Prions Flashcards
Pathology of TSE?
Multifocal spongiform changes*, astrogliosis, neuronal loss, sometimes amyloid, minimal inflammation
Prion protein on what chromosome?
20
How is PrPc different from PrPSc
Differential folding (alpha helices vs. beta sheets, respectively)
T/F – PrPSc is selectively resistant to proteases
T
How does PrPSc cause cell death?
Aggregates in intracellular vesicles, causes APOPTOSIS (not necrosis)
How does PrPSc amplify misfolding?
Acts as template for folding intermediate to take on its conformation
What does the concept of species barrier mean?
Initial infectivity of new species poor, subsequent passage within species is good
Is it common for a pathogenic form of PrP to arise spontaneously?
No
MC human TSE?
CJD
Main clinical features of CJD?
Myoclonus, dementia
85% of all CJD cases?
sporadic
Inheritance pattern of familial CJD? Difference from sporadic?
AD; younger onset, longer course
Specific finding of sporadic CJD?
Periodic complexes on EEG
Pathophys of GSS?
AD mutation at codon 102 of PrP
Clinical Sx of GSS?
gait/ataxia, atypical but no specific EEG
Unique histopath of GSS?
Amyloid
Pathophys of FFI?
AD mutations at codons 129 and 178
Clinical features of FFI?
Sleep, autonomics
Unique histopath?
Neuronal loss w/o spongiform change or plaques
T/F – vCJD = BSE?
True
Transmission of vCJD?
Contaminated beef AND blood transfusion
Pathophys of vCJD?
Homozygous for methionine at codon 129 of PrP
Clinical characteristics of vCJD?
Anxiety, depression, visual problems
Histopath of vCJD?
numerous FLORID (daisy-like) plaques and changes in basal ganglia
