Abstract
The development of in vitro amplification systems allows detecting femtomolar amounts of prion protein scrapie (PrPSc) in human cerebrospinal fluid (CSF). We performed a CSF study to determine the effects of prion disease type, codon 129 genotype, PrPSc type, and other disease-related factors on the real-time quaking-induced conversion (RT-QuIC) response. We analyzed times to 10,000 relative fluorescence units, areas under the curve and the signal maximum of RT-QuIC response as seeding parameters of interest. Interestingly, type of prion disease (sporadic vs. genetic) and the PRNP mutation (E200K vs. V210I and FFI), codon 129 genotype, and PrPSc type affected RT-QuIC response. In genetic forms, type of mutation showed the strongest effect on the observed outcome variables. In sporadic CJD, MM1 patients displayed a higher RT-QuIC signal maximum compared to MV1 and VV1. Age and gender were not associated with RT-QuIC signal, but patients with a short disease course showed a higher seeding efficiency of the RT-QuIC response. This study demonstrated that PrPSc characteristics in the CSF of human prion disease patients are associated with disease subtypes and rate of decline as defined by disease duration.Electronic supplementary materialThe online version of this article (doi:10.1007/s12035-014-8709-6) contains supplementary material, which is available to authorized users.
Highlights
Prion diseases are characterized by the accumulation of abnormally misfolded prion protein (PrPSc) in the brain
We propose that the application of the real-time QuIC (RT-QuIC) method as a reliable diagnostic test for prion diseases can be extended to show that prion protein scrapie (PrPSc) seeds from different prion diseases convert recombinant PrP with a different efficiency
The optimal running time for RT-QuIC reaction was 80 h because no additional sporadic Creutzfeldt-Jakob disease (sCJD) case became positive after this time period
Summary
Prion diseases are characterized by the accumulation of abnormally misfolded prion protein (PrPSc) in the brain. Spontaneous (sporadic), genetic, and transmitted forms of prion diseases are known. In sporadic Creutzfeldt-Jakob disease (sCJD), molecular characteristics of PrPSc, and codon 129 genotype of the prion protein gene (PRNP) determine molecular sCJD subtypes [1, 2] with distinct clinicopathological phenotypes and transmission characteristics [3]. Human prion diseases are unique with respect to their selfpropagating replication of the abnormally folded host-derived prion protein (PrPC), which in its pathological conformation (PrPSc) is prone to aggregation and seeding. Various in vitro conversion assays, such as protein misfolding cyclic amplification (PMCA), enhanced quaking-induced conversion (eQuIC), or real-time QuIC (RT-QuIC) use this high aggregation and seeding activity to amplify miniscule amounts of PrPSc to a detectable level
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call