A possible blood test for prion infection

It is thought the prions that cause BSE in cattle, if transmitted to humans, cause the invariably lethal dementia known as new variant Creutzfeldt–Jakob disease. Despite a low disease prevalence in humans and the enforcement of a zero tolerance for infected animals, there may be a reservoir of individuals who are infected but asymptomatic. These people may then infect others through donated blood or surgical instruments.

The only available diagnostic procedure requires tissue biopsies from brain or tonsils, but a simple and reliable test is urgently needed to help prevent the spread of disease. In March Nature Medicine a team from the Roslin Institute in Scotland report the first identification of a molecular marker that is easily detectable in readily accessible tissues.

Most research has attempted to identify brain-specific genes that undergo expression changes upon prion infection. But Miele et al. reasoned that prions replicate in lymphoreticular organs (spleen, tonsils...