EBV antibodies are ordered to help diagnose Mono in patients who are symptomatic but have a negative Mono test. NCID recommends ordering a VCA-IgM, VCA-IgG, EA-D, and an EBNA. The VCA-IgM, VCA-IgG and EA-D are ordered to detect a current or recent infection, the VCA-IgG and EBNA to detect a previous infection. In pregnant women with symptoms of a viral illness, one or more of these EBV antibodies may be ordered to help distinguish between EBV, CMV, toxoplasmosis, and other infections that may cause similar symptoms. Occasionally, a VCA-IgG or other EBV antibody may be repeated 2-4 weeks after the first test, either to see if a test changes from negative to positive or to measure changes in antibody concentrations (to see if they rise or fall).

A VCA-IgG test (and sometimes an EBNA test) may be ordered on an asymptomatic patient to see if that person is susceptible to EBV infection or has been previously exposed. This is not routinely done, but it may be ordered when a patient, such as an adolescent or an immune compromised patient, has been in close contact with a person who has Mono.

EBV antibodies may be ordered when a patient has symptoms suggesting Mono, but a negative Mono test and when a pregnant woman has flu-like symptoms and the doctor wants to determine whether the symptoms are due to EBV or another microorganism. VCA-IgG and EBNA may be ordered whenever a doctor wants to establish previous exposure. Testing may occasionally be repeated when the doctor wants to track antibody concentrations and/or when the first test was negative, but the doctor still suspects that the patient’s symptoms are due to EBV.

If a patient has positive VCA-IgM antibodies, then it is likely that he has a current (or had a very recent) EBV infection. If he also has the symptoms associated with Mono, then it is most likely that he will be diagnosed with Mono, even if his Mono test (the heterophile antibody) was negative. If he also has positive VCA-IgG and EA-D IgG concentrations, then it is highly likely that he has (or recently had) an EBV infection.

If the VCA-IgM is negative but the others and an EBNA antibody are positive, then it is likely that the person had a previous EBV infection. If an asymptomatic person is negative for VCA-IgG, then he has not been previously exposed to EBV and is vulnerable to infection. In general, rising VCA-IgG levels tends to indicate an active EBV infection, while falling concentrations tend to indicate a recent EBV infection that is resolving. However, care must be taken with interpreting EBV antibody concentrations as the amount of antibody present does not correlate with the severity of the infection or with the length of time it will last. High levels of VCA-IgG may be present and may persist at that concentration for the rest of the patient’s life.

Results in table form:

	Test results most likely indicate:
EBV Antibody Test	Susceptible to EBV	Current EBV Infection	Past EBV Infection	Comments
VCA-IgM		+	+	Appears first, gone in 4-6 weeks
VCA-IgG	–	+	+	If negative susceptible, it appears within a week of infection, then present for life
EBNA-IgG			+	Becomes positive in 2 – 4 months, then present for life
EA-D IgG		+	+	Positive in about a week, usually gone in 2 weeks, persists in 20% of people
Heterophile IgM (Mono test)		+		Associated with Mono, false positives with other conditions, false negatives common in children

There are at least two other antibodies that arise during an EBV infection -- an IgA antibody to the EBV viral capsid antigen (EBV VCA-IgA) and an IgG antibody to the EBV early antigen restricted (EA-R IgG). While it is possible to test for these antibodies as part of the EBV diagnostic workup, it is rarely necessary to do so.

The most common complication of Mono is a ruptured spleen. Other complications of EBV infection that can occur include trouble breathing due to a swollen throat, strep throat (a Group A streptococcus infection) at the same time, and rarely, jaundice, skin rashes, pancreatitis, seizures, and/or encephalitis. EBV is also associated with (and probably plays a role in) several rare forms of cancer, including Burkitt’s lymphoma and nasopharyngeal carcinoma.

Reactivation of the virus is rarely a health concern unless the patient is significantly and persistently immune compromised (as may happen in those who have HIV/AIDS or in those who have received an organ transplant). Primary infections in these patients can be more severe.