Table of Contents
Epstein-Barr Virus Definition
A member of the herpesvirus family best known for causing the illness infectious mononucleosis. Infection with the epstein-barr virus, also called human herpesvirus-4 (HHV-4), causes other disease as well and was the first virus researchers linked with cancer (notably Burkitt’s lymphoma).
Epstein-Barr virus is ubiquitous; it infects more than 90 percent of Americans by age 25.
Causes of Epstein-Barr virus
As is characteristic of herpesvirus infections, Epstein-Barr virus causes first an acute illness (infectious mononucleosis), then retreats into a state of dormancy and remains in the body as a latent infection that does not cause illness or symptoms.
B-cell lymphocytes, white blood cells key to antibody-mediated immunity, harbor the latent Epstein-Barr virus. Though the virus does not change the ability of its host B-cell lymphocytes to function within the immune response, it does alter their DNA such that they become immortalized-they lose their genetic encoding for apoptosis, the natural process for cell death.
Only a small percentage of B-cell lymphocytes contain the virus, so for the most part immune function continues as normal. A healthy immune system maintains a balance between B-cell lymphocytes and T-cell lymphocytes (white blood cells key to cell-mediated immunity) that prevents B-cell lymphocytes containing the latent Epstein-Barr virus from endlessly proliferating. As a result of this balance, in most people the virus never regains enough presence to again cause illness.
Circumstances that challenge the immune system allow the Epstein-Barr virus to reactivate. The most notable of these circumstances are hiv/aids and immunosuppressive therapy after organ transplantation.
The reactivated Epstein-Barr virus may cause symptoms similar to infectious mononucleosis (chronic infectious mononucleosis) during which the person may spread the virus to others. It may also cause lymphoproliferative disorders: abnormal growth (tumors) of lymphatic structures such as lymph nodes and mucosa-associated lymphoid tissue (MALT).
Though research is under way to develop a vaccine to prevent infection with Epstein-Barr virus, at present there are no effective measures to prevent infection with the virus and no treatments to eradicate the virus once it establishes infection.
Diseaseas Associated With Epstein-Barr Virus
|DISEASES ASSOCIATED WITH EPSTEIN-BARR VIRUS|
|acute infectious||aids-associated lymphoma|
|chronic infectious mononucleosis||generalized lymphoproliferative disease|
|nasopharyngeal carcinoma||post-transplant lymphoproliferative disorder (PTLD)|
See also B-CELL LYMPHOCYTE; CELL STRUCTURE AND FUNCTION; HERPES SIMPLEX; HERPES ZOSTER; KAPOSI’S SARCOMA; LYMPH NODE; LYMPHOCYTE; MONONUCLEOSIS, INFECTIOUS; OPPORTUNISTIC INFECTION; T-CELL LYMPHOCYTE.
Page last reviewed: