Detection of PrPSc in subclinical BSE with the paraffin-embedded tissue (PET) blot
The appearance of a new variant of CJD (vCJD) in young patients has caused considerable public concern and there is evidence that this novel disease is caused by the same agent as BSE. BSE is a prion disease that became epidemic in the UK, with a peak incidence in January 1993. New test systems should aim to identify BSE-infected cattle early in the incubation period. We compared the established histological and im-munohistochemical methods and the Western blot method used by Prionics with the PET blot method that detects prion PrPSc deposits in formalin-fixed and paraffin-embedded tissue. Investigating the obex region with the PET blot, all BSE cases were detectable and no false positive cases occurred. From the Swiss culling program, five clinically healthy cattle out of 1761 were identified as incubating BSE. With the PET blot method four of them showed the same PrPSc deposition pattern that was seen in clinical BSE, though less conspicuous. In one of the five cases, PrPSc was restricted to two brain stem nuclei, a pattern that was reported to be the first manifestation of PrPSc deposits in the brain after peripheral infection and one that occurs after half of the incubation time. In this case, histology and Western blot were negative.
KeywordsPrion Disease Bovine Spongiform Encephalopathy Dorsal Motor Nucleus Western Blot Method Solitary Tract Nucleus
Unable to display preview. Download preview PDF.
- 1.Anderson RM, Donnelly CA, Ferguson NM, Woolhouse MEJ, Watt CJ, Udy HJ, MaWhinney S, Dunstan SP, Southwood TRE, Wilesmith JW, Ryan JBM, Hoinville LJ, Hillerton JE, Austin AR, Wells GAH (1996) Transmission dynamics and epidemiology of BSE in British cattle. Nature 382: 779–788PubMedCrossRefGoogle Scholar
- 2.Anonymous (1999) BSE Enforcement Bulletin. See website: http://www. maff. gov. uk/maffhome. htm, 33: 1–22Google Scholar
- 5.Bruce ME, Will RG, Ironside JW, McConnell I, Drummond D, Suttie A, McCardie L, Chree A, Hope J, Birkett C, Cousens S, Fraser H, Bostock CJ (1997) Transmissions to mice indicate that ‘new variant’ CJD is caused by the BSE agent. Nature 398: 489–501Google Scholar
- 11.Korth C, Stierli B, Streit P, Moser M, Schaller O, Fischer R, Schulz-Schaeffer W, Kretzschmar H, Raeber A, Braun U, Ehrensperger F, Hornemann S, Glockshuber R, Riek R, Billeter M, Wüthrich K, Oesch B (1997) Prion (PrPSc)-specific epitope defined by a monoclonal antibody. Nature 390: 74–77PubMedCrossRefGoogle Scholar
- 14.Schaller O, Fatzer R, Stack M, Clark J, Cooley W, Biffiger K, Egli S, Doherr M, Vandevelde M, Heim D, Oesch B, Moser M (1999) Validation of a Western immunoblotting procedure for bovine PrPSc detection and its µse as a rapid surveillance method for the diagnosis of bovine spongiform encephalopathy (BSE). Acta Neuropathol 98: 437–443PubMedCrossRefGoogle Scholar