Analysis of Prion Strains by PrP(Sc) Profiling in Sporadic Creutzfeldt–Jakob Disease

BACKGROUND: Prion diseases are a group of invariably fatal neurodegenerative disorders affecting humans and a wide range of mammals. An essential part of the infectious agent, termed the prion, is composed of an abnormal isoform (PrP(Sc)) of a host-encoded normal cellular protein (PrP(C)). The conversion of PrP(C) to PrP(Sc) is thought to play a crucial role in the development of prion diseases and leads to PrP(Sc) deposition, mainly in the central nervous system. Sporadic Creutzfeldt–Jakob disease (sCJD), the most common form of human prion disease, presents with a marked clinical heterogeneity. This diversity is accompanied by a molecular signature which can be defined by histological, biochemical, and genetic means. The molecular classification of sCJD is an important tool to aid in the understanding of underlying disease mechanisms and the development of therapy protocols. Comparability of classifications is hampered by disparity of applied methods and inter-observer variability. METHODS AND FINDINGS: To overcome these difficulties, we developed a new quantification protocol for PrP(Sc) by using internal standards on each Western blot, which allows for generation and direct comparison of individual PrP(Sc) profiles. By studying PrP(Sc) profiles and PrP(Sc) type expression within nine defined central nervous system areas of 50 patients with sCJD, we were able to show distinct PrP(Sc) distribution patterns in diverse subtypes of sCJD. Furthermore, we were able to demonstrate the co-existence of more than one PrP(Sc) type in individuals with sCJD in about 20% of all patients and in more than 50% of patients heterozygous for a polymorphism on codon 129 of the gene encoding the prion protein (PRNP). CONCLUSION: PrP(Sc) profiling represents a valuable tool for the molecular classification of human prion diseases and has important implications for their diagnosis by brain biopsy. Our results show that the co-existence of more than one PrP(Sc) type might be influenced by genetic and brain region–specific determinants. These findings provide valuable insights into the generation of distinct PrP(Sc) types

Histological Analysis of Central-Nervous-System Sections in One Patient with sCJD with Co-Occurrence of Multiple PrP^Sc Types

<p>H&E-stained (A and B) and PrP-immunostained (C and D) cortical areas showing pronounced spongiosis and deposition of PrP^Sc in a plaque-like (C; PrP^Sc type 2, see <a href="http://www.plosmedicine.org/article/info:doi/10.1371/journal.pmed.0030014#pmed-0030014-g002" target="_blank">Figure 2</a>, frontal area on the lower panel) and synaptic (D; PrP^Sc type 1, see <a href="http://www.plosmedicine.org/article/info:doi/10.1371/journal.pmed.0030014#pmed-0030014-g002" target="_blank">Figure 2</a>, occipital area on the lower panel) pattern.</p

Comparison of PrP^Sc Profiles to Lesion Profiles

<div><p>(A) Schematic drawing indicating sampled areas which are used for the generation of PrP^Sc profiles (red boxes).</p> <p>(B) Biochemical PrP^Sc profiles are indicated in the upper panel, whereas histological lesion profiles are shown in the lower panel. Patients were grouped according to [<a href="http://www.plosmedicine.org/article/info:doi/10.1371/journal.pmed.0030014#pmed-0030014-b012" target="_blank">12</a>] in MM1, MV1, MV2, and VV2. Brain regions are shown on the <i>x</i>-axis. Values for PrP^Sc amounts are given in arbitrary units measured in relation to the PrP^Sc standard. Values for lesion profiles were obtained by averaging the scores for spongiosis (scored on a scale from 0–4), astrogliosis, and PrP immunoreactivity (both scored on a scale from 0–3). Black dots represent individual patients and black lines within boxes represent medians; boxes encompass 25th and 75th percentiles of distribution. One outlier (denoted by asterisk: MV2, cerebellum, PrP^Sc content = 84.1) has been omitted in the graphical representation.</p></div

Antibody-Mediated Status Epilepticus: A Retrospective Multicenter Survey

Background: In recent years, an increasing number of autoantibodies (AB) have been detected in the CSF and serum of patients with new onset epilepsy. Some of these patients develop convulsive or nonconvulsive status epilepticus (ABSE), necessitating intensive medical care and administration of multiple antiepileptic and immunomodulatory treatments of uncertain effectiveness. Objectives: In this retrospective multicenter survey we aimed to determine the spectrum of gravity, the duration and the prognosis of the disorder. In addition, we sought to identify the antibodies associated with this condition, as well as determine whether there is a most effective treatment regime. Methods: 12 European Neurology University Clinics, with extensive experience in the treatment of SE patients, were sent a detailed questionnaire regarding symptoms and treatment of AB-SE patients. Seven centers responded positively, providing a total of 13 patients above the age of 16. Results: AB-SE affects mainly women (12/13, 92%) with a variable age at onset (17– 69 years, median: 25 years). The duration of the disease is also variable (10 days to 12 years, median: 2 months). Only the 3 oldest patients died (55–69 years). Most patients were diagnosed with anti NMDAR encephalitis (8/13) and had oligoclonal bands in the CSF (9/13). No specific treatment regimen (antiepileptic, immunomodulatory) was found to be clearly superior. Most of the surviving 10 patients (77%) recovered completely or nearly so within 2 years of index poststatus. Conclusion: AB-SE is a severe but potentially reversible condition. Long duration does not seem to imply fatal outcome; however, age older than 50 years at time of onset appears to be a risk factor for death. There was no evidence for an optimal antiepileptic or immunomodulatory treatment. A prospective multicenter study is warranted in order to stratify the optimal treatment algorithm, determine clear risk factors of unfavorable outcome and long-term prognosis

Antibody-mediated status epilepticus: a retrospective multicenter survey

Background: In recent years, an increasing number of auto-antibodies (AB) have been detected in the CSF and serum of patients with new onset epilepsy. Some of these patients develop convulsive or nonconvulsive status epilepticus (AB-SE), necessitating intensive medical care and administration of multiple antiepileptic and immunomodulatory treatments of uncertain effectiveness. Objectives: In this retrospective multicenter survey we aimed to determine the spectrum of gravity, the duration and the prognosis of the disorder. In addition, we sought to identify the antibodies associated with this condition, as well as determine whether there is a most effective treatment regime. Methods: 12 European Neurology University Clinics, with extensive experience in the treatment of SE patients, were sent a detailed questionnaire regarding symptoms and treatment of AB-SE patients. Seven centers responded positively, providing a total of 13 patients above the age of 16. Results: AB-SE affects mainly women (12/13, 92%) with a variable age at onset (17-69 years, median: 25 years). The duration of the disease is also variable (10 days to 12 years, median: 2 months). Only the 3 oldest patients died (55-69 years). Most patients were diagnosed with anti NMDAR encephalitis (8/13) and had oligoclonal bands in the CSF (9/13). No specific treatment regimen (antiepileptic, immunomodulatory) was found to be clearly superior. Most of the surviving 10 patients (77%) recovered completely or nearly so within 2 years of index poststatus. Conclusion: AB-SE is a severe but potentially reversible condition. Long duration does not seem to imply fatal outcome; however, age older than 50 years at time of onset appears to be a risk factor for death. There was no evidence for an optimal antiepileptic or immunomodulatory treatment. A prospective multicenter study is warranted in order to stratify the optimal treatment algorithm, determine clear risk factors of unfavorable outcome and long-term prognosis