Prion diseases, including sporadic Creutzfeldt-Jakob disease (CJD) and variant CJD in humans, scrapie in sheep, and mad cow disease in cattle, destroy the brain and damage other organs. The diseases are difficult to diagnose, untreatable, and ultimately fatal. People and animals can be infected for years before symptoms appear.
NIAID scientists are working to develop a blood test to diagnose prion diseases in people and animals. A blood test would likely be faster and more practical than current diagnostic tests, which require samples of cerebral spinal fluid or brain tissue. Such a test would help prevent the spread of prion diseases within and between species, including the transmission of variant CJD through blood transfusions.
The latest in a series of blood-test advances by NIAID researchers is called enhanced quaking-induced protein conversion (eQuIC). The test is 10,000 times more sensitive for detecting abnormal prion protein than previously described tests for variant CJD, and it accurately differentiated between healthy hamsters and those infected with scrapie. NIAID and its project partner, Swiss diagnostics manufacturer Prionics AG, have applied for a patent on the eQuIC test.
The test could be used by blood banks, hospitals, livestock operations, and food-processing plants to screen for prion diseases and might ultimately improve prospects for treating these diseases. The general test concept also could potentially extend to the diagnosis of other diseases characterized by abnormal proteins in the brain, such as Alzheimer’s, Huntington’s, and Parkinson’s diseases, but much more research is needed.
Orrú CD, Wilham JM, Raymond LD, Kuhn F, Schroeder B, Raeber AJ, Caughey B. Prion disease blood test using immunoprecipitation and improved quaking-induced conversion. MBio. 2011 May 10;2(3):e00078-11.
Last Updated January 08, 2013