Neuropathology of prion diseases

Prion diseases include sporadic forms such as Creutzfeldt-Jakob disease (CJD), familial forms (familial CJD), fatal familial insomnia, Gerstmann-Sträussler-Scheinker disease, and acquired forms (ie, kuru, iatrogenic CJD). The most frequent of the latter include acquired forms secondary to injections of human cadaveric pituitaryderived growth hormone and the new variant of CJD —probably related to bovine spongiform encephalopathy. The communal lesions are neuronal loss, spongiosis and gliosis and, inconstantly, the presence of amyloid plaques and different kinds of small deposits immunolabeled with antiprion (PrP) antibodies. Their number and topography are variable. Recent works have shown the role of the host genotype, especially of codon 129, in the susceptibility to these diseases. We have tried to correlate neuropathology with the genotype of codon 129 and the type of PrP to establish a molecular classification.