Neurofilaments in blood and CSF for diagnosis and prediction of onset in Creutzfeldt-Jakob disease

While cerebrospinal fluid (CSF) biomarkers for Creutzfeldt-Jakob disease (CJD) are established and partly included in the diagnostic criteria, no blood biomarkers are available. Here, we assessed the utility of serum neurofilament light chain (NF-L) and tau protein in comparison to CSF markers (NF-L and phosphorylated NF heavy chain (pNF-H), tau, S100B, 14-3-3) and prion conversion assay (realtime quaking induced conversion (RT-QuIC)) for sporadic and genetic CJD. Importantly, a Gerstmann-Straussler-Scheinker mutation carrier in the asymptomatic phase and at disease onset was included as well. Both NF-L and tau were markedly increased in CJD serum, reaching similar or even better performance as in CSF (sensitivity and specificity for serum NF-L 100% and 85.5%, and for serum tau 84.6% and 96.2%, respectively). Serum S100B showed high sensitivity as well (84.2%), but lower specificity (63%). CSF neurofilaments were increased before symptom onset, while prion seeding assay was negative. Just before a clinical diagnosis could be made, all CSF markers and NF-L in the serum were increased and CSF prion conversion assay was positive. The data suggest that neurofilaments are sensitive and specific blood markers for the diagnosis of genetic and sporadic CJD and might represent promising tools to predict disease onset

Cerebrospinal fluid biomarker supported diagnosis of Creutzfeldt-Jakob disease and rapid dementias: a longitudinal multicentre study over 10 years

To date, cerebrospinal fluid analysis, particularly protein 14-3-3 testing, presents an important approach in the identification of Creutzfeldt-Jakob disease cases. However, one special point of criticism of 14-3-3 testing is the specificity in the differential diagnosis of rapid dementia. The constant observation of increased cerebrospinal fluid referrals in the national surveillance centres over the last years raises the concern of declining specificity due to higher number of cerebrospinal fluid tests performed in various neurological conditions. Within the framework of a European Community supported longitudinal multicentre study (‘cerebrospinal fluid markers') we analysed the spectrum of rapid progressive dementia diagnoses, their potential influence on 14-3-3 specificity as well as results of other dementia markers (tau, phosphorylated tau and amyloid-β1-42) and evaluated the specificity of 14-3-3 in Creutzfeldt-Jakob disease diagnosis for the years 1998-2008. A total of 29 022 cerebrospinal fluid samples were analysed for 14-3-3 protein and other cerebrospinal fluid dementia markers in patients with rapid dementia and suspected Creutzfeldt-Jakob disease in the participating centres. In 10 731 patients a definite diagnosis could be obtained. Protein 14-3-3 specificity was analysed for Creutzfeldt-Jakob disease with respect to increasing cerebrospinal fluid tests per year and spectrum of differential diagnosis. Ring trials were performed to ensure the comparability between centres during the reported time period. Protein 14-3-3 test specificity remained high and stable in the diagnosis of Creutzfeldt-Jakob disease during the observed time period across centres (total specificity 92%; when compared with patients with definite diagnoses only: specificity 90%). However, test specificity varied with respect to differential diagnosis. A high 14-3-3 specificity was obtained in differentiation to other neurodegenerative diseases (95-97%) and non-neurological conditions (91-97%). We observed lower specificity in the differential diagnoses of acute neurological diseases (82-87%). A marked and constant increase in cerebrospinal fluid test referrals per year in all centres did not influence 14-3-3 test specificity and no change in spectrum of differential diagnosis was observed. Cerebrospinal fluid protein 14-3-3 detection remains an important test in the diagnosis of Creutzfeldt-Jakob disease. Due to a loss in specificity in acute neurological events, the interpretation of positive 14-3-3 results needs to be performed in the clinical context. The spectrum of differential diagnosis of rapid progressive dementia varied from neurodegenerative dementias to dementia due to acute neurological conditions such as inflammatory diseases and non-neurological origi

Cerebrospinal fluid biomarker supported diagnosis of Creutzfeldt-Jakob disease and rapid dementias:a longitudinal multicentre study over 10 years

To date, cerebrospinal fluid analysis, particularly protein 14-3-3 testing, presents an important approach in the identification of Creutzfeldt–Jakob disease cases. However, one special point of criticism of 14-3-3 testing is the specificity in the differential diagnosis of rapid dementia. The constant observation of increased cerebrospinal fluid referrals in the national surveillance centres over the last years raises the concern of declining specificity due to higher number of cerebrospinal fluid tests performed in various neurological conditions. Within the framework of a European Community supported longitudinal multicentre study (‘cerebrospinal fluid markers’) we analysed the spectrum of rapid progressive dementia diagnoses, their potential influence on 14-3-3 specificity as well as results of other dementia markers (tau, phosphorylated tau and amyloid-b1–42) and evaluated the specificity of 14-3-3 in Creutzfeldt–Jakob disease diagnosis for the years 1998–2008. A total of 29 022 cerebrospinal fluid samples were analysed for 14-3-3 protein and other cerebrospinal fluid dementia markers in patients with rapid dementia and suspected Creutzfeldt–Jakob disease in the participating centres. In 10 731 patients a definite diagnosis could be obtained. Protein 14-3-3 specificity was analysed for Creutzfeldt–Jakob disease with respect to increasing cerebrospinal fluid tests per year and spectrum of differential diagnosis. Ring trials were performed to ensure the comparability between centres during the reported time period. Protein 14-3-3 test specificity remained high and stable in the diagnosis of Creutzfeldt–Jakob disease during the observed time period across centres (total specificity 92%; when compared with patients with definite diagnoses only: specificity 90%). However, test specificity varied with respect to differential diagnosis. A high 14-3-3 specificity was obtained in differentiation to other neurodegenerative diseases (95–97%) and non-neurological conditions (91–97%). We observed lower specificity in the differential diagnoses of acute neurological diseases (82–87%). A marked and constant increase in cerebrospinal fluid test referrals per year in all centres did not influence 14-3-3 test specificity and no change in spectrum of differential diagnosis was observed. Cerebrospinal fluid protein 14-3-3 detection remains an important test in the diagnosis of Creutzfeldt–Jakob disease. Due to a loss in specificity in acute neurological events, the interpretation of positive 14-3-3 results needs to be performed in the clinical context. The spectrum of differential diagnosis of rapid progressive dementia varied from neurodegenerative dementias to dementia due to acute neurological conditions such as inflammatory diseases and non-neurological origin.peerReviewe

Silver and Palladium Complexes Containing Ditopic N-Heterocyclic Carbene-Thione Ligands

The mixed donor N-heterocyclic carbene (NHC)/thione ligand precursors [1-(3-R-2H-imidazol-1-yl-2-thione)methyl-3-R-2H-imidazol-2-ium]X, [HCSR]X (R = methyl, benzyl; X = Br, I), have been utilized to prepare a range of silver and palladium complexes. The coordination of CSR to silver(I) salts has been explored, providing dimeric complexes of the type [AgX(CSR)]2 (where R = methyl, benzyl; X = Br, I). Structural characterization of [AgX(CSBn)]2 revealed a bidentate coordination mode for the mixed donor ligand and dinuclear structures where the silver centers are bridged by two bromido centers. Palladium complexes bearing one or two CSR ligands have additionally been prepared either directly, utilizing [Pd(OAc)2] as precursor, or via transmetalation strategies. The dicationic complexes [Pd(CSR)2][X]2 and neutral complexes [PdX2(CSR)] (where R = methyl, benzyl; X = Br, I, PF6) have been synthesized and fully characterized. The CSR ligand in the aforementioned complexes does not undergo transformation of the NHC unit to a urea function, which had been found to occur in the previously reported copper complexes. Palladium complexes containing both NHC/thione and bis-phosphine ligands were also prepared. Complexes of the type [Pd(CSMe)(L2)][X]2 and [PdX(CSMe)(L2)][X] (where L2 = dppe, dppp; X = Br, OAc, I, PF6) were obtained. The presence of the bis-phosphine appears to destabilize the coordination of the NHC/thione ligand and as a consequence leads to its elimination from the complex

Silver and Palladium Complexes Containing Ditopic N‑Heterocyclic Carbene–Thione Ligands

The mixed donor N-heterocyclic carbene (NHC)/thione ligand precursors [1-(3-R-2<i>H</i>-imidazol-1-yl-2-thione)­methyl-3-R-2<i>H</i>-imidazol-2-ium]­X, [H<b>CS</b>^<b>R</b>]­X (R = methyl, benzyl; X = Br, I), have been utilized to prepare a range of silver and palladium complexes. The coordination of <b>CS</b>^<b>R</b> to silver­(I) salts has been explored, providing dimeric complexes of the type [AgX­(<b>CS</b>^<b>R</b>)]₂ (where R = methyl, benzyl; X = Br, I). Structural characterization of [AgX­(<b>CS</b>^<b>Bn</b>)]₂ revealed a bidentate coordination mode for the mixed donor ligand and dinuclear structures where the silver centers are bridged by two bromido centers. Palladium complexes bearing one or two <b>CS</b>^<b>R</b> ligands have additionally been prepared either directly, utilizing [Pd­(OAc)₂] as precursor, or via transmetalation strategies. The dicationic complexes [Pd­(<b>CS</b>^<b>R</b>)₂]­[X]₂ and neutral complexes [PdX₂(<b>CS</b>^<b>R</b>)] (where R = methyl, benzyl; X = Br, I, PF₆) have been synthesized and fully characterized. The <b>CS</b>^<b>R</b> ligand in the aforementioned complexes does not undergo transformation of the NHC unit to a urea function, which had been found to occur in the previously reported copper complexes. Palladium complexes containing both NHC/thione and bis-phosphine ligands were also prepared. Complexes of the type [Pd­(<b>CS</b>^<b>Me</b>)­(L₂)]­[X]₂ and [PdX­(<b>CS</b>^<b>Me</b>)­(L₂)]­[X] (where L₂ = dppe, dppp; X = Br, OAc, I, PF₆) were obtained. The presence of the bis-phosphine appears to destabilize the coordination of the NHC/thione ligand and as a consequence leads to its elimination from the complex