New test for Creutzfeldt-Jakob Disease

About two years ago, a family member of mine experienced a sudden onset of symptoms similar to dementia/neurodegenerative disease – disorientation, ataxia, etc. The possibility of early dementia in the mid-fifties did not cross our minds. However, symptoms progressed and visits to the doctor become a weekly routine as a slew of diagnostic tests came back negative for viral infections, cancer, MS, Parkinson’s, and much more. It was very difficult watching my family member deteriorate rapidly without any explanation and worse, no solution. As time went on, we knew whatever it was would likely be harder to cure. After about ten months and seemingly endless doctors visits,  a diagnosis was made, Sporadic Creutzfeldt-Jakob Disease by power of deductive rule-out reasoning. This fatal neurodegenerative disease is caused by mis-folded proteins accumulating in the brain causing cell death. Even after a terminal diagnosis, the process of “rule-out” did not seem definitive enough to accept and move on.

In my recent research of CJD diagnostic processes and ethical approaches, I came across an NPR article that very much mirrored my family’s experiences with the diagnostic turmoil associated with this rare and complicated disease. The article describes a woman in her fifties with similar sudden onset of symptoms. The difference being that she had access to a new diagnostic test that confirmed the diagnosis of Sporadic Creutzfeldt-Jakob Disease.

Typically, CJD diagnosis is confirmed in an autopsy which obviously is too late. Previous assays involving spinal fluid analysis were used in symptomatic patients to detect brain cell injury but shed zero light on the cause of the damage. These types of tests contributed to the inefficient, inconclusive, and lengthy process of diagnosis – an agonizing experience for suffering patients and families. A few years ago, a test was developed that has the potential to not only detect CJD but that could differentiate other similarly ambiguous neurodegenerative diagnoses that are more common such as Parkinson’s disease and Lewy body dementia. The test is called RT-QuIC, real-time quaking-induced conversion (Bichell, 2017). The test can detect the mutated PrP gene associated with sporadic and genetic CJD with amazing sensitivity and precision (Orrú et. al., 2015). Furthermore, the most recently updated version of the test has shown improved accuracy and speedier results, approximately one day. The test can use either cerebrospinal fluid via spinal tap or a nasal brush that collects cells from the deepest part of the nasal cavity which is separated from the brain by a relatively thin partition of bone. Though only currently seen in a few labs so far, this diagnostic technology is making its way to CJD surveillance centers across the world. Amazingly, this assay only costs $50 (Bichell, 2017).

This test closes the door on neurodegenerative “rule-out” diagnoses and creates a platform for discovery that could take us leaps closer to potential treatments for CJD and other prion diseases. Though transmission of CJD is rare, the assay technology could also eliminate the possible spread of the disease by more accurately screening infected blood and organs. The wider clinical application and use of RT-QuIC has a profound impact on the more common neurodegenerative diseases that currently lack a reliable diagnostic test. With increasing use, RTQuIC could also help clinicians obtain prognoses earlier and initiate potential therapies sooner. However, treatments still do not exist for most of these neurodegenerative disorders, but that does not make this test any less significant. An accurate diagnosis is vital for patients and families by eliminating doubt and redirecting the focus away from possible treatment and toward quality of life care for affected loved ones. The scope of this diagnostic test goes beyond appropriate diagnosis and extends further into the realm of acceptance for this fatal disease.

References:

Bichell, R. E. (2017, Febuary 6). Prion Test For Rare, Fatal Brain Disease Help

Families Cope. Retrieved September 20, 2017, from

http://www.npr.org/sections/health-shots/2017/02/06/508241181/prion-test-for

rare-fatal-brain-disease-helps-families-cope

Orrú, C.D., Groveman, B.R., Hughson, A.G., Zanusso, G., Coulthart, M.B., & Caughey, B. (2015).

Rapid and Sensitive RT-QuIC Detection of Human Creutzfeldt-Jakob Disease Using

Cerebrospinal Fluid. mBio, 6(1), e02451–14. http://doi.org/10.1128/mBio.02451-14