Creutzfeldt-Jakob Disease Virus Research Articles

Combination Ultrafiltration and 6 MUrea Treatment of Human Growth Hormone Effectively Minimizes Risk from Potential Creutzfeldt-Jakob Disease Virus Contamination

Although genetically engineered human growth hormone (hGH) is now commercially available, native pituitary-derived hGH is still used by physicians in many countries for the treatment of hormone deficiency states. We describe a method using ultrafiltration and 6 M urea that reduced infectivity in human pituitary tissue that had been deliberately contaminated with scrapie virus (an animal analogue of human Creutzfeldt-Jakob disease virus) from an initial level of 10(9.7) infectious units to just 5 infectious units. Based on estimates of the frequency of contamination and infectivity levels in batches of human pituitaries, the use of this protocol to prepare GH from cadaveric human glands yields a calculated probability of exposure to a contaminated vial of not greater than 1 in 3.2 million recipients; therefore, native hormone prepared by this method may be considered to be essentially risk-free. The same methodology may be useful in the preparation of other hormones, such as prolactin, for which no synthetic substitutes are currently available, as well as biological products derived from sheep or cattle, that may be infected with scrapie or bovine spongiform encephalopathy.

Spread of Creutzfeldt-Jakob disease virus along visual pathways after intraocular inoculation

We studied the targeting of spongiform lesions within the visual pathways after intraocular injection with the Fujisaki strain of Creutzfeldt-Jakob disease (CJD) virus. The first lesions were observed 18 weeks postinoculation in the most superficial layer of the superior colliculus and in the lateral geniculate body contralateral to the side of the inoculation. Asymmetrical lesions in the superior colliculus were found also in mice sacrificed at 19, 22, and 27 weeks postinoculation. These results demonstrate that CJD virus spreads within the CNS via central axons of the visual pathways following intraocular inoculation.

Appearance of tubulovesicular structures in experimental Creutzfeldt-Jakob disease and scrapie preceeds the onset of clinical disease

We have consistently observed tubulovesicular structures in brain tissues during the terminal stages of naturally occurring and experimentally induced spongiform encephalopathies, irrespective of the host species and virus strain. In NIH Swiss mice inoculated intracerebrally or intraocularly with the Fujisaki strain of Creutzfeldt-Jakob disease (CJD) virus, tubulovesicular structures, measuring 20-50 nm in diameter, were particularly prominent in dilated, pre- and postsynaptic neuronal processes, occasionally being mixed with synaptic vesicles. These structures appeared 13 weeks following intracerebral inoculation, 5 weeks before the onset of clinical signs, when spongiform changes were also detected. The number and density of tubulovesicular structures increased steadily during the course of clinical disease, and were particularly abundant in mice 47 to 51 weeks after intraocular inoculation. In hamsters infected with the 263 K strain of scrapie virus, these structures were initially detected 3 weeks following intracerebral inoculation and increased dramatically at 10 weeks postinoculation. The appearance of tubulovesicular structures before the onset of overt disease in mice inoculated with CJD virus by either the intracerebral or intraocular route, and before the appearance of other neuropathological changes in hamsters infected with scrapie virus, indicate that they represent either a part or aggregate of the infectious virus or a pathological product of the infection.

REEVALUATION OF THE ULTRASTRUCTURAL PATHOLOGY OF EXPERIMENTAL CREUTZFELDT-JAKOB DISEASE

We describe the serial ultrastructural pathology of experimental Creutzfeldt-Jakob disease (CJD) in mice. Spongiform vacuoles, widespread myelin and axonal pathology, accompanied by abundant macrophagic reaction and neuroaxonal dystrophy, were consistently found in mice infected with CJD virus. By contrast, intranuclear vacuolation and swelling of astrocytic and neuronal processes were nonspecific changes that also occurred in control animals. We conclude that CJD-related neuropathological phenomena do not accumulate gradually through the incubation period but develop relatively abruptly and in complete form.

White matter ultrastructural pathology of experimental Creutzfeldt-Jakob disease in mice

Creutzfeldt-Jakob disease (CJD), previously regarded as a neurodegenerative disorder strictly of the gray matter, occasionally occurs as a panencephalopathic form which is characterized by severe white matter damage. An ultrastructural study of the white matter pathology in mice experimentally infected with the Fujisaki strain of CJD virus revealed: (1) vacuoles within myelin sheaths, formed by splitting either at the major dense or intraperiod lines, or within axons; (2) macrophages filled with numerous myelin figures, lipid droplets and paracrystalline inclusions; (3) astrocytes actively digesting myelin debris; (4) unusual wrapping of several axons by a common myelin sheath; (5) vesicular degeneration of myelin sheaths; (6) close contact between numerous coated pits and outer myelin lamellae; and (7) proliferation of inner mesaxons. Our data indicate that the damage to myelinated axons in the panencephalopathic type of CJD is accomplished primarily by active degradation of myelin by macrophages and astrocytes and by formation of intra-axonal and intra-myelin vacuoles. The myelin vacuolation is most consistent with that produced by leukolysins released from activated macrophages and astrocytes.

Tubulovesicular structures in experimental Creutzfeldt-Jakob disease and scrapie.

Tubulovesicular structures, measuring 20-50 nm in diameter, were found in dilated neuronal processes in brains from mice infected with the Fujisaki strain of Creutzfeldt-Jakob disease virus. These particles were similar to those observed in brains from hamsters infected with scrapie. These structures are consistently present in naturally occurring and experimentally induced spongiform encephalopathies, irrespective of the host species or virus strain. Their role in pathogenesis is undetermined.

Newer data on the inactivation of scrapie virus or Creutzfeldt-Jakob disease virus in brain tissue.

Newer data on the inactivation of scrapie virus or Creutzfeldt-Jakob disease virus in brain tissue.

Familial Creutzfeldt-Jakob disease in Chile

Of the 87 cases of Creutzfeldt-Jakob disease (CJD) ascertained in Chile since 1931, 39 are familial accounting for 45% of all cases, and 25% of the 51 definite cases. There are 11 affected families with an average of 3.5 affected members per family, and a rate of occurrence consistent with autosomal dominant transmission. There is no evidence for maternal lineage, and age at death is not significantly different from that of sporadic cases. About half of the cases died around the same age, suggesting some form of vertical transmission. Three pairs of affected members in 3 different families died at the same time, possibly indicating common exposure to CJD agent. The study of absolute death intervals and temporal and spatial separations between affected members suggests minimum incubation periods ranging from 2 to 37 years, assuming case-to-case transmission. CJD occurring in a woman related by marriage to one of the affected families strongly argues for horizontal transmission. The high proportion of familial CJD observed in Chile is probably the result of both a genetically determined susceptibility to the CJD virus, and a high degree of case ascertainment. However, the present study leaves unanswered the mode of transmission of the agent within the affected families.

Chemical Disinfection of Creutzfeldt–Jakob Disease Virus

RECOMMENDATIONS for the disinfection of virus-contaminated tissues from patients with Creutzfeldt–Jakob disease (CJD), published five years ago in the Journal, 1 relied heavily on data from experiments using mouse-adapted scrapie virus — at that time a more conveniently studied member of the same group of spongiform encephalopathy viruses. We have now accumulated sufficient data on guinea-pig and mouse-adapted viral isolates from two patients with CJD to be able to present current recommendations based on studies of the CJD virus itself. Autoclaving for one hour at a temperature of at least 121°C (15 psi) remains the method of choice for the sterilization . . .

Brain tissue from persons dying of Creutzfeldt-Jakob disease causes scrapie-like encephalopathy in goats.

Two goats became affected with an encephalopathy indistinguishable from scrapie 43 months after they were inoculated intracerebrally with 10% suspensions of brain from two persons dying of Creutzfeldt-Jakob disease. Although this observation does not establish the common identity of Creutzfeldt-Jakob disease virus and scrapie virus, it is thought to provide strong evidence of a close etiological relationship between the two diseases.

Familial Creutzfeldt-Jakob disease: Autosomal dominance in 14 members over 3 generations

Discovery of a second affected branch of a family with transmitted Creutzfeldt-Jakob disease (CJD), originally reported by Buge et al. in 1978, brings the total number of cases to 14 in 3 generations, with at least 20 members of the next young adult generation presently at risk. Complete segregation of the illness to the descendants of these 2 branches, with no skipped generations, and an overall frequency of CJD in affected sibships of 56%, clearly defines a pattern of autosomal dominance. The disease is indifferent to sex, either in terms of affected members (8 males and 6 females) or of lineage (3 fathers and 3 mothers). Acquisition of CJD virus from a point source contamination is unlikely, and case-to-case transmission, if it occurred, would have required an average minimum incubation period of 17 years.