“We make use of a recently described methodology in order to reassess the distribution of integrous prions within the body of patients suffering from Creutzfeldt-Jakob's disease. Our results indicate that the infectious agent, the prion, is much more broadly distributed within the body than previously thought.”

After 280,000 cows have died of bovine spongiform encephalopathy (BSE), or "mad cow" disease, the problem of prion infections has become very relevant, and has occupied a mindshare among both medical experts and laypeople.

We make use of a recently described methodology in order to reassess the distribution of integrous prions within the bodies of patients suffering from Creutzfeldt-Jakob’s disease. Our results indicate that the infectious agent, the prion, is much more broadly distributed within the body than previously thought.

We believe that the findings convey both good news and bad news. The good news is that the agent is not only present in the brain, but also in skeletal muscle. This will lead the way to diagnostic procedures which are much less invasive than those which are currently being used. Rather than having to biopsy the brain, it might be possible in the future to confirm prion infections by needle biopsy of the muscle.

The bad news is that, again, the agent is not only present in brain, but also in muscle. Because most surgical procedures involve opening skeletal muscle, this fact may indicate that the prion might be spread from one patient to another via surgical instruments in a more efficient way than previously thought.

Prion research has been my field of expertise for the past 15 years. Much of my research has focused on understanding how the agent spreads from the site of inoculation to the brain, which is the organ that receives the damage from prion infections. However, while in previous years I had mainly been focusing on small rodent models for prion infections, the work described in this paper marks our transition to studying the prion infections of humans.

It originally took us a while to convince the editors of the New England Journal of Medicine of the importance of our findings, and our submission was not handled by them with much alacrity! However, time has proven that our findings were indeed quite important—as we had predicted all along.

On the one hand, this type of research is fostering new developments in the diagnostics of prion diseases. On the other hand, it is instructing regulators on steps to be taken in order to contain the danger of secondary infections among humans in the wake of the BSE epidemic.

The relevance of this type of research is tragically highlighted by the occurrence of four cases of Creutzfeldt-Jakob disease that have occurred in recipients of blood products derived from a donor who contracted variant Creutzfeldt-Jakob disease shortly after his last blood donation.