Novel technology said to reduce infectious prions from blood

East Hills, NY – July 13, 2004 – Pall Corporation today unveiled a new technology that it says reduces prions from blood prior to a transfusion at the annual meeting of the International Society for Blood Transfusion (ISBT) in Edinburgh, Scotland.

The not-yet-released prion reduction filter will provide the dual benefit of reducing harmful white blood cells while also reducing infectious prions, the rogue proteins that cause variant Creutzfeldt-Jakob Disease (vCJD). The company presented the latest animal model research results in anticipation of launching the new filter in Europe in early 2005, where the problem of vCJD, the human form of bovine spongiform encephalopathy (BSE) or mad cow disease, is most critical.

The company says its prion reduction technology will provide a multi-targeted approach to blood safety by reducing leukocytes and infectious prions that are either cell associated or non-cell associated. In blood, about 60% of prion infectivity resides in leukocytes (cell-associated) and about 40% in plasma (non-cell associated). Research results show that the new filter has an affinity to all types of prions, including aggregated, denatured and normal.

The specter of prion transmission from human-to-human via a blood transfusion came to the forefront in December 2003 when a case of vCJD was identified in a person who received a blood transfusion six years earlier from a donor who later died of the disease. Since vCJD has an unknown, albeit lengthy, incubation period that is asymptomatic, there is no way to know how many people already have the disease and how many could have already transmitted it via blood transfusion.

With support from the New York Institute of Basic Research, Pall says it is studying the new filter using three different assays – Western blot assay, bioassay and animal models of prion disease – to validate reduction of infectious prions. An endogenous infectivity study evaluated the efficacy of a prototype filter for the removal of scrapie-infected prions from red blood cell concentrates. After a 300-day incubation period, none of the hamsters (20) that received the filtered red cells developed scrapie, a transmissible spongiform encephalopathy. During the same period, two out of the 18 hamsters that received unfiltered red cells developed scrapie, exhibiting the clinical signs and symptoms of the disease.

It was found that the prototype Pall prion removal filter removed infectious prions from red cell concentrates below the limit of detection of the Western blot assay, the gold standard used to determine the presence of prions. A bioassay was also used to quantify the amount of prion removal. It was found that the filter removed approximately 4 logs of scrapie-infected prions. The evidence to date, as demonstrated in the animal model, suggests the reduction of prions, both free and leukocyte bound, may provide a higher margin of transfusion safety.

"This is a major milestone in the quest to protect the public from this insidious and always fatal neurodegenerative disease,” says Eric Krasnoff, chairman and CEO of Pall Corporation. “We are moving this technology forward rapidly. Blood centers and hospitals will soon be able to combine both prion and leukocyte reduction in a single, simple step.”