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
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:
This constellation usually indicates an early stage of acute infection, but can also occur due to unspecificity of the VCA IgM test due to 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, auto antibodies, 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
This constellation might appear in patients with primary EBV infection if VCA IgM persists and EBNA-1 IgG have 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:
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:
This constellation is rarely observed in routine EBV serology, and might be due to the lack of VCA IgG production in some individuals, loss over time, or low sensitivity of the assay.
This serological profile is considered indeterminate. Additional testing is required to confirm a past infection. Immunoblots for IgG based on recombinant antigens can confirm the presence of EBNA-1 IgG in past infection.
This constellation is considered implausible. Repeat testing or consider pre-analytical errors.