Sludge Watch ==> Experiments indicate filter may remove prion proteins from blood

[Maureen Reilly]

Sludgewatch Admin:

Among the many pathogens that end up or grow in sewage sludge, one of the 
most difficult to disinfect are prions.  While there are competing theories 
of whether the prions are the infectious particals or whether there are nano 
bacteria/virus like pathogens that persist as infectious agents is not well 
understood.  At this point it is understood that only exposure to high 
temperatures is capable of disinfecting the BSE type pathogens.

If this device/method is successful it may help protect recipients of blood 
donations.

......................................................

Researchers Develop Resin Beads That Capture Mad Cow Disease Agent From 
Blood
http://www.sciencedaily.com/releases/2007/02/070224093334.htm


Science Daily

— For the first time, experimental results indicate that it is possible to 
use a resin filter to remove harmful prion proteins from the blood of an 
infected animal, a finding that has major implications for the removal of 
infectious prion proteins – the agents associated with variant 
Creutzfeldt-Jakob disease, mad cow disease, scrapie and other prion diseases 
in animals – during blood transfusions.


Dr. Ruben Carbonell examines the blood transfusion filter he helped develop. 
It will be manufactured under the trade name P-Capt® Filter by MacoPharma.


Dr. Ruben Carbonell, Frank Hawkins Kenan Professor of Chemical and 
Biomolecular Engineering and director of the Kenan Institute for 
Engineering, Technology and Science at North Carolina State University, and 
scientists from the University of Maryland at Baltimore’s VA Medical Center, 
the American Red Cross and ProMetic BioSciences, a biotechnology company, 
developed small resin beads with molecules that are able to bind to harmful 
prion proteins. The beads serve as an adsorption filter, capturing the bad 
proteins and allowing other blood components to be effectively cleansed of 
the prion-disease-causing agents.

A paper describing the research was published in the Dec. 23/30 version of 
The Lancet.

In prion diseases, which are called transmissible spongiform 
encephalopathies, prion proteins unfold and cause plaques in animal and 
human brains. Transmission of prion diseases has impacted the availability 
and cost of blood donations, especially in Europe.

In the Lancet study, the researchers took the blood of scrapie-infected 
hamsters and removed the white blood cells using a device called a 
leukofilter. The leukoreduced blood was then passed through another filter 
containing the new resin particles engineered to capture the prion proteins. 
A group of disease-free hamsters was inoculated with the blood that passed 
through the leukofilter only. A second group was inoculated with the blood 
that passed through both the leukofilter and the prion-capture filter.

The researchers found that while leukoreduction itself removed a good deal 
of the bad proteins – approximately 72 percent – none of the nearly 100 
hamsters inoculated with the leukoreduced, resin-filtered blood were 
infected with scrapie by the end of the 550-day test. Fifteen of 99 hamsters 
receiving leukoreduced blood not passed through the resin filter were 
infected with scrapie.

After the experiment was completed, the researchers analyzed the brains of 
hamsters still alive at the end of the testing period. No evidence of 
scrapie was discovered in brains of hamsters that were inoculated with the 
resin-filtered blood.

Aided by scientists in NC State’s Nonwovens Cooperative Research Center, 
located in the College of Textiles, Carbonell and his colleagues have now 
developed a new filter to remove prions from donated blood during 
transfusions. The device takes donated blood from a blood bag, passes it 
through several “sandwiches” of the prion-capture resin beads placed between 
nonwoven fabric membranes, and places the filtered blood in a separate blood 
bag prior to infusion into a patient or blood donation recipient.

The filter device, to be manufactured under the trade name P-Capt® Filter by 
MacoPharma, has received CE Mark regulatory approval in Europe.

Carbonell and his colleagues are now looking for ways of targeting other 
pathogens in blood such as Hepatitis A virus, B19 parvovirus and Hepatitis C 
virus. He says it should be possible to engineer new molecules that capture 
prion proteins and viruses and to place them on a single filter to further 
enhance the safety of blood transfusions.

The research was funded by Pathogen Removal and Diagnostic Technologies Inc. 
(PRDT), a joint venture of the American Red Cross and ProMetic BioSciences, 
owned in part by Carbonell and Dr. Robert Rohwer from the University of 
Maryland.

Note: This story has been adapted from a news release issued by North 
Carolina State University.