be ordered to clarify the status. A test for specific immunoglobulins in the blood helps clarify the clinical picture.

Most often, ELISA is used for diagnosis - enzyme-linked immunosorbent assay, or CHLA - chemiluminescence immunoassay. These methods determine the presence of the virus due to the presence of special proteins in the blood - antibodies, or immunoglobulins.

Diagnosis of cytomegalovirus: research methods. Differential diagnosis of cytomegalovirus

Types of antibodies

To fight the virus, the human immune system produces several types of protective proteins that differ in the timing of their appearance, structure and functions. In medicine they are designated by a special letter code. The common part in their names is Ig, which stands for Immunoglobulin, and the last letter indicates a specific class. Antibodies that detect and classify cytomegalovirus: IgG, IgM and IgA.

IgM

The largest immunoglobulins in size, the “rapid response group”. During primary infection or when a “dormant” cytomegalovirus is activated in the body, IgM is produced first. They have the ability to detect and destroy the virus in the blood and intercellular space.

The presence and amount of IgM in a blood test is an important indicator. Their concentration is highest at the beginning of the disease, in the acute phase. Then, if viral activity can be suppressed, the titer of class M immunoglobulins gradually decreases, and after about 1.5 - 3 months they completely disappear. If a low concentration of IgM remains in the blood for a long time, this indicates chronic inflammation.

Thus, a high IgM titer indicates the presence of an active pathological process (recent infection or exacerbation of CMV), a low titer indicates the final stage of the disease or its chronic course. If negative, this indicates a latent form of infection or its absence in the body.

IgG

Class G antibodies appear in the blood later - 10-14 days after infection. They also have the ability to bind and destroy viral agents, but unlike IgM, they continue to be produced in the body of an infected person throughout life. They are usually coded "Anti-cmv-IgG" in test results.

IgG “remembers” the structure of the virus, and when pathogens re-enter the body, they quickly destroy them. Therefore, it is almost impossible to become infected with cytomegalovirus a second time; the only danger is a recurrence of a “dormant” infection with a decrease in immunity.

If the test for IgG antibodies to cytomegalovirus is positive, the body is already “familiar” with this infection and has developed lifelong immunity to it.

IgA

Since the virus mainly attaches and multiplies on the mucous membranes, the body produces special antibodies - IgA - to protect them. Like IgM, they cease to be produced soon after the activity of the virus is suppressed, and 1-2 months after the end of the acute stage of the disease they are no longer detected in blood tests.

The combination of IgM and IgG class antibodies in the test results is of fundamental importance for diagnosing the status of cytomegalovirus.

Avidity of immunoglobulins

Another important characteristic of IgG antibodies is avidity. This indicator is measured as a percentage and indicates the strength of the bond between the antibody (immunoglobulin) and the antigen - the causative virus. The higher the value, the more effectively the immune system fights the infectious agent.

The level of IgG avidity is quite low during primary infection; it increases with each subsequent activation of the virus in the body. Testing antibodies for avidity helps distinguish primary infection from recurrent disease. This information is important for prescribing adequate therapy.

Cytomegalovirus Igg and Igm. ELISA and PCR for cytomegalovirus, avidity for cytomegalovirus

What does positive IgG mean?

A positive test result for IgG to CMV means that the person has already been infected with cytomegalovirus before and has long-term, stable immunity to it. This indicator does not indicate a serious threat and the need for urgent treatment. The “sleeping” virus is not dangerous and does not interfere with leading a normal lifestyle - most of humanity coexists safely with it.

Exceptions are weakened people, those with immunodeficiency conditions, cancer patients and cancer survivors, and pregnant women. For these categories of patients, the presence of the virus in the body can pose a threat.

IgG to cytomegalovirus positive

High titer of IgG in the blood

In addition to the data whether IgG is positive or negative, the analysis indicates the so-called titer of immunoglobulins of each type. This is not the result of a “piecemeal” calculation, but rather a coefficient that gives an idea of the activity of the immune response. Quantitative determination of antibody concentration is carried out by repeated dilution of blood serum. The titer shows the maximum dilution factor at which the sample remains positive.

The value may vary depending on the reagents used and the characteristics of the laboratory test. If the Anti-cmv IgG titer is significantly increased, this may be caused by either reactivation of the virus or a number of other reasons. A more accurate diagnosis will require a number of additional tests.

A titer that goes beyond the reference values does not always indicate a threat. To determine whether there is a need for urgent treatment, it is necessary to consider the data from all studies as a whole; in some cases, it is better to do the analysis again. The reason is the high toxicity of antiviral drugs that are used to suppress the activity of cytomegalovirus.

The infection status can be more accurately diagnosed by comparing the presence of IgG with the presence and amount of “primary” antibodies in the blood - IgM. Based on this combination, as well as the immunoglobulin avidity index, the doctor will make an accurate diagnosis and give recommendations for the treatment or prevention of cytomegalovirus infection. The decoding instructions will help you independently evaluate the test results.

Decoding the analysis results

If antibodies to cytomegalovirus are detected in the blood, it means there is an infection in the body. The interpretation of the examination results and the prescription of therapy (if necessary) should be entrusted to the attending physician, however, to understand the processes occurring in the body, you can use the following diagram:

Anti-CMV IgM negative, Anti-CMV IgG negative: the absence of immunoglobulins shows that the person has never been infected with cytomegalovirus, and he has no immunity to this infection.
Anti-CMV IgM positive, Anti-CMV IgG negative: this combination indicates recent infection and an acute form of the disease. At this time, the body is already actively fighting the infection, but the production of IgG immunoglobulins with “long-term memory” has not yet begun.
Anti-CMV IgM negative, Anti-CMV IgG positive: in this case we can talk about a hidden, inactive infection. The infection occurred a long time ago, the acute phase has passed, and the carrier has developed a strong immunity to cytomegalovirus.
Anti-CMV IgM positive, Anti-CMV IgG positive: indicators indicate either a relapse of infection against the background of favorable conditions, or a recent infection and the acute stage of the disease - during this period, primary antibodies to cytomegalovirus have not yet disappeared, and IgG immunoglobulins have already begun to be produced. The number of antibodies (titers) and additional studies will help the doctor understand more accurately.

There are many nuances in assessing ELISA results that only a specialist can understand. Therefore, in no case should you diagnose yourself; you should entrust the explanation and prescription of therapy to a doctor.

What to do if IgG to CMV is positive

The answer to this question depends on several factors. IgG antibodies to cytomegalovirus found in the blood indicate a previous infection with CMV infection. To determine the algorithm for further actions, it is necessary to consider the diagnostic results as a whole.

Cytomegalovirus detected - what to do?

If the totality of data obtained during the examination indicates the active phase of the disease, the doctor will prescribe a special course of treatment. Since it is impossible to completely get rid of the virus, therapy has the following goals:

protect internal organs and systems from damage;
shorten the acute phase of the disease;
if possible, strengthen the body's immune response;
reduce the activity of infection, achieve stable long-term remission;
prevent the development of complications.

The choice of methods and drugs is based on the individual clinical picture and characteristics of the body.

If the cytomegalovirus is in a hidden, latent state (only IgG is found in the blood), then it is enough to monitor your health and maintain immunity. The recommendations in this case are traditional:

complete healthy nutrition;
rejection of bad habits;
timely treatment of emerging diseases;
physical activity, hardening;
refusal of unprotected sexual intercourse.

The same preventive measures are relevant if no antibodies to CMV have been detected, that is, the primary infection has not yet occurred. Then, when the virus enters the body, the immune system will be able to suppress the development of infection and prevent serious illnesses.

A positive test result for antibodies to cytomegalovirus IgG is not a death sentence; the presence of a latent infection in a healthy adult does not affect the quality of life. However, in order to prevent the activation of the virus and the development of complications, it is necessary to make efforts to maintain physical health - avoid overwork and stress, eat rationally and maintain a high level of immunity. In this case, the body’s own defenses will suppress the activity of the cytomegalovirus, and it will not be able to harm the carrier.