Mononucleosis tests are blood tests to
antibodies that indicate mononucleosis (mono), which is usually caused by the
Epstein-Barr virus (EBV). The antibodies are made by
immune system to fight an infection.
The results of a monospot test are
usually ready within 1 hour.
The blood sample does not
form clumps (no heterophil
antibodies are detected).
The blood sample clumps
(heterophil antibodies are detected). If the blood sample clumps, you probably
Epstein-Barr antibody testing
The results of the
antibody test to detect
Epstein-Barr virus (EBV) may be reported as
positive (antibodies are present) or negative (antibodies are not present). Or the test results may be reported in
The EBV antibody test can also detect the type of antibodies
(immunoglobulins) present in the blood. The type of antibody shows whether
the infection is recent or old. The antibody IgM is only found during the
active phase of mono. The antibody IgG can be found later, when you are
starting to get better.
The results of an EBV antibody test are
usually ready within 3 days.
EBV antibody test
The titer is less than 1 to
10 (1:10). A titer of less than
1:10 means that you have never been exposed to EBV.
against EBV is present. If IgG is present, it may mean that you have been exposed to EBV in
A titer greater than 1 to
10 (1:10) but less than 1:320 usually means that you have
been infected with EBV at some time in the past.
A titer of 1:320 or greater means that you have an
active EBV infection (mononucleosis).
IgM against EBV is
What Affects the Test
Reasons you may not be able to
have the test or why the results may not be helpful include:
- Having an EBV antibody test within the first
few weeks of becoming infected with EBV. This may lead to a
false-negative result. If the first test does not
indicate mono but you still have symptoms, the test may be repeated.
- Other infection or disease, such as
lupus. Although the symptoms of these infections and
diseases are similar to mono, the monospot test usually will be
- Having a weakened immune system.