East Hills, NY (March 17, 2005) -- An update on Transmissible Spongiform Encephalopathies (TSEs), including variant Creutzfeldt-Jakob Disease (vCJD), the human form of "mad cow" disease, was a key topic at the Food & Drug Administration's Blood Products Advisory Committee meeting in Gaithersburg, Maryland today. Issues such as the number of people that could be harboring vCJD as carriers, the impact on the blood supply and new risk reduction measures were addressed. Pall Corporation (NYSE: PLL) presented an overview of the latest research on its prion reduction technology as a new risk reduction measure to help prevent transfusion transmission of infectious prions that can cause vCJD. The Company expects to launch the new filter commercially in Europe this spring.
TSEs, also called prion diseases, are fatal neurodegenerative diseases that include vCJD in humans; bovine spongiform encephalopathy (BSE) in cattle; chronic wasting disease (CWD) in deer, elk and moose; and scrapie in sheep. These diseases are believed to be caused by prions, which are misfolded, or "rogue", infectious proteins.
"So much remains unknown about prion diseases even as new information comes to light practically daily. No one really knows how many people may be harboring vCJD without clinical symptoms and could potentially transmit the infection via blood transfusion," according to Joseph Cervia, MD, a leading infectious disease expert and medical director of Pall Corporation.
He outlined the myriad questions and uncertainties surrounding vCJD and other prion diseases. These include the length of the incubation period from time of exposure to the onset of symptoms; the number of people potentially harboring vCJD who are asymptomatic; the relationship to other neurodegenerative diseases including Alzheimer's Disease; and whether other prion diseases, such as CWD found in elk and deer across the U.S., can also cross the species barrier to humans, as is the case with BSE in cows.
"We do, however, know for certain that vCJD is a devastating, invariably fatal disease and that everything possible should be done to prevent its spread and ensure the safety of the blood supply," he stated. "Removing prions from blood prior to transfusion is an approach that can lead to a greater reduction of risk and also mitigate the issue of blood availability due to donor deferrals."
The Pall Leukotrap® Affinity Prion Reduction Filter simultaneously reduces leukocytes (white blood cells) and all types of prions from red blood cells in a single step. Red cells are the most widely transfused blood component. Leukoreduction of blood is approximately 40 percent effective in reducing risk of vCJD infection, but is not sufficient since prions can be both cell-associated (in leukocytes) and non-cell associated.
Dr. Cervia described the results of studies that show the novel technology concurrently reduces both leukocytes and prions (cell and non- cell associated) from red cell concentrates with a 99 percent reduction of the infectious agent. The research, conducted with vCJD and scrapie prions, showed that the new filter removed the infectious prions to below the limit of detection of the Western blot assay. Dr. Cervia also described the results of studies demonstrating that the filter does not damage red cells thereby not impacting their efficacy, purity and therapeutic value.
Dr. Cervia emphasized the need to balance the efficacy of current measures to prevent the transmission of vCJD via blood transfusion -- specifically donor deferral -- against the safety and availability of life-saving blood components. A loss of one percent of donors involves approximately 75,000 to 85,000 individuals in just the first year with a reverberating impact on blood availability.
Currently, several nations, including the U.S. and Canada, defer blood donors who have stayed in some countries where BSE has been found. Japan, which recently confirmed its first vCJD patient, expanded its ban on blood donations to anyone who stayed in Great Britain or France for one day or longer between 1980 and 1996. According to the Japanese Red Cross Society, this ban would cut potential blood donors by several hundred thousand people per year and may have a serious impact on the blood supply.
"We can no longer afford to view vCJD as a disease that is limited to a few countries but must seriously consider new and better approaches to prevent this devastating problem from escalating here," added Dr. Cervia. "Combined filtration of leukocytes and prions is a cost efficient approach to mitigate potential exposure and it can be easily integrated with current blood handling logistics and good manufacturing practices."
Following CE mark and commercialization of the filter in Europe, Pall Corporation plans to discuss this technology with regulatory agencies in Canada and the U.S. The Company is also studying the new filter as a device to aid in the detection of BSE in cattle before entering the food supply.
Source: Eurekalert & othersLast reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
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