showing a causal relationship
(Annals of Neurology
2010;6:324).
• The team also has investigated
how EBV may interact with
genes or other risk factors
in the development of MS.
They reported that people
who had a specific immune-related gene and high levels
of antibodies to EBV in
the blood serum were nine
times more likely to develop
MS than those without that
gene and with low levels of
viral antibodies (Neurology
2008;70:1113–18). In
another study population,
they showed that current
or previous smokers with
the highest levels of EBV
antibodies were 70 percent
more likely to develop MS
than those with neither risk
factor (Neurology 2010;
74:1365).
These studies provide
intriguing evidence that EBV
plays some role in MS, although
that role is still unclear.
Dr. Ascherio is now funded
by the National MS Society
and the National Institutes
of Health to evaluate blood
samples and data from more
than 1,600 people who were
followed since displaying early
symptoms of possible MS. His
team is evaluating the effects of
vitamin D levels, EBV infection
and cigarette smoking on
whether these early symptoms
eventually turn into MS and
how rapidly they do so.
Human herpes virus 6 (HHV-
6) has also been tagged for
possible involvement in MS,
specifically with triggering
exacerbations. Steve Simpson,
PhD, and colleagues at the
Universities of Tasmania and
Melbourne examined HHV- 6
antibody levels in blood serum
samples taken from 145 people
with MS, who were followed for
three years.
The results, published earlier
this year, show that HHV- 6
antibodies were associated with
a higher risk of relapse. Also,
antibody levels were nearly three
times higher in women with
progressive MS. Although the
findings need to be confirmed,
the team suggests that tracking
HHV- 6 antibodies may help
to predict the clinical course
of MS (Multiple Sclerosis
2012;18:799).
Taking virus research deeper
Advances in technology are
helping MS researchers look
for viral clues. John Kriesel,
MD, and his colleagues at the
University of Utah received a
grant from the Society to use
novel genetics technology to
determine the presence of a virus
that has not yet been associated
with MS—the hepatitis G virus.
“Subtractive sequencing” is a
powerful new technology that
allows researchers to detect
millions of different RNA
molecules in a single specimen.
RNA, or ribonucleic acid, is
the chemical that delivers the
instructions from a gene to a
cell. In subtractive sequencing,
investigators can subtract
human RNA, leaving thousands
of nonhuman, possibly disease-
causing, RNAs.
