Cytomegalovirus (CMV, cytomegalovirus, CMV) is a type 5 herpesvirus. To identify the stage of an infectious disease and its chronicity, 2 research methods are used - PCR (polymerase chain reaction) and ELISA (enzyme-linked immunosorbent assay). They are prescribed when symptoms appear and infection with cytomegalovirus infection is suspected. If the results of a blood test show positive cytomegalovirus igg, what does this mean and what danger does it pose to humans?
Antibodies IgM and IgG to cytomegalovirus - what are they?
When examining for infections, different immunoglobulins are used, they all play a certain role and perform their functions. Some fight viruses, others fight bacteria, and others neutralize excess immunoglobulins.
For the diagnosis of cytomegaly (cytomegalo viral infection) there are 2 classes of immunoglobulins out of 5 existing ones (A, D, E, M, G):
- Immunoglobulin class M (IgM). It is produced immediately upon penetration of a foreign agent. Normally it contains approximately 10% of total number immunoglobulins. Antibodies of this class are the largest; during pregnancy they are present exclusively in the blood of the expectant mother, and are unable to reach the fetus.
- Immunoglobulin class G (IgG). It is the main class, its content in the blood is 70-75%. It has 4 subclasses and each of them is endowed with special functions. It is largely responsible for the secondary immune response. The production begins a few days after immunoglobulin M. It remains in the body for a long time, thereby preventing the possibility of a recurrence of the infection. Neutralizes harmful toxic microorganisms. It is small in size, which facilitates penetration to the fetus during pregnancy through the “baby spot”.
Immunoglobulins of the igg and igm classes help identify CMV carriers Cytomegalovirus igg positive - interpretation of results
The titres, which may differ depending on the laboratory, help decipher the test results. Classification into “negative/positive” is carried out using indicators for the concentration of immunoglobulin G:
- over 1.1 honey/ml ( international units in millimeters) – positive;
- below 0.9 honey/ml – negative.
Table: “Antibodies to cytomegalovirus”
ELISA determines the avidity of immunoglobulins to cytomegalovirus
Positive IgG antibodies indicate a past encounter between the body and the virus, a previous history of cytomegalovirus infection.
Komarovsky about positive IgG in children
At the birth of a child, in maternity ward blood is immediately taken for analysis. Doctors will immediately determine the presence of cytomegalovirus infection in a newborn.
If cytomegaly is acquired, then parents will not be able to distinguish the disease from a viral infection, since their symptoms are identical ( elevated temperature body, signs of respiratory diseases and intoxication). The disease itself lasts up to 7 weeks, and incubation period– up to 9 weeks.
In this case, it all depends on the child’s immunity:
- With a strong immune system, the body will fight back the virus and will not be able to continue its development, but at the same time the same positive antibodies IgG.
- In case of weakened immunity, other antibodies will join the analysis, and a disease with a sluggish head start will give complications to the liver, spleen, kidneys and adrenal glands.
During this period, it is important for parents to monitor drinking regime baby and don’t forget to give vitamins.
Maintaining immunity - effective fight with type 5 virus High igg avidity during pregnancy
During pregnancy, immunoglobulin G avidity is of particular importance.
- With low IgG avidity, we are talking about primary infection.
- IgG antibodies have high avidity (CMV IgG) - this indicates that the expectant mother has already had CMV disease before.
The table shows possible options positive immunoglobulin G in combination with IgM during pregnancy, their significance and consequences.
| IgG in a pregnant woman |
IgM in a pregnant woman |
Interpretation of the result, consequences |
| + –
(doubtful) |
+ | If IgG (+/-) is doubtful, then a repeat test is prescribed after 2 weeks. Since the acute form of IgG is negative for a pregnant woman, it is most dangerous. The severity of complications depends on the timing: the earlier the infection occurs, the more dangerous it is for the fetus. In the first trimester, the fetus freezes or leads to the development of its anomalies. For the second and third trimesters, the risk of danger is lower: pathologies of the internal organs of the fetus, the possibility of premature birth, or complications during labor are noted. |
| + | + | Repeated form of CMV. If we are talking about chronic course disease, even during an exacerbation, the risk of complications is minimal. |
| + | – | Chronic form of CMV, after which immune protection remains. The likelihood that antibodies will penetrate to the fetus is very low. Treatment is not required. |
CMV is dangerous during pregnancy with primary infection When planning a pregnancy, it is necessary to undergo tests for detection of CMV, to avoid unpleasant consequences during pregnancy. Normal indicators IgG (-) and IgM (-) are considered.
Do I need treatment?
Whether treatment is necessary or not depends directly on the stage of the disease. Goal of therapy: transfer of the virus from active stage to inactive.
In the chronic course of the disease, there is no need to prescribe medications. It is enough to support the immune system with vitamins, healthy food, refusal bad habits, walks on fresh air and timely fight against other diseases.
If a positive immunoglobulin class G indicates a recurrence (exacerbation of infection during chronic course) or acute form disease, it is important for the patient to undergo a course of treatment, which includes:
- antiviral agents;
- immunoglobulins;
- immunomodulators.
In general, high avidity of immunoglobulin G is most dangerous for children infected in the womb, pregnant women and those with immunodeficiency. But as practice shows, for the most part it is enough to stick to preventive measures to successfully combat the pathogen. Exclusively when the body’s defenses are reduced, it is required complex treatment drugs.
Cytomegalovirus IgG is positive - the result of a biochemical study that confirms the presence of this herpesvirus in the blood. In the vast majority of cases, the presence of pathogens in the body does not harm the health of an adult or child. But it is extremely, even deadly, dangerous for people with reduced immunity. Due to the weakening of the protective forces, cytomegaloviruses rapidly multiply and invade healthy tissue and organs.
In this article we will address the issue of IgG antibodies, which are produced in response to the introduction of cytomegalovirus into the human body.
Characteristic features of cytomegaloviruses
Cytomegalovirus is a genus of viruses from the Betaherpesvirinae subfamily of the Herpesviridae family. According to numerous studies among the world's population great amount virus carriers and persons with hidden form infections.
The fact of detection of serum IgG antibodies to cytomegaloviruses is recognized as evidence of human infection. This is an indicator that the human body has already encountered the pathogen. Most adults become infected with these members of the herpesvirus family during their lifetime, with 15% of cases occurring in childhood.
The penetration of cytomegaloviruses into the body does not go unnoticed immune system. It begins to intensively produce antibodies - high-molecular proteins immunoglobulins, or Ig. When they come into contact with viruses, antigen-antibody complexes are formed. In this form, infectious pathogens are easily vulnerable to T-lymphocytes - cells of the leukocyte blood unit responsible for the destruction of foreign proteins.
At the initial stage of immune defense, only IgM to cytomegalovirus is produced. They are designed to neutralize cytomegaloviruses directly in the blood. But these antibodies only reduce the activity of pathogens, so a certain amount of them manages to penetrate the cells. Then the production of IgM slows down and soon stops altogether. Only with sluggish chronic infection These antibodies are always present in the systemic circulation.
Soon the immune system begins to produce IgG antibodies. Immunoglobulins are involved in the process of destroying infectious agents. But after the virus is destroyed, they remain in the human blood forever. Antibodies G provide cellular and humoral immunity. If reintroduced, cytomegaloviruses will be quickly detected and destroyed immediately.
For 2-8 weeks after infection with cytomegalovirus, IgG and immunoglobulin A antibodies circulate in the blood simultaneously. Their main function is to prevent the adsorption of agents to the cell surface human body. IgA ceases to be produced immediately after pathogens enter the intercellular space.
Who should be tested for CMV antibodies?
At sharp decline immunity cytomegalovirus (CMV) are activated, but this usually does not cause serious problems with health in children and adults. Clinically, the infection is manifested by fever, weakness, malaise, headaches and joint pain, and runny nose. That is, it disguises itself as laryngitis, pharyngitis, and tonsillitis, which are widespread in childhood. Therefore, when frequent colds The child requires testing for the presence of IgG antibodies to determine further therapeutic tactics.
Necessarily biochemical analysis indicated in the following cases:
- pregnancy planning;
- identifying the causes of developmental disorders in newborns;
- assessment of the functioning of the immune system in patients with immunodeficiency conditions or malignant neoplasms;
- preparation for chemotherapy with drugs that suppress the immune system;
- planning to donate blood for transfusion to other people (donation).
An IgG test is also prescribed when symptoms characteristic of acute or chronic cytomegalovirus infection appear. So in men the testicles and prostate can be affected, in women the inflammation affects more the cervix and inner layer uterus, vagina, ovaries.
Detection method
IgG antibodies can be detected by performing an ELISA - enzyme-linked immunosorbent assay. The study is highly sensitive and informative. If IgG to cytomegalovirus circulates in a person’s blood, they will definitely be detected. The analysis also allows you to determine the form of infection and the stage of its course.
It is possible to detect IgM or IgG cytomegalovirus in the bloodstream in a laboratory setting in a relatively short time. The enzyme immunoassay is based on the antigen-antibody reaction. Venous blood serum is usually used as a biological sample. It is placed in eraser plates with several wells. Each of them contains a specific purified antigen to cytomegalovirus IgG and IgM antibodies.
Read also on the topic
Manifestation and treatment of cytomegalovirus infection in children
After adding biological samples, the formation of immune complexes is observed in the well, but only if there are immunoglobulins for CMV in the blood. Their formation is indicated by the enzymatic reaction of the dye with the formed high-molecular complexes. Now it is possible, using instrumental techniques, to estimate the optical density and draw a conclusion about the results of the study. There are two ways to perform ELISA:
- qualitative. The analysis can have only two results - anti cmv igg positive or negative. That is, the study is designed to determine the presence of cytomegalovirus in the blood;
- quantitative. A complex chain of reactions is launched, which makes it possible to assess the concentration of antibodies in a person’s blood. Combined with quality testing quantitative analysis IgG class antibodies answer the question of how the infectious process develops.
To avoid distortions in the data obtained, it is recommended to donate blood for IgM and IgG to cytomegalovirus on an empty stomach. Especially if the goal of the study is to diagnose chronic, latent infectious diseases. It is necessary to stop taking drugs with antibacterial, antimicrobial and antiviral properties, as well as glucocorticosteroids and cytostatics, for several days. Blood donation for cytomegalovirus is not performed during general feeling unwell person.
A more sensitive type of ELISA is ICL. This is the name of immunochemiluminescent study - laboratory analysis, which is also based on immune reactions antigen with antibody. The difference between ICL and ELISA lies only in the test systems used. The material for the study is venous blood serum taken on an empty stomach or urine.
Decoding
Cmv IgG positive indicates chronicity of cytomegalovirus infection or the development of immunity to the infectious agent. The data obtained does not directly reflect the activity of the process. Therefore, antibodies to cytomegalovirus IgM. This has almost no effect on the cost of the study, and the data obtained is significantly more informative. The assessment of the analysis can be negative, positive, strongly positive or weakly positive. What research results can be obtained:
- negative IgM and IgG, avidity is not determined. Seronegative parameters indicating that a person has never been infected. This also means that specific immunity not worked out. At risk are women carrying a child and people with immunodeficiency conditions. Such results require immediate preventive measures;
- IgG to cytomegalovirus was detected, positive IgM with a low titer, or negative, the avidity index does not exceed 60%. Such results are characteristic of a recent primary infection or indicate an exacerbation of chronic cytomegalovirus pathology. In case of intrauterine infection of the fetus, the risk of developing anomalies is high;
- IgM positive with increasing antibody titer, positive IgG, increasing with subsequent analysis or negative, avidity data below 40%. The parameters indicate a primary infection that is dangerous for intrauterine development fetus;
- IgM is negative, the result of antibodies to cytomegalovirus IgG is positive, practically not decreasing, avidity is above 60%. Such data indicate virus carriage. During pregnancy, the health of the fetus is not in danger;
- IgM is negative, less often positive, IgG is detected, avidity is very low. The obtained parameters indicate an exacerbation of chronic cytomegalovirus infection, but the likelihood of pathological intrauterine development is low.
Cytomegalovirus is positive - this means that the person is infected, but the likelihood of infecting other people is relatively low. Especially when using barrier contraceptives and observing personal hygiene rules. But the absence of CMV antibodies is not always welcome. Primary infection of a pregnant woman or a person with an incorrectly functioning immune system can cause the development of severe complications of cytomegalovirus infection.
Also, when deciphering, the doctor uses the following meanings:
- antibody titer. This is the maximum possible dilution of the serum to include antibodies. When determining immune status One dilution is made in accordance with the instructions attached to the test system. But if necessary, it is recommended to further titrate it by successive twofold dilutions. High titers, such as IGG results above 140, mean no dangerous condition for the body;
- antibody avidity. This distinctive feature stability of the antigen-antibody biocomplex. Avidity is determined by the affinity of the antibody for the antigen, the number of antigen-binding centers in the immunoglobulin molecule and the characteristics of the spatial structures of antigens.
Read also on the topic
What are the symptoms of cytomegalovirus infection (CMV)
Unit of measurement - RE/ml. Antibodies to CMV are usually detected within 1-2 days. But if necessary, for example urgent surgical intervention data can be received in 2-3 hours. Qualitative blood serum analysis does not take longer than half an hour.
Pregnancy and its planning
Determination of class G antibodies in the absence of any symptoms of cytomegalovirus indicates only virus carriage. In such cases, no treatment is required antiviral agents. Typically, this parameter is important only when examining pregnant women or women who are preparing to conceive. A high IgG titer always indicates an exacerbation chronic disease. If it occurs during pregnancy, there is a high probability of developing congenital anomalies.
Gynecologists strongly recommend that women planning pregnancy donate blood to detect antibodies to cytomegalovirus IgG. When a latent infection is determined, treatment will be prescribed to avoid relapses during pregnancy. Revealing high titer class G antibodies during pregnancy indicates the need for urgent treatment even in the absence CMV antibodies M.
Childhood
Cytomegalovirus IGG in a child infancy and older matters only when frequent relapses infections of the upper and lower respiratory tract. But even if antibodies are detected, doctors adhere to a wait-and-see approach. As a rule, as the immune system develops, the child’s body’s defenses also strengthen. Viruses are activated less and less often, the frequency decreases clinical manifestation infections.
If this does not happen, then antiviral therapy is carried out. It will not be possible to completely cleanse the body of infectious agents. But it is quite possible to reduce the likelihood of relapses, including by taking immunostimulants and immunomodulators.
But the detection of antibodies to cytomegalovirus in a newborn is a sign of intrauterine infection. But the diagnosis can be made when positive result repeated biochemical study. The child’s condition is constantly monitored, but treatment is carried out only if there is a significant deterioration in his health.
What methods are still used in the diagnosis of CMV?
When choosing a method for laboratory diagnosis of an infection caused by the introduction of Cytomegalovirus into the body, the doctor must take into account the form of the pathology. Enzyme immunosorbent testing is prescribed mainly for chronic, recurrent diseases. Congenital or acute infection is detected in other ways.
PRC
PRC - polymerase chain reaction. Its implementation makes it possible to determine the DNA of cytomegaloviruses even at their low concentration in the systemic circulation. The PRC analysis is highly sensitive, since only one fragment is sufficient to detect infectious pathogens. The study has one drawback - its high cost.
For PRC, both blood and any other biological material patient. Cytomegaloviruses are detected by polymerase chain reaction in saliva, urine, cerebrospinal fluid, vaginal smear or urethra, feces, washings from mucous membranes. At the initial stage of PCR, cytomegalovirus is isolated. DNA fragments are extracted from the biomaterial and then cloned many times using certain enzymes. Then they are identified - determining the species of infectious pathogens.
PCR is carried out quite quickly, and its accuracy is close to 100%. Particularly informative is the quantitative polymerase chain reaction, which allows one to judge the activity of cytomegaloviruses and the form of the course infectious process. If even one small fragment of DNA is found in the biomaterial, this is enough to make a diagnosis.
Virus cultivation
When conducting this research, the role of the human body is played by specific nutrient media with a complex chemical composition. First, viruses are isolated from the biomaterial. If they are found, then the person is already infected. But the analysis is intended to determine the quantitative content of infectious agents, the severity of the pathology, and the resistance of pathogens to pharmacological drugs.
Therefore, after isolation using a centrifuge, cytomegaloviruses are “added” to nutrient media, and Petri dishes are placed in a thermostat. All conditions are created for active reproduction of viruses for several days. Next, the infected cultures are stained with fluorescent reagents and examined under a microscope.
The advantages of cultivation are high accuracy and information content, the ability to assess the nature of the infectious process. One of the disadvantages of the methodology is the duration of the study.
Detection of IGG antibodies is the leading method for diagnosing infection. Serological testing helps to identify pathogens in a timely manner and, if necessary, carry out treatment.
Data Aug 15 ● Comments 0 ● Views
Doctor Dmitry Sedykh
Cytomegalovirus (CMV) is considered quite common infectious diseases family of herpes viruses. The disease most often affects children immediately after birth and up to 5 years of age, and the virus is also transmitted to the child from the mother before birth. After infection, it is impossible to get rid of the virus, but the body begins to produce antibodies to cytomegalovirus. A blood test for IgG and IgM antibody titers helps determine the presence of the virus and the stage of the disease.
Cytomegalovirus is able to penetrate into the cells of organs and tissues of the body, for this reason the cell increases significantly in size. Typically affects cells of the immune and nervous systems, salivary glands, settles there forever in a dormant state, becoming more active when the body’s defenses weaken.
When infected with cytomegalovirus, the body begins to produce antibodies, which are protein substances (immunoglobulins). Their purpose is to fight the virus, block its activity and development, and reduce the intensity of symptoms.
Each type of bacteria and virus produces its own antibodies, which are active only against it. To diagnose cytomegalovirus, it is necessary to determine antibodies of class M and G, although several other varieties are known.
The presence of class G immunoglobulins reflects immunological memory, that is, such immunoglobulins are formed when the cytomegalovirus has penetrated the body, is inside the cells, and immunity to it has developed.
Detection of antibodies is indicative for the diagnosis of cytomegalovirus IgG classes and IgM. This allows us to determine the stage of infection and the level of immunity. An enzyme immunoassay (ELISA) is performed. At the same time, the concentration of IgM antibodies and the avidity index are determined.
Availability IgM antibodies indicates that the cytomegalovirus has recently entered the body and the latent infection is being reactivated. They can be detected only 4 weeks after the initial infection.
High titers remain in the blood for a year after treatment; a single analysis is ineffective for assessing how the infection is progressing. It is necessary to monitor the dynamics of the number of antibodies: their increase or decrease. Antibodies of this class are large in size.
IgG antibodies to cytomegalovirus are detected in the blood 1-2 weeks after infection. They are characterized by a smaller size and are produced in small quantities throughout the life of the virus carrier.
Their presence serves as evidence of immunological memory to cytomegalovirus, prevents the development of virus cells and their spread.
During exacerbations of the disease, IgG class antibodies can quickly neutralize the virus.
Antibodies to cytomegalovirus
How to interpret tests for antibodies to CMV
ELISA blood examination allows you to determine the exact chemical composition blood, the presence of antibodies to cytomegalovirus. For blood tests, special titers are used to determine the number of positive reactions in the blood and serum.
The analysis can have the following indicators:
- IgG negative, IgM negative. The body does not have antibodies to cytomegalovirus, there is no reaction of the immune system to it, infection is possible.
- IgG positive, IgM negative. Means that there is a small risk of infection depending on the level of immune protection. Immunity has been developed.
- IgG negative, IgM positive. The virus is on initial stage development, recent infection. Treatment is needed.
- IgG positive, IgM positive. The acute stage requires extensive examination and treatment.
ELISA analysis is considered in a reliable way determination of the disease, with a result of 100%. If one of the antibodies is not detected, a repeat test will be required. If antibodies to cytomegalovirus cannot be detected, it can be argued that the child has not previously encountered CMV carriers and the body is particularly susceptible.
The presence of antibodies cannot be considered as a guarantee to avoid infection in the future, since 100% immunity to cytomegalovirus is not developed.
IgG to cytomegalovirus positive
A positive cytomegalovirus IgG in a child means that he has already encountered an infection and his body reacts to it by producing antibodies. A low concentration indicates that the infection occurred a long time ago.
In addition to the number of positive reactions, IgG avidity is examined, that is, the degree of strength of the connection of antibodies with antigens. The higher the avidity index, the faster the antibodies are able to bind viral proteins.
Children with initial infection with cytomegalovirus usually have a low antibody avidity index; an increase is observed after 3 months. That is, avidity shows how long ago CMV entered the child’s body:
- avidity below 50% is evidence of primary infection;
- 50-60% - repeat analysis is required after 2 weeks.
- avidity more than 60% - high rate, chronic virus carriage.
If you need to check the dynamics of antibody development, repeated tests It is better to carry out in the same laboratory, because the norms of indicators for different laboratories may be different.
Cytomegalovirus Igg and Igm. ELISA and PCR for cytomegalovirus. Avidity to cytomegalovirus
Whether a person is a carrier of cytomegalovirus can only be determined with certainty based on the results of laboratory tests.
A disease, if we can talk about a condition when a person is practically healthy and at the same time quite infected dangerous virus, most often occurs asymptomatically, without causing any inconvenience to the person.
Unfortunately, the virus does not always behave correctly - for those who for some reason have problems with immune protection, he is preparing additional troubles, this time “on his own behalf.”
If a person is preparing for a major operation or a woman is expecting a child, such a “time bomb” can be very dangerous for them.
We wrote about what cytomegalovirus infection or simply cytomegalovirus is in this article. You can learn about the symptoms and treatment methods for cytomegalovirus.
Laboratory studies provide an answer not only to the question of the presence of the virus in the body, but also to its activity. This helps the doctor to objectively assess the situation and predict it possible development and, if necessary, begin treatment for CMV infection.
That's who tests for the presence of cytomegalovirus it is necessary to do:
- pregnant women;
- HIV-infected;
- people who have undergone transplant surgery;
- cancer patients.
All representatives of these categories have weakened immunity. If the virus is activated, it will worsen the condition of patients, and in a pregnant woman it will jeopardize not only her own health, but also the future of the baby.
Diagnosis of cytomegalovirus
The main thing in diagnosing CMV infection is laboratory tests: a blood test is done, the virus is looked for in the urine, in a smear, in a scraping. Referrals for tests are usually given by a urologist and gynecologist.
Patients are warned: a man who is going to donate urine should not go to the toilet for several hours beforehand; a woman can donate blood for analysis on any days except “critical” days.
Diagnosis of cytomegalovirus is carried out using a number of methods, including immunological, virological and others.
Immunological
This method is called ELISA, which means - linked immunosorbent assay. Samples taken for research are examined under a microscope. With its help, traces of cytomegalovirus (if any) are detected visually.
To accurately characterize the virus when enzyme immunoassay An indicator such as the “positivity rate” is used.
The method is considered quite effective for determining which immunoglobulin is detected in samples and how active it is.
Molecular Biology
The purpose of studying the samples is to search for the causative agent of the virus. As part of the study, so-called PCR diagnostics are carried out (the term stands for “polymerase chain reaction”).
The DNA contained inside the virus is studied in samples taken for analysis. In this way, the researcher obtains PCR of saliva, blood, urine, and sputum.
Experts consider molecular biological techniques to be the most accurate. Their results can be obtained several days after samples are taken for analysis, even if the virus is not active at that moment.
The disadvantage of PCR is the inability to determine whether the infection is primary or a relapse in the acute stage.
By the way, PCR diagnostics of cancer patients (or rather, cancer analysis DNA) has shown links to the Epstein-Barr virus (human herpes virus type 4). We wrote about what it is and how the Epstein-Barr virus is transmitted in the article.
Laboratory monitoring of the dynamics of ongoing processes will help doctors select the most effective treatment and for this dangerous disease.
Cytological
This method is good if the analysis result needs to be obtained very quickly. He does not explain any nuances, but only states: yes, there is a virus, or no, the body is not infected.
There are situations when such information is enough for the doctor to help the patient. As a study material take saliva and urine.
Samples are examined under a microscope to detect “giant cells” characteristic of CMV infection.
Virological
Detecting a virus using this technique is a rather lengthy process. The biomaterial taken for analysis is placed in a special environment in which microorganisms develop more actively than in natural conditions, after which they are identified - whether they are the desired virus or not.
Positive igg antibodies detected - what does this mean?
Antibodies that can be detected (or not detected) during laboratory research, - This immunoglobulins, a special type of protein. They are usually designated with Latin letters Ig.
The abbreviation igg refers to antibodies that are regularly renewed (cloned) in the body, starting from the moment they appear (they are also called anti cmv igg).
This provides protection against a specific virus throughout human life provided that it does not weaken as a result of any external or internal circumstances.
A positive igg means that the person is a carrier of cytomegalovirus and he himself has normal immunity to this disease, a negative result indicates that there is no CMV infection in the patient’s body.
Types of immunoglobulins (IgA, IgM, IgG, IgD, IgE)
Immunoglobulins are represented by five classes. For CMVI, class g and class m are especially important. There are also classes a, e, d. They are distinguished by their structure, mass, and method of binding to antigens.
Based on their presence in the human body, the researcher can draw conclusions about what stage of development the disease is in, what its dynamics and possible risks. The more complete the picture, the easier it is to choose the right treatment option.
After the body is infected (after 1-2 weeks), protection against the virus begins to form. IgM appears first, they perform their function for 8-20 weeks.
Once again they are able to appear during reactivation, after the virus has already for a long time was in the body. True, in this case there are significantly fewer of them than during the primary infection.
IgG follows IgM, that is, they appear only 1 month after infection with the virus occurs, but they remain in the body throughout its life and help the human immune system quickly cope with the virus as soon as it begins to “raise its head.”
Having discovered one or another class of immunoglobulin in the studied samples, the specialist can draw conclusions about whether the infection is primary, how long ago the infection entered the body and whether the defense built against it is reliable.
Laboratory examination reveals the presence of a process such as “antigen-antibody” in the studied samples. Its essence is that, in contrast to the virus (experts call it “antigen”) protection is formed in the form of immunoglobulin (“antibody”).
A kind of connection is formed in which ig tries to defeat the virus and deprive it of activity.
In the course of research, it is important to establish how strong this ligament is, what, as experts say, is the “avidity index” (avidity in Latin means “appropriation”).
This helps to get answers to important questions:
- when did the infection occur?
- whether the concentration of the virus in the body is high.
The researcher detects both high-avidity and low-avidity antibodies. Zero avidity index means that the body is not infected with CMV.
If it is below 50 percent This means that primary infection with the virus has occurred.
The rate is from 50 to 60 percent indicates the uncertainty of the result, which means that after 3-4 weeks the study needs to be repeated.
The number 60 indicates that the disease is chronic, but the body copes with it thanks to the developed immunity.
Normal blood levels
How to identify an infection and understand how dangerous it is for the body? With the help of analyses. The virus can be detected in the patient's urine, saliva, and blood.
The more data a doctor has, the easier it is for him to select appropriate therapy.
General values
In blood test important has such an indicator as “titles”(this is the designation for the highest serum dilution at which positive reaction for the presence of immunoglobulin).
If the indicator is less than 0.5 lgM, it means that the patient’s body is not infected with cytomegalovirus. Elevated titers (from 0.5 lgM or more) confirm the presence of the virus in the patient’s blood.
In children
Deciphering a blood test for antibodies in each age category gives its own results. In children, the IgM norm is 0.7 - 1.5 (for comparison: in men - from 0.5 to 2.5, in women - from 0.7 to 2.9).
The IgG norm in young patients is from 7.0 to 13.0 (for comparison: in adults – from 7.0 to 16.0).
There are methods that, based on the results of a blood test, help to draw conclusions that the child:
- absolutely healthy, not infected;
- received the virus while in the womb;
- the virus is activated, the risk to the baby’s health is high;
- the body is infected, the risk to health is minimal.
Laboratory blood tests for expectant mothers are mandatory(by the way, not only about CMV infection).
They help determine the infection of the woman herself and her fetus. The first 12 weeks are especially important in this regard.
If the test results cause concern to the doctor, he selects the safest but most effective treatment method for the woman.
In people with immunodeficiency
Availability Determination positive IgG in the tests of a patient with immunodeficiency requires the doctor to accept emergency measures, otherwise the patient may, in addition to the underlying disease, develop pneumonia, hepatitis, various inflammations of the digestive and nervous system, and eye diseases.
The presence or absence of two classes of Ig (IgM and IgG) in the body helps the specialist draw a picture of the processes occurring with great accuracy:
What to do?
Opponents and supporters of treatment for CMV infection, when the infection is in a “preserved” state, have their own reasons and arguments.
However, all experts agree on one thing: There are categories of people for whom treatment should be mandatory. This:
- patients diagnosed with HIV;
- patients who have undergone organ transplantation;
- patients receiving chemotherapy sessions.
Pregnant women are sometimes included in this list, but each case is considered individually.
The child was diagnosed with cytomegalovirus. Despite the widespread distribution of this agent across the planet, ordinary people have virtually no knowledge about it. At best, someone once heard something, but they can’t remember what exactly. Dr. Evgeniy Komarovsky explained in an accessible manner that this is a virus, why it is dangerous, and what to do if this “terrible beast” is found in a child’s blood tests. We give you the opportunity to get information from a renowned doctor.
About the virus
Cytomegalovirus belongs to the family of herpes viruses type 5. It is quite interesting when looked at through a microscope - its shape resembles the round, prickly shell of a chestnut fruit, and in cross-section it looks like a gear.
When this virus infects humans, it causes cytomegalovirus infection. However, it is not so aggressive: after entering the body, it can exist there quite peacefully for a long time, without indicating its presence in any way. For this “tolerance” it is called an opportunistic virus, which reproduces and causes disease only under certain factors. The main one is weakened immunity. The most susceptible to infection are people who take a lot of medications for any reason, live in an environmentally polluted area, and often use household chemicals in large quantities.
Cytomegalovirus loves to settle in salivary glands. From there it travels throughout the body.
By the way, the body gradually produces antibodies to it, and if enough of them have accumulated, even a weakened immune system can no longer cause a cytomegalovirus infection.
Transmission routes
If for adults the main route of infection is sexual, then for children it is through kissing, contact with the saliva of a person infected with the virus, which is why it is sometimes called the kiss virus.
Also, a mother with a large cytomegalovirus infection transmits it to the fetus during pregnancy, and this can cause quite serious defects in its development. A child can become infected during childbirth through contact with mucous membranes birth canal. In addition, the baby can get an infection through mother's milk in the first days of his life.
Another route of transmission of cytomegalovirus is blood. If the baby has had replacement blood transfusions from a donor who has such a virus, as well as organ transplantation operations from an infected donor, then the child will definitely become carriers of cytomegalovirus.
Danger
Evgeny Komarovsky cites the following fact: on the planet, 100% of elderly people have had contact with cytomegalovirus in one way or another. Among adolescents, about 15% of those who already have antibodies to this agent are found (that is, the disease has already been suffered). By the age of 35-40, antibodies to CMV are found in 50-70% of people. By retirement, the number of people who are immune to the virus is even higher. Thus, it is quite difficult to talk about any excessive danger of the type 5 virus, because many people who have recovered do not even know about such an infection - it went completely unnoticed for them.
The virus is dangerous only for pregnant women and their unborn children, but also provided that the collision expectant mother with CMV occurred for the first time during pregnancy. If a woman has previously been ill and antibodies are found in her blood, then there is no harm to the child. But primary infection during pregnancy is dangerous for the baby - he may die or there is a high risk birth defects development.
If the baby is infected during pregnancy or immediately after childbirth, then doctors talk about congenital cytomegalovirus infection. This is a pretty serious diagnosis.
If a child caught the virus already in his own adult life, they speak of an acquired infection. It can be overcome without much difficulty or consequences.
Parents most often ask the question: what does it mean if antibodies to cytomegalovirus (IgG) are found in the baby’s blood test and CMV is set to +? There is nothing to worry about, says Evgeny Komarovsky. This does not mean that the child is sick, but indicates that his body has antibodies that will prevent the cytomegalovirus from doing its “dirty deed.” They developed independently, since the child had already had contact with this virus.
You should start to worry if your child’s blood test results show IgM+. This means that the virus is in the blood, but there are no antibodies yet.
Symptoms of infection
Doctors determine the presence of cytomegalovirus infection in a newborn children's department maternity hospital. Immediately after the baby is born, they do an extensive blood test.
In the case of acquired infection, parents should be aware that the incubation period lasts from 3 weeks to 2 months, and the disease itself can last from 2 weeks to one and a half months.
The symptoms, even for a very attentive mother, will not cause the slightest doubt or suspicion - they are very reminiscent of a common viral infection:
- body temperature rises;
- appear respiratory symptoms(runny nose, cough, which quickly turns into bronchitis);
- signs of intoxication are noticeable, the child has no appetite, he complains of headache and muscle pain.
If everything is in order with the child’s immune system, then it will powerfully fight back the virus, its spread will be stopped, and the same IgG antibodies will appear in the baby’s blood. However, if the toddler’s own defense is not enough, the infection can “lurk” and acquire a sluggish, but deep-seated form, which affects internal organs And nervous system. In the generalized form of cytomegalovirus infection, the liver, kidneys, adrenal glands, and spleen are affected.
Treatment
It is customary to treat cytomegalovirus infection by analogy with herpetic infection, unless they choose drugs that affect not herpes in general, but cytomegalovirus in particular. There are two such drugs - Ganciclovir and Cytoven, both of which are quite expensive.
During the acute phase of the disease, the child is prescribed plenty of fluids and vitamins. For uncomplicated cytomegalovirus infection, antibiotics are not needed because antimicrobials do not help against viruses.
Antibacterial agents can be prescribed by a doctor in case of a complicated course of the disease, when there are inflammatory processes from the internal organs.
Prevention
The best prevention- strengthening the immune system, good nutrition, hardening, sports. If a pregnant woman has not had cytomegaly and no antibodies to this virus are detected during registration, she will automatically be at risk.
This virus is young (it was discovered only in the middle of the 20th century), and therefore little studied. To date, the effectiveness of the experimental vaccine is approximately 50%, which means that half of vaccinated pregnant women will still get CMV.
Dr. Komarovsky’s video will help you learn more about cytomegalovirus infection.
