Skin Biopsies May Be Useful For Early Detection of Prion Infections

MedicalResearch.com Interview with:

Dr-Byron Caughey

Dr-Caughey

Byron Caughey, Ph.D. 
Senior Investigator
Chief, TSE/prion Biochemistry Section
Laboratory of Persistent Viral Diseases
NIH/NIAID Rocky Mountain Laboratories .
Hamilton, MT 59840 USA

MedicalResearch.com: What is the background for this study? Would you briefly explain the significance of prion-induced diseases and why they have been difficult to diagnosis? 

Response: Although prion diseases such as Creutzfeldt-Jakob disease (CJD) are rarer than many other neurodegenerative diseases in humans, they are rapidly fatal, untreatable and transmissible. Therefore it is important to be able to diagnose prion diseases as early as possible, not only to accurately inform patients, families and caregivers, but also to reduce risks of transmission and  improve prospects for developing therapeutics.

Toward these goals, we have shown that our RT-QuIC prion seed amplification assays are highly accurate for diagnosing sporadic CJD using patients’ spinal fluid and/or nasal brushings in the clinical phase of disease. However, these particular specimens may not always be available, and it remains unclear how early they become RT-QuIC-positive in infected individuals in the months or years prior to the onset of overt clinical signs. We also showed recently that skin samples obtained post-mortem from sCJD patients are RT-QuIC positive.

In the current study, we determined how early prion seeds appear in the rodents infected with prions in order to gain clues as to whether analyses of skin biopsies might provide a means of early preclinical detection of prion infections in humans.

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Prions of Creutzfeldt-Jakob Disease Detected Throughout Eye Tissues

MedicalResearch.com Interview with:
Top, retina of a control patient. Bottom, retina from a patient with CJD. Arrowheads point to abnormal prions in the outer plexiform layer (opl), and the asterisk (*) marks more diffuse prions in the inner plexiform layer (ipl).Orrù et al., mBio
Byron Caughey, Ph.D.
Senior Investigator
Chief, TSE/prion Biochemistry Section
Laboratory of Persistent Viral Diseases
NIH/NIAID Rocky Mountain Laboratories
Hamilton, MT 59840 USA 

MedicalResearch.com: What is the background for this study? What are the main findings? 

Response: Corneal transplants have caused the transmission of Creutzfeldt-Jakob disease (CJD) in at least two cases, and pathological prion protein has been detected in the retinas of the eyes of sporadic CJD cases. To build on these previous indications of prions in eye tissue, we tested the distribution of prions in various components of eyes from 11 sCJD decedents.

We applied a highly sensitive surrogate test for prions (RT-QuIC) that indicated that all of the sCJD cases had prions in multiple parts of their eye, including the cornea and sclera, which is the white outer surface of the eye. Retinas were usually contained the highest levels, in some cases approaching levels in the brain. Some other parts such as the cornea, lens and vitreous had much lower, but detectable, levels. 

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