(CMV) is one of the pathogens herpetic infection. Detection of immunoglobulins (Ig) in the blood allows us to determine the stage of development of the disease, severity infectious process and the state of immunity. The class of immunoglobulins G indicates immunological memory - penetration of cytomegalovirus into the body, carriage of infection, formation of stable immunity. For correct diagnosis diseases are carried out in parallel with the blood concentration of Ig M and the avidity index. Next, we will consider in detail what this means - cytomegalovirus Ig G positive.
When infectious agents, including viral ones, enter the body, the immune system produces protective protein substances - antibodies or immunoglobulins. They bind to pathogenic agents, block their reproduction, cause death and are removed from the body. For each bacterium or virus, specific immunoglobulins are synthesized that are active against only these infectious agents. When CMV enters the body, it penetrates into the cells of the nervous and immune systems, cells salivary glands and remain in them in a latent state. This is the carrier phase of the virus. With a significant decrease in immunity, exacerbation of infection occurs.
Antibodies come in different classes: A, M, D, E, G. When detecting cytomegalovirus infection, immunoglobulins of class M and G (Ig M, Ig G) are of diagnostic importance.
Antibodies come in different classes: A, M, D, E, G. When detecting cytomegalovirus infection, immunoglobulins of class M and G (Ig M, Ig G) are of diagnostic importance. Immunoglobulins M are produced from the first days of infection into the body and during exacerbation of the disease. Ig M have large protein molecules, neutralize viruses, and lead to recovery. Ig G is smaller in size, synthesized 7-14 days after the onset of the disease and is produced in small quantities throughout a person’s life. These antibodies are an indicator of immunological memory to CMV and keep the virus under control, preventing it from multiplying and infecting new host cells. In case of re-infection or exacerbation of infection, they participate in the rapid neutralization of viruses.
Evaluation of the results of an analysis for the detection of immunoglobulins G
Antibodies in the blood are detected using immunological laboratory diagnostics - enzyme immunoassay(ELISA). To determine the stage of the disease and the level of immunity to cytomegalovirus, the presence of Ig G, Ig M, in the blood or other biological fluid is assessed. Analysis only for the content of class G immunoglobulins does not have sufficient diagnostic value and is not prescribed separately.
The structure of the immunoglobulin G (Ig G) molecule.
Possible ELISA results for the determination of antibodies to CMV.
- Ig M – negative, Ig G – negative. This means that the body has never encountered, there is no stable immunity, there is a high probability of infection with CMV.
- Ig M – positive, Ig G – negative. This means the initial penetration of infection into the body, the acute phase of the disease, stable immunity has not yet been developed.
- Ig M – positive, Ig G – positive. This means an exacerbation of the disease against the background of a chronic course or carriage, which is associated with a sharp suppression of the body’s defenses.
- Ig M – negative, Ig G – positive. This means the recovery phase after a primary infection or exacerbation of the disease, the period of the chronic course of the disease, carriage, and stable immunity to CMV has been developed.
To correctly interpret the stage of the disease, the presence of Ig G and Ig M in the blood is carried out together with determining the value of the Ig G avidity index - the ability of antibodies to bind to the virus. At the beginning of the disease, this indicator is low; as the infectious process develops, the avidity index increases.
Evaluation of Ig G avidity index results.
- Avidity index less than 50% – low binding ability of class G immunoglobulins to cytomegalovirus, early phase acute period diseases.
- An avidity index of 50-60% is a questionable result; the analysis must be repeated after 10-14 days.
- An avidity index of more than 60% – high binding ability of class G immunoglobulins to the virus, late phase acute period, recovery, carriage, chronic form of the disease.
- Avidity index 0% – there is no cytomegalovirus infection in the body.
When determining Ig G in blood or other biological fluid, the avidity index cannot be equal to 0%.
The role of determining immunoglobulins G
Primary infection and carriage of CMV in normal level immunity is asymptomatic without significant harm to health. Sometimes, when the infection becomes infected and worsens, mononucleosis syndrome occurs, the clinical signs of which are similar to those of a cold: weakness, headache, low-grade fever(37-37.6), sore throat, enlarged regional lymph nodes. In most cases, cytomegalovirus infection goes unnoticed, diagnostics to detect antibodies is not carried out.
For a contingent of people who are at risk for developing severe forms of the disease, the detection of Ig G in the blood is of significant importance. In such patients, CMV affects the brain (meningoencephalitis), liver (hepatitis), kidneys (nephritis), eyesight (retinitis), lungs (pneumonia), which can cause death. During pregnancy, infection or exacerbation of infection leads to intrauterine fetal death, the formation of malformations, and prenatal cytomegalovirus infection. Assessment of the level of class G antibodies is carried out to prescribe antiviral therapy and determine the prognosis of the disease.
At-risk groups:
- congenital immunodeficiencies;
- acquired immunodeficiencies;
- artificial immunodeficiencies (taking glucocorticoids, chemotherapy, radiation therapy);
- transfer internal organs;
- severe chronic diseases;
- intrauterine development of the fetus.
Test for determination of Ig G and Ig M in blood or other biological fluids prescribed regularly for early detection primary infection and exacerbation of the disease.
Risk group – patients with immunodeficiency conditions
A sharp decrease in the body's defenses during immunodeficiency leads to a decrease in the synthesis of class G immunoglobulins, which occurs constantly after primary infection with CMV. Against this background, the virus passes from a latent (“sleeping”) state into the active phase of life - it destroys cells of the salivary glands, the nervous and immune systems, multiplies, and infects the tissues of the brain and internal organs. When the immune system is suppressed, they develop severe forms diseases.
To monitor the activity of cytomegalovirus in the body, patients with immunodeficiency conditions are prescribed routine tests for blood levels of Ig G, avidity index Ig G, Ig M. For patients receiving immunosuppressive therapy - treatment of cancer, autoimmune diseases, after organ transplantation, immunological diagnostics are carried out for timely appointment antiviral drugs and preventing disease progression.
Risk group – fetus during intrauterine development
At the stage of pregnancy planning, in the first and second half of gestation, a woman needs to take a blood test to check for antibodies to CMV. Assessment of immunological memory for cytomegalovirus infection determines the risks of intrauterine infection and fetal death.
The main risk group is people with immunodeficiency conditions (HIV, AIDS, consequences of chemotherapy).
- Ig G – positive, avidity index more than 60%, Ig M – negative. Means that . The mother's body has developed immunity to cytomegalovirus infection. Exacerbation of the disease is unlikely, in most cases it is safe for the fetus.
- Ig G – negative, avidity index 0%, Ig M – negative. This means that the mother’s body does not have immunity to CMV. There is a risk of primary infection with cytomegolovirus infection during pregnancy. A woman needs to adhere preventive measures to prevent infection and donate blood for antibodies to CMV.
- Ig G is positive, avidity index is more than 60%, Ig M is positive. This means that, against the background of decreased immunity, an exacerbation of the infection has occurred. It is necessary to monitor the development of the disease and the condition of the fetus. In most cases, the child’s intrauterine development proceeds normally, since the mother has an immunological memory of the cytomegalovirus.
- Ig G – negative, avidity index less than 50%, Ig M – positive. The test result means a high risk of intrauterine infection of the fetus and a lack of immunity in the mother. When infected in the first 12 weeks of pregnancy, malformations are formed or intrauterine death of the child occurs. In the second half of pregnancy, prenatal cytomegalovirus infection of the fetus develops. Depending on the severity of the infection, observation, antiviral therapy, medical abortion, or premature delivery are prescribed.
The diagnostic results for the detection of antibodies to CMV are assessed by a doctor. When establishing the severity of the disease and prescribing therapy, the clinical picture, anamnesis of the disease, and the presence of concomitant pathology, results of other diagnostic methods.
The presence of class G immunoglobulins in the blood and other biological fluids indicates a previous cytomegalovirus infection and the formation of stable immunity. In people with a healthy immune system, this is an indicator of protection against re-infection and exacerbation of the disease.
Cytomegalovirus belongs to the herpes virus family, namely. A blood test for the virus will help detect it.
Cytomegalovirus affects different types of cells:
- salivary glands;
- kidney;
- liver;
- placenta;
- eyes and ears.
But, although the list is impressive, in most cases cytomegalovirus is not dangerous to human health!
What is the danger of cytomegalovirus?
- hearing loss;
- impairment or even loss of vision;
- mental retardation;
- the occurrence of seizures.
Such consequences can occur both during the primary infection and during activation. You just need to remember the likelihood of such serious consequences occurring.
An infant who becomes infected during pregnancy may have: external manifestations cytomegalovirus infection:
- intracerebral calcifications;
- ventriculomegaly (enlarged lateral ventricles of the brain);
- the liver and spleen are enlarged;
- excess fluid occurs in the peritoneum and chest cavity;
- microcephaly (small head);
- petechiae (small hemorrhages on the skin);
- jaundice.
What is analysis on igg?
If the igg is positive, this is evidence that the patient has developed immunity to the virus, but at the same time the person is its carrier.
This does not mean that cytomegalovirus is active or that the patient is in danger. The primary role will be played by the patient’s physical condition and immunity.
Most important It has positive test for a pregnant woman, since the baby’s body is still developing and does not produce antibodies to cytomegalovirus.
During the cytomegalovirus igg study, samples are taken from the patient's body to find specific antibodies to the cytomegalovirus igg. Igg is an abbreviation for the Latin word “immunoglobulin”.
This is a type of protective protein produced by the immune system to fight the virus.
The immune system begins to produce special antibodies for each new virus that appears in the body.
As a result, upon reaching , a person may already possess a whole “bouquet” of such substances. The letter G denotes a certain class of immunoglobulins, marked in humans with the letters A, D, E, G, M.
Thus, an organism that has not yet encountered the virus is unable to produce antiviral antibodies. This is why the presence of antibodies in a person indicates that the body has previously been exposed to the virus.
Please note: antibodies of the same type, which are designed to fight different viruses, have significant differences. This is why the results of cytomegalovirus tests on igg are quite accurate.
How is the analysis deciphered?
An important feature of cytomegalovirus is that after the initial damage to the body, it remains in it forever. No treatment will help get rid of its presence.
The virus functions practically without harm in the internal organs, blood and salivary glands, and its carriers do not even suspect that they are carriers of the virus.
What are the differences between immunoglobulins M and G?
Igm combines fast “large” antibodies produced by the body in order to respond to the virus as soon as possible.
Igm do not provide immunological memory, dying off within six months, and the protection that they are supposed to provide is eliminated.
igg refers to antibodies that the body clones from the moment they appear. This is done with the aim of maintaining protection against a particular virus throughout a person's life.
These cytomegalovirus antibodies are smaller in size and have a later production time. Typically, they are produced from igm antibodies after the infection has been suppressed.
That is why, having detected cytomegalovirus igm in the blood, which reacts to , it can be argued that the person became infected with the virus relatively recently and at the moment there may be an exacerbation of infection.
To get more full information, additional research indicators need to be studied.
Antibodies to cytomegalovirus igg
What additional tests can be done?
It may consist not only of information about cytomegalovirus, but also carry other necessary data. Specialists interpret the data and prescribe treatment.
To better understand the values, it is worth familiarizing yourself with the laboratory test indicators:
- Іgg– , igm+: specific igm antibodies were found in the body. With a high degree of probability, the infection occurred recently, and now there is an exacerbation of the disease;
- igg+, igm– means: the disease is inactive, although the infection occurred a long time ago. Since immunity has already developed, virus particles that re-enter the body are quickly destroyed;
- igg– , igm– – evidence of a lack of immunity to cytomegalovirus, since this virus has not yet been recognized by the body;
- igg+, igm+ – evidence of reactivation of cytomegalovirus and exacerbation of infection.
Another important indicator is called immunomodulins:
- below 50% is evidence of primary infection;
- 50 – 60% – the result is uncertain. Should be carried out reanalysis after 3 - 4 weeks;
- over 60% – there is immunity to the virus, although the person is a carrier or the disease has become chronic;
- 0 or negative result – the body is not infected.
If a person does not have immune system diseases, a positive one should not be a cause for concern.
At any stage of the disease, good immunity is a guarantee of an imperceptible and asymptomatic course of the disease.
Only occasionally does cytomegalovirus manifest itself with the following symptoms:
- general malaise.
It is important to remember that intensive and aggravated infection, even in the absence of external signs, it is recommended to reduce your activity for several weeks:
- appear less often in public places;
- communicate as little as possible with children and pregnant women.
At this stage, the virus is actively spreading, capable of infecting another person and requiring serious treatment for cytomegalovirus.
?
The greatest danger to the fetus occurs when the virus enters the female body during pregnancy. The danger increases if a woman becomes infected for the first time and is between 4 and 22 weeks pregnant.
If we are talking about reactivation of cytomegalovirus during pregnancy, the risk of infection for the fetus is minimal, but during pregnancy, cytomegalovirus infection can lead to the following consequences:
- birth of a mentally retarded child;
- The baby develops seizures, hearing or vision loss.
But one should not panic: the tragic consequences of cytomegalovirus are registered in 9% of cases with primary cytomegalovirus infection and 0.1% with re-infection.
Thus, the vast majority of women with such an infection give birth to healthy children!
Situations typical for pregnant women:
- If, even before pregnancy, a blood test showed antibodies to cytomegalovirus), then such a woman will never have a primary infection during pregnancy, since it has already occurred in the past - this is evidenced by antibodies in the blood.
- A blood test for antibodies was taken for the first time during pregnancy and antibodies to the virus were detected. In such cases, reactivation of the infection may occur during pregnancy, and the probability of serious damage to the fetus is 0.1%.
- The blood test was taken before pregnancy. The woman did not have antibodies to cytomegalovirus (igg-, CMV igm-).
Based on other medical publications, it can be argued: unfortunately, in domestic medicine, everything bad that happens to a child is usually attributed to cytomegalovirus infection.
Therefore, repeat tests for CMV IgG and CMV IgM are prescribed, as well as a PCR test for CMV mucus from the cervix.
Given the evidence of constant levels of CMV igg and the absence of CMV igg in the cervix, it can be safely denied that possible complications pregnancies are caused by cytomegalovirus.
Treatment of cytomegalovirus infection
It should be emphasized: none of the available treatment methods completely eliminates the virus.
If cytomegalovirus is asymptomatic, women with normal immunity do not need treatment.
Therefore, even if cytomegalovirus or antibodies to it were detected in a patient with good immunity, there are no indications for treatment.
Efficiency of use, polyoxidonium, etc. is not a panacea.
It can be argued: immunotherapy for cytomegalovirus infection, as a rule, is driven not so much by medical as by commercial considerations.
Treatment of cytomegalovirus in people with weakened immune systems is reduced to the use of (ganciclovir, foscarnet, cidofovir).
Cytomegalovirus penetrates the child’s cells immediately, remaining there for life, existing in an inactive state.
Children aged 2–6 months become infected with virtually no symptoms or any serious problems for good health.
But if a child becomes infected in the first months of life, infection can provoke a real tragedy.
We are talking about congenital infection, when the child became infected in the mother’s stomach during childbirth.
Which children are more dangerous from the virus?
- children who have not yet been born become infected during intrauterine development;
- with a weakened immune system;
- children of all ages with weakened or absent immunity.
Congenital infection with cytomegalovirus carries the risk of affecting the child with serious damage to the nerves, digestive system, blood vessels and musculoskeletal system.
There is a possibility of irreversible damage to the organs of hearing and vision.
Diagnosed using laboratory analysis. Enzyme immunoassay is widely used in the Russian Federation today.
Preventive measures
Using condoms reduces the risk of acquiring infection during sexual intercourse.
Those with a congenital infection should avoid casual intimate relationships during pregnancy.
You donated blood for an enzyme-linked immunosorbent assay (ELISA) and found out that cytomegalovirus IgG antibodies were detected in your biofluid. Is it good or bad? What does this mean and what actions should you take now? Let's understand the terminology.
What are IgG antibodies
Antibodies of the IgG class are a type of serum immunoglobulins involved in the body’s immune response to pathogens in infectious diseases. The Latin letters ig are an abbreviated version of the word “immunoglobulin”; these are protective proteins that the body produces to resist the virus.
The body responds to an infection attack with immune restructuring, forming specific antibodies of the IgM and IgG classes.
- Fast (primary) IgM antibodies are formed in large quantities immediately after infection and “pounce” on the virus to overcome and weaken it.
- Slow (secondary) IgG antibodies gradually accumulate in the body to protect it from subsequent invasions of the infectious agent and maintain immunity.
If the ELISA test shows positive cytomegalovirus IgG, it means that this virus is present in the body, and you have immunity to it. In other words, the body keeps the dormant infectious agent under control.
What is cytomegalovirus
In the mid-20th century, scientists discovered a virus that causes inflammatory swelling of cells, causing the latter to significantly exceed the size of surrounding healthy cells. Scientists called them “cytomegales,” which means “giant cells.” The disease was called “cytomegaly”, and the infectious agent responsible for it acquired the name known to us - cytomegalovirus (CMV, in Latin transcription CMV).
From a virological point of view, CMV is almost no different from its relatives, the herpes viruses. It is shaped like a sphere, inside which DNA is stored. Introducing itself into the nucleus of a living cell, the macromolecule mixes with human DNA and begins to reproduce new viruses, using the reserves of its victim.
Once CMV enters the body, it remains there forever. The periods of its “hibernation” are disrupted when a person’s immunity is weakened.
Cytomegalovirus can spread throughout the body and infect several organs at once.
Interesting! CMV affects not only humans, but also animals. Each species has a unique one, so a person can only become infected with cytomegalovirus from a person.
"Gateway" for the virus
Infection occurs through sperm, saliva, cervical mucus, blood, and breast milk.
The virus replicates itself at the site of entry: on the epithelium of the respiratory tract, gastrointestinal tract or genital tract. It also replicates in local lymph nodes. Then it penetrates into the blood and spreads throughout the organs, in which cells are now formed that are 3-4 times larger than normal cells in size. There are nuclear inclusions inside them. Under a microscope, infected cells resemble the eyes of an owl. Inflammation is actively developing in them.
The body immediately forms an immune response that binds the infection, but does not destroy it completely. If the virus has won, signs of the disease appear one and a half to two months after infection.
To whom and why is a test for antibodies to CMV prescribed?
Determining how protected the body is from cytomegalovirus attack is necessary under the following circumstances:
- planning and preparation for pregnancy;
- signs of intrauterine infection of the child;
- complications during pregnancy;
- intentional medical suppression of immunity in certain diseases;
- increase in body temperature for no apparent reason.
There may be other indications for immunoglobulin tests.
Methods for detecting the virus
Cytomegalovirus is recognized by laboratory research biological fluids of the body: blood, saliva, urine, genital secretions.- A cytological study of the cell structure identifies the virus.
- The virological method allows you to assess how aggressive the agent is.
- The molecular genetic method makes it possible to recognize the DNA of an infection.
- The serological method, including ELISA, detects antibodies in the blood serum that neutralize the virus.
How can you interpret the results of an ELISA test?
For an average patient, the antibody test data will be as follows: IgG – positive result, IgM – negative result. But there are other configurations as well.| Positive | Negative | Analysis transcript | |
| IgM | ? | The infection occurred recently, the disease is at its peak. | |
| ? | The body is infected, but the virus is not active. | ||
| ? | There is a virus, and right now it is being activated. | ||
| ? | There is no virus in the body and there is no immunity to it either. |
It seems that a negative result in both cases is the best, but, it turns out, not for everyone.
Attention! It is believed that the presence of cytomegalovirus in the modern human body is the norm; in its inactive form it is found in more than 97% of the world's population.
At-risk groups
For some people, cytomegalovirus is very dangerous. This: - citizens with acquired or congenital immunodeficiency;
- patients who have undergone organ transplantation and are being treated for cancer: they are artificially suppressed immune reactions body to eliminate complications;
- women carrying pregnancy: primary CMV infection may cause miscarriage;
- infants infected in the womb or while passing through birth canal.
In these most vulnerable groups, with negative IgM and IgG values for cytomegalovirus in the body, there is no protection from infection. Consequently, if it does not meet counteraction, it can cause serious illnesses.
What diseases can be caused by cytomegalovirus?
In immunocompromised individuals, CMV causes inflammatory reaction in internal organs:
- in the lungs;
- in the liver;
- in the pancreas;
- in the kidneys;
- in the spleen;
- in the tissues of the central nervous system.
According to WHO, diseases caused by cytomegalovirus rank second among causes of death.
Does CMV pose a threat to expectant mothers?
If before pregnancy a woman experienced an encounter with cytomegalovirus, then neither she nor her baby is in danger: the immune system blocks the infection and protects the fetus. This is the norm. In exceptional cases, a child becomes infected with CMV through the placenta and is born with immunity to cytomegalovirus.
The situation becomes dangerous if the expectant mother becomes infected with the virus for the first time. In her analysis, antibodies to cytomegalovirus IgG will show a negative result, since the body has not had time to acquire immunity against it.
Primary infection of a pregnant woman was recorded in an average of 45% of cases.
If this occurs at the time of conception or in the first trimester of pregnancy, there is a likely risk of stillbirth, spontaneous abortion, or fetal abnormalities.
In the later stages of pregnancy, infection with CMV leads to the development of a congenital infection in the baby with characteristic symptoms:
- jaundice with fever;
- pneumonia;
- gastritis;
- leukopenia;
- pinpoint hemorrhages on the baby’s body;
- enlarged liver and spleen;
- retinitis (inflammation of the retina of the eye).
- developmental defects: blindness, deafness, dropsy, microcephaly, epilepsy, paralysis.
According to statistics, only 5% of newborns are born with symptoms of the disease and serious disorders.
If a baby becomes infected with CMV while feeding on the milk of an infected mother, the disease may occur without visible signs or may manifest itself as a prolonged runny nose, swollen lymph nodes, fever, or pneumonia.
An exacerbation of cytomegalovirus disease in a woman preparing to become a mother also does not bode well for the developing fetus. The child is also sick, and his body cannot yet fully defend itself, and therefore the development of mental and physical defects is quite possible.
Attention! If a woman becomes infected with cytomegalovirus during pregnancy, this DOES NOT MEAN that she will necessarily infect the child. She needs to see a specialist in time and undergo immunotherapy.
Why can herpes disease worsen during pregnancy?
During gestation, the mother's body experiences certain changes, including weakened immunity. This is the norm, since it protects the embryo from rejection, which the female body perceives as a foreign body. This is why an inactive virus can suddenly manifest itself. Recurrences of infection during pregnancy are safe in 98% of cases. If antibodies to IgG in a pregnant woman’s test are negative for cytomegalovirus, the doctor prescribes her individual emergency antiviral treatment.
So, the result of an analysis of a pregnant woman, in which cytomegalovirus IgG antibodies were detected, but IgM class immunoglobulins were not detected, indicates the most favorable situation for the expectant mother and her baby. What about the ELISA test for a newborn?
Tests for IgG antibodies in infants
Here, reliable information is provided by antibodies of the IgG class rather than by the titer of antibodies of the IgM class. Positive IgG in an infant is a sign of intrauterine infection. To confirm the hypothesis, the baby is tested twice a month. An IgG titer exceeding 4 times indicates neonatal (occurring in the first weeks of a newborn’s life) CMV infection.
In this case, careful monitoring of the newborn's condition is indicated to prevent possible complications.
Virus detected. Do I need treatment?
Strong immunity resists the virus that has entered the body for life and restrains its effect. Weakening of the body requires medical monitoring and therapy. It will not be possible to completely expel the virus, but it can be deactivated.In the presence of generalized forms of infection (determination of a virus that has affected several organs at once), patients are prescribed drug therapy. It is usually carried out in a hospital setting. Drugs against the virus: ganciclovir, foxarnet, valganciclovir, cytotec, etc.
Therapy for an infection when antibodies to cytomegalovirus turn out to be secondary (IgG) is not only not required, but is even contraindicated for a woman carrying a child for two reasons:
- Antiviral drugs are toxic and cause a lot of complications, and means for maintaining protective functions The body contains interferon, which is undesirable during pregnancy.
- The presence of IgG antibodies in the mother is an excellent indicator, because it guarantees the formation of full immunity in the newborn.
Titers indicating IgG antibodies decrease over time. A high value indicates recent infection. A low rate means that the first encounter with the virus occurred a long time ago.
There is no vaccine against cytomegalovirus today, so the best prevention is hygiene and healthy image life, significantly strengthening the 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 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 after 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 protective immunity occurs in a shorter 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.
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 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 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, 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:
- 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.
- The plate with samples is placed in a thermostat, where it is kept for 30-60 minutes.
- 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.
- The wells are washed and an indicator solution is added to them and kept in a thermostat.
- A stop reagent is added to stop the reaction.
- 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, 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 high sensitivity(80-100%), seeding of cell cultures is rarely done, since the following restrictions exist:
- the method is very labor intensive, the analysis time takes 5-10 days;
- the need for highly qualified medical personnel;
- the accuracy of the study greatly depends on the quality of the sample biological material and the time between the test and the culture;
- a large number of false negative results, especially when diagnostics are performed later than 2 days.
Just as with PCR analysis, it is possible to determine the specific type of pathogen. The essence of the study is that samples taken from the patient are placed in a special nutrient medium in which microbes grow and are subsequently studied.
Cytology for the diagnosis of cytomegalovirus
Cytological examination is one of the primary types of diagnosis. Its essence lies in the study of cytomegal cells under a microscope, the presence of which indicates a typical change in CMV. Saliva and urine are usually taken for analysis. This method cannot serve as the only reliable method for diagnosing cytomegalovirus infection.
What to do if IgG to CMV is positive?
Antibodies to cytomegalovirus found in blood and other biological fluids may indicate three possible conditions: primary or reinfection, recovery and carriage of the virus. The test results require a comprehensive assessment.
If IgG is positive, then to determine the acute phase, which is the most dangerous to health, you need to contact an infectious disease doctor and conduct additional research ELISA for IgM, IgA, avidity or PCR analysis.
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, the following treatment methods are used:
- for detoxification of the body - droppers with saline solution, acesol, di- and trisol;
- to reduce swelling and inflammation in case of damage to the central nervous system - corticosteroid drugs (Prednisolone);
- in case of secondary bacterial infection, antibiotics (Ceftriaxone, Cefepime, Ciprofloxacin and others).
During pregnancy
Pregnant women with CMV are treated with one of the following agents listed in the table below:
| Name | Release form | Daily dosage | Average price, rub. |
| Acute phase, primary infection | |||
| Cytotect (human anticytomegalovirus immunoglobulin) | 2 ml per 1 kg of weight every 2 days | 21,000/10 ml | |
| Interferon recombinant alpha 2b (Viferon, Genferon, Giaferon) | Rectal suppositories | 1 suppository 150,000 IU 2 times a day (every other day). At 35-40 weeks of pregnancy - 500,000 IU 2 times a day daily. Course duration – 10 days | 250/ 10 pcs. (150,000 IU) |
| Reactivation or reinfection | |||
| Cymevene (ganciclovir) | Solution for intravenous administration | 5 mg/kg 2 times a day, course – 2-3 weeks. | 1600/ 500 mg |
| Valganciclovir | Oral tablets | 900 mg 2 times a day, 3 weeks. | 15,000/60 pcs. |
| Panavir | Intravenous solution or rectal suppositories | 5 ml, 3 injections with an interval of 2 days between them. Candles – 1 pc. at night, 3 times, every 48 hours. | 1500/ 5 ampoules; 1600/ 5 candles |
Drugs
The basis treatment of CMV antiviral drugs are:
The doctor may prescribe the following as immunomodulatory agents:
- Cycloferon;
- Amiksin;
- Lavomax;
- Galavit;
- Tiloron and other drugs.
Immunomodulators used in the remission phase can also be used during relapse. After the end of the acute phase of the disease, restorative and physiotherapeutic treatment is also indicated; it is necessary to eliminate chronic inflammatory and infectious foci.
Folk remedies
In folk medicine, there are several recipes for the treatment of CMV infection:
- Grind fresh wormwood herb and squeeze the juice out of it. Heat 1 liter of dry wine over a fire to approximately 70° C (at this point a whitish haze will begin to rise), add 7 tbsp. l. honey, mix. Pour 3 tbsp. l. wormwood juice, turn off the heat, stir. Take 1 glass of “wormwood wine” every other day.
- Wormwood, tansy flowers, crushed elecampane roots are mixed in equal proportions. 1 tsp. pour 0.5 liters of boiling water into the mixture. This amount is drunk in equal portions 3 times a day half an hour before meals. The duration of treatment with the collection is 2 weeks.
- Crushed alder, aspen and willow bark are mixed in equal proportions. 1 tbsp. l. collection, brew 0.5 liters of boiling water and take it in the same way as in the previous recipe.
Prognosis and complications
Cytomegalovirus infection most often occurs benignly, and its symptoms are confused with ARVI, since patients experience the same symptoms - fever, headaches and muscle pain, general weakness, chills.
In severe cases, infection can lead to the following complications:
This infection is most dangerous on early stages pregnancy, as this often results in fetal death and miscarriage.
The surviving child may have the following congenital abnormalities:
- reduction in brain size or dropsy;
- malformations of the heart, lungs and other organs;
- liver damage - hepatitis, cirrhosis, bile duct obstruction;
- hemolytic disease of newborns - hemorrhagic rash, hemorrhages in the mucous membranes, stool and vomiting with blood, bleeding from the umbilical wound;
- strabismus;
- muscle disorders - cramps, hypertonicity, asymmetry of the facial muscles and others.
There may be a delay later mental development. IgG antibodies detected in the blood are not a sign that there is an active CMV infection in the body. A person may already have lifelong immunity to cytomegalovirus. It is most difficult to determine the diagnostic picture in newborns. The disease in its passive form does not require treatment.
Article format: Lozinsky Oleg
Video about antibodies to cytomegalovirus
Cytomegalovirus Igg and Igm. ELISA and PCR for cytomegalovirus:
Cytomegalovirus is herpes type 5. In medicine it is referred to as CMV, CMV, cytomegalovirus.
Doctors diagnose the disease using polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA). The patient receives a referral if symptoms of CMV are present.
If the blood test response to cytomegalovirus IgG is positive, a person must know what this means, because The virus constantly lives in the body and carries the risk of exacerbation in a generalized form.
The meaning of an IgG test for cytomegalovirus
CMV is transmitted by airborne droplets, contact and household contact. Unprotected sex and kissing also lead to infection with cytomegalovirus, since the infection is concentrated in the semen of men, and in women it is contained in discharge from the vagina and cervix. In addition, the virus is found in saliva and urine. Positive cytomegalovirus IgG occurs in almost all adults.
The essence of the IgG analysis for cytomegalovirus comes down to searching for specific antibodies in various biomaterials of a person who is suspected of having an infection. IgG is a shortened version of the Latin word immunoglobulin. It is a protective protein that is produced by the immune system to destroy the virus. With the entry of each new virus into the body, the immune system produces specific immunoglobulins, or antibodies. As a person grows older, there are more of them.
The letter G identifies the immunoglobulin class. In addition to IgG, antibodies of other classes are found:
If the body has never encountered a particular virus, there will be no antibodies to it at the moment. If immunoglobulins are present in the blood and the test shows a positive result, it means that the virus has entered the body. It is impossible to completely get rid of CMV, however, it may not bother its owner for a long time as long as his immunity remains strong. In latent form, viral agents live in the cells of the salivary glands, blood and internal organs.
IgG can be described this way. These are antibodies against a specific virus that are cloned by the body from the moment of their initial appearance. The production of IgG antibodies occurs after the infection has been suppressed. You also need to know about the existence of fast immunoglobulins - IgM. These are large cells that react with maximum speed to the penetration of the virus. But this group antibodies do not form immunological memory. After 4 to 5 months, IgM becomes useless.
The detection of specific IgM in the blood indicates recent infection with the virus. At the current time, most likely, the disease is acute. To fully understand the situation, the specialist must pay attention to other blood test indicators.
The relationship between cytomegalovirus and immunity with a positive test
If a patient with a strong immune system learns from a doctor that his cytomegalovirus hominis IgG is elevated, there is no need to worry. An immune system that works smoothly keeps the virus under control and the infection goes unnoticed. Occasionally a person notices causeless malaise, sore throat and increased body temperature. This is how mononucleosis syndrome manifests itself.
But even without pronounced signs of illness, a person should spend less time in society and refuse close contact with relatives, children and pregnant women. The active phase of the infection, which is manifested by an increase in IgG levels, makes a person a spreader of the virus. It can infect weakened others, and for them CMV will be a dangerous pathogen.
People with various forms immunodeficiency are susceptible to cytomegalovirus and any pathogenic flora. They have positive cytomegalovirus hominis IgG is early sign such serious illnesses, How:
- Encephalitis is brain damage.
- Hepatitis is a liver pathology.
- Retinitis is an inflammation of the retina of the eye, leading to blindness.
- Gastrointestinal diseases - new or chronic recurrent.
- Cytomegalovirus pneumonia - combination with AIDS is fraught fatal. According to medical statistics, death occurs in 90% of cases.
In patients with severe immunodeficiency, positive IgG signals chronic course diseases. Exacerbation occurs at any time and gives unpredictable complications.
CMV Igg positive in pregnancy and newborns
In pregnant women, the purpose of analysis for cytomegalovirus is to determine the degree of risk of viral damage to the fetus. The test results help the doctor develop an effective treatment regimen. Positive IgM test adversely affects pregnancy. It signals a primary lesion or relapse of chronic CMV.
The virus poses an increased danger in the first trimester during the initial infection of the expectant mother. Without treatment, herpes type 5 causes fetal malformations. With relapses of the disease, the likelihood of a teratogenic effect of the virus on the fetus decreases, but the danger of mutations still exists.
Infection with cytomegalovirus in the second or third trimester of pregnancy is fraught with the development of a congenital form of the disease in the child. Infection can also occur at the time of birth.
If a blood test shows a positive result for cytomegalovirus IgG during pregnancy, what such a response means, the doctor should explain to the expectant mother. The presence of specific antibodies indicates the presence of immunity to the virus. But the fact of exacerbation of infection is associated with a temporary weakening of the immune system.
In the absence of IgG to cytomegalovirus, the analysis indicates that the female body first encountered the virus after conception. There is a high risk of damage to the fetus and maternal body.
A positive IgG in a newborn child confirms that the baby was infected either during fetal development, or during passage through the birth canal of an infected mother, or immediately after birth.
An increase in IgG titer by 4 times during a double blood test with an interval of 1 month confirms the suspicion of a neonatal infection. If, in the first 3 days after birth, specific IgG to cytomegalovirus is detected in the child’s blood, the analysis indicates a congenital disease.
IN childhood Cytomegalovirus infection can be either asymptomatic or with severe symptoms. The complications the virus causes are quite serious - blindness, strabismus, jaundice, chorioretinitis, pneumonia, etc.
What to do if cytomegalovirus hominis igg is elevated
If there are no obvious health problems and a strong immune system, you can do nothing. It is enough to consult a doctor and allow the body to fight the virus on its own. Medications, intended to suppress viral activity, doctors prescribe in extreme cases and only to those patients who have been diagnosed with immunodeficiencies of varying complexity, or have a history of chemotherapy or organ transplantation.
Strictly under the supervision of a physician, patients with cytomegalovirus undergo treatment using the following means:
