Series of tests shown to identify prion infections affecting people and animals, and has potential for early diagnosis of dementia. A suite of blood tests has been shown to detect prion diseases such as variant Creutzfeldt-Jakob Disease (vCJD) long before signs of illness are apparent. The development helps meets the need for an accessible test for the rare but serious neurodegenerative disease, caused by misfolding proteins that form toxic deposits. It also offers scope to develop a blood test for prion infections in live animals as well as tests for early detection of other neurodegenerative diseases affecting humans. Researchers from the Roslin Institute together with prion specialist teams from France used archived samples of blood recovered from sheep carrying the prion disease bovine spongiform encephalopathy (BSE), as a proxy for the equivalent human disease, vCJD. Tests for prion diseases are shown to be effective in detecting diseases affecting humans, such as vCJD. Early detection The team compared three tests using two separate technologies designed to amplify the presence of prions in blood samples, to determine their ability to detect infection before disease symptoms appear. Two tests were established methods configured using Protein Misfolding Cyclic Amplification (PMCA), and a third test was developed using Real-Time quaking Induced Conversion (RT-QuIC). These methods utilise slightly different technologies, but all rely on self-propagation and amplification of misfolded proteins to detect the tiny quantities of prions present in blood. All three tests were able to indicate presence of prions more than two years before the appearance of clinical signs. The results also showed that positive test results were a good predictor of infection risk. Wider applications The resulting tests could be further refined to enable routine blood testing of individuals in the context of blood or organ donation. They could also be applied to control of emerging prion diseases affecting animals, such as chronic wasting disease in deer, or for early detection of other neurological conditions caused by protein misfolding, such as Alzheimer’s and Parkinson’s disease. The study, funded by the UK Department of Health and Social Care, was carried out in collaboration with INRAe/ Ecole Nationale Vétérinaire de Toulouse and Établissement Français du Sang. It was published in Blood. A non-invasive test, such as a blood test, would be a valuable tool in detecting prion diseases in people and animals, causing minimal stress to patients compared with, for example, a test involving a sample of spinal fluid. The ability to diagnose conditions before clinical signs develop offers an optimal opportunity to prevent spread of infection and effectively treat and manage disease. Dr Fiona Houston Roslin Institute ** The Roslin Institute receives strategic investment funding from the Biotechnology and Biological Sciences Research Council and it is part of the University of Edinburgh’s Royal (Dick) School of Veterinary Studies. ** Scientific publication This article was published on 2024-12-02
