Cytomegalovirus (CMV) | One hundred IgG

Cytomegalovirus (CMV) belongs to Of viruses The same family as the herpes simplex and varicella-zoster viruses.

Cytomegalovirus was isolated in 1956 and given its name because of its characteristic cytopathic effect: virus-infected cells hypertrophy and contain large amounts of eosinophilic intrathecal inserts reminiscent of "owl eyes".

Cytomegalovirus infection is widespread, and clinical disease is a more rare outcome of this infection (80–100% of the adult population has specific antibodies as the predominant outcome of asymptomatic infections).

Cytomegalovirus infection is currently considered a significant public health problem for the following reasons: Increased incidence of congenital infections, persistent viral infection with reactivation, especially in immunocompromised and organ transplant recipients, and its frequent manifestations in posttransfusion syphilis (posttransfusion syphilis).

Humans are the only natural reservoir of human cytomegalovirus (animal cytomegalovirus does not infect humans). Ways of transmitting the infection are varied. The virus is found in the urine and saliva of an infected person, as well as in vaginal secretions, semen and breast milk. The fetus can be infected within the uterus; However, more often, the infection develops perinatally, by contact of the newborn with the cervix, mucus-rich secretions, or postnatally - by contact of the newborn with the mother's secretions (saliva, milk, etc.). Another common route of transmission (more than 50% of infections) is through kissing and sex. Iatrogenic routes of transmission are also common - infection through blood transfusions (the virus is in leukocytes) or by organ transplants (eg kidneys).

The virus stays in the body for a long time. Infection does not give a person strong immunity, the virus continues to be excreted from the body even in the presence of specific antibodies. When the body's resistance is reduced (prolonged immunosuppressive therapy, AIDS), latent infection may be clinically manifested (hepatitis, pneumonia, encephalitis), sometimes with lethal consequences. The contagious period lasts (intermittently) for months, years or a lifetime.

Primary infection Is asymptomatic in most cases in adults; The clinical picture of its manifestation is diverse: febrile condition of unspecified etiology, picture of infectious mononucleosis with negative heterophilic antibodies, hepatitis with jaundice.

In pregnant women There is an increase in susceptibility to cytomegalovirus infection (6 times more than in the rest of the adult population). During primary infection of a pregnant woman, the risk of infection of the fetus is maximal (up to 50%). Vertical transmission of the infection during the first 4 months of pregnancy can have particularly serious consequences (hepatitis, deafness, microcephaly). In case of reactivation of latent infection (0,7-0,9% of pregnant women) the risk of fetal infection is very low or non-existent.

Posttransfusion syndrome Manifested after blood transfusion with fever, lymphadenopathy, hepato-splenomegaly, rash and immunopathological changes (rheumatoid factor, antibodies, cold agglutinins, cryoglobulins, positive Coombs test). Patients experience an increase in the titer of antibodies specific for cytomegalovirus infection, confirming cytomegalovirus disease.

IgG - Appears in the body 2-3 weeks after infection, is highly specific to the pathogen, persists throughout life and its level does not reflect process activity. Identification of immunoglobulins of this class allows us to assess the body's immune memory against the virus. The presence of these antibodies before pregnancy indicates a low risk of developing intrauterine infection, so the most optimal time for screening is during pregnancy planning. Detection of these antibodies during pregnancy does not rule out the first infection to develop during pregnancy. In these situations it is necessary to determine the avidity of IgG, which allows to determine the duration of the infection, the acute stage of the infectious process, reactivation or reinfection. An increase in IgG antibody levels indicates the activity of the process and the need to address the issue of management tactics (further investigation, treatment). This test is necessary in situations where IgM is positive to rule out possible false-positive results in the detection of these antibodies, and in situations where IgM is negative to confirm the absence of reactivation of the infectious process.

When should I get tested for cytomegalovirus IgG?

IgG Is a marker of the presence of immune memory against cytomegalovirus.

• When planning a pregnancy, assess the risk of intrauterine infection of the fetus during pregnancy;
• Differential diagnostics of the etiology of the infectious process in the following cases: Clinic of mononucleosis syndrome, fever of unknown origin, pneumonia, hepatitis, encephalitis, meningoencephalitis, myelitis, neuropathy, pericarditis, myocarditis, colitis, etc.

How to prepare for the test?

No special preparation is required for the test.

Research material

Venous blood

Possible interpretation of the results

In case of doubtful result it is necessary to repeat the test after 2 weeks (determination of IgM and IgG)

Positive result:

• The presence of a viral infection;
• After 2 weeks, increase the dynamics by 4 or more times - confirm the activity of the process.

Negative result:

• Viral infection is not noted;
• Early stage of primary infection (up to 2-3 weeks) - It is recommended to monitor the dynamics after 2 weeks, along with the determination of IgM.

Resources

https://www.synevo.ro/shop/citomegalovirus-anticorpi-igm/

https://spravochnik.synevo.ua/ru/torch-infekcii/cytomegalovirus.html