Prions Flashcards
What is the most common human prion disease?
CJD
What are the causes of CJD?
1- sporadic
2- familial
3- Iatrogenic
What are the signs and symptoms of sporadic CJD?
1- spongiform encephalopathy
2- RAPID loss of brain function
3- mental deterioration
What causes prion disease?
No virus particles, bacteria or fungi associated with the condition.
No nucleic acid is associated with infectivity.
What is the immune response to prion infection?
There is no immune response
Explain the protein only hypothesis:
Prions are encoded by the host
PrPc misfolds and converts to PrPsc
The misfolding arises via mutation
PrPsc causes more PrPsc to be make
Who can PrPsc be transmitted to?
An animal that encodes PrPc only
What is the normal function of PrPc?
Maintaining the brain white matter, regulating the innitation of immune cells, has responses to oxidative stress, and is involved in neuron formation
How many types of PrPsc are there?
4
Which forms of PrPsc are associated with sCJD? vCJD?
sCJD= type 1
vCJD=type 4
What do accumulations of PrPsc become?
amyloid fibers
How is sCJD diagnosed?
1- Brain biopsy (spongiform change)
2- CSF
3- MRI and EEG changes
How is sCJD treated?
There is no treatment
Which population si sCJD more prevalent in?
older populations
How do humans contract vCJD?
Transmission of BSE (cows to humans)
What are the symptoms of vCJD?
similar to sCJD. slower loss of brain function and prominent involvement of lymphoreticular tissues
How is vCJD diagnosed?
Need a brain biospy…vacuoles are formed. CSF is not typically sensitive.
Which form of CJD can be transmitted from human-to-human?
vCJD
Which CJD has peripheral pathogenesis?
vCDJ (lymph node involvement)
What are proper sterilization procedures for prions?
keep instruments moist and autoclaving only!!
