Prions Flashcards
What are the 3 clinical manifestations of Kuru?
1) Severe Ataxia
2) Dementia
3) Choreiform movements.
After diagnosis how long does someone live with Kuru? And what accumulates in the brain?
Fatal in 3-15 months
Amyloid plaques accumulate.
How is Kuru Spread?
Cannibalistic consumption/ mourning rituals of the dead.
What is the most frequent age associated with CJD?
How long is the Incubation period?
How does it present clinically?
Persons in their 60’s and 70’s
15-20 months
Dementia with ataxia, seizures.
How does one become infected with CJD?
Infection by corneal transplants, neurosurgery, pituitary derived growth hormone.
Do prions which are infections proteins contain a RNA or DNA genome?
NO
Describe the propagation process of prions and what is increased, decreased and unchanged.
Post-translational process in which PrPc undergoes a conformation change= decrease in alpha helix; increase in Beta sheet; mRNA remains unchanged for that protein.
== PrPsc.
What are the 2 disease manifestations of Prions?
Is there a immune system response?
1) Spongiform degeneration and Astrocytic gliosis.
There is NO immune response.
4 ways to diagnose Prions
1) elevated 14-3-3 proteins in CSF
2) PrPsc is detected by antibody
3) Progressive subacute or chronic decline in cognitive or motor fxn.
4) PCR screens for genetic predisposition.
What is the treatment of prions?
Supportive therapy.
the disease in invariably fatal with a rapid decline after diagnosis.
What are the 3 ways prions appear?
1) Inherited form- point mutation; destabilizes PrPc.
2) Sporadic form- Most cases; horizontal transfer from infected animals or Spontaneous conversion of PrPc to PrPsc.
Mutations in the PrP gene are NOT found in these patients.
3) Infectious form- direct inoculation with PrPsc agent from medical procedures.
Describe vCJD and how BSE is caused.
vCJD: occurs in younger patients
Core amyloid-like deposits with intense halo spongiform degeneration.
BSE: caused by feeding MBM to livestock.
MBM has allowed the Scrapie prion to go from sheep to cattle
Transmitted by oral consumption of prions.
How are Prions transmissible?
Blood.
Who is affected by Subacute sclerosing panencephalitis? SSPE
How does this cause disease?
SSPE is a slowly progressive dementing illness.
Affects children.
Evident 2-10 years after infection with Measles virus.
It causes intracellular inclusions in neuronal cells, lymphocytic infiltration and destruction of nerve cells.
Progressive Multifocal Leukoencephalopathy (PML) is asssociated with an underlying _______.
Immune system disorder
reactivation of latent JC virus.
With AIDS, more PML cause will manifest.
