Specifically, we will review the issue
of blood donation from PD patients. We will present the evidence, sample the
prevailing attitudes and policies, and then make our recommendations.
Part I of this
series discussed the similarities between the possible cell to cell
progression of Parkinson’s pathogenesis and contagious proteinaceous pathogens
called prions. Despite these similarities, there is no evidence of person to
person transmission of Parkinson’s disease. Parkinson’s disease is not
contagious.
However, the next form of transmission we need to consider is
transmission through blood and tissue. We have seen the evidence that human
α-synuclein is the prion-like culprit of PD pathogenesis, capable of
transmission. Here is a brief review:
• α-synuclein
aggregates are toxic in living
cells
• Pathological human
α-synuclein can be inoculated or seeded into the brains of animals, initiating a
PD-like disease in those animals
• Animals can even be
“infected” by injecting the protein into their
muscle tissue. This “infection” then appears to travel up the
sciatic nerve on its way to the brain.
• Transplantation
of fetal cells in PD subjects became “infected” 14 years after grafting.
Animals don’t get PD and it is difficult to make conclusions from
these animal experiments about the possibility for inoculation of PD
in humans. However, since α-synuclein seeding appears to occur in animals, it
would be wise to be cautious about human PD inoculation.
The best evidence against PD transmission comes from two
epidemiological studies.
1. A group of 6018
people with hemophilia in the UK were tracked for between 2 and 23 years. This
disease is traditionally controlled with regular infusions of blood clotting
factor extracted from human blood serum. The study did
not find increases in mortality other than from HIV and from those
causes that would be expected from this population of patients. There was also
no evidence of deaths from Creutzfeldt-Jakob disease (CJD), a human prion
disease.
2. Patients treated
with human growth hormone (hGH) have traditionally used a product extracted
from cadaveric pituitary glands. These patients were followed and their cause
of death determined. The mean age of death was a young 27.2 years. This study
did indeed find instances of CJD transmitted through this procedure. However, they
did not find evidence of PD transmission.
These observations cast doubt on the possibility of PD
transmission, however there are alternate explanations for these
observations:
• Infectious
α-synuclein material does not survive the extraction process.
• A long incubation
time for PD obscures the analysis and tracking for reduced lifespan illnesses
or short tracking times. Assuming a 20 year
incubation time and a 15 year post diagnosis lifespan,
tracking would likely miss this population.
A recent review of
this issue recommended that “a thorough decontamination of
surgical instruments and other medical devices from aggregated Aβ-, tau- and
α-synuclein by effective and routinely applicable reprocessing procedures may
possibly add to patient safety.”
Yet despite the conflicting evidence, PD patients are typically not
discouraged from donating blood or organs.
• The American Red
Cross, does not list
Parkinson’s disease on their list of those not eligible to give
blood.
• The New Zealand
Blood Service does not allow
PD patients to give blood only because it considers donating a
health risk to PD patients.
• The Central
California Blood Center explicitly
allows PD patients to give blood.
• The Australian Red
Cross explicitly
encourages PD patients to donate blood. In fact, PD patient, Alan
Harvey, is celebrated in marketing material for having made 400 blood donations
as of Winter, 2013.
The only blood service in our limited sampling that forbids
blood donation from PD patients in order to protect its blood supply is the
United Kingdom’s NHS Blood and Transplant. The official statement on Parkinson’s
patients is: “We are very sorry but sadly you are not able to
donate blood. This is either for the safety of yourself in giving blood or for
the safety of patients that receive your blood.” A BBC article suggests the
reason is the “uncertain origin” of the disease.
PD professionals and pundits almost universally approve of
blood donation from PD patients:
• Monique L. Giroux,
MD. Medical Director of the Northwest Parkinson’s Foundation states very
confidently “Parkinson’s disease is not a condition transmitted
by blood so having PD does not exclude a person from giving blood.”
• Michael S. Okun,
M.D. National Medical Director of NPF, UF Center for Movement Disorders &
Neurorestoration feels PD
patients can give blood as long as they don’t have low blood
pressure.
• The Answers.com
entry on the issue states: “Depending on medications and general
health it would be fine.”
• Chacha.com answers
that donating blood
would be fine “Since Parkinson’s is not a transmittable disease“.
In our opinion, of all the blood donation services and PD
professionals, the UK’s NHS has provided the only accurate statement on this
serious issue. As of the date of this post, evidence suggesting at least the
possibility of blood to blood transmission of PD is not insignificant. To
proclaim otherwise is irresponsible at best. We propose, therefore, the
following recommendations until definitive conclusions about blood-borne
transmission of PD are possible.
1. That worldwide
blood donation policy groups PD with prion diseases like CJD.
2. Until such policy
is enacted we urge all PD patients to voluntarily refrain from giving blood
and from consenting to donate organs.
3. We urge the tracking
of blood donors who either had PD at the time of blood donation or who gave
blood at any time prior to being diagnosed with PD.
4. Recipients who have
received such blood should be informed and tracked by PD status,
including testing for early pre-motor symptoms
(a smell test,
for example) and PD markers (when they are developed).
5. Recipients should
initiate a neuroprotective prevention protocol based on all applicable
research. Our team has a good idea what such a protocol would look like and we
plan to publish a prevention protocol in the near future.
6. All references to
blood donation also include organ donation.
It is our hope that concern about blood supplies will provide
an additional incentive to better fund research on Parkinson’s disease and
indeed all those diseases of uncertain origin.
Dr. Steve
Researcher at Stop Parkinson's
Dr. Steve is a biochemist, specializing in medical bioinformatics and nutrition. Dr. Steve directs a biomedical consulting laboratory, focusing primarily on biomedical investing and health policy.
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