A widely available, accurate blood test would enable people to be diagnosed earlier and could also help identify carriers of the disease. This would help measure how widespread the prion infection is in the general population and identify those who are at risk of passing on the infection to others.
The research team from the MRC Prion Unit at the NHNN's National Prion Clinic tested 190 blood samples, including 21 from individuals known to have vCJD. The blood test was able to detect blood spiked with a dilution of vCJD to within one part per ten billion - 100,000 times more sensitive than any other method developed so far.
Variant CJD, the human form of BSE (or mad cow disease) first emerged in 1995. The disease, which affects the brain, is believed to have passed from cattle to humans through infected food. It causes personality change, loss of body function, and eventually death.
Professor John Collinge, Director of the Prion Unit based at the NHNN, who worked on the study, said:
“One of the reasons that vCJD is such a dreaded disease and has caused such disruption and expense to health services is the lack of knowledge of who is and who is not a carrier of this infection. The next step will be to test anonymously several thousand blood donors from a country unaffected by BSE in order to gain a better idea of how the test fares in practice. Longer term studies will also be needed to assess what proportion of individuals who test positive for prion infection will then go on to develop the disease later in life.
“The MRC Prion Unit’s research with the NHS National Prion Clinic to improve early diagnosis is an essential part of the wider MRC strategy to develop better treatments for patients. For this to develop, it will be crucial for clinicians to be able to offer treatment before extensive irreversible damage to the brain has occurred. At the moment, a firm diagnosis of vCJD can usually be made only once serious symptoms of the disease have developed which indicate extensive damage to the brain.”
For more information visit the National Prion Clinic web page or the Medical Research Council website.