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From: TSS (wt-d6-144.wt.net)
Subject: Request for a scientific opinion:'The safety of human-derived products with regard to variant Creutzfeldt-Jakob Disease
Date: November 10, 2004 at 7:19 am PST
-------- Original Message --------
Subject: Request for a scientific opinion:'The safety of human-derived products with regard to variant Creutzfeldt-Jakob Disease
Date: Wed, 10 Nov 2004 08:20:41 -0600
From: "Terry S. Singeltary Sr."
Reply-To: Bovine Spongiform Encephalopathy
To: BSE-L@UNI-KARLSRUHE.DE
##################### Bovine Spongiform Encephalopathy #####################
Scientific Committee on Emerging and Newly Identified Health Risks (SCENIHR)
Request for a scientific opinion: The safety of human-derived products with regard to variant
Creutzfeldt-Jakob
Disease 1. Background On July 2004, the United Kingdom announced that a second case of
possible vCJD prion
transmission via blood transfusion had been confirmed. The patient
received the blood
donated by an individual who was confirmed in 2001 as a definite vCJD
case. Although, the
receiver died of unrelated causes, and showed no clinical signs of vCJD
at the time of death,
abnormal prion protein was found in spleen tissue (post-mortem). This
patient was found to
have a genetic type that differed from that found so far in patients who
have developed the
disease.
As a safeguard against the possible transmission of vCJD and in order to
protect the blood
supply the British Government introduced a number of precautionary
measures. This second
case has led to the introduction of further precautionary measures
because of a small but
unquantifiable risk, according to the Minister for Health, tightening
the exclusion criteria.
The significance of the new case of vCJD transmission by blood is that
while all previous
clinical cases of vCJD were genotyped as homozygotes (MET-MET) at codon
129 of the
prion protein gene, this new case was heterozygote (MET-VAL) at codon
129. It is known
from past transmissions of CJD by pituitary growth hormone that codon
129 affects the
susceptibility of individuals to prion disease with longer incubation
times being seen in the
less susceptible genotypes.
The following considerations should be taken into account:
A second human case with evidence for vCJD in a recipient of a
transfusion from a donor
who subsequently developed vCJD gives further confirmation that vCJD can be
transmitted by blood transfusion. The finding was consistent with there
being a substantial
risk associated with the receipt of non-leucodepleted blood from a donor
incubating vCJD.
The extent to which leucodepletion reduces that risk is not known.
Studies published
confirm that intra-species (sheep, primates) infection by blood
transfusion is possible.
This case provides evidence that vCJD can be transmitted to
heterozygotes, and is not just
restricted to homozygotes. It is unknown whether vCJD will only affect
methionine
homozygotes or cases will emerge in the other genotypes at a later time
because of a longer
incubation period.
Although it cannot be known whether this individual would have
eventually developed the
disease, the finding of evidence of vCJD is significant for possible
iatrogenic transmission
by blood in the incubation phase, through surgical instruments or by
instruments used in
invasive procedures.
According to the UK Spongiform Encephalopathy Advisory Committee (SEAC)
statement of
7 August 2004, the Committee agreed inter alia that careful post-mortem
examination of all
recipients of blood (leucodepleted or not) from donors incubating vCJD
would help to
quantify the nature and magnitude of the risks of transmission of the
vCJD agent through
blood [donated by preclinical cases of vCJD].
The Scientific Committee for Medicinal Products and Medical Devices
(SCMPMD) issued its
last Opinion on the Risk quantification of CJD transmission via
substances of human origin
in February 2000 (SANCO/SCMPMD/2000/0005) and on the Safety of
Human-derived
Products with regards to TSEs in January 2002 (SANCO/SCMPMD/2002/0001).
The latter
did not cover exclusion criteria for donors (covered in the opinion
adopted 21.10.98 and
16.02.2000) nor the substitution with alternative products and is not up
to date with regard to
recent developments in the science e.g. in the infectivity in blood and
transmissibility via
blood.
In the light of the above, a new scientific a request for an updated
Opinion on the risk
quantification of vCJD transmission by blood including an up-date with
regard to recent
scientific developments should be sought.
It should also be noticed that all previous opinions issued were related
to the use of certain
products and did not address other possible paths of transmission such
as mother-foetus or the
infectivity of umbilical cord cells stored in donation banks.
Considering that there is a
relatively high possibility that the onset of clinical signs of vCJD
occur during the fertile
period of human beings, it is desirable to extend the scope of the
request to include these two
items.
The Committee for Medicinal Products for Human Use (CHMP) of the EMEA
has recently
issued a review of its Position Statement on Creutzfeldt-Jakob disease
and Plasma-derived
and Urine-derived Medicinal Products (EMEA/CPMP/BWP/2879/02/rev1). In
it, several
recommendations and proposals related to vCJD were issued.
2. Terms of reference
In the light of recent evidence, the Scientific Committee on Emerging
and Newly Identified
Health Risks (SCENIHR) is requested
to review the previous scientific SCMPMD Opinion on the Safety of
Human-Derived
Products with regard TSE's adopted on 18 January 2002 and the SCMPMD
Opinion on
Quality and Safety of Blood adopted on 16 February 2000 in order to
quantify, if
possible, the nature and magnitude of the risks of transmission of the
vCJD agent through
blood donated by preclinical cases of vCJD, through surgical instruments
or by instruments
used in invasive procedures.
to evaluate the risk of vertical transmission of vCJD in pregnant women.
to evaluate the risk of vCJD transmission by the tissues stored in
umbilical cord cell banks.
3. Deadlines
------------------------------------
Supporting Documents:
Opinions
SCMPMD Opinion on the safety of Human-Derived Products with regard TSE's
adopted
on 18 January 2002.
SCMPMD Opinion on Quality and Safety of Blood adopted on 16 February 2000.
SCMPMD Opinion on update of the opinion on the Risk Quantification for vCJD
Transmission via Substances of Human Origin, adopted on 16 February 2000.
SCMPMD Opinion on the Policy Regarding the Use of Blood and Blood Products
adopted by Written Procedure on 24 March 1999.
EMEA/CPMP/BWP/2879/02 Revision 1 CHMP Position Statement on
Creutzfeldt-Jakob
disease and Plasma-derived and Urine-derived Medicinal Products
Press releases of UK government
http://www.dh.gov.uk/PublicationsAndStatistics/PressReleases/PressReleasesNotices/fs/en?C
ONTENT_ID=4076608&chk=MTwE%2Bl
http://www.dh.gov.uk/PublicationsAndStatistics/PressReleases/PressReleasesNotices/fs/en?C
ONTENT_ID=4086160&chk=9/Ni4w
Scientific articles
Herzog C, Salès N., Etchegaray N., Charbonnier A., Freire S., Dormont
D., Deslys J-P,
Lasmézas C I. Tissue distribution of bovine spongiform encephalopathy
agent in primates
after intravenous or oral infection. THE LANCET, Volume 363 Issue 9407
Page 422
Houston F, Foster J D, Chong A, Hunter N, Bostock C J. Transmission of
BSE by blood
transfusion in sheep. THE LANCET, Volume 356 Issue 9234 Page 999
Gregori L, McCombie N, Palmer D, Birch P, Sowemimo-Coker S O, Giulivi A,
Rohwer R
G. Effectiveness of leucoreduction for removal of infectivity of
transmissible spongiform
encephalopathies from blood. THE LANCET Volume 364 Issue 9433 Page 529 "Request for a scientific opinion:'The safety of human-derived products with regard to variant Creutzfeldt-Jakob Disease'" http://europa.eu.int/comm/health/ph_risk/committees/04_scenihr/docs/scenihr_q_001.pdfTSS ################# BSE-L-subscribe-request@uni-karlsruhe.de #################
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