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From: TSS ()
Subject: vCJD case study highlights blood transfusion risk
Date: December 9, 2006 at 10:57 am PST

vCJD case study highlights blood transfusion risk

Friday 8th December 2006

Scientists have confirmed that Variant Creutzfeldt-Jakob disease (vCJD) can
be

passed from person to person through blood transfusion. A case study
published

in The Lancet reports on the third person known to have contracted vCJD from

blood transfusion. The patient, who has since passed away, is the first to
have

been diagnosed whilst still alive. Two others from a group of 66 people who

received prion-infected blood from donors known to have developed vCJD, died

before their illness was confirmed.

At the age of 23, the patient was given a blood transfusion from a donor who

later developed vCJD. Seven and a half years later he was referred to the
NHS

National Prion Clinic at the National Hospital for Neurology and
Neurosurgery

where his symptoms were confirmed to be caused by vCJD. The patient opted to

join the experimental MRC treatment trial Prion-1 which began in 2004, in
which

patients are given a drug called quinacrine. Sadly, he died a year later at
the age

of 32.

Professor John Collinge of the Medical Research Council Prion Unit explains:

''That three individuals from this small group of people that we

know to have been exposed through blood transfusion have

already developed vCJD infection suggests that the infection may

be efficiently passed by this route, so the risk to remaining

individuals is likely to be substantial."

''A national tonsil tissue screening study being performed by the

Health Protection Agency may soon give estimates of the

number of people who are silently infected with prions. This

information is vital for public health planning given the relative

ease with which prions seem to be passed on by blood

transfusion."

Prion infections in humans are known to have long incubation periods, a
person

could be silently infected for more than 50 years before developing symptoms
of

the disease. During this time such a carrier of infection poses a potential
risk to

others through blood transfusion and contamination of surgical and medical

instruments.

The incubation period when prions pass from human to human is thought to be

much shorter than when they pass from one species to another. As a result,

prions that enter the body through blood transfusion as opposed to eating

infected cattle meat, like BSE prions do, probably cause vCJD to develop
more

2

quickly. When blood transfusion is the source of prions, vCJD seems, based
on

these cases, to develop in as little as 6 to 7 years.

Professor Collinge concludes:

''Analysis of samples of the patient's tonsil tissue after death,

confirmed that they were infected with prions. Examining tonsil

tissue is an established way to diagnose vCJD early if there is

reason to suspect a person has prion disease. There was

uncertainty about whether this test would also be helpful in

patients infected by blood transfusion. Study of tissue from the

patient in this case study was extremely helpful in answering this

question. In fact, it is likely that prion infection could be

diagnosed by tonsil biopsy in people who are known to be at high

risk because they have received blood from an infected donor

should they wish. Although we do not yet have an effective

treatment for any form of CJD, a reliable tonsil test could allow

people with vCJD to access experimental treatments early."

Key facts

. The prions that cause vCJD are an altered form of one of the body's

own proteins. This is why the immune system fails to recognise the

danger prions represent.

. Scientists know that a person's genetic profile plays a role in their

relative risk of developing vCJD.

MRC/42/06

Press Office

Phone: 020 7637 6011

press.office@headoffice.mrc.ac.uk

Notes to editors

1. Clinical presentation and pre-mortem diagnosis of variant Creutzfeldt-

Jakob disease associated with blood transfusion: a case report is

published in The Lancet volume 368.

2. Dissociation of pathological and molecular phenotype of vCJD in

transgenic human PrP heterozygous mice was published early this year

in Proceedings of the National Academy of Sciences. The paper

describes how a person's genetic profile influences their susceptibility

to prion disease.

3. The Medical Research Council (MRC) is funded by the UK tax-payer. It

aims to improve human health. The research it supports and the

scientists it trains meet the needs of the health services, the

pharmaceutical and other health-related industries and universities.

The MRC has funded work which has led to some of the most significant

discoveries and achievements in medicine in the UK. http://www.mrc.ac.uk

4. The National Prion Clinic (NPC) is based at the National Hospital for

Neurology and Neurosurgery, Queen Square, London.The NPC provides

3

diagnosis and care for patients with, or suspected of having, any form

of human prion disease. The NPC is the national referral centre for

prion disease, and works closely with the MRC Prion Unit, based at the

Institute of Neurology, Queen Square, London. An extensive research

programme seeking to promote early diagnosis and develop treatments

for this group of diseases is now supported by the first clinical trial for

prion disease in the UK.

http://www.mrc.ac.uk/consumption/groups/public/documents/content/mrc003431.pdf

TSS

----- Original Message -----
From: "ProMED-mail"
To:
Sent: Friday, December 08, 2006 4:48 PM
Subject: PRO/AH/EDR> CJD (new var.), blood transfusion risk


> CJD (NEW VARIANT), BLOOD TRANSFUSION RISK
> ***************************************************
> A ProMED-mail post
>
> ProMED-mail is a program of the
> International Society for Infectious Diseases
>
>
> [1]
> Date: Fri 8 Dec 2006
> From: Pablo Nart
> Source: BBC News online, Fri 8 Dec 2006 [edited]
>
>
>
> A study of transfusion patients given blood contaminated with the
> human form of mad cow disease has indicated the 24 still alive are at
> "substantial" risk. Prof John Collinge's assessment follows his
> investigation into the third person infected from the original group of
66.
>
> The patient, the first to be diagnosed with variant Creutzfeldt-Jakob
> disease [abbreviated as CJD (new var.) or vCJD in ProMED-mail] while
> still alive, has since died. Two others died before their illness was
> confirmed. The name of the 3rd patient to be infected has not been
> released, but it is known that he received the blood transfusion at
> the age of 23. He later became ill, and 7.5 years later he was
> referred to the NHS National Prion Clinic at the National Hospital
> for Neurology and Neurosurgery where his symptoms were confirmed to
> be caused by vCJD. He joined an experimental Medical Research
> Council trial for a treatment called Prion-1 which began in 2004, in
> which patients were given a drug called quinacrine, but he died a
> year later at the age of 32. The diagnosis of vCJD was confirmed
> after his death after his tonsil tissue was examined.
>
> Diseases in humans such as vCJD which are caused by prions, rogue
> proteins, are known to have long incubation periods, and it is
> possible that a person could be silently infected for more than 50
> years before developing symptoms of the disease. During this time
> such a carrier of infection poses a potential risk to others through
> blood transfusion and contamination of surgical and medical
> instruments. The incubation period when prions pass from human to
> human is thought to be much shorter than when they pass from one
> species to another. So prions that enter the body through a blood
> transfusion rather than through eating meat infected with BSE (bovine
> spongiform encephalopathy) are thought to cause vCJD to develop more
quickly.
>
> Experts believe that, based on the cases seen so far, infection from
> a blood transfusion can develop in just 6 or 7 years. Professor John
> Collinge of the MRC Prion Unit said: "That 3 individuals from this
> small group of people that we know to have been exposed through blood
> transfusion have already developed vCJD infection suggests that the
> infection may be efficiently passed by this route. Professor Collinge
> told BBC Radio 4's Today programme: "We know about these particular
> instances because individuals went on to develop vCJD. "But of course
> people who are silently incubating vCJD at the moment may be blood
> donors and there is no way of knowing where that blood is going."
>
> He added: "'A national tonsil tissue screening study being performed
> by the Health Protection Agency may soon give estimates of the number
> of people who are silently infected with prions. He said it was
> possible people at high risk could have their tonsil tissue tested in
> a bid to diagnose if they are infected. Professor Collinge added:
> "Although we do not yet have an effective treatment for any form of
> CJD, a reliable tonsil test could allow people with vCJD to access
> experimental treatments early."
>
> Writing in the Lancet, Kumanan Wilson of Toronto General Hospital and
> Maura Ricketts of the Public Health Agency of Canada said: "This
> third case considerably strengthens the inference that transfusion
> transmission is possible and suggests that the causative prion can be
> efficiently transmitted via this route."
>
> A spokeswoman for the National Blood Service said a large number of
> measures had been put in place to protect people receiving
> transfusions including withdrawing any blood products donated from a
> person who later develops vCJD. She added: "Whilst no medical
> procedure, including blood transfusion, can be 100 percent safe, our
> prime concern is always the safety of patients through the quality of
> blood. To date there have been three cases of vCJD infection where
> blood transfusion is a possible source of infection. However, the
> National Blood Service issues nearly two million units of blood every
year."
>
> --
> Pablo Nart
>
>
> [ProMED-mail acknowledges receipt of the same report from
> . - Mod.CP]
>
> ******
> [2]
> Date: Fri 8 Dec 2006
> From: Brent Barrett
> Source: Timesonline, Fri 8 Dec 2006 [edited]
>
>
>
> Infected blood threatens fresh outbreak of vCJD
> -----------------------------------------------
> Thousands of people are at risk from an outbreak of variant
> Creutzfeld-Jakob disease [abbreviated as CJD (new var.) or vCJD in
> ProMED-mail] spread by contaminated blood or infected surgical
> instruments. An analysis of the death of a 3rd patient after a
> transfusion of infected blood, published yesterday, shows that the
> disease is very easily transmitted by blood. Nobody knows how many
> donors may have given infected blood in the past, or may still be
> giving it today. That it can be transmitted by infected blood means
> that there is a serious risk of a self-sustaining secondary epidemic
> of vCJD. Transmission is much easier than by eating contaminated
> meat, where a species barrier must be overcome. The evidence of the 3
> cases is that vCJD can develop in as little as 6 to 7 years if
> transmitted by blood. The incubation period for vCJD [contracted]
> from infected beef is significantly longer.
>
> The National Blood Service said that it had taken all the
> precautionary measures it could. "The trouble is that there is no
> test we can use," a spokesman said. At greatest risk are a handful of
> people known to have had blood transfusions from healthy donors who
> went on to develop vCJD. There are 24 such recipients still alive,
> and their risk is substantial, Professor John Collinge, Britain's
> leading expert on the disease, said.
>
> The unnamed 3rd patient to [contract] vCJD from contaminated blood
> had a transfusion when he was 23. Seven years later he developed
> symptoms. He opted to join an experimental treatment trial organised
> by the Medical Research Council in which patients are given the drug
> quinacrine. He died a year later, aged 32. He was one of 66 people
> identified by the National Blood Service as having received blood
> from a donor who later developed vCJD. Of these, 34 died of other
> causes within 5 years of the transfusions. Of the remaining 32, 8
> have now died, 3 from vCJD.
>
> Professor Collinge, who reports on the case in The Lancet (see [3]
> below), said: "That 3 individuals from this small group of people
> that we know to have been exposed through blood transfusion have
> already developed vCJD infection suggests that the infection may be
> efficiently passed by this route, so the risk to remaining
> individuals is likely to be substantial."
>
> So far, about 160 people, mostly young, are known to have died of the
> disease by eating contaminated beef. The numbers were relatively low
> because of the species barrier between cows and humans.
>
> Measures taken so far to prevent transmission by blood include
> importing blood plasma from the US, excluding as donors all those who
> have themselves had a transfusion as well as those whose blood has
> gone to recipients who have later developed vCJD, and removing white
> blood cells from all blood components in the belief that they are the
> most likely carriers of the rogue prions that cause the disease.
>
> But without a test it is impossible to screen all blood donations, as
> is done for HIV and other diseases. Nor is it yet known how many
> potentially contaminated donors there are. The incubation period for
> vCJD acquired from beef is so long that there is ample opportunity
> for a blood donor to be carrying the rogue prions for years without
> any knowledge. Experiments in mice show that such subclinical
> infections can still act as a source of full-blown infection if
> transmitted to other mice.
>
> Studies of tonsils removed in routine operations suggest, the
> Spongiform Encephalopathy Advisory Committee (SEAC) says, that there
> could be several thousand subclinical carriers of the disease.
>
> They might infect others in 2 ways: either through blood
> transfusions, if the precautions prove inadequate, or -- more likely
> in SEAC's view -- through contaminated surgical instruments. A big
> potential danger is in dental surgery. "The large number of dental
> procedures coupled with good patient survival implies that any
> significant risk via this route could have a major impact on the
> dynamics of secondary infection," the Committee said. But nobody yet
> knows how infective the mouth and gum tissues of vCJD victims are.
> Dental instruments are sterilised between patients, but routine
> sterilisation is not enough to destroy the prions that cause the disease.
>
> The Lancet paper says that tests on the tonsils of the patient who
> died showed that they were infected with prions. Testing tonsil
> tissue is a way of determining early if there is reason to suspect
> prion disease, Professor Collinge said.
>
> [Byline: Nigel Hawkes]
>
> --
> Brent Barrett
> Indianapolis, IN, USA
>
>
> [The Lancet paper entitled "Clinical presentation and pre-mortem
> diagnosis of variant Creutzfeldt-Jakob disease associated with blood
> transfusion: a case report", on which the preceding BBC News and
> Timesonline reports are based is reproduced below. - Mod.CP]
>
> ******
> [3]
> Date: Fri 8 Dec 2006
> From: Terry S. Singeltary Sr.
> Source: The Lancet 2006; 368:2061-2067, 2996 [edited]
>
act>
>
>
> [Terry Singeltary Sr has provided the abstract of the Lancet paper
> upon which the above BBC and Times-Online reports are based. - Mod.CP]
>
> Clinical presentation and pre-mortem diagnosis of vCJD associated
> with blood transfusion: a case report
> --------------------------------------------------
> Stephen J Wroe FRCP a b, Suvankar Pal MRCP a b, Durrenajaf Siddique
> MRCP a b, Harpreet Hyare FRCR a b, Rebecca Macfarlane MRCS a b, Susan
> Joiner MSc b, Jacqueline M Linehan BSc b, Sebastian Brandner MRCPath
> b, Jonathan DF Wadsworth PhD b, Patricia Hewitt FRCPath c and Prof
> John Collinge FRS a b
>
>
> (a. National Prion Clinic, National Hospital for Neurology and
> Neurosurgery, Queen Square, London WC1N 3BG, UK
> b. MRC Prion Unit and Department of Neurodegenerative Disease,
> Institute of Neurology, University College London, London, UK
> c. National Blood Service, London, UK.)
>
> Background
> ----------
> Concerns have been raised that variant Creutzfeldt-Jakob disease
> (vCJD) might be transmissible by blood transfusion. Two cases of
> prion infection in a group of known recipients of transfusion from
> donors who subsequently developed vCJD were identified post-mortem
> and reported in 2004. Another patient from this at-risk group
> developed neurological signs and was referred to the National Prion
Clinic.
>
> Methods
> -------
> The patient was admitted for investigation and details of blood
> transfusion history were obtained from the National Blood Service and
> Health Protection Agency; after diagnosis of vCJD, the patient was
> enrolled into the MRC PRION-1 trial. When the patient died, brain and
> tonsil tissue were obtained at autopsy and assessed for the presence
> of disease-related PrP by immunoblotting and immunohistochemistry.
>
> Findings
> --------
> A clinical diagnosis of probable vCJD was made; tonsil biopsy was not
> done. The patient received experimental therapy with quinacrine, but
> deteriorated and died after a clinical course typical of vCJD.
> Autopsy confirmed the diagnosis and showed prion infection of the tonsils.
>
> Interpretation
> --------------
> This case of transfusion-associated vCJD infection, identified
> ante-mortem, is the 3rd instance from a group of 23 known recipients
> who survived at least 5 years after receiving a transfusion from
> donors who subsequently developed vCJD. The risk to the remaining
> recipients of such tranfusions is probably high, and these patients
> should be offered specialist follow-up and investigation. Tonsil
> biopsy will allow early and pre-symptomatic diagnosis in other
> iatrogenically exposed individuals at high risk, as in those with
> primary infection with bovine spongiform encephalopathy prion
>
> --
> Terry S. Singeltary Sr.
>
>
> [see also:
> CJD (new var.) - UK: 3rd transfusion-related case 20060209.0432
> CJD (new var.) update 2006 20060111.0101
> CJD (new var.) update 2006 (02) 20060206.0386
> CJD (new var.) update 2006 (03) 20060306.0728
> CJD (new var.) update 2006 (04) 20060404.1005
> CJD (new var.) update 2006 (05) 20060508.1332
> CJD (new var.) update 2006 (06) 20060605.1566
> CJD (new var.) update 2006 (07) 20060703.1831
> CJD (new var.) update 2006 (08) 20060807.2207
> CJD (new var.) update 2006 (09) 20060904.2519
> CJD (new var.) update 2006 (10) 20061002.2820
> CJD (new var.) update 2006 (11) 20061106.3190
> CJD (new var.) update 2006 (12) 20061205.3431]
> ............................cp/pg/mpp
>
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