New blood tests can detect prions

Tine Hesman Saey of Science News reports a new blood test can detect even tiny amounts of infectious proteins called prions, two new studies show.

prion-test-dec-16Incurable prion diseases, such as mad cow disease (BSE) in cattle and variant Creutzfeldt-Jakob disease (vCJD) in people, result from a normal brain protein called PrP twisting into a disease-causing “prion” shape that kills nerve cells in the brain. As many as 30,000 people in the United Kingdom may be carriers of prions that cause vCJD, presumably picked up by eating BSE-tainted beef. Health officials worry infected people could unwittingly pass prions to others through blood transfusions. Four such cases have already been recorded. But until now, there has been no way to screen blood for the infectious proteins.

In the test, described December 21 in Science Translational Medicine, magnetic nanobeads coated with plasminogen — a protein that prions grab onto — trap prions. Washing the beads gets rid of the rest of the substances in the blood. Researchers then add normal PrP to the beads. If any prions are stuck to the beads, the infectious proteins will convert PrP to the prion form, which will also stick to the beads. After many rounds, the researchers could amplify the signal enough to detect vCJD prions in all the people in the studies known to have the disease.

No healthy people or people with other degenerative brain diseases (including Alzheimer’s and Parkinson’s) in either study had evidence of the infectious proteins in their blood. And only one of 83 people with a sporadic form of Creutzfeld-Jakob disease tested positive. Those results indicate that the test is specific to the vCJD prion form, so a different test is needed to detect the sporadic disease. 

In two cases, researchers detected prions in frozen blood samples collected 31 months and 16 months before people developed vCJD symptoms.

Mad cow disease cover-up? Mum exposed toxic beef conspiracy after son died in agony

During his final lucid moments Andrew Black looked up at his mother with violet eyes and begged her: “Find out who did this to me.”

Three years earlier, Andrew was a ­promising radio and TV producer, but by the time he died in his mother’s arms he was bedbound, blind and unable to remember anything before his illness.

mad.cows.mother's.milkAndrew would this week have celebrated his 30th birthday.

Instead he was killed by vCJD – the human form of mad cow disease BSE – when he was just 24 years old.

Mum Christine Lord vowed to honour her son’s dying wish, channelling her grief into a five-year investigation to uncover what the Government knew about BSE and when.

Her findings exposing an apparent cover up are published this week in her book, Who Killed My Son?

Christine says: “Watching Andrew die was the worst pain I have ever experienced in my life and it never goes away. It will be with me to the end of my days.

“You don’t get over losing a child to something as horrendous as that.

Documents showed the ­Government was warned to cull cattle as early as 1988 amid fears BSE could spread to and kill humans.

Meanwhile sources, many of whom were too scared to speak out publicly, told ­Christine infected cattle were smuggled into abattoirs at night.

And scientists in the know began boycotting beef during the late 1980s – even though the Government was still telling the public it was safe to eat.

One abattoir worker revealed infected cattle were delivered late at night to be turned into mechanically recovered meat which made its way into all kinds of food.

“One time they even had dead animals arriving in yellow sacks with radioactive signs on them,” says Christine.

Yet fears about the spread of BSE and the threat to humans emerged years before the public was warned.

Christine found official documents on BSE dating back to 1986, which she gave to the gummer.burger.kidDaily Mirror.

They are marked “confidential” as investigators ­recommended “playing it low key.”

Experts warned the Government there was “a real possibility that doing nothing could prove extremely costly”.

Yet ­officials were reluctant to cull cattle to contain the disease because of the cost.

The then Minister of Agriculture John Gummer even appeared on TV in 1990 feeding a beefburger to his daughter.

It was only in 1996 that the Government finally confirmed the risk to humans – after victims were already struck down.