Cytomegalovirus igg is positive. Cytomegalovirus CMV iG positive: what does it mean. Norms of igg antibodies in children

Cytomegalovirus is a herpetic type infection, diagnosed in a child or adult by a blood test for igg, igm antibodies. Carriers of this infection are 90% of the world's population. It manifests itself with a significant decrease in immunity and is dangerous for intrauterine development. What are the symptoms of cytomegaly, and when is drug treatment necessary?

What is cytomegalovirus infection

Cytomegalovirus infection is a herpetic type virus. It is called hepres type 6 or CMV. The disease caused by this virus is called cytomegaly. With it, infected cells lose the ability to divide and greatly increase in size. Inflammation develops around the infected cells.

The disease can be localized in any organ - the sinuses (rhinitis), bronchi (bronchitis), bladder (cystitis), vagina or urethra (vaginitis or urethritis). However, the CMV virus more often chooses the genitourinary system, although its presence is found in any fluid media of the body ( saliva, vaginal discharge, blood, sweat).

Conditions of infection and chronic carriage

Like other herpes infections, cytomegalovirus is a chronic virus. It enters the body once (usually in childhood) and is stored there for the rest of one’s life. The form of storage of the virus is called carriage, while the virus is in a latent, dormant form (stored in the ganglia of the spinal cord). Most people do not realize they carry CMV until their immune system fails. The dormant virus then multiplies and produces visible symptoms.

Unusual situations lead to a significant decrease in immunity in healthy people: organ transplant operations (accompanied by taking medications that purposefully reduce immunity - this prevents rejection of a transplanted foreign organ), radiation and chemotherapy (in the treatment of oncology), long-term use of hormonal drugs (contraceptives), alcohol.

Interesting fact: The presence of cytomegalovirus infection is diagnosed in 92% of examined people. Carriage is a chronic form of the virus.

How the virus is transmitted

Just 10 years ago, cytomegalovirus infections were considered sexually transmitted. CMV was called " kissing disease", believing that the disease is transmitted through kisses. Modern research has proven that cytomegalovirus is transmitted in various household situations- using shared utensils, towels, and shaking hands (if there are cracks, abrasions, or cuts on the skin of the hands).

The same medical studies have found that children are most often infected with cytomegalovirus. Their immunity is at the stage of formation, so viruses penetrate the child’s body, cause illness or form a carrier state.

Herpetic infections in children manifest visible symptoms only with low immunity ( for frequent illnesses, vitamin deficiency, serious immune problems). With normal immunity, exposure to the CMV virus is asymptomatic. The child becomes infected, but no symptoms (fever, inflammation, runny nose, rash) follow. The immune system copes with foreign invasion without raising the temperature (forms antibodies and remembers the program for their production).

Cytomegalovirus: manifestations and symptoms

External manifestations of CMV are difficult to distinguish from ordinary acute respiratory infections. The temperature rises, a runny nose appears, and the throat hurts. Lymph nodes may become enlarged. The complex of these symptoms is called mononucleosis syndrome. It accompanies many infectious diseases.

CMV can be distinguished from a respiratory infection by the protracted duration of the disease. If a common cold goes away in 5-7 days, then cytomegaly lasts longer - up to 1.5 months.

There are special signs of cytomegalovirus infection (they rarely accompany ordinary respiratory infections):

• Inflammation of the salivary glands(in them the CMV virus multiplies most actively).
• In adults - inflammation of the genital organs(for this reason, CMV has long been considered a sexually transmitted infection) - inflammation of the testicles and urethra in men, uterus or ovaries in women.

Interesting to know: Cytomegalovirus in men often occurs without visible symptoms if the virus is localized in the genitourinary system.

CMV has a long incubation period. When infected with herpes infection type 6 ( cytomegalovirus) signs of the disease appear 40-60 days after the virus enters.

Cytomegaly in infants

The danger of cytomegaly for children is determined by the state of their immunity and the presence of breastfeeding. Immediately after birth, the child is protected from various infections by the mother’s antibodies (they entered his blood during intrauterine development, and continue to do so during breastfeeding). Therefore, in the first six months or a year (the time of predominantly breastfeeding), the baby is protected by the mother’s antibodies. Cytomegalovirus in children under one year of age does not cause any symptoms due to the presence of maternal antibodies.

Infection of a child becomes possible by reducing the number of breastfeedings and incoming antibodies. The source of infection becomes the closest relatives (when kissing, bathing, general care - let us remind you that the majority of the adult population is infected with the virus). The reaction to primary infection can be strong or invisible (depending on the state of immunity). Thus, by the second or third year of life, many children develop their own antibodies to the disease.

Is cytomegalovirus dangerous in an infant?

With normal immunity - no. With a weak and insufficient immune response - yes. It can cause long-term extensive inflammation.

Dr. Komarovsky also speaks about the connection between CMV symptoms and immunity: “ Cytomegalovirus in children does not pose a threat if the immune system is normal. Exceptions from the general group are children with special diagnoses - AIDS, chemotherapy, tumors».

If a child was born weakened, if his immunity is impaired by taking antibiotics or other potent drugs, infection with cytomegalovirus causes an acute infectious disease - cytomegaly(symptoms of which are similar to long-term acute respiratory infections).

Cytomegaly in pregnant women

Pregnancy is accompanied by a decrease in maternal immunity. This is a normal reaction of the female body, which prevents the rejection of the embryo as a foreign organism. Row physical and chemical processes and hormonal changes are aimed at reducing the immune response and limiting the action of immune forces. Therefore, it is during pregnancy that dormant viruses can be activated and cause relapses of infectious diseases. So, if cytomegalovirus did not manifest itself in any way before pregnancy, then during pregnancy it can increase the temperature and form inflammation.

Cytomegalovirus in a pregnant woman can be the result of a primary infection or a secondary relapse. Primary infection poses the greatest danger to the developing fetus.(the body does not have time to give a worthy response and the CMV virus penetrates the placenta to the child).

Recurrences of infection during pregnancy are not dangerous in 98% of cases.

Cytomegaly: danger and consequences

Like any herpetic infections, the CMV virus is dangerous for a pregnant woman (or rather, for the child in her womb) only during primary infection. Primary infection forms various malformations, deformities or defects of the brain, and pathologies of the central nervous system.

If infection with the CMV virus or another herpes-type pathogen occurred long before pregnancy (in childhood or adolescence), then this situation is not terrible for the child in the womb, and is even useful. During primary infection, the body produces a certain amount of antibodies, which are stored in the blood. In addition, a program of protective reaction to this virus is developed. Therefore, the relapse of the virus is brought under control much faster. For a pregnant woman, the best option is to become infected with CMV in childhood and develop certain mechanisms to fight the infection.

The most dangerous situation for a child is a woman’s sterile body before conception. You can get infections anywhere (more than 90% of the planet's population are carriers of herpes viruses). At the same time, infection during pregnancy causes a number of disturbances in the development of the fetus, and infection in childhood passes without serious consequences.

Cytomegaly and uterine development

The CMV virus poses the greatest danger to a child in the womb. How does cytomegalovirus affect the fetus?

Infection of the fetus is possible during initial exposure to the virus during pregnancy. If infection occurs before 12 weeks, a miscarriage occurs in 15% of cases.

If infection occurs after 12 weeks, a miscarriage does not occur, but the child develops symptoms of the disease (this happens in 75% of cases). 25% of children whose mothers become infected with the virus during pregnancy for the first time are born completely healthy.

Cytomegalovirus in a child: symptoms

What symptoms can be used to suspect congenital cytomegaly in a child:

• Retarded physical development.
• Severe jaundice.
• Enlarged internal organs.
• Foci of inflammation (congenital pneumonia, hepatitis).

The most dangerous manifestations of cytomegaly in newborns are damage to the nervous system, hydrocephalus, mental retardation, loss of vision and hearing.

Analyzes and decoding

The virus is found in any body fluid - blood, saliva, mucus, urine in children and adults. Therefore, an analysis to determine CMV infection can be taken from blood, saliva, semen, as well as in the form of a smear from the vagina and pharynx. In the samples taken, they look for cells affected by the virus (they are large in size, they are called “huge cells”).

Another diagnostic method examines the blood for the presence of antibodies to the virus. If there are specific immunoglobulins that are formed as a result of the fight against the virus, it means there has been an infection and there is a virus in the body. The type of immunoglobulins and their quantity can indicate whether this is a primary infection or a relapse of an infection that was previously ingested.

This blood test is called enzyme immunoassay (abbreviated as ELISA). In addition to this analysis, there is a PCR test for cytomegalovirus. It allows you to reliably determine the presence of infection. For PCR analysis, a vaginal smear or amniotic fluid sample is taken. If the result shows the presence of infection, the process is acute. If PCR does not detect the virus in mucus or other secretions, there is no infection (or relapse of infection) now.

Analysis for cytomegalovirus: Igg or igm?

The human body produces two groups of antibodies:

• primary (they are designated M or igm);
• secondary (they are called G or igg).

Primary antibodies to cytomegalovirus M are formed when CMV first enters the human body. The process of their formation is not related to the severity of symptoms. Infection may be asymptomatic, but igm antibodies will be present in the blood. In addition to the primary infection, type G antibodies are formed during relapses when the infection got out of control and the virus began to actively multiply. Secondary antibodies are produced to control the dormant virus stored in the ganglia of the spinal cord.

Another indicator of the stage of infection formation is avidity. It diagnoses the maturity of antibodies and the primacy of infection. Low maturity (low avidity - up to 30%) corresponds to primary infection. If the analysis for cytomegalovirus shows high avidity ( more than 60%), then this is a sign of chronic carriage, the latent stage of the disease. Average indicators ( from 30 to 60%) - correspond to a relapse of infection, activation of a previously dormant virus.

Note: deciphering a blood test for cytomegalovirus takes into account the number of antibodies and their type. These data make it possible to draw conclusions about the primary or secondary nature of the infection, as well as about the level of the body’s own immune response.

Blood for cytomegalovirus: interpretation of results

The main test to determine the presence of CMV infection is a blood antibody test (ELISA). Almost all women are tested for cytomegalovirus during pregnancy. The results of the analysis look like a list of types of antibodies and their quantities:

• Cytomegalovirus igg igm - “-” (negative)- this means that there has never been contact with the infection.
• "Igg+, igm-"- this result is obtained in most women when they are examined when planning pregnancy. Since CMV carriage is almost universal, the presence of group G antibodies indicates familiarity with the virus and its presence in the body in a dormant form. “Igg+, igm-” - normal indicators, which allow you not to worry about possible infection with a virus while carrying a baby.
• “Igg-, igm+” - presence of acute primary disease(igg is absent, which means that the body has encountered an infection for the first time).
• “Igg+, igm+” - presence of acute relapse(against the background of igm there are igg, which indicates an earlier acquaintance with the disease). Cytomegalovirus G and M are signs of relapse of the disease and the presence of decreased immunity.

The worst result for a pregnant woman is cytomegalovirus igm positive. During pregnancy, the presence of group M antibodies indicates an acute process, primary infection or relapse of infection with the manifestation of symptoms (inflammation, runny nose, fever, enlarged lymph nodes). It’s even worse if, against the background of igm+, the cytomenalovirus igg has a “-”. This means that this infection entered the body for the first time. This is the most depressing diagnosis for an expectant mother. Although the probability of complications in the fetus is only 75%.

Interpretation of ELISA analysis in children

Cytomegalovirus igg in children is usually detected in the first year of life, especially in breastfed babies. This does not mean that the child became infected with CMV from the mother. This means that, along with milk, maternal immune bodies enter his body, which protect against acute manifestations of infection. Cytomegalovirus igg in a breastfed child is the norm, not a pathology.

Is it necessary to treat cytomegalovirus?

Healthy immunity itself controls the amount of CMV and its activity. If there are no signs of illness, treatment for cytomegalovirus is not necessary. Therapeutic measures are necessary when an immune failure occurs and the virus becomes active.

Chronic cytomegalovirus during pregnancy is characterized by the presence of type G antibodies. This is a chronic carriage and is present in 96% of pregnant women. If cytomegalovirus igg is detected, treatment is not necessary. Treatment is necessary in the acute stage of the disease when visible symptoms appear. It is important to understand that a complete cure for the CMV virus is impossible. Therapeutic measures are aimed at limiting the activity of the virus, transferring it to a dormant form.

The titer of group G antibodies decreases over time. For example, cytomegalovirus igg 250 is detected if the infection occurred in the last few months. A low titer means that the primary infection occurred quite a long time ago.

Important: a high titer of the immunoglobulin g test for cytomegalovirus indicates a relatively recent infection with the disease.

From the point of view of the pharmaceutical industry, it is necessary to treat everyone who has antibodies to CMV (of any type and titer). After all, this is primarily profit. From the point of view of a woman and her child in the womb, treating a dormant infection in the presence of igg antibodies is not beneficial, and possibly harmful. Drugs to support immunity contain interferon, which is not recommended for use during pregnancy without special indications. Antiviral drugs are also toxic.

How to treat cytomegalovirus during pregnancy

Treatment of cytomegalovirus occurs in two directions:

• Means for general immunity boosting (immunostimulants, modulators) - drugs with interferon (Viferon, Genferon).
• Specific antiviral drugs (their action is directed specifically against herpes virus type 6 - CMV) - foscarnet, ganciclovir.
• Vitamins (injections of B vitamins) and vitamin-mineral complexes are also indicated.

How to treat cytomegalovirus in children? The same drugs are used (immune stimulants and antivirals), but in reduced dosages.

How to treat cytomegalovirus with folk remedies

To treat any viruses, traditional medicine uses natural antimicrobial agents:

• garlic, onion;
• propolis (alcohol and oil tinctures);
• silver water;
• hot spices
• herbal treatment - garlic greens, raspberry leaves, wormwood, echinacea and violet flowers, ginseng rhizomes, rhodiola.

[07-018 ] Cytomegalovirus, IgM

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Antibodies of the IgM class to cytomegalovirus are specific immunoglobulins produced in the human body during the acute period of cytomegalovirus infection and are an early serological marker of this disease.

Synonyms Russian

Antibodies of the IgM class to cytomegalovirus (CMV).

English synonyms

Anti-CMV-IgM, CMV Antibody, IgM.

Research method

Electrochemiluminescent immunoassay (ECLIA).

What biomaterial can be used for research?

Venous, capillary blood.

How to properly prepare for research?

Do not smoke for 30 minutes before the test.

General information about the study

Cytomegalovirus (CMV) belongs to the herpes virus family. Just like other representatives of this group, it can persist in a person throughout his life. In healthy people with normal immunity, the primary infection occurs without complications (and is often asymptomatic). However, cytomegalovirus is dangerous during pregnancy (for the child) and during immunodeficiency.

Cytomegalovirus can be infected through various biological fluids: saliva, urine, semen, blood. In addition, it is transmitted from mother to child (during pregnancy, childbirth or breastfeeding).

As a rule, cytomegalovirus infection is asymptomatic. Sometimes the disease resembles infectious mononucleosis: the temperature rises, the throat hurts, and the lymph nodes become enlarged. The virus then remains inside the cells in an inactive state. But if the body is weakened, the virus will begin to multiply again.

It is important for a woman to know whether she has been infected with CMV in the past because this is what determines whether she is at risk for pregnancy complications. If she has already been infected before, then the risk is minimal. During pregnancy, an exacerbation of an old infection may occur, but this form usually does not cause serious consequences.

If a woman has not yet had CMV, then she is at risk and should pay special attention to the prevention of cytomegalovirus infection. It is the infection that the mother contracted for the first time during pregnancy that is dangerous for the child.

During a primary infection in a pregnant woman, the virus often enters the child’s body. This does not mean that he will get sick. As a rule, CMV infection is asymptomatic. However, in approximately 10% of cases it leads to congenital pathologies: microcephaly, cerebral calcification, rash and enlargement of the spleen and liver. This is often accompanied by a decrease in intelligence and deafness, and even death is possible.

Thus, it is important for the expectant mother to know whether she has been infected with CMV in the past. If so, then the risk of complications due to possible CMV becomes negligible. If not, you need to take special care during pregnancy:

• avoid unprotected sex,
• do not come into contact with another person’s saliva (do not kiss, do not share dishes, toothbrushes, etc.),
• observe the rules of hygiene when playing with children (wash your hands if saliva or urine gets on them),
• get tested for CMV if there are signs of general malaise.

In addition, cytomegalovirus is dangerous if the immune system is weakened (for example, due to immunosuppressants or HIV). In AIDS, CMV is severe and is a common cause of death in patients.

The main symptoms of cytomegalovirus:

• inflammation of the retina (which can lead to blindness),
• colitis (inflammation of the colon),
• esophagitis (inflammation of the esophagus),
• neurological disorders (encephalitis, etc.).

The production of antibodies is one way to fight a viral infection. There are several classes of antibodies (IgG, IgM, IgA, etc.), which differ in their functions.

Immunoglobulin M (IgM) usually appears first in the blood (earlier than other types of antibodies). Then their number gradually decreases (this process can last several months). If an exacerbation of a latent infection occurs, the IgM level will increase again.

Thus, IgM is detected:

• during primary infection (in this case the IgM level is highest),
• during exacerbation of the disease (as well as during reinfection, i.e. infection with a new form of the virus).

What is the research used for?

For the diagnosis of acute cytomegalovirus infection.

When is the study scheduled?

• During pregnancy.
• With immunodeficiency (in particular, with HIV infection).
• When a person with normal immunity has symptoms of mononucleosis (if tests do not reveal the Epstein-Barr virus).
• If CMV infection is suspected in newborn children.
• During pregnancy:
  • for symptoms of the disease,
  • if ultrasound reveals fetal developmental abnormalities,
  • for screening.

CMV infection in pregnant women is often asymptomatic. However, in some cases, the temperature rises, the lymph nodes, liver and/or spleen become enlarged.

In case of immunodeficiency, the symptoms of CMV infection can be quite varied: from general malaise to retinitis, colitis, encephalitis, etc.

• A test may be prescribed for a newborn if the child:
  • jaundice, anemia,
  • enlarged spleen and/or liver,
  • head size is smaller than normal,
  • have hearing or vision impairments,
  • there are neurological disorders (mental retardation, convulsions).

What do the results mean?

Reference values

Result: negative.

S/CO ratio (signal/cutoff): 0 - 0.7.

Negative result

• There is currently no current CMV infection. If there are symptoms of a certain disease, then they are caused by another pathogen. In this case, CMV may be present in a latent form. However, if the infection occurred quite recently (several days ago), then IgM antibodies may not have had time to appear in the blood yet.

Positive result

• Recent infection (primary infection). During a primary infection, the IgM level is higher than during an exacerbation.

  After the primary infection, IgM can be detected for several months.

• Exacerbation of latent infection.

Important Notes

• Sometimes you need to find out whether a newborn baby is infected with cytomegalovirus. For this purpose, PCR is used and antibodies are additionally determined. If IgM is detected in the child’s blood, it means that he is truly infected with CMV.
• What is reinfection? There are several varieties of CMV in nature. Therefore, it is possible that a person already infected with one type of virus becomes infected with another.

Who orders the study?

General practitioner, therapist, infectious disease specialist, gynecologist.

Literature

• Adler S. P. Screening for Cytomegalovirus during Pregnancy. Infect Dis Obstet Gynecol. 2011:1-9.
• Goldman's Cecil Medicine. 24th ed. Goldman L, Schafer A.I., eds. Saunders Elsevier; 2011.
• Lazzarotto T. et al. Why is cytomegalovirus the most frequent cause of congenital infection? Expert Rev Anti Infect Ther. 2011; 9(10): 841–843.

A positive test result for IgG to cytomegalovirus means that the person is immune to this virus and is a carrier of it.

Moreover, this does not at all mean that the cytomegalovirus infection is in the active stage or any guaranteed dangers for a person - it all depends on his own physical condition and the strength of the immune system. The most pressing question of the presence or absence of immunity to cytomegalovirus is for pregnant women - it is on the developing fetus that the virus can have a very serious impact.

Let's look at the meaning of the analysis results in more detail...

IgG analysis for cytomegalovirus: the essence of the study

An IgG test for cytomegalovirus means looking for specific antibodies to the virus in various samples from the human body.

For reference: Ig is an abbreviation for the word “immunoglobulin” (in Latin). Immunoglobulin is a protective protein produced by the immune system to destroy the virus. For each new virus that enters the body, the immune system produces its own specific immunoglobulins, and in an adult, the variety of these substances becomes simply enormous. For simplicity, immunoglobulins are also called antibodies.

The letter G is a designation for one of the classes of immunoglobulins. In addition to IgG, humans also have immunoglobulins of classes A, M, D and E.

Obviously, if the body has not yet encountered the virus, then it has not yet produced the corresponding antibodies to it. And if there are antibodies to the virus in the body, and the test for them is positive, then, consequently, the virus has already entered the body at some point. Antibodies of the same class against different viruses are quite different from each other, so an IgG test gives a fairly accurate result.

An important feature of the cytomegalovirus itself is that once it infects the body, it remains in it forever. No medicine or therapy will help you get rid of it completely. But since the immune system develops a strong defense against it, the virus remains to exist in the body in an invisible and practically harmless form, persisting in the cells of the salivary glands, some blood cells and internal organs. Most carriers of the virus are not even aware of its existence in their bodies.

You also need to understand the differences between the two classes of immunoglobulins - G and M - from each other.

IgM are fast immunoglobulins. They are large in size and are produced by the body for the fastest possible response to the penetration of the virus. However, IgM does not form immunological memory, and therefore, with their death after 4-5 months (this is the lifespan of the average immunoglobulin molecule), the protection against the virus with their help disappears.

IgG are antibodies that, once produced, are cloned by the body and maintain immunity against a specific virus throughout life. They are much smaller than the previous ones, but are produced later on the basis of IgM, usually after the infection has been suppressed.

We can conclude: if cytomegalovirus-specific IgM is present in the blood, this means that the body became infected with this virus relatively recently and, perhaps, an exacerbation of the infection is currently occurring. Other details of the analysis can help clarify more subtle details.

Decoding of some additional data in the analysis results

In addition to just a positive IgG test, the test results may contain other data. The attending physician should understand and interpret them, but just to understand the situation it is useful to know the meanings of some of them:

1. Anti- Cytomegalovirus IgM+, Anti- Cytomegalovirus IgG-: cytomegalovirus-specific IgM is present in the body. The disease occurs in an acute stage; most likely, the infection was recent;
2. Anti- Cytomegalovirus IgM-, Anti- Cytomegalovirus IgG+: inactive stage of the disease. The infection occurred a long time ago, the body has developed a strong immunity, and viral particles that enter the body again are quickly eliminated;
3. Anti-Cytomegalovirus IgM-, Anti-Cytomegalovirus IgG-: There is no immunity to CMV infection. The organism had never encountered it before;
4. Anti- Cytomegalovirus IgM+, Anti- Cytomegalovirus IgG+: reactivation of the virus, exacerbation of infection;
5. Antibody avidity index below 50%: primary infection of the body;
6. Antibody avidity index above 60%: immunity to the virus, carriage or chronic form of infection;
7. Avidity index 50-60%: uncertain situation, the study must be repeated after a few weeks;
8. Avidity index 0 or negative: the body is not infected with cytomegalovirus.

It should be understood that the different situations described here may have different consequences for each patient. Accordingly, they require individual interpretation and approach to treatment.

A positive test for CMV infection in a person with normal immunity: you can just relax

In immunocompetent people who do not have diseases of the immune system, positive tests for antibodies to cytomegalovirus should not cause any alarm. Whatever the stage of the disease, with strong immunity it usually proceeds asymptomatically and unnoticed, only sometimes expressing itself in the form of a mononucleosis-like syndrome with fever, sore throat and malaise.

It is only important to understand that if tests indicate an active and acute phase of the infection, even without external symptoms, then from a purely ethical point of view, the patient needs to independently reduce social activity for a period of a week or two: be less in public, limit visits to relatives, not communicate with small children and especially with pregnant women (!). At this moment, the patient is an active spreader of the virus and is capable of infecting a person for whom CMV infection can be truly dangerous.

Presence of IgG in immunocompromised patients

Perhaps the most dangerous virus is cytomegalovirus for people with various forms of immunodeficiency: congenital, acquired, artificial. Their positive IgG test result may be a harbinger of complications of the infection such as:

• hepatitis and jaundice;
• cytomegalovirus pneumonia, which is the cause of death in more than 90% of AIDS patients in developed countries of the world;
• diseases of the digestive tract (inflammation, exacerbation of peptic ulcers, enteritis);
• encephalitis, accompanied by severe headaches, drowsiness and, in advanced conditions, paralysis;
• retinitis is an inflammation of the retina of the eye, leading to blindness in a fifth of patients with immunodeficiencies.

The presence of IgG to cytomegalovirus in these patients indicates a chronic course of the disease and the likelihood of an exacerbation with a generalized course of infection at any time.

Positive test results in pregnant women

In pregnant women, the results of an analysis for antibodies to cytomegalovirus can determine how likely the fetus is to be affected by the virus. Accordingly, it is based on the test results that the attending physician makes a decision on the use of certain therapeutic measures.

A positive test for IgM to cytomegalovirus in pregnant women indicates either a primary infection or a relapse of the disease. In any case, this is a rather unfavorable development of the situation.

If this situation is observed in the first 12 weeks of pregnancy, it is necessary to take urgent measures to combat the virus, since with primary infection of the mother there is a high risk of teratogenic effects of the virus on the fetus. With a relapse, the likelihood of fetal damage decreases, but still persists.

With later infection, it is possible for the child to develop a congenital cytomegalovirus infection or become infected at the time of birth. Accordingly, specific pregnancy management tactics will be developed in the future.

The doctor can determine whether the doctor is dealing with a primary infection or a relapse in this case by the presence of specific IgG. If the mother has them, it means that she has immunity to the virus, and the exacerbation of the infection is caused by a temporary weakening of the immune system. If there is no IgG for cytomegalovirus, this indicates that the mother became infected with the virus for the first time during pregnancy, and the fetus will most likely be affected by it, as well as the mother’s entire body.

To take specific therapeutic measures, it is necessary to study the patient’s medical history, taking into account many additional criteria and features of the situation. However, the mere presence of IgM already indicates that there is a risk to the fetus.

The presence of IgG in newborns: what does it mean?

The presence of IgG to cytomegalovirus in a newborn indicates that the baby was infected with the infection either before birth, or at the time of birth, or immediately after it.

Neonatal CMV infection is clearly indicated by a fourfold increase in IgG titer in two tests at a monthly interval. In addition, if the presence of specific IgG in the blood of a newborn is observed already in the first three days of life, they usually speak of a congenital cytomegalovirus infection.

CMV infection in children can be asymptomatic, or can be expressed by quite serious symptoms and have complications such as inflammation of the liver, chorioretinitis and subsequent strabismus and blindness, pneumonia, jaundice and the appearance of petechiae on the skin. Therefore, if cytomegalovirus is suspected in a newborn, the doctor must carefully monitor his condition and development, remaining ready to use the necessary means to prevent complications.

What to do if you test positive for antibodies to CMV infection

If you test positive for cytomegalovirus, you should first consult your doctor.

In most cases, the infection itself does not lead to any consequences, and therefore, in the absence of obvious health problems, it makes sense not to carry out treatment at all and entrust the fight against the virus to the body itself.

The drugs used to treat CMV infection have serious side effects, and therefore their use is prescribed only in cases of urgent need, usually in patients with immunodeficiencies. In these situations use:

1. Ganciclovir, which blocks the multiplication of the virus, but at the same time causes digestive and hematopoietic disorders;
2. Panavir in the form of injections, not recommended for use during pregnancy;
3. Foscarnet, which can cause kidney problems;
4. Immunoglobulins obtained from immunocompetent donors;
5. Interferons.

All these drugs should be used only on the recommendation of a doctor. In most cases, they are prescribed only to patients with immunodeficiencies or those who are prescribed chemotherapy or organ transplants that involve artificial suppression of the immune system. Only sometimes they treat pregnant women or infants.

In any case, it should be remembered that if previously there were no warnings about the danger of cytomegalovirus for the patient, then everything is fine with the immune system. And a positive test for cytomegalovirus in this case will only inform about the fact of the presence of already formed immunity. All that remains is to maintain this immunity.

Video about the danger of cytomegalovirus infection for pregnant women

Cytomegalovirus infection is the leading disease among congenital viral infections of newborns. This virus can be a silent lifelong cohabitant in the human body or become a potential killer under certain conditions. This is one of the most dangerous viruses for newborns, since CMV infection can cause mental retardation and death in children. Both primary infection with the virus during pregnancy and reactivation of an infection already living in the body are dangerous.

The concept of “immunity to CMV” does not exist!

Cytomegalovirus was discovered relatively recently - in 1956, and has not yet been sufficiently studied. It belongs to the group of herpes viruses. Carriers of the CMV virus aged 30 to 40 years are 50-90% of the population. IGG antibodies to cytomegalovirus are also detected in people who did not have any symptoms of herpetic diseases at the time of examination.

CMV is transmitted from person to person through contact with infected blood, saliva, urine, breast milk, and also through sexual intercourse. The virus is not very contagious and requires close contact to become infected through household contact. However, he feels great in the salivary glands, and any, even the most innocent kiss, a sip of water from a shared bottle or a cup of coffee “for two” can turn out to be fatal.

The latent (incubation) period lasts from 28 to 60 days. The likelihood of infection increases with, and this condition is natural during pregnancy. That's why Pregnant women are much more likely to become infected with this virus. And it is even higher in pregnant women undergoing immunosuppressive therapy (receiving metipred).

Primary infection occurs in 0.7-4% of all pregnant women. Return infection (reactivation) can occur in 13% of infected pregnant women. In some cases, secondary infection is observed, but with other strains of cytomegalovirus (a total of 3 strains have been registered).

The majority of people (95-98%) infected with CMV do not have clear symptoms during primary infection - usually the disease occurs under the guise of an acute respiratory viral infection. Symptoms include fever, muscle pain, and diarrhea. The main difference between cytomegalovirus infection and the common cold is that the course of cytomegaly is usually longer - up to 4-6 weeks.

With a generalized (general, severe) form of cytomegalovirus infection damage to internal organs is possible. This form of cytomegaly usually occurs against the background of a sharp decrease in immunity. In this case, a layered septic bacterial infection is possible, which is usually difficult to cure. The parotid and submandibular salivary glands may enlarge, inflammation of the joints occurs, and the skin becomes covered with a rash. About a third of patients will have cervical lymphadenitis (tender neck lymph nodes), pharyngitis (sore throat), and splenomegaly (enlarged spleen). Changes in the blood: decreased hemoglobin level, leukopenia (decrease in the level of white blood cells), increased number of lymphocytes (observed with any viral exacerbation), thrombocytopenia (decreased level of platelets), transaminases (a special substance in the blood) are moderately increased in more than 90% of patients.

Genital cytomegalovirus infection in women may be characterized by the development of inflammatory reactions in the form of vulvovaginitis, colpitis, inflammation of the inner layer of the uterus, salpingoophoritis. Patients are concerned about discharge from the genital tract and rectum of a whitish-bluish color. During examination, seals with a diameter of 1-2 mm are often found, located on the labia minora and majora. The mucous membrane is usually hyperemic (reddened) and edematous.

In men, a generalized form of cytomegalovirus infection affects the testicles, causes inflammation of the urethra and discomfort when urinating.

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After infection with CMV, an immune restructuring occurs in the human body, which adapts the body to new conditions. pursues the virus in the blood, driving it, as a rule, into the salivary glands and kidney tissue, where the virus becomes inactive and “sleeps” for many weeks and months.

How does a fetus become infected with cytomegalovirus?

At primary infection infection of the fetus with cytomegalovirus occurs in 30-40% of cases, and according to some data from European scientists, infection of the fetus can be observed in 75% of cases. At reactivation of current infection transmission of the virus to the fetus is observed in only 2% of cases, although there is evidence indicating a much higher likelihood of damage. Congenital CMV infection is present in 0.2-2% of all newborns.

There are three main mechanisms of transmission of the virus to the fetus:

1. the embryo may be infected with a virus from the sperm;
2. cytomegalovirus can penetrate from the endometrium or cervical canal through the fetal membranes and infect the amniotic fluid, and then the fetus;
3. cytomegalovirus can infect the fetus transplacentally.
4. Possible infection during childbirth.

(Different studies estimate the likelihood of one or another route of infection differently.)

The CMV infection virus is transmitted to the fetus through the placenta in any period of pregnancy in the same way (although the likelihood of reactivation of a latent infection in the maternal body is higher in the third trimester). If the mother is infected in the first trimester, then in 15% of these women the pregnancy ends in spontaneous miscarriage without viral infection of the embryo itself, that is, the infectious process is found only in the placenta. Therefore, there is an assumption that the placenta is infected first, which nevertheless continues to act as a barrier in the transmission of CMV to the fetus. The placenta also becomes a reservoir for CMV infection. It is believed that CMV multiplies in the placental tissue before it infects the fetus.

In the early stages of pregnancy, spontaneous miscarriage due to cytomegalovirus infection occurs 7 times more often than in the control group.

How is cytomegalovirus infection dangerous for the fetus? What are the consequences of infection with cytomegalovirus for the fetus?

Transmission of the virus to the fetus in some cases leads to

• birth of a low birth weight child,
• development of infection with intrauterine fetal death (miscarriage, spontaneous abortion, stillbirth - up to 15%),
• the birth of a child with congenital CMV infection, which is manifested by developmental defects (microcephaly, jaundice, enlarged liver, spleen, hepatitis, heart defects, inguinal hernia, congenital deformities),
• the birth of a child with congenital CMV infection, which does not appear immediately, but in 2-5 years of life (blindness, deafness, speech inhibition, mental retardation, psychomotor impairment).

It is possible to exclude transmission of cytomegalovirus to the fetus if both partners who are CMV carriers undergo a course of therapy before conceiving the child.

Cytomegalovirus infection can provoke the appearance of antiphospholipids in the mother’s body, which will attack the cells of her body (autoaggression). This is a very dangerous complication of CMV. Antiphospholipids can damage placental vessels and disrupt uteroplacental blood flow.

Diagnosis of CMV. Analysis for cytomegalovirus

Over the past thirty years, many laboratories around the world have developed many diagnostic methods for detecting CMV in the human body. Diagnostic testing in pregnant women is important at the slightest suspicion for the presence of cytomegalovirus infection, especially with an unfavorable outcome of a previous pregnancy and with clinical manifestations (symptoms) of CMV infection.

Clinical manifestations of cytomegalovirus infection

• If a person has both the herpes simplex virus and CMV in the body at the same time, they often become aggravated at the same time. Therefore, a “cold” on the lip is a reason to be examined for CMV.
• White-bluish discharge from the vagina.
• Any rash on the skin (even isolated ones). They differ from pimples in that they appear simultaneously and do not have a purulent head - just red dots.
• The appearance of small hard subcutaneous formations on the labia minora or majora.
• In some cases, the only sign of the disease is inflammation of the salivary glands, where the cytomegalovirus feels most comfortable.

If you have at least one of these symptoms during pregnancy, you need to urgently start testing for cytomegalovirus!

Toxicosis in the first half of pregnancy and spotting in the second can be associated with cytomegalovirus.

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

The test for antibodies to CMV includes the determination of two specific immunoglobulins: IgM and IgG. For IgM they write “positive” or “negative” (qualitative characteristic), while for IgG the titer is determined (quantitative characteristic).

IgM antibodies appear in the blood during primary infection (always, but their appearance may be delayed for up to 4 weeks) and upon activation of an existing infection (in 10% of cases). If the CMV test says “IgM positive,” this means the infection is active. You cannot become pregnant against the background of active CMV!!! In this case, you should determine the level of IgM antibodies over time (quantitative method) to find out whether your IgM titers are rising or falling, and, accordingly, at what stage the infection is at. A rapid drop in IgM titers indicates a recent infection/exacerbation; a slow drop indicates that the active phase of the infection has passed. If IgM is not found in the blood serum of an infected person, then this indicates that the infection occurred at least 15 months before the time of diagnosis, but does not completely exclude the current reactivation of the virus in the body, that is, the absence of IgM in the blood test does not give reason to believe that that you can start conceiving! More research is required (see below). Question: why then take this test at all? Answer: it is still able to detect the active form of the virus and is inexpensive. In some situations, as a result of the very high sensitivity of the tests, false positive results are possible when determining IgM.

If a person has never encountered CMV, the IgG titer will be lower than the reference value indicated on the analysis form. This means there is a high risk of CMV infection during pregnancy. Women who do not have an IgG titer to CMV are at risk!

After primary infection with CMV, IgG antibodies remain in the blood for life. But this - not immune to cytomegalovirus! The presence of IgG allows for the possibility of reactivation of the infection against the background of weakened immunity by pregnancy. After infection/reactivation, IgG titers increase (activation of CMV is indicated by an increase in titer of 4 or more times relative to the baseline level characteristic of a given patient), then fall VERY SLOWLY.

The level of latent IgG antibodies depends both on the state of the virus at the moment and on the state of the person’s immunity, therefore a single analysis that shows the presence of Ig G antibodies in the body, even at values ​​several times higher than the reference value, does not clearly indicate an exacerbation of CMV.

What do IgM and IgG antibodies show against cytomegalovirus?

Primary infection or reactivation? If IgM is positive, the avidity of IgG antibodies should be determined. Avidity (lat. - avidity)- characteristic of the strength of the connection of specific antibodies with the corresponding antigens. During the body's immune response, IgG antibodies initially have low avidity, that is, they bind the antigen quite weakly. Then the development of the immune process gradually (this can be weeks or months) moves towards the synthesis by lymphocytes of high-avidity IgG antibodies, which bind more firmly to the corresponding antigens. Low-avidity IgG antibodies (avidity index (AI) up to 35%), on average, are detected within 3-5 months from the onset of infection (this may depend to some extent on the determination method), but are sometimes produced over a longer period. In itself, the detection of low-avidity IgG antibodies is not an unconditional confirmation of the fact of fresh infection, but serves as additional confirmatory evidence among other serological tests. The high avidity of specific IgG antibodies (avidity index greater than 42%) allows us to exclude recent primary infection.

However, a blood test for antibodies, especially a single one, cannot provide sufficient information about the course of cytomegalovirus infection in the body. If the result of an antibody test is positive, one of the other methods is usually used, both to confirm the presence of antibodies and to determine the presence of the active virus itself.

Polymerase chain reaction (PCR) method for diagnosing cytomegalovirus

This method of diagnosing cytomegalovirus is based on identifying the DNA of the infectious agent, since cytomegalovirus is a DNA-containing virus. The material for research may be discharge from the urethra, cervix, vagina, urine, saliva, cerebrospinal fluid. The time from taking material for research to obtaining results is usually 1-2 days, and this is the main advantage of the PCR method over the method of cultural diagnostics (seeding).

The PCR method, due to its high sensitivity, detects even a segment of CMV DNA and is considered very progressive. Its most important advantage is the ability to diagnose early stages of the process, latent and persistent infection, but it has a low predictive value due precisely to the fact that PCR detects viral DNA even in a latent state. In other words, this method does not distinguish between an active virus and a dormant one.

Qualitative and quantitative determination of CMV DNA in almost any fluid of the human body has an accuracy of up to 90-95% - if the virus is currently present in this tissue. A feature of CMV is its optional presence in all biological fluids at once.

Detection of CMV by PCR in human biological tissues does not make it possible to determine whether the infection is a primary infection or a reactivation of a current infection.

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

This is a diagnostic method in which the test material, taken from blood, saliva, semen, discharge from the cervix and vagina, amniotic fluid, is placed in a special nutrient medium favorable for the growth of microorganisms. The disadvantage of this method is that obtaining results requires a lot of time: a week or more.

A positive test (“the virus has been detected”) has 100% accuracy; a negative test may be false.

Cytology for the diagnosis of cytomegalovirus

Cytological examination reveals typical giant cells with intranuclear inclusions, but is not a reliable method for diagnosing CMV infection.

Probability of fetal infection and antibody levels

The likelihood of fetal infection is directly proportional to the concentration of the virus in the blood. It does not matter whether it is a primary infection or reactivation, it is the concentration of the virus that is important. The concentration of the virus is determined by the level of protective antibodies: the more antibodies, the lower the concentration of the virus. People who are exposed to CMV for the first time do not have antibodies, and therefore the concentration of the virus is high, which means that infection of the fetus is most likely. Carriers of CMV have antibodies, and the concentration of the virus in the blood is lower. An exception is for pregnant women receiving immunosuppressive therapy (usually metipred). Metypred suppresses the production of all types of antibodies in the body, which means that protection against CMV is weaker than it would be in the absence of Metypred, and the likelihood of transmitting the virus to the fetus increases.

There is another aspect related to the degree of damage that the virus causes to the fetus. IgG antibodies penetrate the placenta and in the blood of the fetus are able to fight the cytomegaly virus. The level of antibodies in the fetus's body is determined by the level of antibodies in the mother's body. If this level is high enough, the harm caused by CMV may be reduced to zero: a child infected with CMV in utero may not show signs of CMV infection either immediately or later.

The most severe lesions occur in children whose mothers were primarily infected with CMV. In second place are those whose mothers received immunosuppressive therapy. The third category includes cases of CMV reactivation during pregnancy that were not detected and treated. The latter includes cases of reactivation in pregnant women not receiving immunosuppressive therapy, in whom reactivations were detected and who received treatment in the form of intravenous infusion of immunoglobulins.

Management of pregnancy, childbirth and the postpartum period in women with CMV infection. Necessary tests for CMV in pregnant women

In conditions of risk of exacerbation of CMV, it is necessary to carry out a quick and, most importantly, reliable diagnosis in order to start using the necessary drugs on time and prevent the virus from spreading in the body. The method for determining antibodies is not suitable, since antibodies are formed with a long delay. The PCR method gives an answer almost instantly, but cannot distinguish a live virus from a dead one. The only way out is sowing, although it takes a long time.

In this case, it is worth doing blood cultures at least twice - at the beginning and at the end of the first trimester, since infection of the fetus during this period is most dangerous.

The length of pregnancy has a significant influence on the incidence of infection in the mother. In the early stages of pregnancy, the production of cytomegalovirus is suppressed, but this suppression decreases as pregnancy progresses, and the likelihood of cytomegalovirus release as a consequence of reactivation of the infection increases. Therefore, it is a good idea to do a blood culture in both the second and third trimester, since intrauterine infection is possible at any stage.

Activation of CMV in the body of a pregnant woman does not mean intrauterine infection of the fetus. Carefully selected powerful therapy and strict adherence to the doctor’s recommendations can significantly reduce the risk of transmission of infection to the child, which directly depends on the activity of the virus in the mother’s body. I’ll say right away that the only cure for the virus during pregnancy is immunoglobulin.

Against the background of cytomegaly, the weight of the fetus often exceeds the gestational age, and partial accretion of the child’s place, premature abruption of a normally located placenta, blood loss during childbirth, reaching 1% of the woman’s body weight, and clinical manifestations of latent postpartum endometritis with the development of menstrual irregularities in the future are also observed.

Infection of a child can occur during childbirth when he ingests cervical mucus and vaginal discharge from the mother. This virus is also found in breast milk, so more than half of breastfed children become infected with CMV infection in the first year of life. Intranatal or early postnatal transmission of cytomegalovirus occurs 10 times more often than transplacental transmission.

Women who actively shed the virus during pregnancy can give birth on their own, since a cesarean section does not provide any benefit in protecting the baby from infection in this case.

Obstetricians often face the question: should a woman infected with cytomegalovirus continue pregnancy or should she consider it contraindicated? This issue must be resolved on the basis of dynamic monitoring using ultrasound monitoring of fetal development (malformations), prenatal study of anti-cytomegalovirus IgM antibodies in the fetus when collecting amniotic fluid by amniocentesis.

After birth, it is important to confirm the diagnosis of congenital CMV infection within the first two weeks, and to carry out a differential diagnosis with primary infection during childbirth during passage through the birth canal or infection through milk in the first days of breastfeeding.

Diagnosis of CMV infection in the fetus

Determination of IgM in fetal blood is not a reliable diagnostic method, since the appearance of these antibodies can be greatly delayed. However, the detection of IgM in umbilical cord blood is unambiguous evidence of infection of the fetus, since these antibodies, due to their significant molecular weight, do not penetrate the placental barrier.

Currently, detection of a virus culture in amniotic fluid (culture) and polymerase chain reaction (PCR) make it possible to make a correct diagnosis in 80-100% of cases. The level of all virological parameters (viremia, antigenemia, DNAemia, etc.) in the blood of fetuses with developmental abnormalities is higher than in fetuses in which no abnormalities were found. Also, the level of specific IgM immunoglobulins in normally developing fetuses is much lower than the level of these antibodies in children with developmental disabilities. These data suggest that congenital CMV infection in infected fetuses with normal biochemical, hematological and ultrasound features, as well as low levels of the viral genome and antibodies to it, has a more favorable outcome.
Determination of viral DNA in amniotic fluid can be a good prognostic factor: its level is lower if no developmental abnormalities are found in the fetus.
Negative test results are not a reliable sign of the absence of infection in the fetus.
The risk of transmission of the virus from mother to child during diagnostic procedures when the mother has active virus is small.

Treatment of cytomegalovirus

CMV infection in a latent state generally does not require treatment.

In certain cases, antiviral drugs may be prescribed. The effect of these drugs on the body of a pregnant woman and the fetus has not been fully studied. The use of antiviral drugs is also limited in pediatrics due to the high toxicity of the drugs.

Treatment with immunomodulators usually lasts for several weeks; they are prescribed only by a doctor.

Specific anticytomegalovirus immunoglobulin is administered intravenously (dropper). It contains 60% CMV-specific antibodies. Intramuscular administration of immunoglobulin is allowed, but this significantly reduces its effectiveness. It should be noted that the use of immunoglobulin only reduces the likelihood of infection of the fetus or reduces the negative consequences of this infection, however, even such an inferior result gives a gain in the health of children, so a specific immunoglobulin should definitely be used, especially considering the complete harmlessness of the drug.

Nonspecific immunoglobulins for intravenous administration are prescribed for the prevention of CMV infection in immunocompromised individuals. However, their effectiveness is much lower than that of specific immunoglobulins. However, they can also help in the fight against cytomegalovirus infection.

The cytomegalovirus is almost insensitive to the action of , which is an important factor determining the significant frequency of latent cytomegalovirus infection. At the same time, cytomegalovirus interferes with the production of interferon in conditions of mixed infection, one of the components of which is a virus that has interferonogenic activity in monoinfection. Thus, it is known that in patients with cytomegaly, influenza occurs in a more severe form.

Leukocyte interferon introduced into tissue culture protects cells from extracellular cytomegalovirus, but does not have a protective effect against intracellular one.

So, the drug of choice during pregnancy is immunoglobulin. The level of damage to the fetus directly depends on the level of antibodies in the mother’s blood.

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 occur either asymptomatically or with multiple lesions of 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 allows diagnosing the disease in the early stages, as well as monitoring 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 at a 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 of protective immunity occurs in a shorter period of time - up to 1-2 weeks. A feature of cytomegalovirus infection is that the pathogen can avoid the action of immune forces by creating other varieties of the virus. Therefore, infection with modified microbes proceeds as during primary contact.

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 a low standard of living, 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 of a chronic form of the disease.

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 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 the general condition, lifestyle, activity of the immune system 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 interpreted in the manner indicated in the table below.

Table:

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

Children during the neonatal period and breastfeeding may have IgG in their blood that they received in utero from their 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.

Taking into account the overall 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.

The antenatal clinic doctor should issue directions for monitoring the IgG titer also in the second and third 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 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 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, and secretions from the cervical canal can be used as biological fluids for analysis.

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 strongly depends on the quality of the collection of biological material and the time between the analysis and 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.

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:

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 - fever, headaches and muscle pain, general weakness, chills.

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

This infection is most dangerous in the early stages of pregnancy, as fetal death and miscarriage often occur.

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.

Subsequently, mental retardation may become apparent. 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: