Scientists are working on a procedure that they hope will lead to a simple blood test for mad cow disease in humans, called variant Creutzfeldt-Jakob Disease.
Variant CJD develops after infection to the bovine spongiform encephalopathy (BSE) prion from eating infected cattle meat. Following exposure, there can be a long silent period before the prion spreads to the brain and causes symptoms. During this silent period, infected individuals can pass the disease on to others by blood transfusion.
At present, the only way to confirm a case of mad cow disease is after a patient has died of the disease, when doctors can test brain tissue for the presence of abnormal proteins called prions.
No blood test has existed because BSE prions appear in very low levels in the blood.
Now, a team from Edinburgh University team has found a way to boost prion numbers cells to improve the sensitivity of current detection tests and to confirm a diagnosis.
The technique, known as protein misfolding cyclic amplification (PMCA), works by mimicking and accelerating the replication of prions so they are more easily detected in test samples.
Their work features in the Journal of Pathology.
So far, the method has been tested mainly in animal models. But the Edinburgh team has shown for the first time that it is possible to use the technique to amplify the number of vCJD prions in infected human brain tissue extracts by using normal human blood cells (platelets) to drive the reaction.
The team stresses that the work is at an early stage, but co-researcher James Ironside, of the National CJD Surveillance Unit at the University of Edinburgh says the findings "provide us with an invaluable tool to study one of the fundamental aspects of variant CJD and take us one step closer towards supporting a test to screen for individuals."
