What Makes Lethal Prion Proteins So Wily?

Patients at a North Carolina hospital got an apology this week after being exposed to the deadly organism that causes the brain-wasting Creutzfeld-Jakob disease (CJD), but it could take years to determine whether or not they are safe. Experts say the toxic protein, or prion, responsible for CJD is hard to detect and nearly impossible to destroy.

“People are looking for a silver bullet, but there isn’t one yet,” said Byron Caughey, senior investigator at the National Institute of Allergies and Infectious Diseases Rocky Mountain Laboratories. “Somehow you have to stop this protein from this pathological protein from folding and becoming toxic, and prevent toxicity of material already there. Nobody knows how to do that yet.”

Prions are proteins that don’t carry their own genes, which unlike bacteria, viruses or protozoa, make them tough to locate and kill.

Novant Health officials apologized this week to 18 patients and their families for exposing those patients to surgical instruments that had been used on a CJD patient at Forsyth Medical Center in Winston-Salem, N.C. The instruments underwent normal hospital sterilization, but did not undergo a more rigorous procedure required to limit the risk of the CJD agent. Caughey says there have been very few cases of person-to-person transmission through infected instruments or blood transfusions.

Worldwide, only one person in a million contracts CJD each year. However, a recent study in the United Kingdom found a higher proportion of patients (493 per 1 million) had appendixes infected with prions, even though the people had not contracted the disease itself. CJD progresses into the brain and is related to “mad cow disease” which struck the British Isles nearly 20 years ago.

“It doesn’t happen very often, but even the perception of risk is a critical issue,” Caughey said. Caughey and other researchers are working on a diagnostic test that would detect whether the person has been exposed to CJD. Unlike other diseases, the body doesn’t show an immune response after exposure. After the disease progresses, the infected person’s brain begins to turn into a sponge-like matter, leading to death in months or possibly years.

So what are doctors and medical providers to do about CJD? Pierluigi Gambetti, director of the National Prion Disease Pathology Surveillance Center in Cleveland, says that surgical instruments have to be sterilized with extreme heat and chemicals.

“The problem is that this may ruin delicate instruments,” Gambetti said. In the past 30 years, only four patients have been infected in this way, none in the United States. Via What Makes Lethal Prion Proteins So Wily?

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