Second passage of chronic wasting disease of mule deer to sheep by intracranial inoculation compared to classical scrapie.

The origin of chronic wasting disease (CWD) in cervids is unclear. One hypothesis suggests that CWD originated from scrapie in sheep. We compared the disease phenotype of sheep-adapted CWD to classical scrapie in sheep. We inoculated sheep intracranially with brain homogenate from first-passage mule deer CWD in sheep (sCWDmd). The attack rate in second-passage sheep was 100% (12 of 12). Sheep had prominent lymphoid accumulations of PrPSc reminiscent of classical scrapie. The pattern and distribution of PrPSc in the brains of sheep with CWDmd was similar to scrapie strain 13-7 but different from scrapie strain x124. The western blot glycoprofiles of sCWDmd were indistinguishable from scrapie strain 13-7; however, independent of sheep genotype, glycoprofiles of sCWDmd were different than x124. When sheep genotypes were evaluated individually, there was considerable overlap in the glycoprofiles that precluded significant discrimination between sheep CWD and scrapie strains. Our data suggest that the phenotype of CWD in sheep is indistinguishable from some strains of scrapie in sheep. Given our results, current detection techniques would be unlikely to distinguish CWD in sheep from scrapie in sheep if cross-species transmission occurred naturally. It is unknown if sheep are naturally vulnerable to CWD; however, the susceptibility of sheep after intracranial inoculation and lymphoid accumulation indicates that the species barrier is not absolute.

Comparison of Two US Sheep Scrapie Isolates Supports Identification as Separate Strains.

Scrapie is a naturally occurring transmissible spongiform encephalopathy of sheep and goats. There are different strains of sheep scrapie that are associated with unique molecular, transmission, and phenotype characteristics. However, in the United States, very little is known about the potential presence of scrapie strains. Scrapie strain and PRNP genotype could both affect susceptibility, potential for transmission, incubation period (IP), and control measures required for eliminating scrapie from a flock. The investigators evaluated 2 US scrapie isolates, No. 13-7 and x124, after intranasal inoculation to compare clinical signs, IPs, spongiform lesions, and patterns of PrPSc deposition in sheep with scrapie-susceptible PRNP genotypes (QQ171). After inoculation with x124, susceptibility and IP were associated with valine at codon 136 (V136) of the prion protein: VV136 sheep had short IPs (6.9 months), those in AV136 sheep were 11.9 months, and AA136 sheep did not develop scrapie. All No. 13-7 inoculated sheep developed scrapie, with IPs of 20.1 months for AA136 sheep, 22.8 months for AV136 sheep, and 26.7 months for VV136 sheep. Patterns of immunoreactivity in the brain were influenced by inoculum isolate and host genotype. Differences in PrPSc profiles versus isolate were most striking when examining brains from sheep with the VV136 genotype. Inoculation into C57BL/6 mice resulted in markedly different attack rates (90.5% for x124 and 5.9% for No. 13-7). Taken together, these data demonstrate that No. 13-7 and x124 represent 2 distinct strains of scrapie with different IPs, genotype susceptibilities, and PrPSc deposition profiles.

Enfermedad de creutzfeldt-jakob en el Perú: reporte de once casos / Creutzfeldt-jakob disease in Peru: report of eleven cases

La enfermedad de Creutzfeldt-Jakob (ECJ) es una enfermedad neurológica fatal producida por la isoforma patológica de la proteína priónica humana. Se reporta las características clínicas de seis casos de la forma esporádica de ECJ con diagnóstico definitivo por histopatología, y cinco casos con diagnóstico probable, en pacientes atendidos en el Instituto Nacional de Ciencias Neurológicas del Perú. La edad de inicio en los casos definitivos fue de 55,8 años y, en los probables, de 59,6 años, con predominio del sexo masculino. El tiempo de enfermedad fue de 8,8 meses. Se encontró un EEG típico en 50% de los casos definitivos y 80% de los probables. La proteína 14-3-3 en líquido cefalorraquídeo fue positiva en un caso probable y los hallazgos típicos en resonancia magnética se observaron en dos casos probables. Todos los casos cursaron con una evolución clínica típica de la enfermedad, y se considera el primer reporte de ECJ en el Perú.

Creutzfeldt-Jakob disease (CJD) is a fatal neurological disease caused by pathological isoform of the human prion protein. Clinical features of six cases of the sporadic form of CJD with definitive diagnosis by histopathology, and five cases with probable diagnosis were reported in patients treated at the Peruvian National Institute of Neurological Sciences. The average age of onset in definite cases was 55.8 years and in probable cases was 59.6, mostly males. The average disease duration was 8.8 months. A typical EEG was found in 50% of definite cases and in 80% of probable. The 14-3-3 protein in cerebrospinal fluid was positive in a probable case, and typical MRI findings were observed in two probable cases. All cases studied had a typical clinical course of the disease, and it is considered as the first report of CJD in Peru.

Enfermedad de Creutzfeldt-Jakob: hallazgos clínicos, electroencefalográficos, imagenológicos y de patología / Creutzfeldt-Jakob disease: clinical, electroencephalografic, pathologic, and imaging characteristics

La enfermedad de Creutzfeld-Jakob (ECJ) hace parte de un grupo de enfermedades transmisibles que se caracterizan por la presencia de encefalopatía espongiforme, donde también se encuentran el kuru, el síndrome Gerstmann-Straussler- Scheinker, y el insomnio fatal familiar. De ellas, la más común es la ECJ (representando aproximadamente el 85 por ciento de casos de encefalopatías espongiformes), con una incidencia anual estimada en 1-2 casos por millón en la población general y de 5 casos por millón en personas entre 60 y 74 años. A pesar de que fue descrita hace ya más de 50 años, no hay hasta el momento ningún tratamiento efectivo, por lo cual la enfermedad es siempre fatal. El promedio de sobrevida es de apenas 1 año una vez hecho el diagnóstico. Describimos el caso de una paciente femenina de 62 años, quien ingresó a nuestra institución con un cuadro de 1 año de evolución de cambios en el comportamiento rápidamente progresivos, demencia y posteriormente alteraciones motoras. La enfermedad progresó hasta llevar a la postración e incapacidad de la paciente para entablar comunicación con su entorno, lo cual obligó a sus familiares a consultar a nuestro centro para su estudio. Los hallazgos neuropatológicos, clínicos e imagenológicos fueron compatibles con una enfermedad de Creutzfeldt-Jakob esporádica.

Creutzfeldt-Jakob Disease (CJD) belongs to a group of infectious diseases characterized by spongiform encephalitis, which also includes Kuru, Gerstmann-Straussler- Scheinker syndrome, and fatal familial insomnia. Amongst these, the most common is CJD (responsible for aproximately 85 per cent of all cases of spongiform encephalitis) with an anual incidence of 1-2 cases in the general population and 5 cases in people with ages 60-74 years. Even though it was described more than 50 years ago there is still no effective treatment, being invariably fatal. Life expectancy is only 1 year after diagnosis. We describe the case of a 65 year old female patient, who was seen at our institution with a 1 year history of rapid decline of her mental function, initially manifest as behavioral changes followed by dementia and later by motor disfunction. During the last months she was bedridden and unable to communicate, which led her family to seek help in our institution. Clinical, neuropathological and imaging characteristics were compatible with sporadic Creutzfeldt-Jakob disease.

Studies on codon 129 genotype of PrP gene and phenotypic features of sporadic Creutzfeldt-Jakob disease in China / 中华神经科杂志

Objective To investigate the relationship between polymorphism at codon 129 of prion protein gene and the phenotypic features of sporadic Creutzfeldt Jakob disease(CJD)in China Methods The prion protein genotype of 14 cases with sporadic CJD were tested and clinical data were analysed Results (1) 8 cases with definite CJD and 6 cases with probable CJD were diagnosed depending on diagnostic criteria (2) Of the 8 definite CJD cases,6 were homozygous for methionine at codon 129, 2 cases were methionine/valine at codon 129,while all the probable CJD cases were methionine homozygotes (3) There were four group symptoms at onset in 12 cases with methionive homozygous at codon 129: cognitive and mental impairment as first symptom in 8 cases,ataxia in 1 case,blurred sight in 2 cases,myoclonus in 1 case;during illness there were epilepsy in 5 cases,myoclonus in 6 cases,blurred sight in 6 cases,PSD in 7 cases The longest illness duration was 20 months,and the shortest was two and a half months (4) Ataxia was the first symptoms in 2 cases with metionine/ valine at codon 129 The illness duration was 6 and 20 months,and there was no PSD (5) Spongyform degeneration in different degree and neuronal loss were seen in the 8 cases with definite CJD,synaptic deposition of abnormal PrP was shown in 5 cases Conclusions (1)Of the 14 cases with CJD, homozygosity for methionine at condon 129 of the prion protein gene was shown in 12 cases,but there was distinct phenotypic variant (2)The frequence of methionine and valine of 129 allilic distribution for sCJD was similar to that in Japan,and different from that in Western cases There was no sCJD case with valine homozygous genotype at codon 129 in our study