Photo by Alex Luster
with The Storyhive
Two groups of researchers have reported that an assay can accurately diagnose patients with variant Creutzfeldt-Jakob disease (vCJD), and this could allow for effective detection of prion contamination in donated blood.
The groups both said they were able to detect vCJD with 100% sensitivity and specificity.
One group even detected abnormal prion proteins in the blood of 2 subjects before the individuals exhibited any signs of vCJD.
The researchers said this work paves the way to a noninvasive, early diagnostic screen for vCJD and possibly other conditions involving protein misfolding.
Both studies were published in Science Translational Medicine.
“Our findings, which need to be confirmed in further studies, suggest that our method of detection could be useful for the noninvasive diagnosis of this disease in pre-symptomatic individuals,” said Claudio Soto, MD, author of one of the studies and a professor at the University of Texas Medical School in Houston.
“Early diagnosis would allow any potential therapy to be given before substantial brain damage has occurred. In the case of the blood supply, availability of a procedure to efficiently detect small quantities of the infectious agent would allow removal of blood units contaminated with prions so that new cases can be minimized substantially.”
For their study, Dr Soto and his colleagues used a protein misfolding cyclic amplification assay (PMCA) they developed, which mimics the prion replication process in vitro that occurs in prion disease.
The team used the assay to screen for abnormal prion proteins in blood from 14 individuals with vCJD and 153 control subjects.
In another study, Daisy Bougard, PhD, of Etablissement Français du Sang, INSERM, Université de Montpellier in France, and her colleagues tested a similar technique on blood samples from 18 individuals with vCJD and 238 without vCJD.
Dr Bougard’s group used the same PMCA as Dr Soto’s group. But Dr Bougard and her colleagues first captured prions from blood using plasminogen-coated beads.
In both studies, the PMCA diagnosed vCJD with 100% sensitivity and 100% specificity.
Dr Bougard and her colleagues were able to detect small amounts of prions in 2 blood donors more than a year before the onset of symptoms.
The researchers stressed that these results will need to be confirmed in a larger number of blood samples.
