Summary

This is a group of tests that detect Epstein-Barr Virus (EBV) antibodies and they are used to help diagnose infectious mononucleosis or glandular fever. Glandular fever develops in about half of people who are infected with the EB virus. Antibodies are made by the immune system to fight off infection. Some people with glandular fever can be diagnosed through their symptoms together with a Full Blood Count test and a Monospot test. However, other people have a negative result to the Monospot and an antibody test is needed instead to make their diagnosis. EBV antibody testing is also used to differentiate between an EBV infection and other illnesses with similar symptoms. It is used to assess whether the EBV infection is active or has occurred at some time in the past.

Why get tested?

EBV is a type of herpes virus that causes an infection which is very common.  As many as 95 per cent of adults in the world have been infected at some point in their lives.

Once someone has been exposed to the virus there is an incubation period of several weeks before symptoms start. Symptoms gradually lessen over the following weeks but the virus itself stays in the body for the rest of that person's life. It can be reactivated from time to time usually causing only mild symptoms or complications.

EBV can infect people of any age, but it usually occurs in children and teenagers. Children usually have few or no symptoms even in the acute phase of the infection.  However, when the infection occurs in adolescents or adults it causes glandular fever in up to half of those infected. Symptoms include tiredness, fever, sore throat, swollen lymph nodes, an enlarged spleen and sometimes an enlarged liver. Symptoms can last for weeks or months.

People are typically diagnosed by their symptoms and a screening test known as a Monospot or Heterophile Antibody test. However, in some cases, especially in children, the Monospot test result is negative. This is when it is necessary to look for antibodies that are specific to the EBV virus.

EBV infection can have similar symptoms to infection by other viruses such as cytomegalovirus (CMV), toxoplasmosis, hepatitis and Human Immunodeficiency Virus (HIV). The treatment of EBV is different and so it is important to diagnose and differentiate EBV from these other infections. This is particularly important in pregnancy as some other viruses can cause serious complications.

The antibodies which are being tested for are those produced by the immune system to defend the body against EBV. They are designed specifically to target antigens on the surfaces of the viruses. There are several different EBV antigens and each of them is recognised by a different antibody.

Several antibodies can be detected and they include IgM and IgG antibodies to the viral capsid antigen (VCA) and antibodies to the nuclear antigen (EBNA).

The VCA-IgM antibody is usually detectable at the time of the first blood test when symptoms first appear and then tends to disappear between four and six weeks. The VCA-IgG antibody develops soon after VCA-IgM and persists for life. 

The EBNA antibody usually develops at between two and four months after the initial infection, so does not usually appear until the acute infection has resolved and then it persists for life.

Using a combination of these EBV antibody tests and the clinical presentation, a doctor is able to diagnose an EBV infection and to assess whether it is a current, recent, or a past infection.

Having the test

Sample

Blood test

Any preparation

None 

Your results

The Table shows results for the three different EBV antibodies - VCA-IgM, VCA-IgG and EBNA-IgG - together with that of the initial Monospot test. There are four major findings:

• If you have positive VCA-IgM antibodies it is likely that you have a current or very recent EBV infection. If you also have symptoms associated with glandular fever it is likely that you will be diagnosed with an EBV infection even if your monospot test was negative. 
• If you also have a positive VCA-IgG test result it is highly likely that you have or recently had an EBV infection.
• If the VCA-IgM is negative but the other antibodies including EBNA antibody are detected it is likely that you had a previous EBV infection. 
• If you are asymptomatic and have a negative VCA-IgG test, then you have not been previously exposed to EBV and could now be infected.

Questions to ask your doctor

The choice of tests your doctor makes will be based on your medical history and symptoms.   It is important that you tell them everything you think might help.

You play a central role in making sure your test results are accurate. Do everything you can to make sure the information you provide is correct and follow instructions closely.

Talk to your doctor about any medications you are taking. Find out if you need to fast or stop any particular foods or supplements. These may affect your results. Ask:

• Why does this test need to be done?
• Do I need to prepare (such as fast or avoid medications) for the sample collection?
• Will an abnormal result mean I need further tests?
• How could it change the course of my care?
• What will happen next, after the test?

Any more to know?

There are other antibodies that arise during an EBV infection including:

• IgG antibody to EBV D early antigen (EA-D IgG) 
• IgA antibody to the EBV viral capsid antigen (EBV VCA-IgA) 
• IgG antibody to the EBV early antigen restricted (EA-R IgG).

Although it is possible to test for these antibodies as part of the EBV diagnosis it is rarely necessary to do so.

There are molecular tests that can detect and measure EBV DNA. They can be helpful in diagnosing and monitoring EBV-related diseases such as Burkitt's lymphoma, Hodgkin's lymphoma, and post-transplant lymphoproliferative disease (PTLD).

A VCA-IgG test, and sometimes an EBNA test, may be ordered for someone who does not have symptoms to decide if they have been previously exposed to EBV or have an EBV infection. This is not routinely requested but may be ordered when someone such as an adolescent or an immune-compromised person, has been in close contact with someone with glandular fever.
 

More information

Get further trustworthy health information and advice from healthdirect.