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: cells infected with the virus become hypertrophied and contain voluminous eosinophilic intranuclear inclusions that resemble "owl eyes".

Cytomegalovirus infection is widespread, and clinical disease is a rare consequence of this infection (80-100% of the adult population will have antibodies in the absence of clinical signs).

Cytomegalovirus infection remains an urgent problem of public health because: it is transmitted transplacentally to the fetus and creates a risk of congenital viral infection; The constant presence of the virus in the body makes its reactivation possible and compromises the immune system.

Humans are the only natural reservoir of cytomegalovirus. 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 become infected in the womb; However, infection often occurs during childbirth, when coming in contact with infected mucus, or after giving birth - when a newborn comes into contact with breast milk. There is also an iatrogenic (related to medical procedures) way of transmission - in case of blood transfusion, organ transplantation or manipulation with infected instruments.

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, to assess the risk of intrauterine infection of the fetus during pregnancy;
• For differential diagnostics of the etiology of the infectious process: mononucleosis syndrome clinic, fever of unknown origin, pneumonia, hepatitis, encephalitis, meningoencephalitis, myelitis, neuropathy, pericarditis, myocarditis, colitis, uveitis, retinitis, 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:

• Confirms the presence of a viral process in the body
• After 2 weeks of incubation, the dynamics of virus growth is characteristic of an active 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