About this test
This test measures the level of IgM and IgG antibodies in the blood serum against Epstein-Barr virus antigens, EBV, which is the cause of infectious mononucleosis. Determining antibodies to the EBV virus can help confirm whether you are currently experiencing infectious mononucleosis or have had it in the past. Antibodies to the viral capsid antigen, anti-VCA, of the IgM and IgG classes, are determined. Anti VCA IgM antibodies appear in the early phase of infection and usually disappear within a few weeks. Anti VCA IgG antibodies appear in the acute phase of infection, reach a maximum within a few weeks. They then drop to lower levels and persist for life. Next, antibodies to the EBV nuclear antigen, anti-EBNA IgG, are determined, which are not present in the acute phase of infection and appear several months after the onset of symptoms, then persist for life. The presence of anti-VCA IgG and anti-EBNA IgG antibodies in the absence of anti-VCA IgM antibodies indicates past Epstein-Barr virus infection. The results of these tests should be interpreted in the context of the patient's current clinical status, medical history, and other laboratory findings.
Infectious mononucleosis, commonly referred to as the “kissing disease,” is caused by the Epstein-Barr virus (EBV), a member of the human herpesvirus family (1). The clinical presentation of the disease is variable and may be asymptomatic or may present with symptoms similar to angina (fever, swollen lymph nodes, sore throat, fatigue, loss of appetite, and whitish tonsil plaques) (2). Mononucleosis is most often diagnosed based on clinical presentation, complete blood count with differential, liver function tests, specific antibodies to EBV, and abdominal ultrasonography.
Why should I undergo serological testing for antibodies to infectious mononucleosis?
Serological testing measures antibodies to the viral capsid antigen, anti-VCA IgM and IgG, and antibodies to the nuclear antigen, anti-EBNA (4). In practice, the determination of anti-VCA IgM and IgG antibodies and anti-EBNA IgG (4) is used, which is advantageous mainly for the following reasons:
- Determination of antibodies to EBV is important to confirm infection, to determine whether an individual has previously had infectious mononucleosis or is susceptible to EBV infection (2) (3).
- Testing for antibodies to EBV is recommended for symptoms of infectious mononucleosis if the rapid monotest is negative (5).
When is it appropriate to perform a serological test for antibodies to mononucleosis?
The clinical picture of mononucleosis is variable, as it can be a) asymptomatic, b) with symptoms typical of infectious mononucleosis, or c) rarely with very severe symptoms (2). The first symptoms appear approximately four to six weeks after infection with Epstein-Barr virus, may develop very slowly, and may not all appear at the same time (6). In children and adolescents, mononucleosis is “confused” with tonsillitis due to symptoms such as fever, extreme fatigue, sore throat and headache, swollen lymph nodes in the neck and armpits, and white-gray necrotic plaques on the tonsils (4).
The liver and spleen are enlarged in at least 50% of cases. In some cases, the liver, spleen, or both remain enlarged long after the fatigue has subsided. While most recover within two to four weeks, some may experience extreme fatigue for several weeks after starting treatment. Occasionally, symptoms of infectious mononucleosis may persist for more than six months (6). In adults, a subacute course is more typical, with symptoms such as a mildly elevated temperature (not reaching fever level), malaise, enlarged lymph nodes, and an enlarged liver and spleen; these persist for several months (4) (2).
Complications are rare but can be more serious. Liver involvement is typical, with liver function tests being two to three times higher than normal. Less commonly, lung involvement or a reduced red blood cell count are seen (4) (5) (1).
What should you know about infectious mononucleosis before undergoing serological testing?
Serological testing for antibodies to specific EBV antigens can be helpful in diagnosing infectious mononucleosis (4).
- Antibodies to viral capsid antigen (anti-VCA) IgM and IgG
IgM anti-VCA appears early in EBV infection and usually disappears within four to six weeks, while IgG anti-VCA appears in the acute phase of EBV infection and peaks two to four weeks after the onset of symptoms, then declines slightly and then persists throughout life. Everyone who has had EBV infection has anti-VCA IgG antibodies (7).
- Antibodies to early antigen (anti-EA) IgG
Anti-EA IgG appears in the acute phase of the disease and generally declines to undetectable levels after three to six months. The detection of anti-EA antibodies is a sign of active infection in many individuals. However, in approximately 20% of healthy individuals, anti-EA antibodies can be detected even years after EBV infection (7).
- Antibodies to EBV nuclear antigen (anti-EBNA)
Anti-EBNA is determined by conventional immunofluorescence and is not present in the acute phase of EBV infection. They appear slowly, usually about two to four months after the onset of the first symptoms, and persist throughout life. In a small part of the population, they may not develop at all. The absence of anti-EBNA in the presence of EBV-VCA-IgM positivity indicates a primary (new, current) EBV infection (EBNA IgG antibodies are used to distinguish primary infection from reactivation) (7) (8).
- Monospot test
Some laboratories also offer the so-called monospot test, but according to experts, it is not suitable for widespread use. The antibodies detected by the Monospot test may be associated with other disease states such as infectious mononucleosis. Studies have shown that Monospot sometimes provides false positive or negative results and cannot confirm the presence of EBV infection ( 7).
What’s inside
anti EBV (VCA) lgG
anti EBV (VCA) lgM
anti EBV (EBNA-1) IgG (ELISA)
What’s measured
About EBV and infectious mononucleosis
Epstein-Barr virus (EBV), also known as human herpesvirus 4, is a herpesvirus found only in humans. Serological testing for the presence of antibodies to EBV is not usually necessary to diagnose infectious mononucleosis, but may be useful in the following cases:
a) when the patient does not have typical symptoms of infectious mononucleosis,
b) when he has an illness caused by EBV infection, but it is not mononucleosis,
c) to determine susceptibility to EBV infection
d) to verify whether the individual has previously had infectious mononucleosis (7).
The virus persists in the body throughout life and can reactivate at any time with a slightly different clinical picture, especially in cases of weakened immunity, chronic illness or prolonged stress. Almost everyone comes into contact with EBV during their lifetime. In countries with high hygiene standards, the first wave of contact with the virus occurs around the age of five, the second wave occurs in adolescents and young adults. In adulthood, 90 to 95% of the population has antibodies to EBV (1) (4) (7) (8).
Infectious mononucleosis occurs mainly in children and adolescents. Its incidence decreases with increasing age. The source of infection is a sick individual or a carrier of the virus who has no obvious symptoms. Transmission occurs by droplet infection, direct contact, or saliva (e.g., kissing). The upper respiratory tract is the gateway through which the virus enters the body. There is currently no vaccination against infectious mononucleosis, as there is no approved vaccine (9) (4) (3). Interpretation of test results should always be done in combination with clinical information about the patient.
Susceptibility to infection
In the absence of IgG antibodies to EBV-VCA, the subject is considered susceptible to EBV infection (7).
Primary (active) infection
Active infection is characterized by the presence of anti-VCA IgM and the absence of EBNA antibodies (at least four weeks after the onset of symptoms). The disease may resolve before diagnostic antibody levels appear. Rarely, EBV-specific antibodies are not detectable in individuals with active infection (7).
Past infection
Previous infection is characterized by the presence of antibodies to VCA and EBNA (months to years ago) (7).
Instructions before collection
We do not recommend entry of patients/clients with clinical signs of disease (temperature, cough, signs of respiratory tract infection, etc.) to undergo this test.
We recommend hand disinfection prior to entry to the clinics/collection points.
It is advised to fast for a minimum of 8 hours by refraining from eating or drinking anything expect water. Faiing to fast before the test may affect result quality. If you are currently on medications, consult your healtcare provider to determine whether you should continue taking them prior to the test.
PREPARATION FOR BLOOD COLLECTION
The recommended time to collect blood is between 7 a.m. and 9 a.m., to obtain comparable results from different blood draws. To assess the numerical test result, so-called reference intervals are used, which are based on morning fasting collections and are used for population comparison. This time interval is also recommended in light of the biological cycles that naturally take place in the body.
GENERAL PRE-SAMPLING INSTRUCTIONS
It is necessary to come to the testing site earlier, so that you can rest in the waiting room for approximately 20 minutes to have a relatively relaxed body and mind.
It is necessary to arrive on an empty stomach for the collection itself, in the case of collections at a later time in the day, at least three hours on an empty stomach. At home, it is desirable to drink a sufficient amount of pure water (at least up to half a liter) - this is important for a successful blood collection. Mineral water, juice, coffee and tea are not recommended.
Herbs included in tea may contain substances affecting the blood count. Coffee and black tea increase gastric acid production and release insulin from the pancreas, thereby affecting glucose metabolism. Since everything in the body is interrelated, they can impact other tests. Another extreme is when your body is running out of fluids. In this case, the number of red blood cells, the level of protein and lipids bound to the protein increase and the level of urea in the blood can also increase. It is therefore advisable to drink pure water when you wake up.
Generally, it is recommended to:
• around 6 p.m. eat only light meals, do not eat fatty food (cheese, butter, cream, meat, smoked meat, bacon) and sweet meals,
• fast for 10-12 hours (Attention: it is not advisable to starve for more than 16 hours!), in the case of later collection (after 9:30 a.m.), a lighter breakfast is allowed, no later than 3 hours before collection,
• drink non-alcoholic beverages and drinks without sugar in the usual quantity, in the case of adult clients 24 hours before blood collection (Alcohol in the blood changes lipid levels, the level of glucose is reduced, uric acid levels increase and liver enzymes are released into the blood),
• take only prescribed medicines in the evening,
• avoid increased physical activity, and strength and endurance exercise the day before blood collection (Lipid, glucose, some enzyme levels in the blood and other parameters may change during physical activity. The recovery of normal values to maintain the accuracy of laboratory results may take a longer time, depending on the duration of the exercise, your physical fitness in general and other factors. We recommend maintaining normal daily physical activity such as light stretching, short cycling to work, gardening, etc.),
• avoid psychological stress, which raises blood glucose levels and causes the release of stress hormones in particular,
• avoid smoking for at least 6 hours prior to blood collection because it increases the level of carbonylhemoglobin produced by the reaction of the blood dye with carbon monoxide and alters the permeability and elasticity of the vessels, affecting the ratios of blood analytes,
• do not chew gum for at least 6 hours before blood collection, as this may affect glucose and enzyme levels,
• do not undergo stressful diagnostic or therapeutic interventions for at least 24 hours prior to blood collection.
If any of the tests you have selected require special preparation, you will be informed of the fact by email with the order and blood collection instructions attached. These specific instructions have priority over the general recommendations for preparation.
MEDICINES
It is recommended to have blood collected before the planned doses of medicines. If it is not possible to take the medicine later, you should inform the nurse during blood collection and specify what medication you have taken.
Take the medicines prescribed by your doctor in the morning or bring them with you to take them after blood collection (thyroid medicines, antihypertensive medicines, blood thinners, contraceptives, etc.) In the case of later collection (after 9:30 a.m.), you can take the prescribed medication in the morning.
Do not take iron, vitamin, nutritional supplements or other supplements, including homeopathics, for at least three (3) days prior to blood collection.
SPECIFIC SITUATIONS
In order to obtain the appropriate answers to your questions with regard to the laboratory tests, it is important to accurately notify the nurse at the healthcare provider about the following facts prior to your blood test:
• regularly used medicines and supplements (ideally come with a written list to the blood collection site),
infectious diseases you suffer from (e.g., HIV, hepatitis, mononucleosis...),
• contact with an infected person or presence in an infectious environment,
• if you have received an infusion within the last 5 days, specify into which limb,
• intramuscular injections within 3 days prior to the blood collection date,
• long-term immobilisation, lost ability to move,
• activities at higher altitudes,
• allergy to common band-aids,
• if you feel unwell when looking at blood or needles, please also notify our blood collection staff of the fact.
OTHER FACTORS
Please note that prolonged use of medication or other important factors may affect the values measured by the tests you have selected. For more information, please see the description of the specific test. To obtain objective test results, take the time to properly prepare for your blood collection.
Results
In case of purchasing the interpretation of the results, this interpretation is created by an internist from uLékaře.cz.
Sources
- Mononucleosis - Symptoms & causes - Mayo Clinic. (2022). Mayo Clinic. Available at: https://www.mayoclinic.org/diseases-conditions/mononucleosis/symptoms-causes/syc-20350328. [cit. 05-01-2024].
- Holečková, K. & Klinika infektológie a geografickej medicíny SZÚ, Bratislava. (2006). INFECTIOUS MONONUCLEOSIS. Via Pract, 3–1, 25–27. Available at: https://www.solen.sk/storage/file/article/Holeckova.pdf. [cit. 05-01-2024].
- De Paschale, M. (2012). Serological diagnosis of Epstein-Barr virus infection: Problems and solutions. World Journal of Virology, 1(1), 31. Available at: https://doi.org/10.5501/wjv.v1.i1.31. [cit. 05-01-2024].
- Kleinerová, J. (2008). Infekční mononukleóza. In MEDICÍNA PRO PRAXI (Vol. 5, Issue 10, p. 372). Available at: https://www.medicinapropraxi.cz/pdfs/med/2008/10/06.pdf. [cit. 05-01-2024].
- Mononucleosis Tests | HealthLink BC. (n.d.). Available at: https://www.healthlinkbc.ca/tests-treatments-medications/medical-tests/mononucleosis-tests. [cit. 05-01-2024].
- About Infectious Mononucleosis (Mono). (2024). Epstein-Barr Virus and Infectious Mononucleosis. Available at: https://www.cdc.gov/epstein-barr/about/mononucleosis.html. [cit. 05-01-2024].
- Laboratory Testing for Epstein-Barr Virus (EBV). (2024). Epstein-Barr Virus and Infectious Mononucleosis. Available at: https://www.cdc.gov/epstein-barr/php/laboratories/index.html. [cit. 05-01-2024].
- EBV Epstein-Barrové virus (anti-VCA IgM a IgG, anti-EA IgG, anti-EBNA IgG). Available at: https://www.nemjh.cz/documents/laboratorni_prirucka_olm/HVEZDAJAEZ.htm. [cit. 05-01-2024].
- National Library of Medicine. (n.d.). Infectious Mononucleosis. Mono | Mono Symptoms | MedlinePlus. Available at: https://medlineplus.gov/infectiousmononucleosis.html. [cit. 05-01-2024].
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