Not immune | Acute infection | Transient phase** | Past infection | |
---|---|---|---|---|
VCA IgM | - | + | + | - |
VCA IgG | - | +* | + | + |
EBNA-1 IgG | - | - | + | + |
* Can be negative in very early phase of acute infection
** Indeterminate infection stage. Requires additional testing. Same result constellation can be observed during reactivation of infection.
Adapted from:
a) for use on the cobas® e 411 analyzer and the cobas® e 601 / 602 modules;
b) for use on the cobas® e 402 and cobas® e 801 analytical units
* In a small number of cases EBV EBNA-1 IgG may be detectable early (10 days after the onset of illness in <5 %)3.
VCA IgM | VCA IgG | EBNA-1 IgG | Interpretation |
---|---|---|---|
- | - | - | Seronegative, no immunity |
+ | - | - | Presumed early phase of infection# |
+ | + | - | Acute infection |
+ | + | + | Transient phase of primary infection, or reactivation# |
- | + | + | Past infection |
- | + | - | Isolated VCA IgG# |
- | - | + | Isolated EBNA-1 IgG# |
+ | - | + | Implausible result# |
Note: EBV serology is not recommended to diagnose immunocompromised individuals.
# Indeterminate EBV serology. Additional testing required.
Adapted from:
Seronegative, no immunity.
Presumed early phase of infection.
This constellation usually indicates an early stage of acute infection, but can also occur due to unspecificity of the VCA IgM test (interferences or cross-reactivity).
This serological profile is considered indeterminate and additional testing is required to confirm acute infection, including:
Potential interfering or cross-reacting factors (e.g. Rheumatoid factor, autoantibodies, CMV, Parvovirus B19) in case of an isolated VCA IgM profile
Immunoblots for IgM, based on recombinant antigens
EBV DNA testing
Heterophilic antibodies and anti-EA (D) IgG, both commonly found in acute infection, but not very sensitive or specific.
Serial testing (after about 30 days) to observe changes in antibody profiles
Acute infection.
Transient phase of primary infection, or reactivation.
This constellation might appear in patients with primary EBV infection if VCA IgM persists and EBNA-1 IgG has already been produced (recent infection, transient phase, or convalescence), or in those with viral reactivation.
This serological profile is considered indeterminate. Additional testing is required to confirm or resolve indeterminate EBV profiles obtained with screening assays (VCA IgM, VCA IgG and EBNA IgG), in particular to distinguish acute and past infections:
Immunoblots based on recombinant antigens
IgG avidity: low avidity indicates recent infection (<12 weeks after symptom onset)
EBV DNA testing: the presence of EBV DNA in plasma/serum is considered a sign of primary infection. Particularly useful in immunocompromised patients, and when antibody test results are inconclusive, but acute infection is suspected (isolated VCA IgM, or reactivity of all three markers).
Heterophilic antibodies and anti-EA (D) IgG, both commonly found in acute infection, but not very sensitive or specific.
Potential interfering or cross-reacting factors (e.g. Rheumatoid factor, auto-antibodies, CMV, Parvovirus B19) in case of an isolated VCA IgM profile
Serial testing (after about 30 days) to observe changes in antibody profiles
Past infection confirmed.
Isolated VCA IgG.
This constellation may be found in cases of past infection with the loss or disappearance of EBNA-1 IgG, or in cases of acute infection with the delayed or early disappearance of VCA IgM.
This serological profile is considered indeterminate and is observed in approximately 7% of laboratory routine. Additional testing is required to distinguish transient infection and reactivation, including:
Immunoblots for IgG, based on recombinant antigens
IgG avidity: low avidity indicates recent infection (<12 weeks after symptom onset)
EBV DNA testing: the presence of EBV DNA in plasma/serum is considered a sign of primary infection.
Heterophilic antibodies and anti-EA (D) IgG, both commonly found in acute infection, but not very sensitive or specific.
Serial testing (after about 30 days) to observe changes in antibody profiles
Implausible result.
Repeat testing or consider pre-analytical errors.
Presumed acute infection.
Presumed past infection.
Presumed acute or past infection.
Isolated VCA IgG.
Past infection.
Presumed early phase of infection.
Implausible result.