Serological tests used to detect virus Epstein-Barr and antibodies thereto
Clinically, infection with Epstein-Barr manifests itself as follows:
- temperature rise;
- pain and catarrhal changes (redness) in the throat;
- the increase of some groups of cervical lymph nodes: castagnera, at least – prednesenych;
- changes in the blood.
This disease is dangerous for its complications. In some cases, may develop neurologic abnormalities, pathology of the blood system – anaemia, thrombocytopenia or neutropenia. Symptoms caused by the virus Epstein-Barr, similar to angina, but are treated quite differently. It is therefore important the correct laboratory diagnosis of the disease.
Diagnosis is based on clinical picture of the disease, changes in the blood test and interpretation of results of specific research methods. The latter include immuno-serological and molecular-genetic methods of research:
- Determination of the level of classici antibodies (IgG) against capsid proteins of the virus or to nuclear antigens.
- Determining the level of antibodies of class M (IgM) kopsidis proteins.
- Polymerase chain reaction – identification in biological material DNA of the virus itself.
These methods are subject to the rules of preparation for the tests with a probability close to 100% confirmed that infection with the virus Epstein-Barr. They also allow us to determine the fact of infection, to carry out differential diagnostics with diseases with a similar clinic.
When the analysis for IgG to Epstein-Barr
Transcript analyses serology for IgG to virus of allows to confirm the presence of infection or to determine that the man already had her. It is advisable to assign the analysis in the following cases:
- the suspected infection;
- a comprehensive survey of pregnant women (along with blood tests nacatamales, toxoplasmosis);
- with proven contact with the sick patient to assess susceptibility to infection and strength of immune system.
Study the concentration of immunoglobulin G are most often carried out on the principle of paired sera. This produces the analysis of two samples of blood taken with an interval of 10-14 days, allowing you to track the dynamics of the process. In particular, using such tests as VCA IgG, Anti-EBV, EBV EA-IgG Ab.
There are studies indicating acute or chronic infection. One of these serological tests is the definition of antinuclear antibodies– anti-EBNA (Epstein-Barr Nuclear Antigen) or EBNA-IgG Ab. Nuclear antibody (NA) appear on later stages of the disease.
What does a positive IgM
All antibodies of class IgM are formed on the first stage of infection, when the human body begins to react to the penetration into the body of antigens. Is no exception and the infection of Epstein-Barr.
Assign a blood test for EBV VCA-IgM Ab (antibodies to the capsid protein should be at the first suspicion of infection. A positive result allows the correct diagnosis at an early stage, which can be confirmed by PCR or later analysis on the IgG dynamics."
Avidity to antibodies – what is it? In addition to the concentration of antibodies in the interpretation of analysis are used such as avidity.
Avidity is the functional characteristic – it describes the degree of relationship of antibodies to the antigen, i.e. how "hard" they are associated. Increase this value if the result of analysis for IgG is evidence of the development of body most effective antibodies that is observed during prolonged infection.
Discouvery the presence of antibodies indicates a recent infection, vysokoavidnyh – the formation of immunity to the virus.
PCR, or DNA of the pathogen
Despite the reliability of modern diagnostic systems to determine the concentration of immunoglobulins the most reliable method is PCR – polymerase chain reaction. This method allows to determine the presence in a biological material, a DNA virus that is a sure sign of infection.
Assign analysis of PCR in the following cases:
- in the presence of clinical signs of disease: uvelichelos, liver, spleen;
- in the presence of laboratory signs: the appearance in blood of atypical lymphocytes;
- after transplantation of various organs or bone marrow.
Timely identification of the blood of the causative agent will allow you to begin the preventive treatment of the disease or enhance prevention methods to prevent re-activation of the virus.