Probably
many factors contribute to the development of a cancer, and often it's
difficult to determine the causative factors. That said, the
evidence connecting Epstein Barr virus (EBV) with some
kinds of lymphoma is building. For example, there is a
strong association between EBV an Burkitts lymphoma, but other factors
may also be needed for a cancer to develop, such as suppressed
immunity. Therefore, having an EBV-positive lymphoma may not
always mean the lymphoma was caused by this virus.
About Epstein
Barr Virus: Evidence is building that Epstein-Barr
virus can "change normal cells into cancerous ones."
"That virus already is known to cause infectious mononucleosis in
humans and has been associated with such malignancies as Burkett’s
lymphoma, Hodgkin’s lymphoma and nose and throat cancer. It is
especially hazardous to AIDS patients and other patients whose immune
systems have weakened." - unc.edu
Technical
background on EBV: "Epstein-Barr virus was
discovered by observation of herpes-like virions in electron
micrographs of biopsies of Burkitt's lymphoma. It was later identified
as the cause of infectious mononucleosis and nasopharyngeal
carcinoma.
In immunodeficient individuals it
can cause B-cell lymphomas. The receptor for EB virus is also the
receptor for the C3d component of the complement system. It is
expressed only on B-cells and epithelial cells of the oropharynx and
nasopharynx. Infection of the epithelial cells of the oro- and
nasopharynx is permissive.
Virus is shed into the saliva and
infects B lymphocytes in lymphatic tissue and blood. Infection of B
cells can cause a latent infection, stimulate their growth, or
immortilize the cells. In mononucleosis the characteristic
lymphocytosis is due to activation and proliferation of supressor
(CD8) T cells. This causes the swollen lymph glands as well as the
hepato- and splenomegaly.
The disease is quite mild in
children but more severe in adolescents and adults. It produces
life-long immunity. Thus a good strategy for control of disease would
be to ensure infection of children at a young age. Clinical diagnosis
of mononucleosis is usually based on the presence of lymphocytosis,
atypical lymphocytes, pharyngitis, and the presence of heterophile
antibody (Ab to sheep and horse RBC's), which is the basis for the
monospot test." - medinfo.ufl.edu
"In normal individuals, latent
EBV infection is controlled by humoral immunity, cytotoxic T cells,
and the interferon (IFN) system (Jabs et al., 1996)." - uq.edu.au
Types
of lymphomas associated with EBV:
Staging: Staging
refers to the how widespread the disease is. Imaging
tests (CT MRI, PET, Gallium) and bone marrow biopsies are commonly
done to estimate this. See Staging for
more detail.
Treatment:
The type of treatment will depend on the type of lymphoma, how
aggressive it is, and other clinical details, such as the patient's
age, general health, and the number and types of prior
treatments. Also see Treatment
Decisions
Resources:
