No subject
Fri Oct 12 15:41:10 EDT 2007
<BR> &nb=
sp; =20
EAST HILLS, N.Y.-- There is increasing evidence that infectious prions =
that can=20
cause=20
variant<BR> &n=
bsp; =20
Creutzfeldt-Jakob Disease (vCJD), the human form of "mad cow" disease, =
can be=20
transmitted through=20
blood<BR> &nbs=
p; =20
transfusion, according to Roger Eglin, Ph.D., Head of National =
Transfusion=20
Microbiology Laboratories for=20
the<BR> =
=20
English National Blood Service. He spoke at a symposium on Transmissible =
Spongiform=20
Encephalopathies<BR>  =
; =20
(TSEs) where he was joined by prominent government, public health and =
blood=20
safety experts from=20
around<BR> &nb=
sp; =20
the globe, including the U.S. and Canada, who raised concerns about a =
second=20
wave of the disease=20
brought<BR> &n=
bsp; =20
about by human-to-human transmission via blood=20
transfusions.<BR> &n=
bsp; =20
The panelists convened to discuss the adequacy of safeguards and =
precautionary=20
measures to=20
prevent<BR> &n=
bsp; =20
human-to-human transmission of this fatal, neurodegenerative prion =
disease at a=20
symposium held last=20
night<BR> &nbs=
p; =20
at the annual AABB blood banking conference in Baltimore, Maryland. The=20
symposium was sponsored by=20
Pall<BR>  =
; =20
Corporation (NYSE: PLL), the global leader in filtration=20
technology.<BR> &nbs=
p; =20
Citing two confirmed cases in the UK, where vCJD was transmitted via =
blood=20
transfusions from donors=20
who<BR> =
=20
were young and apparently healthy at the time of donation, Dr. Eglin =
said the=20
current decline in=20
reported<BR> &=
nbsp; =20
cases could be followed by a new wave of vCJD infections around the =
world of=20
unknown magnitude.=20
These<BR> &nbs=
p; =20
concerns were echoed by the panelists, who noted the increase of vCJD in =
France=20
from six to eight cases=20
in<BR> &=
nbsp; =20
just the past few months and the news that blood from a vCJD-infected =
donor was=20
transfused to 10=20
people<BR> &nb=
sp; =20
and used to manufacture=20
medicines.<BR>  =
; =20
"This may not be a disease in decline, despite the low number of cases =
today,"=20
said Dr. Eglin. "There is=20
much<BR>  =
; =20
uncertainty over the number of cases predicted for the UK. Estimates of =
up to=20
25,000 total cases have=20
been<BR>  =
; =20
predicted with an incidence of one in 24,000 of the UK=20
population."<BR> &nb=
sp; =20
The second case of transfusion-transmitted vCJD in the UK demonstrated =
that two=20
human genotypes=20
are<BR> =
=20
susceptible to the infectious prion, rather than one, as had been =
previously=20
reported. According to Dr.=20
Eglin,<BR> &nb=
sp; =20
thisextends the number of people at risk from 40 to 90 percent of the UK =
population.<BR> &nbs=
p; =20
Since people can incubate vCJD with no clinical signs or symptoms of =
disease for=20
a decade or more, there=20
is<BR> &=
nbsp; =20
no way to determine who or how many people may be harboring the fatal =
prion nor=20
how many of=20
these<BR> &nbs=
p; =20
people may be blood donors. A single vCJD-infected blood donor has the =
potential=20
to amplify transmission=20
to<BR> &=
nbsp; =20
several people, creating the basis for a far more widespread=20
infection.<BR>  =
; =20
Dr. Eglin described the measures taken by the UK, including deferral of=20
previously transfused donors and=20
100<BR> =
=20
percent leukocyte (white blood cell) reduction, to increase the safety =
of the=20
blood=20
supply.<BR> &n=
bsp; =20
Heightened vCJD Blood Concern in=20
U.S.<BR>  =
; =20
David M. Asher, M.D., Chief and Supervisory Medical Officer with the FDA =
Division of Emerging=20
and<BR> =
=20
Transfusion-Transmitted Diseases at the Center of Biologics Evaluation =
and=20
Research (CBER),=20
expressed<BR> =
=20
heightened concern about vCJD transmission by blood due to the two cases =
in the=20
UK. He concurred that=20
a<BR> &n=
bsp; =20
second wave is possible and said that the number of people who may be =
harboring=20
the infection in the=20
UK,<BR> =
=20
237 per million, is a minimum estimate and may be too=20
low.<BR>  =
; =20
The U.S. has a number of measures in place to protect blood safety, he =
said, but=20
stated that it is not=20
possible<BR> &=
nbsp; =20
to remove every blood risk by donor deferral. "If we attempt to defer =
every=20
donor who spent time in the=20
UK<BR> &=
nbsp; =20
from 1980 to 1996, the blood donor loss would be enormous," he =
explained. On=20
October 14, the FDA=20
TSE<BR> =
=20
Advisory Committee made the recommendation that no additional residency=20
deferrals are necessary in=20
the<BR> =
=20
U.S. at this=20
time.<BR> &nbs=
p; =20
"If exposure to an infectious agent can be stopped, then the disease can =
be=20
stopped," said Dr.=20
Asher.<BR> &nb=
sp; =20
"Physical removal of vCJD from blood appears to be the most promising =
line of=20
attack."<BR> &=
nbsp; =20
Dr. Asher also commented that species barrier protection from TSEs other =
than=20
BSE is not absolute. He=20
listed<BR> &nb=
sp; =20
several TSE infections found in animals in the U.S., including Chronic =
Wasting=20
Disease (CWD), which is=20
found<BR> &nbs=
p; =20
in both farmed and wild deer and elk in many Midwestern and Western =
states and=20
parts of Canada.=20
Although<BR> &=
nbsp; =20
there is no evidence of transmission to humans, hunters are being warned =
to=20
avoid contact with or eating=20
the<BR> =
=20
meat of animals that may be infected with=20
CWD.<BR>  =
; =20
Precautionary Principle in=20
Canada<BR> &nb=
sp; =20
Although Canada has detected only one case of BSE and one of vCJD to =
date, the=20
country has taken=20
a<BR> &n=
bsp; =20
number of precautionary measures to help prevent further infections, =
similar to=20
those taken in the=20
UK,<BR> =
=20
according to Dr. Peter R. Ganz, Director of the Centre for Biologics =
Evaluation=20
(CBE), Health Canada.=20
Dr.<BR> =
=20
Ganz cited the Precautionary Principle - "If risk is possible, then we =
must err=20
on the side of caution" -=20
which,<BR> &nb=
sp; =20
he said, drove Canada's actions even before the emergence of possible =
vCJD=20
transmission through=20
blood.<BR> &nb=
sp; =20
Dr. Ganz noted that Canada's surveillance system, its three deferral =
directives=20
to exclude donors with=20
the<BR> =
=20
potential for infectious disease and the implementation of universal =
leukocyte=20
reduction has reduced=20
the<BR> =
=20
potential risk of vCJD transfusion transmission by about 92 percent. He =
also=20
spoke about the problems=20
of<BR> &=
nbsp; =20
balancing more stringent donor exclusion policies against the loss of =
available=20
supplies of=20
blood.<BR> &nb=
sp; =20
Laurie Garrett, Gates Senior Fellow in Global Health for the Council on =
Foreign=20
Relations and=20
award-winning<BR> &n=
bsp; =20
author and journalist, stressed the need to take measures to prevent the =
spread=20
of newly=20
emerging<BR> &=
nbsp; =20
infectious threats before they reach epidemic proportions. "Whatever =
microbes=20
exist in developing and=20
third<BR> &nbs=
p; =20
world nations will eventually exist in our blood system because =
humankind is on=20
the move as never=20
before,"<BR> &=
nbsp; =20
she stated. "Because of the speed of global travel, the risks of =
developing=20
countries are our risks. You=20
may<BR> =
=20
not feel global, but your microbes=20
are."<BR> &nbs=
p; =20
She explained that we cannot rely on the developing world or even =
countries such=20
as China, as evidenced=20
by<BR> &=
nbsp; =20
SARS, to stop infections before they are on everyone's doorstep. =
"Fortunately,=20
SARS is=20
not<BR> =
=20
transfusion-transmitted, but our own history of dealing with AIDS, our =
lack of=20
proactive policies and=20
the<BR> =
=20
economics of action beg the question of whether we are ready to stop the =
spread=20
of the next=20
major<BR> &nbs=
p; =20
blood-borne infection," Ms. Garrett added. "The most cost-effective =
approach is=20
to be proactive and=20
keep<BR>  =
; =20
microbes out of the blood in the first place," she=20
concluded.<BR>  =
; =20
Sam Coker, Ph.D., principal scientist and technical director at Pall =
Medical,=20
presented the results of two=20
new<BR> =
=20
research studies with its Leukotrap(R) Affinity Prion Reduction Filter, =
which is=20
in late stage testing. The=20
filter<BR> &nb=
sp; =20
has been shown to reduce infectious vCJD prions from red blood cell =
concentrates=20
below the limit of=20
detection<BR> =
=20
of the Western blot assay. It was also found that the filter can remove=20
different strains of infectious=20
prions<BR> &nb=
sp; =20
from blood, including scrapie. The new filter, which reduces both =
leukocytes and=20
prions in a single step,=20
is<BR> &=
nbsp; =20
expected to be introduced commercially in Europe early next year =
followed by=20
submission to the U.S.=20
FDA.<BR>  =
; =20
Paul M. Ness, M.D., Director of Transfusion Medicine at The Johns =
Hopkins=20
Hospital in=20
Baltimore,<BR>  =
; =20
editor-in-chief of Transfusion and former president of AABB, who =
moderated the=20
symposium, reviewed=20
issues<BR> &nb=
sp; =20
in the U.S.,commenting that inadequate reimbursement often prevents or =
delays=20
the adoption of=20
new<BR> =
=20
technology to enhance blood safety. He said that improvements in =
transfusion=20
safety are not likely to=20
be<BR> &=
nbsp; =20
implemented in the U.S. without patient=20
advocacy.<BR> =
=20
Dr. Ness reviewed U.S. blood safety measures and noted that leukocyte =
reduction=20
removes prions=20
from<BR>  =
; =20
blood, resulting in a 45 percent reduction of risk of vCJD transmission. =
He=20
pointed out that=20
although<BR> &=
nbsp; =20
leukocyte reduction is valuable, and explained the importance of 100 =
percent=20
implementation to=20
improve<BR> &n=
bsp; =20
patient safety, it is still not sufficient. "Filtration technology that =
removes=20
both prions and leukocytes would=20
be<BR> &=
nbsp; =20
an example of adding value without adding another process that would=20
significantly increase costs,"=20
he<BR> &=
nbsp; =20
concluded.</FONT></DIV></BODY></HTML>
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