Epstein–Barr virus viral-capsid antigen is an immunogenic
antigen
In immunology, an antigen (Ag) is a molecule, moiety, foreign particulate matter, or an allergen, such as pollen, that can bind to a specific antibody or T-cell receptor. The presence of antigens in the body may trigger an immune response.
...
derived from the protein shell of the
Epstein Barr Virus The surname Epstein () is one of the oldest Ashkenazi Jewish family names. It is probably derived from the German town of Eppstein, in Hesse; the place-name was probably derived from Gaulish ''apa'' ("water", in the sense of a river) and German '' - ...
.
Epstein Barr Virus (EBV) causes the illness referred to as
Mononucleosis
Infectious mononucleosis (IM, mono), also known as glandular fever, is an infection usually caused by the Epstein–Barr virus (EBV). Most people are infected by the virus as children, when the disease produces few or no symptoms. In young adu ...
. In the infectious stage of this illness, individuals will have Epstein Barr viral capsid
antigens
In immunology, an antigen (Ag) is a molecule, moiety, foreign particulate matter, or an allergen, such as pollen, that can bind to a specific antibody or T-cell receptor. The presence of antigens in the body may trigger an immune response.
An ...
(EBV-VCA) in their mouth and blood.
The
viral capsid
A capsid is the protein shell of a virus, enclosing its genetic material. It consists of several oligomeric (repeating) structural subunits made of protein called protomers. The observable 3-dimensional morphological subunits, which may or ma ...
of a virus is the complex of proteins that surrounds the genetic material inside the virus. Epstein Barr virus capsid antigens (VCA) are any sections of the viral capsid that the hosts' antibodies bind to. The hosts, or individuals infected with the virus, will produce
antibodies
An antibody (Ab) or immunoglobulin (Ig) is a large, Y-shaped protein belonging to the immunoglobulin superfamily which is used by the immune system to identify and neutralize antigens such as bacteria and viruses, including those that caus ...
to target these Epstein Barr viral capsid antigens.
IgG
Immunoglobulin G (IgG) is a type of antibody. Representing approximately 75% of serum antibodies in humans, IgG is the most common type of antibody found in blood circulation. IgG molecules are created and released by plasma B cells. Each IgG ant ...
VCA antibodies will be produced during the early stage of the EBV infection. In contrast,
IgM
Immunoglobulin M (IgM) is the largest of several isotypes of antibodies (also known as immunoglobulin) that are produced by vertebrates. IgM is the first antibody to appear in the response to initial exposure to an antigen;
causing it to also ...
VCA antibodies will be produced at later stages on the infection.
Testing
Several types of tests are used to diagnose individuals with Mononucleosis. For immunocompetent individuals, antibodies targeting the viral capsid antigen have been found to be more effective and accurate than alternative testing methods.
Immunocompromised individuals will not have the same results to VCA IgG and IgM antibody tests as immunocompetent individuals.
References
Epstein–Barr virus
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