Epstein – Barr Virus for nuclear antigen, Ig G (EBNA-1 IgG)

General Information:

Epstein-Barr Virus (EBV) is a widespread human gamma herpes virus (herpes type 4), which is an etiological agent of infectious mononucleosis.

The disease occurs predominantly in infancy and adolescence and sometimes it is difficult to diagnose. The most common symptoms include:

• severe fatigue, fatigue, loss of appetite, cold chills and chills in the first few days
• severe sore throat (angina with sticks)
• swollen lymph nodes (cervical)
• severity and pain in the left and right sub-bursa (hepato-spleen megali)
• measles-like rash

The virus is also the cause of some other diseases, such as hepatitis, lymphadenitis, hairy leukoplakia, Hodgkin's disease, non-Hodgkin's lymphoma, nasopharyngeal carcinoma, stomach carcinoma etc. The infection is by Aerosol Transmission.

EBV infection is diagnosed by:

• blood count and smear for specific changes (atypical lymphocytes)
• biochemical tests to assess liver function (liver enzymes and bilirubin)
• serological tests
• confirmatory tests (Blot tests)
• EBV PCR test

Diagnosis of EBV infection is usually based on determination of serological status and clinical picture data.

Serological testing is considered the gold standard for distinguishing acute from past EVB infection in immunocompetent patients.

In immunosuppressed patients, however, there is an insufficient humoral response against EBV, so serological testing is not a reliable marker for determining clinical status. In these patients, direct detection of viral nucleic acid is more appropriate for determining clinically significant EBV infection.

The following markers are examined in the laboratory:

• Heterophilic Antibody Test (Paul-Bunell)
• EBV VCA IgM (Epstein Barr Virus Virus Capsid Antigen) – main marker. Indicates an acute infection. It is prescribed when mononucleosis is suspected. It is proven up to 2 months from the onset of the disease.
• EBV VCA IgG (Epstein Barr Virus Capsid Antigen) – indicates past infection. These antibodies remain in the body for life.
• EBNA IgG (Epstein Barr Virus Nuclear Antigen) – is tested when necessary to differentiate acute from chronic infection. This is important because almost 90% of the adult population has EBV VCA IgG.

These antibodies are synthesized last and serologically positive during the course of the disease after 2-3 weeks of clinical symptoms and are strongly increased during the following 3-12 months. Their absence and VCA positivity confirm acute infection with the virus.

 The diagnosis is confirmed when:

• clinical data, changes in blood and liver indicators
• heterophile antibody test (20% of adults, over 50% of children and almost 90% < 3 years do not form these antibodies)
• EBV VCA Ig M positive
• EBV VCA Ig G positive after 3 weeks
• EBNA Ig G when tested too early may be negative

Sample Required:

Venous blood

Keywords:

Epstein-Barr Virus (EBV)