Cytomegalovirus igg meanings. Cytomegalovirus CMV iG positive: what does it mean

Cytomegalovirus is a common infectious disease. According to statistics, more than 80% of the population encounters it during their lifetime. An Anti CMV IgG test helps determine the presence of the disease, as well as the stage of its progression.

CMV and its prevalence

Cytomegalovirus is a member of the herpesvirus family. Has great incubation period- about 2 months. During this time, the disease may not manifest itself in any way.

Refers to opportunistic infections - symptoms of infection appear only when sharp decline immunity.

The virus is highly invasive. It is especially dangerous for pregnant women, as in advanced cases it can cause fetal pathology.

Transmission options for cytomegalovirus:

It is impossible to diagnose the disease based only on symptoms. Often the first manifestations of infection are similar to the symptoms colds. To accurately determine the virus, a method is used to detect antibodies in blood serum.

What is Anti CMV IgG?

The disease may not manifest itself in any way throughout a person’s life. However, the immune system of the infected person certainly produces specific antibodies to this virus. They can be detected in the patient’s blood even several years after infection.

The tests carried out are aimed at identifying immunoglobulins (proteins responsible for the immune response) of two types:

• Class M (Anti CMV IgM). They provide the primary immune response during infection.
• Class G (Anti CMV IgG). Specific immunoglobulins formed in response to specific pathogen. They have immune memory. When re-infected, they are produced in larger quantities, providing protection against infection.

The presence of class M immunoglobulins in the blood serum indicates primary infection with the virus and the acute course of the infection. The presence of class G can be interpreted in different ways. They can be like residual phenomenon after an outbreak of the disease, and a sign of secondary infection.

Avidity is the basic concept necessary for diagnosing CMV!

Avidity is the ability of specific antibodies to form bonds with the CMV antigen, neutralizing its pathogenic effect. The avidity index (AI) indicates how strong the resulting connections are and directly characterizes the strength of the body's immune response. It is the Anti CMV IgG AI that is crucial for the diagnosis of cytomegalovirus.

Interpretation of analysis results

To diagnose CMV, a chemiluminescence immunoassay, or chemiluminescence test, is used. The patient's urine or deoxygenated blood. The analysis demonstrates the presence of specific antibodies in the blood, allows you to determine the stage of the disease and predict its further course. The accuracy of this method is more than 90%.

If it turns out that Anti CMV IgM or Anti CMV IgG is elevated, the following tables will help determine what this means:

If primary immunoglobulins are present in the blood, the following diagnostic results are possible:

It must be remembered that quantitative indicators are not of great importance if the serum was taken once.

A significant amount of antibodies is diagnosed at a titer of 1:100. But laboratory reagents have varying degrees sensitivity, so the decoding result may be different.

Consequences for the body

A small amount of antibodies to cytomegalovirus in the blood is normal. However, if a high avidity index is detected, it is necessary to undergo full course treatment. This is especially important for men and women planning to have a child.

The herpes virus is one of those pathogens that may not manifest itself long time, but they are occasionally activated, causing a full-fledged disease. A total of 8 types of this virus have been identified, the most common of which are: herpes simplex (), (varicella zoster), viruses and roseola. Medicine is not yet able to completely rid the body of herpes, but it is possible to suppress the acute form or relapse by transferring it to a latent state.

Your own immunity plays a key role in fighting the virus. In response to infection, the immune system produces specific proteins - antibodies to the herpes virus (immunoglobulins). In the absence of infection, antibodies are not detected; their presence always indicates the presence of a virus.

Indications for analysis

The analysis is prescribed in cases of visible external manifestations of infection or if infection is suspected. hidden form. Detection of immunoglobulins in the blood allows us to confirm the presence of herpes in the body and determine its type. Once infection has been established, treatment is prescribed to suppress the activity of the virus.

The test for antibodies to herpes is included in the diagnostic program for TORCH infections, which women undergo when planning pregnancy and during pregnancy. Diagnosis for the presence of herpes is also prescribed for HIV-infected patients. This examination is also important before organ transplantation.

What does positive IgG for herpes mean?

Among viral herpes infections, the most common is herpes simplex - HSV (HSV - Herpes Simplex Virus, herpes simplex). There are two types: HSV-1, which affects the mouth area, and HSV-2, which is characterized by manifestations in the genital area (genital herpes).

Immunoglobulins are divided into 5 classes: IgM, IgG, IgA, IgE, IgD. Each class has its own characteristics for diagnosis; IgM and IgG are most often studied.

IgM antibodies are a marker of primary viral infection, and IgG can be detected several days after infection and during the latent period. The level of immunoglobulins below normal means a negative result, or seronegativity, increased content ( high titer) antibodies – positive, or seropositivity.

The unit of measurement is the ratio of the optical density of the material under study to the critical optical density - OPiss/OPcr; reference values ​​are indicated on the form. Some laboratories are limited to the answer “positive” or “negative”.

To decipher the analysis data, it is necessary to compare two classes of antibodies - M and G. Positive IgG with negative IgM means that the body is under immune protection, the primary infection is suppressed, and the possibility of reactivation depends on additional factors. If antibodies M and G are positive, there is a relapse.

During pregnancy

Testing for HSV is of great importance for women during pregnancy. A positive test result for antibodies to herpes G together with M means a threat: from the risk of miscarriage to intrauterine infection with negative impact on fetal development and newborn health. There is a risk of infection of the child during childbirth.

In children

Positive IgG to the herpes virus is rare in newborns. Infection most often occurs during the perinatal period (approximately 85% of cases). The greatest danger is posed by primary infection and severe progression of the disease in pregnant women. Asymptomatic detection of HSV in the mother has minimal risk to the fetus.

Primary infection in a child manifests itself as a herpetic rash on the body, lasting no more than 2 weeks. Approximately 30% of newborns infected with HSV in utero develop encephalitis.

What is herpes avidity?

Testing for antibodies to the herpes simplex virus does not provide high reliability in differentiating between primary infection and exacerbation. Since treatment regimens for primary and chronic infections differ, it is recommended to conduct an additional study - an antibody avidity test, which allows obtaining retrospective information about the virus.

Avidity of antibodies to herpes is the strength of the bond between immunoglobulin and a foreign substance (virus). A small presence of antigens causes an increase in avidity faster than a large one. The first stages of infection are characterized by high content antigens, therefore, during this period, predominantly low-avidity immunoglobulins are produced; their detection indicates a primary acute infection. The presence of high-avidity IgG antibodies in the blood indicates that immunity to the virus exists and provides a response to secondary infection in the body.

In diagnostics, the avidity index is used, which allows combining low-avid and high-avid antibodies into one indicator.

If the cytomegalovirus IgG test is positive, many people become concerned. They believe that this indicates a hidden serious illness which needs to be treated immediately. However, the presence of IgG antibodies in the blood is not a sign developing pathology. The vast majority of people become infected with cytomegalovirus childhood and they don't 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 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 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:

1. In childhood, the infection is transmitted by airborne droplets.
2. Adults become infected mainly through sexual contact.
3. After the initial invasion, herpes viruses settle permanently in the body. It is impossible to get rid of them.
4. 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 development serious illnesses. 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.

Relapse poses a significantly less threat to the embryo cytomegalovirus infection. 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 pathological process in the body are 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.

On different stages CMV activity produces different antibodies. 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 humoral immunity, protecting 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:

1. The results are assessed automatically using special equipment.
2. This minimizes the influence of the human factor and ensures error-free diagnosis.
3. 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 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 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. On initial stage 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 treatment for the disease is started during the first 3–4 months of a child’s life, the likelihood of developing serious pathologies will decrease significantly.

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 persist in non- active state in different 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 PCR method will show 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.

It may also be prescribed cytological examination sediments of saliva and urine. The collected material is examined 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 may be detected hemolytic anemia or pneumonia. 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 found, alternating increased tone muscles.

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

Cytomegalovirus is a virus belonging to the herpesvirus family. This virus has a high prevalence in the human population.

Ten to fifteen percent of adolescents and forty percent of adults have antibodies to cytomegalovirus in their blood.

The incubation period is quite long - up to two months. During this period, the disease is always asymptomatic. Then a pronounced manifest beginning. Which is provoked by stress, hypothermia, or simply reduced immunity.

The symptoms are very similar to acute respiratory infections or acute respiratory viral infections. The body temperature rises, the head hurts severely, and general discomfort occurs. An untreated virus can result in inflammation of the lungs and joints, brain damage, or other dangerous diseases. The infection remains in the body throughout a person's life.

The year the virus was discovered is 1956. It is still being actively studied, its action and manifestations. Every year brings new knowledge.

The contagiousness of the virus is low.

Routes of transmission: sexual, household contact (through kisses and saliva), from mother to child, through blood products.

Infected people are usually asymptomatic. But sometimes, in those who suffer from poor immunity, the disease manifests itself as a mononucleosis-like syndrome.

It is characterized by increased body temperature, feelings of chills, fatigue and general malaise, and severe pain in the head. Mononucleosis-like syndrome has a happy ending - recovery.

There is a particular danger for two categories of people - those with weak immunity and infants infected in utero from a sick mother.

An increase in the titer of antibodies in the blood to cytomegalovirus by four times or even more indicates activation of cytomegalovirus.

What does cytomegalovirus IgG positive mean?

At positive decoding analysis to determine IgG antibodies to cytomegalovirus infection, what is the conclusion?

The human immune system successfully coped with cytomegalovirus infection about a month ago, or even more.

This organism has developed a lifelong, stable immunity. About 90% of people are carriers, so there is no norm of antibodies to this virus. There is also no concept of increased or decreased level.

Determination of antibodies to cytomegalovirus is only necessary to establish the correct diagnosis.

Cytomegalovirus infection is considered to be the presence of a virus in a PCR analysis, when material containing certain DNA is examined.

From the tenth to fourteenth day after infection, IgG antibodies to cytomegalovirus infection appear in the blood. Antibodies easily pass through the placenta. Therefore, newborns are not always infected; it may be the mother's immunoglobulins.

The level of immunoglobulin in the blood is checked after three weeks to clarify the diagnosis and the severity of the process. The process is considered active if the level of immunoglobulins increases.

Cytomegalovirus in children

Cytomegalovirus infection is very similar to herpes infection. And it happens often too.

Even if the infection occurred in early childhood, but a person has good strong immunity all his life, then a cytomegalovirus infection may never manifest itself. A person is only a virus carrier all his life.

There are children who suffer greatly from cytomegalovirus:

• those exposed to intrauterine infection, since the placental barrier is not an obstacle to cytomegalovirus;
• newborns with weak and unstable immunity;
• at any age, with a severely weakened immune system, or, for example, in patients with AIDS.

Infection is most often diagnosed using ELISA ( enzyme immunoassay). This method can determine not only the presence of cytomegalovirus infection in the child’s body. But it’s also possible to say for sure whether it is congenital or acquired.

For newborns, cytomegalovirus is infectious mononucleosis. Affected lymphatic system – The lymph nodes the tonsils become inflamed, the liver and spleen become enlarged, and it becomes difficult to breathe.

Besides, congenital infection characterized by:

• prematurity;
• squint;
• jaundice of newborns;
• disorders of swallowing and sucking reflexes.

Poor nasal breathing can cause the following symptoms:

• loss of appetite and weight loss;
• sleep disorders;
• crying and worrying.

Congenital infection of a child most often occurs in utero. But sometimes through the mother's birth canal or breast milk during feeding.

Most often, a very dangerous asymptomatic course of cytomegalovirus infection is observed. Even two months after being born into this world.

For such children, complications are possible:

• 20% of children with asymptomatic, actively occurring cytomegalovirus after months are characterized by the presence of severe convulsions, abnormal movements of the limbs, changes in the bones (for example, in the skull), and insufficient body weight;
• after five years, 50% have speech impairment, intellect suffers, and the cardiovascular system and vision suffers greatly.

If a child becomes infected at a later time, and not during the neonatal period, when the immune system is already well formed, then there are practically no consequences.

Most often, it is asymptomatic or reminiscent of classic childhood ARVI.

Characterized by:

• lethargy and drowsiness;
• cervical lymphadenitis;
• pain in the musculoskeletal system (muscles and joints);
• chills and low-grade fever.

This lasts two weeks – two months. Ends with self-healing. Very rarely, if the disease does not go away for two to three months, medical consultation and treatment is necessary.

Most early diagnosis cytomegalovirus infection and timely treatment, significantly reduce the risk of complications. It is best to start treatment within seven to nine days after infection. Then the cytomegalovirus infection will not leave a trace.

Cytomegalovirus in women

Cytomegalovirus infection in females occurs in a chronic form. Most often this is asymptomatic, but sometimes symptoms are present. A weak immune system contributes to the active manifestation of the disease.

Unfortunately, cytomegalovirus infection affects women at any age. Provoking factors are cancer, HIV infection or AIDS, and gastrointestinal pathologies. Another similar effect is observed from taking antitumor drugs and antidepressants.

In its acute form, the infection is characterized by damage to the cervical lymph nodes.

Then there is an increase in the submandibular, axillary and inguinal lymph nodes. As I already said, this clinical picture is similar to infectious mononucleosis. It is characterized by headache, general poor health, hepatomegaly, and atypical mononuclear cells in the blood.

Immunodeficiency (for example, HIV infection) causes a severe, generalized form of cytomegalovirus infection. Internal organs, blood vessels, nerves and salivary glands. Cytomegalovirus hepatitis, pneumonia, retinitis and sialadenitis occur.

Nine out of ten women with AIDS have cytomegalovirus infection. They are characterized by bilateral pneumonia and encephalitis.

Encephalitis is characterized by dementia and memory loss.

Women with AIDS and cytomegalovirus suffer from polyradiculopathy. Such women are characterized by damage to the kidneys, liver, pancreas, eyes and MPS organs.

Cytomegalovirus during pregnancy

An infection that comes from a person who has acute form diseases, the worst option for pregnant women.

There are still no antibodies in the pregnant woman's blood.

The active virus of an infecting person passes through all barriers without difficulty and has a detrimental effect on the child. According to statistics, this happens in half of infections.

If factors that weaken the immune system aggravate latent virus carriage, then this is a less dangerous situation.

There are already immunoglobulins (IgG) in the blood, the virus is weakened and not so active. The virus is dangerous by infecting the fetus in only two percent of cases. Early pregnancy is more dangerous in terms of infection. Pregnancy often ends in spontaneous miscarriage. Or the fetus develops abnormally.

Infection with cytomegalovirus infection for more than later pregnancy leads to polyhydramnios or premature birth (“congenital cytomegaly”). Unfortunately, it is impossible to completely destroy cytomegalovirus in the body. But you can make it inactive. Therefore, pregnant women and those planning to become pregnant should be especially careful about their health. Cytomegalovirus is very dangerous for the fetus.

Cytomegalovirus IgM positive

IgM is the first protective barrier against all kinds of viruses. They do not have a specification, but they are produced urgently, as a response to the penetration of cytomegalovirus infection into the body.

An IgM test is carried out to determine:

• primary infection by the virus (maximum antibody titer);
• stages of aggravated cytomegalovirus (the number of the virus is growing and the number of IgM is growing);
• reinfection (a new strain of cytomegalovirus has caused infection).

Later, from IgM, specific antibodies, IgG, are formed. If the strength of the immune system does not decrease, then IgG will fight cytomegalovirus all their lives. The IgG antibody titer is highly specific. From it you can determine the specification of the virus. Despite the fact that an IgM test shows the presence of any virus in the material being tested.

The number of cytomegalovirus is subject to control by immunoglobulin G, preventing the development of a picture of an acute disease.

If the results are “IgM positive” and “IgG negative”, this indicates an acute recent infection and the absence of permanent immunity against CMV. Aggravation chronic infection indicators are characteristic when IgG and IgM are present in the blood. The body is in a stage of serious deterioration of immunity.

There has already been infection in the past (IgG), but the body cannot cope, and nonspecific IgM appears.

The presence of positive IgG and negative IgM is the best test result for a pregnant woman. She has specific immunity, which means the child will not get sick.

If the situation is reversed, with positive IgM and negative IgG, then this is also not scary. This indicates a secondary infection that is being fought in the body, which means there should be no complications.

It’s worse if there are no antibodies at all, of both classes. This indicates a special situation. Although this situation is very rare.

IN modern society Almost all women are infected with the infection.

Treatment of cytomegalovirus and treatment results

If a person has a healthy immune system, then he can cope with cytomegalovirus infection on his own. You don't have to carry out any therapeutic actions. Immunity will only be weakened if treated for a cytomegalovirus infection that does not manifest itself. Drug treatment necessary only when immune defense does not cope and the infection actively intensifies.

Pregnant women also do not need treatment if they have specific IgG antibodies in their blood.

If the test for IgM is positive, for transfer acute condition during the latent course of the disease. It must always be remembered that medicines from cytomegalovirus infection have many side effects. Therefore, they can only be prescribed knowledgeable specialist, self-medication should be avoided.

The active stage of infection is the presence of positive IgM. It is necessary to take into account other test results. It is especially necessary to monitor the presence of antibodies in the body for pregnant and immunodeficient people.

Cytomegalovirus (abbreviated CMV or CMV) is a causative agent of an infectious disease belonging to the herpesvirus family. Once it enters the human body, it remains there forever. Antibodies produced by the immune system in response to the penetration of the virus are the main diagnostic sign for detecting infection.

Cytomegalovirus infection can be asymptomatic or with multiple lesions internal organs and systems. In damaged tissues, normal cells turn into giant ones, which is why this disease got its name (cytomegaly: from the Greek cytos - “cell”, megalos - “big”).

In the active stage of infection, cytomegaloviruses cause significant changes in the immune system:

• dysfunction of macrophages that destroy bacteria and viruses;
• suppression of the production of interleukins that regulate the activity of immune cells;
• inhibition of the synthesis of interferon, which provides antiviral immunity.

Antibodies to cytomegalovirus, determined using laboratory methods, serve as the main markers of CMV. Their detection in blood serum makes it possible to diagnose the disease at early stages and also monitor the course of the disease.

Types of antibodies to CMV and their features

When foreign bodies enter the body, a response occurs from the immune system. Special proteins are produced - antibodies, which contribute to the development of protective inflammatory reactions.

Highlight the following types antibodies to CMV, differing in structure and role in the formation of immunity:

• IgA, the main function of which is to protect the mucous membranes from infections. They are found in saliva, tear fluid, breast milk, and are also present on the mucous membranes of the gastrointestinal tract, respiratory tract and genitourinary tract. Antibodies of this type bind to microbes and prevent them from adhering to and penetrating the body through the epithelium. Immunoglobulins circulating in the blood provide local immunity. Their lifespan is only a few days, so periodic examination is necessary.
• IgG, making up the bulk of antibodies in human serum. They can be transmitted from a pregnant woman to the fetus through the placenta, ensuring the formation of its passive immunity.
• IgM, which are the largest type of antibodies. They occur during primary infection in response to the penetration of previously unknown foreign substances. Their main function is receptor function - transmitting a signal into the cell when a molecule of a certain chemical substance is attached to the antibody.

By the ratio of IgG and IgM, it is possible to determine at what stage the disease is - acute (primary infection), latent (latent) or active (reactivation of a “dormant” infection in its carrier).

If infection occurs for the first time, then the amount of IgM, IgA and IgG antibodies increases rapidly during the first 2-3 weeks.

From the second month from the onset of infection, their level begins to decline. IgM and IgA can be detected in the body within 6-12 weeks. These types of antibodies are taken into account not only for the diagnosis of CMV, but also for the detection of other infections.

igg antibodies

IgG antibodies are produced by the body late stage, sometimes only 1 month after infection, but they persist throughout life, providing lifelong immunity. If there is a risk of re-infection with another strain of the virus, their production increases sharply.

Upon contact with the same culture of microorganisms, the formation protective immunity occurs in a shorter time - up to 1-2 weeks. A feature of cytomegalovirus infection is that the pathogen can evade the action of immune forces by creating other varieties of the virus. Therefore, infection with modified microbes proceeds as during primary contact.

Antibodies to cytomegalovirus. Photo courtesy of igg Antibodies.

However, the human body also produces group-specific immunoglobulins, which prevent their active reproduction. Antibodies to class G cytomegalovirus are more often detected among the urban population. This is due to the high concentration of people in small areas and weaker immunity than that of rural residents.

In families with low level In life, CMV infection among children is observed in 40-60% of cases even before they reach 5 years of age, and by adulthood, antibodies are detected in 80%.

Antibodies igm

IgM antibodies act as the first line of defense. Immediately after the introduction of microorganisms into the body, their concentration increases sharply, and its peak is observed in the interval from 1 to 4 weeks. Therefore, they serve as a marker of recent infection, or the acute stage of CMV infection. In blood serum they persist for up to 20 weeks, in rare cases – up to 3 months or more.

The latter phenomenon is observed in patients with impaired immunity. A decrease in IgM levels in subsequent months occurs even if no treatment is given. However, their absence is not a sufficient basis for a negative result, since the infection can occur in a chronic form. During reactivation they also appear, but in smaller quantities.

IgA

IgA antibodies are detected in the blood 1-2 weeks after infection. If treatment is carried out and it is effective, then their level decreases after 2-4 months. With repeated infection with CMV, their level also increases. A consistently high concentration of antibodies of this class is a sign chronic form diseases.

In people with weakened immune systems, IgM is not formed even in the acute phase. For such patients, as well as for those who have undergone organ transplantation, a positive IgA test result helps to recognize the form of the disease.

Avidity of immunoglobulins

Avidity refers to the ability of antibodies to bind to viruses. In the initial period of the disease it is minimal, but gradually increases and reaches a maximum by 2-3 weeks. During the immune response, immunoglobulins evolve, the efficiency of their binding increases, due to which the “neutralization” of microorganisms occurs.

Laboratory diagnostics of this parameter are performed to estimate the time of infection. Thus, acute infection is characterized by the detection of IgM and IgG with low avidity. Over time they become highly avid. Low-avidity antibodies disappear from the blood after 1-5 months (in rare cases, longer), while high-avidity antibodies remain until the end of life.

Such a study is important when diagnosing pregnant women. This category of patients is characterized by frequent false-positive results. If high-avidity IgG antibodies are detected in the blood, this will exclude an acute primary infection that is dangerous for the fetus.

The degree of avidity depends on the concentration of viruses, as well as on individual differences in mutations at the molecular level. In older people, the evolution of antibodies occurs more slowly, so after 60 years of age, resistance to infections and the effect of vaccination decreases.

Norms for CMV levels in the blood

There is no numerical value for the “normal” level of antibodies in biological fluids.

The concept of counting IgG and other types of immunoglobulins has its own characteristics:

• Antibody concentration is determined by titration. Blood serum is gradually diluted with a special solvent (1:2, 1:6 and other concentrations that are multiples of two). The result is considered positive if the reaction to the presence of the test substance remains during titration. For cytomegalovirus infection, a positive result is detected at a dilution of 1:100 (threshold titer).
• Titers represent an individual reaction of the body, which depends on general condition, lifestyle, immune activity and metabolic processes, age, and the presence of other pathologies.
• Titers give an idea of ​​the total activity of antibodies of classes A, G, M.
• Each laboratory can use its own test systems to detect antibodies with a certain sensitivity, so they must produce a final interpretation of the results, which indicates reference (borderline) values ​​and units of measurement.

Avidity is assessed as follows (units of measurement - %):

• <30% – low-avidity antibodies, primary infection that occurred about 3 months ago;
• 30-50% – it is not possible to accurately determine the result, the analysis must be repeated after 2 weeks;
• >50% – high-avidity antibodies, infection occurred a long time ago.

In adults

The results for all groups of patients are deciphered in the manner indicated in the table below.

Table:

IgG value	IgM value	Interpretation
positive	positive	Secondary reinfection. Treatment is required
negative	positive	Primary infection. Treatment required
positive	negative	Immunity has been formed. A person is a carrier of the virus. Exacerbation of the disease is possible with decreased immunity
negative	negative	There is no immunity. There was no CMV infection. There is a risk of primary infection

Antibodies to cytomegalovirus can be at low levels for several years, and when reinfected with other strains, the amount of IgG increases rapidly. To obtain an accurate diagnostic picture, the level of IgG and IgM is determined simultaneously, and a repeat analysis is carried out after 2 weeks.

In children

In children during the neonatal period and breastfeeding IgG may be present in the blood, received in utero from the mother. After a few months, their level begins to gradually decrease due to the lack of a constant source. IgM antibodies often give false-positive or false-negative results. In this regard, diagnosis at this age causes difficulties.

Considering the general clinical picture, immunological tests are interpreted as follows:

Repeated testing allows you to determine the time of infection:

• after birth– increasing titer;
• intrauterine– constant level

During pregnancy

Diagnosis of CMV in pregnant women is carried out according to the same principle. If in the first trimester it is discovered that IgG is positive and IgM is negative, then it is necessary to take a PCR test to confirm the absence of reactivation of the infection. In this case, the fetus will receive maternal antibodies that will protect it from the disease.

Doctor antenatal clinic must issue directions for monitoring the IgG titer also in the 2nd and 3rd trimesters.

If a low avidity index is detected at a period of 12-16 weeks, then infection could have occurred before pregnancy, and the probability of infection of the fetus is almost 100%. At 20-23 weeks this risk decreases to 60%. Determining the time of infection during pregnancy is of great importance, since transmission of the virus to the fetus leads to the development of severe pathologies.

To whom and why is a test for antibodies to CMV prescribed?

The analysis is indicated for those individuals who are at risk of developing infection:

In healthy people with strong immunity Primary infection is often asymptomatic and without complications. But CMV in active form dangerous in case of immunodeficiency and pregnancy, as it causes numerous complications. Therefore, doctors recommend undergoing examination before the planned conception of a child.

Methods for detecting the virus and deciphering research results

All research methods for determining CMV can be divided into 2 groups:

• Direct– cultural, cytological. Their principle is to grow a culture of viruses or study the characteristic changes that occur in cells and tissues under the influence of a microorganism.
• Indirect– serological (ELISA, fluorescent antibody method), molecular biological (PCR). They serve to detect the immune response to infection.

The standard for diagnosing this disease is to use at least 2 of the methods listed above.

Test for antibodies to cytomegalovirus (ELISA - enzyme-linked immunosorbent assay)

The ELISA method is the most common due to its simplicity, low cost, high accuracy and the possibility of automation, eliminating laboratory technician errors. The analysis can be completed in 2 hours. Antibodies of the IgG, IgA, IgM classes are detected in the blood.

Determination of immunoglobulins to cytomegalovirus is carried out as follows:

1. The patient’s blood serum, control positive, negative and “threshold” samples are placed in several wells. The titer of the latter is 1:100. The plate containing the wells is made of polystyrene. Purified CMV antigens are pre-precipitated on it. When reacting with antibodies, specific immune complexes are formed.
2. The plate with samples is placed in a thermostat, where it is kept for 30-60 minutes.
3. The wells are washed with a special solution and a conjugate is added to them - a substance with antibodies labeled with an enzyme, then again placed in a thermostat.
4. The wells are washed and an indicator solution is added to them and kept in a thermostat.
5. A stop reagent is added to stop the reaction.
6. The results of the analysis are recorded in a spectrophotometer - the optical density of the patient's serum is measured in two modes and compared with the values ​​for control and threshold samples. To determine the titer, a calibration graph is constructed.

If the test sample contains antibodies to CMV, then under the influence of the indicator its color (optical density) changes, which is recorded by a spectrophotometer. Disadvantages of ELISA include the risk of false-positive results due to cross-reactions with normal antibodies. The sensitivity of the method is 70-75%.

The avidity index is determined similarly. A solution is added to the patient's serum samples to remove low-avidity antibodies. The conjugate and organic dye are then injected, the absorbance is measured and compared with control wells.

Polymerase chain reaction (PCR) method for diagnosing cytomegalovirus

The essence of PCR is to detect fragments of DNA or RNA of the virus.

After preliminary cleaning of the sample, the results are recorded using one of 2 methods:

• Electrophoretic, in which viral DNA molecules move in an electric field, and a special dye causes them to fluoresce (glow) under the influence of ultraviolet rays.
• Hybridization. Artificially synthesized sections of DNA labeled with a dye bind to the viral DNA in the sample. Next, they are fixed.

The PCR method is more sensitive (95%) compared to ELISA. The duration of the study is 1 day. Not only blood serum, but also amniotic or cerebrospinal fluid, saliva, urine, secretion from the cervical canal.

Currently, this method is the most informative. If viral DNA is found in blood leukocytes, this is a sign of primary infection.

Isolation of cell culture (seeding) for the diagnosis of CMV

Despite the high sensitivity (80-100%), seeding of cell cultures is rarely performed, since the following restrictions exist:

• the method is very labor intensive, the analysis time takes 5-10 days;
• the need for highly qualified medical personnel;
• the accuracy of the study greatly depends on the quality of the sample biological material and the time between the test and the culture;
• a large number of false negative results, especially when diagnostics are carried out later than 2 days.

Just as with PCR analysis, it is possible to determine the specific type of pathogen. The essence of the study is that samples taken from the patient are placed in a special nutrient medium in which microbes grow and are subsequently studied.

Cytology for the diagnosis of cytomegalovirus

Cytological examination is one of the primary types of diagnosis. Its essence lies in the study of cytomegal cells under a microscope, the presence of which indicates a typical change in CMV. Saliva and urine are usually taken for analysis. This method cannot serve as the only reliable method for diagnosing cytomegalovirus infection.

What to do if IgG to CMV is positive?

Antibodies to cytomegalovirus found in blood and other biological fluids may indicate three possible states: primary or re-infection, recovery and carriage of the virus. The test results require a comprehensive assessment.

If IgG is positive, then to determine the acute phase, which is the most dangerous to health, you need to contact an infectious disease doctor and conduct additional research ELISA for IgM, IgA, avidity or PCR analysis.

If IgG is detected in a child under 1 year of age, it is recommended that the mother also undergo this examination. If approximately the same antibody titers are detected, then it is highly likely that simple transfer of immunoglobulins occurred during pregnancy, and not infection.

It should be taken into account that small amounts of IgM can be detected for 2 or more years. Therefore, their presence in the blood does not always indicate recent infection. In addition, the accuracy of even the best test systems can produce both false positive and false negative results.

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

If antibodies to CMV are re-detected and there are no other signs of acute infection, test results indicate that the person is a lifelong carrier of the virus. In itself, this condition is not dangerous. However, before planning pregnancy, as well as in case of immunodeficiency, it is necessary to periodically monitor the level of immunoglobulins.

In healthy people, this disease occurs silently, sometimes with flu-like symptoms. Recovery indicates that the body has successfully coped with the infection, and lifelong immunity has been developed.

To monitor the dynamics of the disease, tests are prescribed every 2 weeks. If the IgM level gradually decreases, the patient recovers, otherwise the disease progresses.

Is it necessary to treat cytomegalovirus?

It is impossible to completely get rid of cytomegalovirus. If a person is a carrier of this infection, but there are no symptoms, then treatment is not required. Prevention of CMV, which is aimed at strengthening the immune system, is of great importance. This allows you to keep the virus in a “dormant” state and avoid exacerbation.

The same tactics are used against pregnant women and children. In people with severe immunodeficiency, cytomegalovirus infection may develop complications such as pneumonia, inflammation of the colon and retina. To treat this category of people, strong antiviral drugs are prescribed.

How to treat cytomegalovirus

CMV therapy is carried out in stages:

Depending on which organs are affected by the virus, the doctor prescribes additional medications.

In severe cases, the following treatment methods are used:

• for detoxification of the body - droppers with saline solution, acesol, di- and trisol;
• to reduce swelling and inflammation in case of damage to the central nervous system - corticosteroid drugs (Prednisolone);
• in case of secondary bacterial infection, antibiotics (Ceftriaxone, Cefepime, Ciprofloxacin and others).

During pregnancy

Pregnant women with CMV are treated with one of the following agents listed in the table below:

Name	Release form	Daily dosage	Average price, rub.
Acute phase, primary infection
Cytotect (human anticytomegalovirus immunoglobulin)		2 ml per 1 kg of weight every 2 days	21,000/10 ml
Interferon recombinant alpha 2b (Viferon, Genferon, Giaferon)	Rectal suppositories	1 suppository 150,000 IU 2 times a day (every other day). At 35-40 weeks of pregnancy - 500,000 IU 2 times a day daily. Course duration – 10 days	250/ 10 pcs. (150,000 IU)
Reactivation or reinfection
Cymevene (ganciclovir)	Solution for intravenous administration	5 mg/kg 2 times a day, course – 2-3 weeks.	1600/ 500 mg
Valganciclovir	Oral tablets	900 mg 2 times a day, 3 weeks.	15,000/60 pcs.
Panavir	Intravenous solution or rectal suppositories	5 ml, 3 injections with an interval of 2 days between them. Candles – 1 pc. at night, 3 times, every 48 hours.	1500/ 5 ampoules; 1600/ 5 candles

Drugs

The basis treatment of CMV antiviral drugs are:

The doctor may prescribe the following as immunomodulatory agents:

• Cycloferon;
• Amiksin;
• Lavomax;
• Galavit;
• Tiloron and other drugs.

Immunomodulators used in the remission phase can also be used during relapse. After the end of the acute phase of the disease, restorative and physiotherapeutic treatment is also indicated; it is necessary to eliminate chronic inflammatory and infectious foci.

Folk remedies

IN folk medicine There are several recipes for the treatment of CMV infection:

• Grind fresh wormwood herb and squeeze the juice out of it. Heat 1 liter of dry wine over a fire to approximately 70° C (at this point a whitish haze will begin to rise), add 7 tbsp. l. honey, mix. Pour 3 tbsp. l. wormwood juice, turn off the heat, stir. Take 1 glass of “wormwood wine” every other day.
• Wormwood, tansy flowers, crushed elecampane roots are mixed in equal proportions. 1 tsp. pour 0.5 liters of boiling water into the mixture. This amount is drunk in equal portions 3 times a day half an hour before meals. The duration of treatment with the collection is 2 weeks.
• Crushed alder, aspen and willow bark are mixed in equal proportions. 1 tbsp. l. collection, brew 0.5 liters of boiling water and take it in the same way as in the previous recipe.

Prognosis and complications

Cytomegalovirus infection most often occurs benignly, and its symptoms are confused with ARVI, since patients experience the same symptoms - fever, headaches and muscle pain, general weakness, chills.

In severe cases, infection can lead to the following complications:

This infection is most dangerous on early stages pregnancy, as this often results in fetal death and miscarriage.

The surviving child may have the following congenital abnormalities:

• reduction in brain size or dropsy;
• malformations of the heart, lungs and other organs;
• liver damage – hepatitis, cirrhosis, bile duct obstruction;
• hemolytic disease of newborns - hemorrhagic rash, hemorrhages in the mucous membranes, stool and vomiting with blood, bleeding from the umbilical wound;
• strabismus;
• muscle disorders - cramps, hypertonicity, asymmetry of the facial muscles and others.

There may be a delay later mental development. IgG antibodies detected in the blood are not a sign that there is an active CMV infection in the body. A person may already have lifelong immunity to cytomegalovirus. It is most difficult to determine the diagnostic picture in newborns. The disease in its passive form does not require treatment.

Article format: Lozinsky Oleg

Video about antibodies to cytomegalovirus

Cytomegalovirus Igg and Igm. ELISA and PCR for cytomegalovirus: