Coexistence of multiple PrPSc types in individuals with CJD

http://neurology.thelancet.com Published online October 31, 2005 Coexistence of multiple PrPSc types in individuals with Creutzfeldt-Jakob disease Magdalini Polymenidou, Katharina Stoeck, Markus Glatzel, Martin Vey, Anne Bellon, and Adriano Aguzzi Summary Background The molecular typing of sporadic Creutzfeldt-Jakob disease (CJD) is based on the size and glycoform ratio of protease-resistant prion protein (PrPSc), and on PRNP haplotype. On digestion with proteinase K, type 1 and type 2 PrPSc display unglycosylated core fragments of 21 kDa and 19 kDa, resulting from cleavage around amino acids 82 and 97, respectively. Methods We generated anti-PrP monoclonal antibodies to epitopes immediately preceding the differential proteinase K cleavage sites. These antibodies, which were designated POM2 and POM12, recognise type 1, but not type 2, PrPSc. Findings We studied 114 brain samples from 70 patients with sporadic CJD and three patients with variant CJD. Every patient classified as CJD type 2, and all variant CJD patients, showed POM2/POM12 reactivity in the cerebellum and other PrPSc-rich brain areas, with a typical PrPSc type 1 migration pattern. Interpretation The regular coexistence of multiple PrPSc types in patients with CJD casts doubts on the validity of electrophoretic PrPSc mobilities as surrogates for prion strains, and questions the rational basis of current CJD classifications. snip... The above results set the existing CJD classifications into debate and introduce interesting questions about human CJD types. For example, do human prion types exist in a dynamic equilibrium in the brains of affected individuals? Do they coexist in most or even all CJD cases? Is the biochemically identified PrPSc type simply the dominant type, and not the only PrPSc species? http://neurology.thelancet.com Published online October 31, 2005 what i been saying for years, that the diagnostic criteria differentiating between the nvCJD (i.e. 'the chosen ones') and the sCJD (i.e. 'the forgotten ones') has been terribly flawed from the beginning. .... TSS HUMAN TSE USA 2005 Animal Prion Diseases Relevant to Humans (unknown types?) Thu Oct 27, 2005 12:05 71.248.128.109 About Human Prion Diseases / Animal Prion Diseases Relevant to Humans Bovine Spongiform Encephalopathy (BSE) is a prion disease of cattle. Since 1986, when BSE was recognized, over 180,000 cattle in the UK have developed the disease, and approximately one to three million are likely to have been infected with the BSE agent, most of which were slaughtered for human consumption before developing signs of the disease. The origin of the first case of BSE is unknown, but the epidemic was caused by the recycling of processed waste parts of cattle, some of which were infected with the BSE agent and given to other cattle in feed. Control measures have resulted in the consistent decline of the epidemic in the UK since 1992. Infected cattle and feed exported from the UK have resulted in smaller epidemics in other European countries, where control measures were applied later. Compelling evidence indicates that BSE can be transmitted to humans through the consumption of prion contaminated meat. BSE-infected individuals eventually develop vCJD with an incubation time believed to be on average 10 years. As of November 2004, three cases of BSE have been reported in North America. One had been imported to Canada from the UK, one was grown in Canada, and one discovered in the USA but of Canadian origin. There has been only one case of vCJD reported in the USA, but the patient most likely acquired the disease in the United Kingdom. If current control measures intended to protect public and animal health are well enforced, the cattle epidemic should be largely under control and any remaining risk to humans through beef consumption should be very small. (For more details see Smith et al. British Medical Bulletin, 66: 185. 2003.) Chronic Wasting Disease (CWD) is a prion disease of elk and deer, both free range and in captivity. CWD is endemic in areas of Colorado, Wyoming, and Nebraska, but new foci of this disease have been detected in Nebraska, South Dakota, New Mexico, Wisconsin, Mississippi Kansas, Oklahoma, Minnesota, Montana, and Canada. Since there are an estimated 22 million elk and deer in the USA and a large number of hunters who consume elk and deer meat, there is the possibility that CWD can be transmitted from elk and deer to humans. As of November 2004, the NPDPSC has examined 26 hunters with a suspected prion disease. However, all of them appeared to have either typical sporadic or familial forms of the disease. The NPDPSC coordinates with the Centers for Disease Control and state health departments to monitor cases from CWD-endemic areas. Furthermore, it is doing experimental research on CWD transmissibility using animal models. (For details see Sigurdson et al. British Medical Bulletin. 66: 199. 2003 and Belay et al. Emerging Infectious Diseases. 10(6): 977. 2004.) http://www.cjdsurveillance.com/abouthpd-animal.html SEE STEADY INCREASE IN SPORADIC CJD IN THE USA FROM 1997 TO 2004. SPORADIC CJD CASES TRIPLED, and that is with a human TSE surveillance system that is terrible flawed. in 1997 cases of the _reported_ cases of cjd were at 54, to 163 _reported_ cases in 2004. see stats here; p.s. please note the 47 PENDING CASES to Sept. 2005 p.s. please note the 2005 Prion D. total 120(8) 8=includes 51 type pending, 1 TYPE UNKNOWN ??? p.s. please note sporadic CJD 2002(1) 1=3 TYPE UNKNOWN??? p.s. please note 2004 prion disease (6) 6=7 TYPE UNKNOWN??? http://www.cjdsurveillance.com/resources-casereport.html CWD TO HUMANS = sCJD ??? AS implied in the Inset 25 we must not _ASSUME_ that transmission of BSE to other species will invariably present pathology typical of a scrapie-like disease. snip... http://www.bseinquiry.gov.uk/files/yb/1991/01/04004001.pdf ATYPICAL TSEs in USA CATTLE AND SHEEP ? http://www.bseinquiry.gov.uk/files/sc/seac17/tab03.pdf TSS