CMV m positive. What does cytomegalovirus IgG positive mean?

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Is cytomegalovirus dangerous?

Hello, please tell me, I was tested for viruses, cytomegalovirus IgG negative, IgM positive 1.2 when the norm is 1.0. Duration 11 weeks. Does this seriously threaten the baby? Herpes is also positive, but it is IgG and, as I understand it, it is not dangerous. And even before taking the test, I had to eat a little and did not take the test on an empty stomach, since on an empty stomach one vomits and may faint, could this have influenced and given a false result?

please decipher UAC

Child 1.9 was tested again after some kind of viral infection, where mononuclear cells slipped through. Hemoglobin (HGB) 125 g/l red blood cells (RBC) 4.41 10^12/l white blood cells (WBC) 7.4 10^3/μl hematocrit (HCT) 38.3% Mean erythrocyte volume (MCV) 86.7 fL 80-100 fL mean hemoglobin content in erythrocyte (MCH) 28.3 pg/ml 27-34 pg/ml anisocytosis rate of erythrocytes 13.3% 11.5-14.5% (RDW_CV) platelets (PLT) 345 10^3/μl ESR 7 mm/hour Leukocyte formula: band neutrophils 1% 1- 6% segmented neutrophils 30.5% 47-72% eosinophils 2.9% 0.5-5% monocytes 14.1% 3-11% lymphocytes...

Among infections with a hidden course, it deserves special attention from doctors. It primarily affects people with weakened immune systems and is often found in children and pregnant women. An antibody test to cytomegalovirus helps identify the presence of the pathogen.

What does antibody to cytomegalovirus mean?

Cytomegalovirus infection (CMV) is a common viral infection of the body by a pathogenic agent belonging to the group of herpes viruses. Distinctive feature This virus is characterized by the long-term persistence of its residual forms in the body: after infection, a person remains a carrier for almost life. At risk are children 5–6 years old, adults 16–30 years old and pregnant women.

As a result of prolonged persistence in the body, the virus negatively affects the links immune system. As a result, the body’s defense reaction begins, during which specific antibodies to cytomegalovirus IgG and IgM are formed. Their presence in the bloodstream indicates a current infection in the body or recent infection with CMV.

Antibodies to CMV IgM

IgM antibodies (immunoglobulins class M) present in the body indicate the presence of a current infection. It can be primary or recurrent. The presence of this type of antibody in the bloodstream is an indication for repeated studies. They are carried out after 10–14 days. This allows doctors to know what stage the infection is at. The results are assessed as follows:

1. Rapid decline in IgM antibody titers– infection has occurred recently or the infection is worsening.
2. Slow, gradual drop in titer– indicates the end of the active phase of the disease.

Antibodies to CMV IgG

Antibodies to CMV class G are present in the human body during latent infection and during exacerbation, as well as during primary infection. The level of these immunoglobulins increases in the first weeks after infection of the body and can remain high for several years. In addition to the quantitative characteristics, the avidity of IgG is also taken into account.

This term refers to the strength with which the resulting antibody binds to the antigen. The higher the indicator, the faster the binding of antigens to viral proteins occurs. Based on the nature of this indicator, doctors are able to determine when the infection occurred in the body.

Using an IgG test, doctors determine:

• whether the patient had previously been initiated with CMV;
• whether the observed symptoms are related to CMV.

Analysis for cytomegalovirus

Determination of antibodies to cytomegalovirus IGg and IgM is the main method for diagnosing infection. For IgM, the laboratory report form indicates a qualitative characteristic: the patient finds “positive” or “negative”. To evaluate IgGB, the antibody titer is displayed in the laboratory test results - this is a quantitative characteristic.

When do you get tested for cytomegalovirus?

Before being tested for cytomegalovirus, the patient must undergo preparation. It is practically no different from that which is carried out on the eve of a regular blood test. Thus, blood sampling for testing is carried out in the morning on an empty stomach - to correctly display the test results. Blood is taken from the cubital vein.

A CMV immunoglobulin test may be prescribed in the following cases:

• the process of preparing for pregnancy;
• presence of signs in the baby;
• immunosuppression: HIV, neoplastic diseases, taking cytostatics;
• suspicion of mononucleosis;
• hepato-splenomegaly of unknown origin;
• increased concentration of liver transaminases;
• atypical pneumonia in children;

Analysis for cytomegalovirus is normal

When antibodies to CMV are in the body in normal concentrations or are absent, the conclusion indicates “negative”. This means that the body is not infected or no more than 2-3 weeks have passed since the virus entered the body, during which the concentration of antibodies did not have time to reach high values. To exclude this option, reanalysis carried out after 14 days. Reference values ​​are fixed when antibodies to cytomegalovirus do not exceed 0–0.5 U/ml.

Quantitative determination of antibodies to cytomegalovirus

Only a doctor should evaluate the results of laboratory tests. By comparing the obtained values ​​with normal indicators, doctors draw conclusions regarding the need further observation for the patient. Above is a table indicating the norm that antibodies to cytomegalovirus IgM and IgG. Based on its meaning, doctors adhere to the following tactics:

• IgG(-) IgM(-)– a repeat test is performed if the result is obtained during pregnancy (once every 3 months);
• IgG(+) IgM(-)– the patient has immunity after an infection and does not need observation. If an active infection is suspected, the test is repeated after 10–14 days;
• IgG(-) IgM(+)– repeat test after 21 days to exclude the onset of active stage infection or false positive result;
• IgG(+) IgM(+)– possible availability acute stage infections, perform an avidity test.

Avidity of antibodies to cytomegalovirus

The avidity of IGg antibodies to cytomegalovirus is determined in the case of positive test for IgM. Avidity (Latin – avidity) is the nature of the strength of the formed bond between antibody and antigen. Initially, during the formation of an immune response, IgG antibodies have low avidity. Over time, this figure increases. This gives doctors an idea of ​​the time that has passed since the body became infected.

Thus, an avidity index of up to 35% is observed when infection occurred 3–5 months ago. However, it must be taken into account that the detection of low-avidity IgG antibodies cannot be considered as confirmation of recent infection of the body with the virus. Recent primary infection can be excluded when the avidity of antibodies to cytomegalovirus exceeds 42%.

Antibodies to CMV during pregnancy

CMV infection is dangerous for the pregnant woman and her unborn baby. In women with this infection, there is increased risk fetal infection. However, if a pregnant woman was infected several months ago, then the risk of transmitting the virus to the fetus is minimal. Interpretation of test results for IgM, IgG during pregnancy is carried out as follows.

Analysis of IgG and IgM antibodies to cytomegalovirus helps to timely understand the cause of many diseases caused by the virus. Cytomegalovirus is a virus related to herpesvirus that causes the infectious disease cytomegaly. This disease affects most of the world's population and is predominantly asymptomatic.

Is the virus dangerous?

Despite the fact that the virus related to human herpes virus type 5 does not cause serious problems health, CMV can worsen some chronic diseases. CMV is especially dangerous for women during pregnancy, as it can negatively affect the development of the fetus in the prenatal period and the baby after birth. For timely detection of the disease and provision of proper therapy, it is recommended to conduct a blood test for cytomegalovirus during pregnancy planning and during it, as well as for people who have problems with the immune system. Early diagnosis allows you to effectively and quickly stop the development of the virus in the body, preventing it from causing any particular harm to health.

Blood test for CMV - what is it?

As diagnostic method To detect CMV in the blood, several types of tests can be used, but the most effective and common is enzyme-linked immunosorbent assay (ELISA). This type of diagnosis makes it possible to evaluate the quantitative and characteristic antibodies specific to cytomegalovirus (immunoglobulins), and based on the data obtained, conclusions can be drawn about the presence or absence of immunity to the pathogenic pathogen in the body. Enzyme immunoassay is accurate, fast and publicly available.

Antibodies to CVM

When active restructuring of the immune system begins. The duration of the incubation period is 15-90 days, depending on the initial state of the person’s immunity. This infection does not leave the body, that is, it remains in it forever. The virus makes the body’s immunity unstable, reducing it, and this can only mean one thing – Negative influence on the general health of a person and the likelihood of secondary infection with viruses or other types of infections. As a result of the protective reaction of the immune system to the actions of CMV, specific immunoglobulins of two classes, IgG and IgM, are produced.

Antibodies in the blood to cytomegalovirus are active proteins that bind and neutralize virus particles.

Immunoglobulins of the igg type to cytomegalovirus in the patient’s blood may indicate ongoing or past CMV infection. IgM antibodies to CMV are produced by the infected organism 4-7 weeks after infection and remain in the blood for the next 4-5 months. If these components are found in the blood (the test response is “positive”), it means that an infection is currently occurring in the body or there was a recent, primary infection. As the virus develops in the body, IgM levels decrease, which means the condition is normal and the disease enters a latent period, but at the same time, IgG immunoglobulin levels with a positive value increase.

With long-term development viral infection human body, immunoglobulins of the igg class gradually decrease, but do not disappear completely, and antibodies to CMV proteins remain active throughout life. When the virus is reactivated, which can occur due to a significant decrease in immunity, IgG levels increase again, but do not reach high values, as in the case of primary infection.

What is the difference between IgG and IgM tests?

When receiving answers as a result of an ELISA test for cytomegalovirus, it is necessary to know the differences between the two classes of antibodies IgG and IgM.

So, IgM is a fast immunoglobulin, which has a significant size and is produced by the body in order to react to the development of the virus in the body in the shortest possible period of time. But at the same time, IgM is not able to form the memory of the immune system to the virus, and this means that after 4-5 months active protection against cytomegalovirus disappears.

IgG antibodies appear when CMV activity decreases and are cloned by the body to provide lifelong immunity to the virus. They are smaller in size compared to class M immunoglobulins and are produced later than them, as a rule, after the active phase of suppression of cytomegaly, as exemplified by the igg antibodies themselves. This means that if there are immunoglobulins of a specific type IgM in the blood, then the body is affected by the virus relatively recently and possibly in this moment infection occurs in acute form. To specify the answer, it is necessary to carry out additional research CMVI by other methods.

Cytomegalovirus IgG positive

If the igg result for CMV is positive, we can safely say that the body has already had the infection and has developed a special immunity to it in the form of immunoglobulins, which protect the person for life from re-infection.

To put it simply, for people who do not suffer from immunodeficiency, such results are the most acceptable of all possible, since a negative answer in this case means that the person does not have immunity to CMV and can become infected with the disease at any time. This shows that a positive ELISA response to igg for cytomegalovirus indicates a successful infection at least a month ago.

A positive result can be considered favorable, in the absence special conditions patient and abnormalities in the immune system. For example, for women planning pregnancy or who are pregnant, people planning to undergo organ transplantation or chemotherapy, a positive cytomegalovirus igg in the blood can trigger the re-development of cytomegaly in the body and lead to a number of undesirable consequences for the patient in terms of his health.

Results of analysis for cytomegalovirus decoding

To decipher the enzyme immunoassay, the reference values ​​adopted to determine the amount of antibodies in each individual laboratory are taken into account. As a rule, they must be indicated on the answer forms of all studies, so that the attending physician can decipher the final data.

Specific immunoglobulins of the IgM type identified as a result of diagnosis indicate a current infection in acute period primary infection, or its recent completion.

In the absence of concomitant symptoms, we can assume that the body has easily tolerated cytomegaly, and CMV no longer poses a danger to the body.

Titers (indicators of the amount of antibodies in the blood) igg with high values, for example, igg results for CMV are more than 250 or igg are detected above 140, this means that no dangerous condition for the body. If during diagnosis exclusively immunoglobulins of the igg class are determined, this indicates the likelihood of the body’s contact with CMV in the past and the absence of an acute course in the present time. From this we can judge that single igg indicators indicate that a person is a carrier of cytomegalovirus.

In order to accurately determine the stage of CMV, it is necessary to assess the level of avidity of immunoglobulins of the igg class. If the indicators give low-avidity indicators, this means primary infection, while high-avidity indicators are in the carrier’s blood throughout his entire life. During the reactivation of chronic cytomegalovirus in the body, immunoglobulins G also have high avidity levels.

Avidity of antibodies to cytomegalovirus

Antibody avidity is an indicator of the ability of immunoglobulins to bind to free proteins of the virus to further suppress it, that is, it is the strength of their connection with each other.

IN initial stages cytomegaly, IgG antibodies have low avidity, that is, little connection with viral proteins. With the development of CMV and the immune system response, igg avidity levels increase and the indicator becomes positive.

The connection of the protein with antibodies during the study is assessed using calculated indicators - the avidity index, which is the ratio of the results of the concentration of immunoglobulin G with treatment with special active solutions to the result of the concentration of the same immunoglobulin igg without treatment.

Cytomegalovirus IgG positive during pregnancy

Separate coverage requires results with a “positive” indicator of an enzyme immunoassay for the presence of antibodies to. At the same time, the timing of pregnancy during which these studies were carried out is of particular importance.

If, at a period of more than 4 weeks of pregnancy, a woman’s analysis shows a positive result with high-avidity indicators, then such an answer can be interpreted ambiguously and require additional, more specific research. After all, the infection could have taken place either a year ago or a few weeks ago, which in the latter case is fraught with serious consequences for the fetus. negative consequences. But at the same time, if the titer is high with a positive response to CMV, then this result may indicate a suppressed infection in the body and the absence of danger to the fetus and unborn baby.

The list of pathological conditions and diseases that a person suffers throughout his life largely depends on the way of life. After pathogenic microorganisms enter the body, the immune system is activated and begins to take measures to combat them.

In the case when the protective properties are reduced, the body is not able to fight pathogenic microflora. As a result, the development and progression of the disease occurs, and the mass reproduction of microorganisms: bacteria, viruses, fungi.

One of the most commonly diagnosed pathogenic microorganisms is the herpes virus. It is represented by several strains. No person is immune from the penetration of pathogens of various diseases into the body. This pathology can affect both men, women and children. The worst thing is that there is still no method of therapy that can destroy the virus and cure the pathology.

It deserves special attention. Quite often, after undergoing an examination, people ask the question: “Cytomegalovirus IgG is positive: what does this mean?” The infection can affect any system and organ. Active reproduction of the virus is fraught with critical consequences.

CMV: what is it

Before understanding the issue of a positive result for cytomegalovirus IgG, as well as what this means, you should learn in more detail about the pathogenic infection itself. CMV was first identified in 1956. Scientists and doctors have not fully studied it to this day. But despite this, there is the possibility of timely diagnosis of pathology, and, consequently, timely therapy, and prevention of the development of complications.

According to statistics, a third of the world's population is carriers of the herpes virus. The spread of the pathogen is weak, and in order to become infected, you must be with the infected person for an extended period. Infection can occur through sexual contact, during childbirth and through saliva.

It is quite difficult to immediately identify and diagnose the disease. And this is due to the presence of an incubation period. The patient or carrier of the infection can live with the disease, feel normal and not even suspect the presence of CMV.

Pathology is insidious, as it can masquerade as other, less dangerous diseases, especially colds.

In the initial stages, the disease is accompanied by the following manifestations:

• hyperthermia;
• chronic fatigue, weakness;
• enlarged lymph nodes;
• chills;
• frequent headaches;
• sleep disorder;
• dyspeptic disorders;
• joint pain;
• decreased appetite.

Timely detection of the disease is very important, since the lack of appropriate therapy is fraught with serious complications, in particular the development of encephalitis, pneumonia, and arthritis. With a weakened immune system, eye damage and malfunctions in the kidneys and urinary system, as well as the gastrointestinal tract, may occur.

If alarming symptoms appear, you should undergo an examination. A positive test result for cytomegalovirus IgG means that the infected person has protection against CMV and is its carrier.

It is not at all necessary that a person is sick and that he is extremely dangerous to others. Everything will depend on the protective properties of his body. CMV is dangerous during pregnancy.

The essence of analysis

The essence of the IgG test is to look for antibodies to CMV. To do this, they take different samples (blood, saliva). To make it clearer, Ig is an immunoglobulin. This substance is a protective protein that is produced by the body to destroy pathogenic microorganisms. The immune system produces a specific antibody to any new pathogenic organism. The G in the abbreviation IgG stands for one of the classes of antibodies. In addition to IgG, there are also groups A, M, E and D.

If a person is healthy, then specific Igs have not yet been produced. The danger is that, having entered the body once, the infection will remain in it forever. It is impossible to destroy it. But since the immune system produces protection against it, the virus exists in the body harmlessly. It is important to know that in addition to IgG there is also IgM. These are two absolutely different groups antibodies.

The second are fast antibodies. They are large and are produced for a quick response to the herpes virus entering the body. But they do not have immunological memory. This means that after their death, after about four to five months, the protection against CMV subsides.

As for IgG, these antibodies tend to clone and maintain protection against a specific pathogenic microorganism throughout life. They are small in size, but are produced later than IgM, usually after suppression of the infectious process.

And it turns out that if IgM antibodies are detected, then the infection occurred recently and most likely infectious process is in the active phase.

How are analyzes deciphered?

In addition to IgG+, the results often contain other data.

A specialist will help you decipher them, but in order to understand the situation, it is useful to familiarize yourself with some meanings:

1. 0 or “-” - there is no CMV in the body.
2. If the avidity index is 50-60%, then the situation is considered uncertain. The study is repeated after one to two weeks.
3. Above 60% - there is immunity, the person is a carrier.
4. Below 50%, the person is infected.
5. Anti-CMV IgM+, Anti- CMV IgG+ - the infection has reactivated.
6. Anti-CMV IgM-, Anti-CMV IgG- - protection against the virus has not been developed, since there has never been penetration of the virus before.
7. Anti-CMV IgM-, Anti-CMV IgG+ - the pathology occurs in an inactive stage. The infection happened a long time ago, the immune system has developed a strong defense.
8. Anti- CMV IgM+, Anti- CMV IgG- - acute stage of pathology, the person became infected recently. Fast Igs to CMV are available.

Result “+” in a person with strong immunity

If there are no health problems, a “+” result should not cause panic or anxiety. Regardless of the degree of the disease, with persistent protective properties, its course is asymptomatic. Occasionally, sore throat and fever may occur.

But it should be understood that if tests indicate activation of the virus, but the pathology is asymptomatic, the patient should temporarily reduce social activity (limiting communication with family, excluding conversations and contacts with pregnant women and children). During the active phase, a sick person is an active spreader of cytomegalovirus infection and can infect a person whose body CMV will cause significant damage.

CMV IgG positive: in immunodeficiency, pregnancy and infants

A CMV “+” result is dangerous for everyone. However, a positive CMV IgG result is most dangerous for a patient with immunodeficiency: congenital or acquired. Such a result signals the development of serious complications.

• Retinitis- development of the inflammatory process in the retina. This pathology can lead to blindness.
• Hepatitis and jaundice.
• Encephalitis. This pathology is characterized by severe headaches, sleep disturbances, and paralysis.
• Gastrointestinal ailments- inflammatory processes, exacerbation of ulcers, enteritis.
• Pneumonia. This complication, according to statistics, is the cause of death in more than 90% of people suffering from AIDS.

CMV IgG positive in such patients signals the course of the pathology in a chronic form and a high probability of exacerbations.

Positive result during pregnancy

No less dangerous IgG result+ for pregnant women. CMV IgG positive signals infection or an exacerbation of the pathology. If IgG to cytomegalovirus is detected in the early stages, urgent measures must be taken. Primary infection with the virus is associated with high risk development of serious anomalies in the fetus. With relapses, the risk of harmful effects on the fetus is significantly reduced.

Infection in the second and third trimester is fraught with the occurrence of congenital CMV infection in the child or its infection during passage through the birth canal. The doctor judges whether the infection is primary or an exacerbation by the presence of specific group G antibodies. Their detection signals that there is protection, and the exacerbation is due to a decrease in the body’s protective properties.

If IgG is absent, this indicates infection during pregnancy. This suggests that the infection can cause enormous damage not only to the mother, but also to the fetus.

Result “+” in a newborn

A fourfold increase in IgG titer during two studies with an interval of thirty days indicates congenital CMV infection. The course of the pathology in infants can be either asymptomatic or characterized by pronounced manifestations. The disease may also be associated with a high risk of complications. Pathology in small child is fraught with the appearance of blindness, the development of pneumonia, and malfunction of the liver.

What to do if you get an IgG+ result

The first thing to do when positive CMV IgG - seek help from a qualified specialist. CMVI itself often does not provoke critical consequences. If obvious signs There are no diseases, there is no point in carrying out treatment. The fight against infection should be left to the immune system.

At severe symptoms The following medications are most often prescribed:

• Interferons.
• Immunoglobulins.
• Foscarnet (taking the drug is fraught with disruptions in the functioning of the urinary system and kidneys).
• Panavira.
• Ganciclovir. Helps block the proliferation of pathogenic microorganisms, but at the same time provokes the appearance of disruptions in the gastrointestinal tract and hematopoietic disorders.

You should not take any medications without your doctor's knowledge. Self-medication can lead to unpredictable consequences. It is important to understand one thing - if everything is in order with the immune system, the “+” result only informs about the presence of a formed defense in the body. The only thing you need to do is support your immune system.

Cytomegalovirus (abbreviated CMV or CMV) is a pathogen 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 a virus are the main diagnostic sign to detect infection.

Cytomegalovirus infection can be either 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.

The following types of antibodies to CMV are distinguished, 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.

Based on 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. Feature 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 or more weak 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 had an organ transplant, 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 initial period the disease 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 research has 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 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

The numerical value of the “normal” antibody content in biological fluids does not exist.

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, 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 interpreted 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. Their level begins to gradually decline after a few months 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:

U healthy people with strong immunity, primary infection is often asymptomatic and without complications. But CMV in active form is 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 CMV definitions can be divided into 2 groups:

• Direct– cultural, cytological. Their principle is to grow a virus culture or study characteristic changes, occurring 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. The disadvantages of ELISA include the risk false positive results because of 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. Then the conjugate is introduced and organic matter with dye, 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 limitations 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 detected in blood and other biological fluids may indicate three possible conditions: 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 consult an infectious disease doctor and conduct additional ELISA tests for IgM, IgA, avidity or PCR analysis.

At detection of IgG In case of 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 secretly, sometimes with manifestations 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. Great importance has CMV prevention, which is aimed at strengthening the immune system. 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 use following methods therapy:

• 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 connecting a 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 of treatment for CMV is antiviral drugs:

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 - elevated temperature, 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: