US 6,605,445 B1 · Rapid method of determining clearance of prion protein

Abstract

Transmissible spongiform encephalopathies (TSEs) are a class of fatal, neurodegenerative diseases found in many mammalian species. Human TSEs include kuru, Creutzfeldt-Jakob disease (CJD), and fatal familial insomnia. Non-human TSEs include sheep scrapie, bovine spongiform encephalopathy (BSE), feline spongiform encephalopathy, and chronic wasting diseases in elk and mule deer. These neurodegenerative diseases are caused by prions and display characteristic amyloid plaque deposition. The only known component of the infectious prion is an abnormal, disease-causing isoform of the prion protein (PrP), called PrP scrapie (PrPSc). During a post-translational process, PrPSc is formed from the normal, cellular PrP isoform (PrPC). The scrapie isoform is less soluble, more proteinase-resistant, and more susceptible to aggregation than the wildtype protein. The claimed invention is directed toward a rapid, specific, sensitive, and quantitative method for the detection of TSE clearance from a plasma product utilizing a chemiluminescent Western blot immunoassay. This immunoassay format can detect picogram concentrations of PrPRES (proteinase resistant PrP fragment) and is linear over a 3-5 log range. The invention is useful for tracking the clearance of PrPSc during plasma manufacturing processes.

Claims22

Dependent claims

A quantitative Western blot immunoassay method useful for the determination of TSE protein clearance during the processing of plasma products, comprising the steps of:

a) preparing an aliquot of a relevant first sample chosen from plasma or a processed plasma sample for a Western blot immunoassay;
b) performing the Western blot assay for TSE protein on such first sample;
c) quantitating TSE protein in the first sample aliquot;
d) submitting the first plasma sample or first processed plasma sample to a processing treatment producing a second sample;
e) performing a Western blot assay for TSE protein on an aliquot of the second sample;
f) quantitating TSE protein results in the second sample;
and
g) comparing the quantitative TSE protein in the first sample to the quantitative TSE protein in the second sample to determine if the processing step provides detectable TSE protein clearance.

5 more elements

Dependencies are inferred from the claim text.

Rapid method of determining clearance of prion protein

Life of this patent

Rapid method of determining clearance of prion protein

Life of this patent

Abstract

Claims22