Cytomegalovirus, IgG antibodies

Why this test?

To determine whether a person has been infected with CMV in the past.

For the diagnosis of cytomegalovirus infection.

To establish the causative agent of the disease, which is similar to cytomegalovirus infection.

In what cases is it prescribed?

During pregnancy (or during its planning) - to assess the risk of complications (examination for verification), with symptoms of cytomegalovirus infection, with abnormalities in the fetus according to the results of ultrasound.

With symptoms of cytomegalovirus infection in people with weakened immunity.

With symptoms of mononucleosis (if the tests did not reveal the Epstein-Barr virus).

Test information

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

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

As a rule, cytomegalovirus infection is asymptomatic. Sometimes the disease resembles infectious mononucleosis: the temperature rises, the throat hurts, and the lymph nodes increase. In the future, the virus is stored inside cells in an inactive state, but if the body is weakened, it will start multiplying again.

It is important for a woman to know whether she has been infected with CMV in the past, because this determines whether there is a risk of complications during pregnancy. If she was previously infected, the risk is minimal. During pregnancy, an old infection may worsen, but this form usually does not cause serious consequences.

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

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

Thus, it is important for the expectant mother to know whether she has been infected with CMV in the past. If so, the risk of complications due to possible CMV becomes insignificant. If not, special care should be taken during pregnancy:

• avoid unprotected sex;
• do not come into contact with another person's saliva (do not kiss, do not use shared dishes, toothbrushes, etc.);
• observe hygiene rules when playing with children (wash hands if saliva or urine gets on them);
• take a test for CMV with signs of general malaise.

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

The main symptoms of cytomegalovirus infection:

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

The production of antibodies is one of the ways to fight against a viral infection. There are several classes of antibodies (IgG, IgM, IgA, etc.).

Class G antibodies (IgG) are present in the blood in the largest amount (compared to other types of immunoglobulins). With a primary infection, their level increases in the first weeks after infection and can then remain high for years.

In addition to the quantity, IgG avidity is also often determined - the strength with which the antibody binds to the antigen. The higher the avidity, the stronger and faster antibodies bind viral proteins. When a person is first infected with CMV, his IgG antibodies have a low avidity, then (after three months) it becomes high. IgG avidity is used to judge how long ago the primary infection with CMV occurred.