flatfish
10-22-2006, 12:54 PM
##################### Bovine Spongiform Encephalopathy #####################
New HPA survey – the ethical and social aspects of a new vCJD test for blood donors
The Health Protection Agency has launched a consultation to look at the social and ethical implications of a blood test for variant (vCJD), should a test become available. There is currently no blood test to detect vCJD infection in people who appear to be well. Such tests may soon be developed, and this consultation aims to seek views about how these tests for vCJD could be used once they become available.
A vCJD test could be used to screen blood donors, allowing the blood services to prevent blood from people with positive tests being given to patients. This is important as there have now been three probable cases of vCJD infection being transmitted through blood transfusions and a measure such as this could further ensure the safety of blood supplies.
The consultation will explore some questions and concerns about introducing a blood test, including:
1. Should a test for vCJD be introduced when it is not known whether people with positive test results would ever develop symptoms of vCJD, and if they would, how long this would take?
2. Should the UK blood services always tell donors if their vCJD tests are positive? And how should donors’ GPs be involved?
3. If donors knew that they would be tested for vCJD, and that they would be told if they tested positive for vCJD, would they be put off giving blood?
Together with an opinion research company, the HPA is asking experts, health professionals, interest groups and members of the public for views on the possible impact and implications of a blood test for vCJD. A stakeholder audit is being complemented by an on-line questionnaire. The answers will be completely confidential and anonymous.
If you would like to join in this consultation, please take part in the online poll at http://www.hpa.org.uk/infections/topics_az/cjd/consultation.htm
http://www.hpa.org.uk/cdr/pages/news.htm#cjd
Report of Seminar on Ethical and Social Aspects
of Testing for vCJD
Chairman: Professor Albert Weale
Report compiled by: HPA Centre for Infections, CJD Section. October 2005
Contact: Helen Janecek (helen.janecek@hpa.org.uk)
FULL TEXT 31 PAGES ;
http://www.hpa.org.uk/infections/topics_az/cjd/ethicalsocialtesting.pdf
Report of Seminar on Ethical and Social Aspects
of Testing for vCJD
Chairman: Professor Albert Weale
Recommendations
Report compiled by: HPA Centre for Infections, CJD Section. October 2005
Contact: Helen Janecek (helen.janecek@hpa.org.uk)
FULL TEXT 6 PAGES ;
http://www.hpa.org.uk/infections/topics_az/cjd/ethicalsocialrecommendations.pdf
October 22, 2006 12:00am
A MELBOURNE grandmother who died this week from suspected Creutzfeldt-Jakob
disease was a blood donor for 25 years.
Valerie Powell, 68, died on Tuesday. Her husband Ron, 70, said his wife was
a regular blood donor until a year ago.
But he said doctors had told him the type of CJD his wife had could not be
transmitted by blood or blood products.
The Australian Red Cross said there had never been a reported case of
classical CJD being passed from a blood donor anywhere in the world.
CJD expert Prof Colin Masters, head of the Department of Pathology at
Melbourne University, said Victorians who may have received blood from Mrs
Powell should not be alarmed because there was no evidence classical CJD was
passed through the blood.
But he said in the past year there had been three cases, all in Britain, of
variant CJD -- more widely known as mad cow's disease -- passed from blood
donors.
Mr Powell said his wife went to her GP in July because she was feeling
unwell.
"He diagnosed depression and put her on medication," he said. "It didn't
help. Valerie's symptoms became worse."
Mrs Powell's family was told a test of her spinal fluid showed she
"probably" had sporadic CJD, which makes up 90 per cent of all classical CJD
cases.
It was not known how she developed the rare, but fatal, brain disease. Only
a biopsy will confirm suspicions that Mrs Powell died from CJD.
Prof Masters said there was no way of screening blood donors. About 20
Australians a year die from classical CJD.
THERE are support groups for families of victims of CJD. Contact Suzanne
Solvyns 1800 052 466, Carol Wilson 1800 181 683 or Mandy Newton 1800 884
897.
http://www.news.com.au/sundayheraldsun/story/0,21985,20622280-661,00.html
Prion infections, blood and transfusions
Adriano Aguzzi* and Markus Glatzel
SUMMARY
Prion infections lead to invariably fatal diseases of the CNS, including
Creutzfeldt-Jakob disease (CJD) in humans, bovine spongiform
encephalopathy (BSE), and scrapie in sheep. There have been hundreds
of instances in which prions have been transmitted iatrogenically among
humans, usually through neurosurgical procedures or administration of
pituitary tissue extracts. Prions have not generally been regarded as
bloodborne
infectious agents, and case-control studies have failed to identify
CJD in transfusion recipients. Previous understanding was, however,
questioned by reports of prion infections in three recipients of blood
donated by individuals who subsequently developed variant CJD. On
reflection, hematogenic prion transmission does not come as a surprise, as
involvement of extracerebral compartments such as lymphoid organs and
skeletal muscle is common in most prion infections, and prions have been
recovered from the blood of rodents and sheep. Novel diagnostic strategies,
which might include the use of surrogate markers of prion infection, along
with prion removal strategies, might help to control the risk of iatrogenic
prion spread through blood transfusions.
SNIP...
TRANSMISSION OF PRION DISEASES
IN HUMANS
The cause of most human prion diseases is
unknown. In the case of sCJD, the term 'sporadic'
is used as a euphemism, meaning that we have
no idea about the origin of this form of CJD. By
contrast, gCJD always segregates within families
with mutations in the gene encoding the prion
protein (PRNP), suggesting that these mutations
are causally involved in disease pathogenesis. As
no families have been described in which gCJD
segregates with mutations in genes other than
PRNP, it has been difficult to use human genetics
to understand the pathogenesis of prion diseases.
The discovery of PRNP mutations in gCJD has
led to the proposal that at least some cases of
sCJD might be due to somatic PRNP mutations
analogous to those found in the germline of
gCJD patients. It is equally possible, however,
that some of the cases of alleged sCJD derive
from hitherto unrecognized infectious causes.
In apparent agreement with the 'intrinsic'
origin of sCJD, which accounts for more than
90% of all human prion diseases, epidemiological
studies were not able to identify a
conclusive link between this form of CJD and
external risk factors.19 This fact is reflected in
the pathological and biochemical features of
these diseases. Although low levels of PrPSc and
prion infectivity can be demonstrated in peripheral
sites such as lymphoid organs or skeletal
muscle,20,21 the highest levels of PrPSc and prion
infectivity appear to occur in the CNS. These
facts might account, at least in part, for the lack
of evidence of sCJD transmission by labile or
stable blood products.22 Indeed, several retrospective
studies have failed to identify blood
transfusion or exposure to plasma products as
risk factors for the development of sCJD,19 and
prion diseases appear to be exceedingly rare
in hemophiliacs, a group of patients that is at
particularly high risk of contracting emerging
blood-borne infectious diseases. Although these
studies cannot exclude the possibility that transmission
of sCJD might have occurred through
blood transfusions in rare cases, and despite
the fact that the etiology of sCJD is unclear,
it would appear that transmission of sCJD by
trans fusion of blood or blood products does
not play a major role in the pathogenesis of this
disease entity.
In the case of acquired prion diseases, however,
the situation is very different. For vCJD, high
levels of prion infectivity and of PrPSc have
been detected in lymphoid organs such as the
appendix and tonsils (Figure 1).23,24 For this
reason, it has been speculated for almost a decade
that vCJD might be associated with a higher risk
of blood-borne transmission than sCJD. It is
important to be cautious, however, as the differences
in the organ tropism of sCJD and vCJD
might be quantitative rather than qualitative, and
PrPSc has been detected in the lymphoid organs
of both vCJD and sCJD patients.21 Initial studies
have failed to detect PrPSc and prion infectivity
in the blood of patients with vCJD, but these
negative data are likely to be attributable to
the lack of sensitivity of the assays available at
the time.23
The recent identification of three indiv iduals
with probable transmission of vCJD via blood
transfusion has provided tragic evidence that vCJD
prions can indeed be transmitted through blood
(Figure 2). On the basis of the epi demiological
and pathogenetic considerations discussed above,
it can only be a matter of time before further
cases of blood-transfusion-associated cases of
vCJD will ensue (Figure 3). ...snip...END
JUNE 2006 VOL 2 NO 6 AGUZZI AND GLATZEL NATURE NEUROLOGY
================================================== =======
CONTINUED
New HPA survey – the ethical and social aspects of a new vCJD test for blood donors
The Health Protection Agency has launched a consultation to look at the social and ethical implications of a blood test for variant (vCJD), should a test become available. There is currently no blood test to detect vCJD infection in people who appear to be well. Such tests may soon be developed, and this consultation aims to seek views about how these tests for vCJD could be used once they become available.
A vCJD test could be used to screen blood donors, allowing the blood services to prevent blood from people with positive tests being given to patients. This is important as there have now been three probable cases of vCJD infection being transmitted through blood transfusions and a measure such as this could further ensure the safety of blood supplies.
The consultation will explore some questions and concerns about introducing a blood test, including:
1. Should a test for vCJD be introduced when it is not known whether people with positive test results would ever develop symptoms of vCJD, and if they would, how long this would take?
2. Should the UK blood services always tell donors if their vCJD tests are positive? And how should donors’ GPs be involved?
3. If donors knew that they would be tested for vCJD, and that they would be told if they tested positive for vCJD, would they be put off giving blood?
Together with an opinion research company, the HPA is asking experts, health professionals, interest groups and members of the public for views on the possible impact and implications of a blood test for vCJD. A stakeholder audit is being complemented by an on-line questionnaire. The answers will be completely confidential and anonymous.
If you would like to join in this consultation, please take part in the online poll at http://www.hpa.org.uk/infections/topics_az/cjd/consultation.htm
http://www.hpa.org.uk/cdr/pages/news.htm#cjd
Report of Seminar on Ethical and Social Aspects
of Testing for vCJD
Chairman: Professor Albert Weale
Report compiled by: HPA Centre for Infections, CJD Section. October 2005
Contact: Helen Janecek (helen.janecek@hpa.org.uk)
FULL TEXT 31 PAGES ;
http://www.hpa.org.uk/infections/topics_az/cjd/ethicalsocialtesting.pdf
Report of Seminar on Ethical and Social Aspects
of Testing for vCJD
Chairman: Professor Albert Weale
Recommendations
Report compiled by: HPA Centre for Infections, CJD Section. October 2005
Contact: Helen Janecek (helen.janecek@hpa.org.uk)
FULL TEXT 6 PAGES ;
http://www.hpa.org.uk/infections/topics_az/cjd/ethicalsocialrecommendations.pdf
October 22, 2006 12:00am
A MELBOURNE grandmother who died this week from suspected Creutzfeldt-Jakob
disease was a blood donor for 25 years.
Valerie Powell, 68, died on Tuesday. Her husband Ron, 70, said his wife was
a regular blood donor until a year ago.
But he said doctors had told him the type of CJD his wife had could not be
transmitted by blood or blood products.
The Australian Red Cross said there had never been a reported case of
classical CJD being passed from a blood donor anywhere in the world.
CJD expert Prof Colin Masters, head of the Department of Pathology at
Melbourne University, said Victorians who may have received blood from Mrs
Powell should not be alarmed because there was no evidence classical CJD was
passed through the blood.
But he said in the past year there had been three cases, all in Britain, of
variant CJD -- more widely known as mad cow's disease -- passed from blood
donors.
Mr Powell said his wife went to her GP in July because she was feeling
unwell.
"He diagnosed depression and put her on medication," he said. "It didn't
help. Valerie's symptoms became worse."
Mrs Powell's family was told a test of her spinal fluid showed she
"probably" had sporadic CJD, which makes up 90 per cent of all classical CJD
cases.
It was not known how she developed the rare, but fatal, brain disease. Only
a biopsy will confirm suspicions that Mrs Powell died from CJD.
Prof Masters said there was no way of screening blood donors. About 20
Australians a year die from classical CJD.
THERE are support groups for families of victims of CJD. Contact Suzanne
Solvyns 1800 052 466, Carol Wilson 1800 181 683 or Mandy Newton 1800 884
897.
http://www.news.com.au/sundayheraldsun/story/0,21985,20622280-661,00.html
Prion infections, blood and transfusions
Adriano Aguzzi* and Markus Glatzel
SUMMARY
Prion infections lead to invariably fatal diseases of the CNS, including
Creutzfeldt-Jakob disease (CJD) in humans, bovine spongiform
encephalopathy (BSE), and scrapie in sheep. There have been hundreds
of instances in which prions have been transmitted iatrogenically among
humans, usually through neurosurgical procedures or administration of
pituitary tissue extracts. Prions have not generally been regarded as
bloodborne
infectious agents, and case-control studies have failed to identify
CJD in transfusion recipients. Previous understanding was, however,
questioned by reports of prion infections in three recipients of blood
donated by individuals who subsequently developed variant CJD. On
reflection, hematogenic prion transmission does not come as a surprise, as
involvement of extracerebral compartments such as lymphoid organs and
skeletal muscle is common in most prion infections, and prions have been
recovered from the blood of rodents and sheep. Novel diagnostic strategies,
which might include the use of surrogate markers of prion infection, along
with prion removal strategies, might help to control the risk of iatrogenic
prion spread through blood transfusions.
SNIP...
TRANSMISSION OF PRION DISEASES
IN HUMANS
The cause of most human prion diseases is
unknown. In the case of sCJD, the term 'sporadic'
is used as a euphemism, meaning that we have
no idea about the origin of this form of CJD. By
contrast, gCJD always segregates within families
with mutations in the gene encoding the prion
protein (PRNP), suggesting that these mutations
are causally involved in disease pathogenesis. As
no families have been described in which gCJD
segregates with mutations in genes other than
PRNP, it has been difficult to use human genetics
to understand the pathogenesis of prion diseases.
The discovery of PRNP mutations in gCJD has
led to the proposal that at least some cases of
sCJD might be due to somatic PRNP mutations
analogous to those found in the germline of
gCJD patients. It is equally possible, however,
that some of the cases of alleged sCJD derive
from hitherto unrecognized infectious causes.
In apparent agreement with the 'intrinsic'
origin of sCJD, which accounts for more than
90% of all human prion diseases, epidemiological
studies were not able to identify a
conclusive link between this form of CJD and
external risk factors.19 This fact is reflected in
the pathological and biochemical features of
these diseases. Although low levels of PrPSc and
prion infectivity can be demonstrated in peripheral
sites such as lymphoid organs or skeletal
muscle,20,21 the highest levels of PrPSc and prion
infectivity appear to occur in the CNS. These
facts might account, at least in part, for the lack
of evidence of sCJD transmission by labile or
stable blood products.22 Indeed, several retrospective
studies have failed to identify blood
transfusion or exposure to plasma products as
risk factors for the development of sCJD,19 and
prion diseases appear to be exceedingly rare
in hemophiliacs, a group of patients that is at
particularly high risk of contracting emerging
blood-borne infectious diseases. Although these
studies cannot exclude the possibility that transmission
of sCJD might have occurred through
blood transfusions in rare cases, and despite
the fact that the etiology of sCJD is unclear,
it would appear that transmission of sCJD by
trans fusion of blood or blood products does
not play a major role in the pathogenesis of this
disease entity.
In the case of acquired prion diseases, however,
the situation is very different. For vCJD, high
levels of prion infectivity and of PrPSc have
been detected in lymphoid organs such as the
appendix and tonsils (Figure 1).23,24 For this
reason, it has been speculated for almost a decade
that vCJD might be associated with a higher risk
of blood-borne transmission than sCJD. It is
important to be cautious, however, as the differences
in the organ tropism of sCJD and vCJD
might be quantitative rather than qualitative, and
PrPSc has been detected in the lymphoid organs
of both vCJD and sCJD patients.21 Initial studies
have failed to detect PrPSc and prion infectivity
in the blood of patients with vCJD, but these
negative data are likely to be attributable to
the lack of sensitivity of the assays available at
the time.23
The recent identification of three indiv iduals
with probable transmission of vCJD via blood
transfusion has provided tragic evidence that vCJD
prions can indeed be transmitted through blood
(Figure 2). On the basis of the epi demiological
and pathogenetic considerations discussed above,
it can only be a matter of time before further
cases of blood-transfusion-associated cases of
vCJD will ensue (Figure 3). ...snip...END
JUNE 2006 VOL 2 NO 6 AGUZZI AND GLATZEL NATURE NEUROLOGY
================================================== =======
CONTINUED