Such a blood test could also help prevent accidental transmission of the malformed proteins that cause variant Creutzfeldt-Jakob disease (vCJD) via blood transfusions and organ transplants, the scientists suggest.
Done in hamsters, the experiments are the first ever to biochemically detect the malformed proteins during the "silent phase" of the disease--just weeks after the animals were infected and months before they showed clinical symptoms.
The scientists say that they detected prions--the infectious proteins responsible for such brain-destroying disorders as bovine spongiform encephalopathy (BSE) in cattle and vCJD in humans--in the blood of the hamsters in as few as 20 days after the animals had been infected. That discovery occurred about three months before the hamsters began showing clinical symptoms of the disease, the Science paper reports.
To detect the very small quantities of prions found in blood samples, UTMB professor Claudio Soto, assistant professor Joaquin Castilla and research assistant Paula Saá used a technique known as protein misfolding cyclic amplification (PMCA), invented by Soto's group, which greatly accelerates the process by which prions convert normal proteins to misshapen infectious forms.
"With this method, for the first time we have detected prions in what we call the silent phase of infection, which in humans can last up to 40 years," said Soto, senior author of the Science paper.
"The concern is that if many people are incubating the disease silently, then secondary transmission from human to human by blood transfusion or surgical procedur
Source:University of Texas Medical Branch at Galveston