Browsing by Author "Parchi, Piero"

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    Incidence and spectrum of sporadic Creutzfeldt–Jakob disease variants with mixed phenotype and co-occurrence of PrPSc types: an updated classification
    (Springer, 2009-11-01) Parchi, Piero; Strammiello, Rosaria; Notari, Silvio; Giese, Armin; Langeveld, Jan P. M.; Ladogana, Anna; Zerr, Inga; Roncaroli, Federico; Cras, Patrich; Ghetti, Bernardino; Pocchiari, Maurizio; Kretzschmar, Hans; Capellari, Sabina; Pathology and Laboratory Medicine, IU School of Medicine
    Six subtypes of sporadic Creutzfeldt–Jakob disease with distinctive clinico-pathological features have been identified largely based on two types of the abnormal prion protein, PrPSc, and the methionine (M)/valine (V) polymorphic codon 129 of the prion protein. The existence of affected subjects showing mixed phenotypic features and concurrent PrPSc types has been reported but with inconsistencies among studies in both results and their interpretation. The issue currently complicates diagnosis and classification of cases and also has implications for disease pathogenesis. To explore the issue in depth, we carried out a systematic regional study in a large series of 225 cases. PrPSc types 1 and 2 concurrence was detected in 35% of cases and was higher in MM than in MV or VV subjects. The deposition of either type 1 or 2, when concurrent, was not random and always characterized by the coexistence of phenotypic features previously described in the pure subtypes. PrPSc type 1 accumulation and related pathology predominated in MM and MV cases, while the type 2 phenotype prevailed in VVs. Neuropathological examination best identified the mixed types 1 and 2 features in MMs and most MVs, and also uniquely revealed the co-occurrence of pathological variants sharing PrPSc type 2. In contrast, molecular typing best detected the concurrent PrPSc types in VV subjects and MV cases with kuru plaques. The present data provide an updated disease classification and are of importance for future epidemiologic and transmission studies aimed to identify etiology and extent of strain variation in sporadic Creutzfeldt–Jakob disease.
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    Phenotypic diversity of genetic Creutzfeldt-Jakob disease: a histo-molecular-based classification
    (Springer, 2021) Baiardi, Simone; Rossi, Marcello; Mammana, Angela; Appleby, Brian S.; Barria, Marcelo A.; Calì, Ignazio; Gambetti, Pierluigi; Gelpi, Ellen; Giese, Armin; Ghetti, Bernardino; Herms, Jochen; Ladogana, Anna; Mikol, Jacqueline; Pal, Suvankar; Ritchie, Diane L.; Ruf, Viktoria; Windl, Otto; Capellari, Sabina; Parchi, Piero; Pathology and Laboratory Medicine, School of Medicine
    The current classification of sporadic Creutzfeldt-Jakob disease (sCJD) includes six major clinicopathological subtypes defined by the physicochemical properties of the protease-resistant core of the pathologic prion protein (PrPSc), defining two major PrPSc types (i.e., 1 and 2), and the methionine (M)/valine (V) polymorphic codon 129 of the prion protein gene (PRNP). How these sCJD subtypes relate to the well-documented phenotypic heterogeneity of genetic CJD (gCJD) is not fully understood. We analyzed molecular and phenotypic features in 208 individuals affected by gCJD, carrying 17 different mutations, and compared them with those of a large series of sCJD cases. We identified six major groups of gCJD based on the combination PrPSc type and codon 129 genotype on PRNP mutated allele, each showing distinctive histopathological characteristics, irrespectively of the PRNP associated mutation. Five gCJD groups, named M1, M2C, M2T, V1, and V2, largely reproduced those previously described in sCJD subtypes. The sixth group shared phenotypic traits with the V2 group and was only detected in patients carrying the E200K-129M haplotype in association with a PrPSc type of intermediate size ("i") between type 1 and type 2. Additional mutation-specific effects involved the pattern of PrP deposition (e.g., a "thickened" synaptic pattern in E200K carriers, cerebellar "stripe-like linear granular deposits" in those with insertion mutations, and intraneuronal globular dots in E200K-V2 or -M"i"). A few isolated cases linked to rare PRNP haplotypes (e.g., T183A-129M), showed atypical phenotypic features, which prevented their classification into the six major groups. The phenotypic variability of gCJD is mostly consistent with that previously found in sCJD. As in sCJD, the codon 129 genotype and physicochemical properties of PrPSc significantly correlated with the phenotypic variability of gCJD. The most common mutations linked to CJD appear to have a variable and overall less significant effect on the disease phenotype, but they significantly influence disease susceptibility often in a strain-specific manner. The criteria currently used for sCJD subtypes can be expanded and adapted to gCJD to provide an updated classification of the disease with a molecular basis.