7/26/2019 MS and EBV
1/5
The connection between Multiple Sclerosis and Epstein-Barr
Virus
Vibhav Singh
Multiple sclerosis (MS) is an autoimmune disease where the bodys
immune system
attacks the myelin that sheaths the nerve fibers of the central
nervous system (CNS)! Clinical
symptoms due to demyelination include progressive muscle
weakness" unusual fatigue" muscle
pain" muscle cramps" slurred speech" progressive neurological
disability" and paralysis"#!
$reathing may also be affected and in such cases respiratory
support in the form of ventilators
would have to be provided! %he onset of MS symptoms happens
abruptly within hours to days
and then the symptoms resolve over the ne&t few days to
weeks #! %his pattern of onset of
symptoms followed by resolving of symptoms is considered to be a
MS attack! 'n the early
stages of MS" attacks occur about once every # to months!
%herefore" this early stage of MS
is also referred to as relapsingremitting MS#! *s the disease
progresses the attacks become much
more fre+uent" persist for a longer period of time" and do not
completely resolve! %his chronic
stage of the disease is referred to as secondary progressive MS
#! %he pathology of MS is
characteri,ed by presence of scarring" also known as sclerosis"
in glial cells of the CNS -! %he
scarring is the result of demyelinating lesions that formed as a
result of inflammatory response
by the immune system against the myelin!
't is estimated that MS affects about #!. million people
worldwide/and at least -.0"000
people in the 1nited States alone! Studies have shown there is
inherited susceptibility to MS
though environmental factors which are not completely understood
are also necessary to cause
MS! 2urthermore" MS seems to be more common in people with
Northern 3uropean descent as
7/26/2019 MS and EBV
2/5
the prevalence of MS is 40 to #00 per 00"000 people in this
population group ! *dditionally" the
disease is two to three times more common in females than in
males /! Currently" there isnt a
permanent cure for MS but there are treatments that at least
slow the progression of MS if started
early enough! 5ne such treatment is 'nterferon betaa which has
been shown to prevent MS
relapse by about -0 percent-! 1nfortunately" some MS patients do
not respond to 'nterferon beta
a therapy! 2urthermore" there is no effective treatment for
secondary progressive MS and
treatments for relapsingremitting MS such as 'nterferon betaa
are not effective for advanced
stages of MS!
6hile the primary cause of MS is unknown" there is an increasing
amount of evidence
that 3pstein$arr virus (3$V) is involved in the development of
MS! 3$V is a herpesvirus
belonging to the gammaherpesvirinae subfamily of herpesviruses!
3$V infects $ cells and
ensures their survival through e&pression of $*72 and $892
which are viral homologues of
the antiapoptotic protein $cl#/! 3$V is able to activate the $
cell which then differentiates into
a memory $ cell that is latently infected with 3$V! %he result
is a lifelong infection of 3$V that
can become reactivated! Normally % cells are able to prevent 3$V
associated se+uelae due to
presence of 3$V antigens! 8owever" studies have shown that in MS
the risk of disease increases
as the level of 3$V antibodies increases."4! 2urthermore"
epidemiological studies since : have
shown that MS development was preceded by a primary infection of
3$V 4";! *s a result" the
relationship between 3$V and MS is no longer +uestioned! 'nstead
the focus is on the
mechanism by which 3$V contributes to MS pathogenesis!
5ne mechanism that has been proposed is that % cells that
recogni,e 3$V antigens also
cross react with CNS antigens resulting in demyelination/!
'ndeed" studies have shown some
