Antibodies to cytomegalovirus class IgM and IgG in the blood

Antibodies of IgM to CMV in serum are normal.

Cytomegalovirus infection is a viral disease predominantly in young children, characterized by a variety of clinical symptoms and a specific morphological pattern with the presence of cytomegal cells on the background of lymphohistiocytic infiltrates. The causative agent belongs to the Herpesviridae family (human herpesvirus type 5). Features of cytomegalovirus: large DNA genome (nucleocapsid diameter 100-120 nm), the possibility of replication without cell damage, slow replication, relatively low virulence, severe inhibition of cellular immunity. Like other viruses of this family, cytomegalovirus can cause persistent and latent infection and reactivate in conditions of weakening of immunity. Cytomegalovirus is ubiquitous. From 0.5% to 2.5% of newborns are infected with it during the period of intrauterine development.

The nature of the affected fetus depends on the timing of infection with cytomegalovirus. Infection in early pregnancy leads in part to intrauterine death of the fetus and miscarriages, stillbirths, the birth of children with malformations (for example, narrowing of the pulmonary trunk and aorta, defects of the interatrial and interventricular septa, fibroelastosis of the myocardium, microcephaly, lung hypoplasia, atresia of the esophagus, anomalies structure of the kidneys, etc.). When infecting in late pregnancy, developmental anomalies are not formed. However, from the first days after birth, the child is exposed to jaundice, hepatosplenomegaly and hemorrhagic syndrome. Other organs and systems are also affected: lungs (interstitial pneumonia), central nervous system (hydrocephalus, meningoencephalitis), gastrointestinal tract (enteritis, colitis, polycystosis of the pancreas), kidneys (nephritis).

With intranatal and early postnatal infection, clinical signs of the disease are detected in the first 1-2 months after birth.

Cytomegalovirus affects many types of blood cells and can persist in monocytes, macrophages, megakaryocytes, which in some cases leads to thrombocytopenia.

Laboratory diagnosis of cytomegalovirus infection is based on the detection of specific antibodies in the blood serum of infected or DNA viruses in body fluids (eg, blood, saliva, urine, ejaculate, punctate liver, lymphatic catch) by PCR, as well as virus antigens in peripheral blood smear lymphocytes indirect immunofluorescence (fast and sensitive method).

In serological diagnosis of cytomegalovirus infection, many reactions are used, but those that are useful for detecting antibodies classified as IgM and IgG are genuinely useful. Recently, the most widely used method ELISA.

Antibodies to the cytomegalovirus class IgM appear within 1-2 weeks after the onset of the disease and indicate a fresh infection or reactivation of a latent and persistent infection. However, it should be borne in mind that in some patients, an increase in the IgM class antibody content may not occur within the first 4 weeks after the onset of the disease. Elevated levels of IgM class antibodies to cytomegalvirus can persist for 12 months in 24% of patients. The presence of IgM antibodies in pregnant women is an indication for cordocentesis and fetal blood test for the presence of antibodies of IgM class. If you have IgM antibody, the fetus is considered infected. With a congenital cytomegalovirus infection IgM antibody titer is high, it gradually decreases, in the 2nd year of the child's life they may be absent. When evaluating the results of detection of IgM antibodies, it should be taken into account that the presence of rheumatoid factor can lead to false positive results of the study.

Antibodies to the cytomegalovirus class IgG appear 2-4 weeks after infection, the sick continue to 10 years. The presence of infection is indicated only by a 4-fold or more increase in the titer of IgG antibodies in the study of paired sera. The frequency of detection of IgG antibodies can reach 100% among different population groups.

The group with the greatest risk for cytomegalovirus infection is people with artificial or natural immunosuppression: HIV-infected, recipients of organs, tissues, cells, cancer patients.

Detection of IgM and IgG antibodies to cytomegalovirus is used to diagnose the acute period of cytomegalovirus infection, including in immunodeficient conditions, HIV infection, lymphoproliferative diseases and the determination of the period of convalescence of cytomegalovirus infection.

[1], [2], [3], [4], [5], [6]