PrP amyloid plaques in Creutzfeldt-Jakob disease of short duration: immunohistochemical studies of 5 cases from Poland

Iatrogenic Creutzfeldt-Jakob disease in three growth hormone recipients: a neuropathological study

Since 1985, several cases of Creutzfeldt-Jakob disease, occurring after a treatment by human cadaveric hormone have been reported. Three new iatrogenic cases observed in French patients (two children and one young adult) are described here. Neuropathological study displayed the classical aspects of previously reported sporadic cases of Creutzfeldt-Jakob disease in adults, including severe cortical spongiform change with numerous vacuoles within neuronal dendrites, diffuse astrogliosis and neuronal loss. In addition, the iatrogenic cases described here included two more unusual points: (i) they were homozygotic for the PrP gene on codon 129 and therefore a genetic predisposition could be suspected; (ii) numerous kuru plaques were scattered in the cerebral cortex, the subcortical white matter and in the cerebellar cortex. They were decorated with a PrP monoclonal antibody, but not with a beta A4 antibody. This last point underlines the similarities between iatrogenic Creutzfeldt-Jakob disease and kuru.

Transmissible cerebral amyloidoses as a model for Alzheimer's disease. An ultrastructural perspective

Alzheimer's disease, a prototypic nontransmissible cerebral amyloidosis, has no adequate experimental model. Several pathogenetic events, however, may be modeled and accurately studied in the transmissible cerebral amyloidoses of kuru, Creutzfeldt-Jakob disease, Gerstmann-Sträussler-Scheinker disease, and scrapie. The common neuropathological denominator in both types of cerebral amyloidoses is the presence of stellate kuru plaques, senile plaques, and pure neuritic plaques. These amyloid plaques consist of amyloid fibers, dystrophic neurites, and reactive astrocytes in different proportions. Microglial cells, which are regarded as amyloid producer/processor cells in Alzheimer's disease, may play the same function in the transmissible cerebral amyloidoses. In both transmissible and nontransmissible amyloidoses, the impairment of axonal transport leads to accumulation of abnormally phosphorylated cytoskeleton proteins (such as neurofilament proteins and microtubule-associated protein tau), which eventually produce dystrophic neurites observed as parts of plaque or as isolated pathological structures.

Human prion diseases (spongiform encephalopathies)

Prion diseases (spongiform encephalopathies) in humans are Creutzfeldt-Jakob disease (CJD), Gerstmann-Sträussler-Scheinker syndrome (GSS), and kuru. Clinically, they are characterized by an inexorably progressing neurological illness with dementia and ataxia as the most prominent signs. The classical neuropathological changes are limited to the central nervous system and consist of spongiform degeneration, amyloid plaques, astrocytic gliosis, and nerve cell loss. The human spongiform encephalopathies, which for many years were considered neurodegenerative disorders of unknown etiology, were finally recognized as transmissible diseases similar to scrapie in sheep in the late 1960's. The infectious agent appears to consist of protein devoid of functional nucleic acid and has been termed prion to distinguish it from viruses. The prion hypothesis has gained wide acceptance through the finding that mutations of the prion protein gene are associated with heritable human prion disease. Different mutations appear to cause prion disease with a distinct pattern of clinical and pathological features in a great number of families. Certain mutations of the PrP gene have been shown to be associated with clinical and neuropathological changes not typical of any variant of human prion disease known to date. A new classification of prion diseases based on the molecular biology and biochemistry of the prion protein is likely to emerge.