Prions detected in blood of presymptomatic hamsters

Prions, the infectious agents in mad cow and Creutzfeldt-Jakob disease, can generally be detected only in brain and lymphoid tissue prior to the development of active disease symptoms. Blood would be much easier to test presymptomatically, and Claudio A. Soto and coworkers at the University of Texas Medical Branch, Galveston, working with hamsters, have now demonstrated this for the first time (Science 2006, 313, 92). Using protein misfolding cyclic amplification, a technique they developed in 2001, they were able to detect prions in hamster blood as few as 20 days after the animals had been infected and about three months prior to the onset of clinical symptoms. The group is currently trying to extend such a capability to cattle and humans, and a start-up firm called Amprion, in Houston, has been formed to commercialize the technology. Detecting infection early could help keep infected beef out of the food chain and infected blood out of the blood supply.