Advancing rapid detection of prion diseases
Prion diseases, such as Creutzfeldt-Jacob disease (CJD) in humans, scrapie in sheep, and mad cow disease in cattle, are difficult to diagnose, currently untreatable, and ultimately fatal. People and animals can be infected for years before symptoms appear. A faster and more practical prion diagnostic test that does not require cerebrospinal fluid sampling or brain tissue could simplify screening for prion diseases and allow earlier diagnostic confirmation to guide healthcare decision-making.
IRP scientists led by Byron Caughey, Ph.D., developed a prion blood test called enhanced Quaking-Induced Conversion (eQuIC), which uses an antibody to isolate abnormal prion protein from blood plasma and then amplifies it to enhance detection. The test is 10,000 times more sensitive for detecting variant CJD than previously described tests. The National Institute of Allergy and Infectious Diseases (NIAID) and its project partner, Swiss diagnostics firm Prionics AG, have applied for a patent on the eQuIC test.
eQuIC could be used by blood banks, hospitals, livestock operations, and rendering plants to screen for prion diseases in a far more efficient and less invasive manner than current diagnostic tools. Additionally, this concept of testing for abnormal proteins could eventually be applied to the diagnosis of other diseases, such as Alzheimer’s, Huntington’s, and Parkinson’s disease, but more research is needed and underway.
Orrú CD, Wilham JM, Raymond LD, Kuhn F, Schroeder B, Raeber AJ, Caughey B. (2011). Prion disease blood test using immunoprecipitation and improved quaking-induced conversion. MBio. 2(3), e00078-11.