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Background: Objective diagnostic biomarkers are needed to support a clinical diagnosis. Objectives: To analyze markers in various neurodegenerative disorders to identify diagnostic biomarker candidates for mainly α‐synuclein (aSyn)‐related disorders (ASRD) in serum and/or cerebrospinal fluid (CSF). Methods: Upon initial testing of commercially available kits or published protocols for the quantification of the candidate markers, assays for the following were selected: total and phosphorylated aSyn (pS129aSyn), neurofilament light chain (NfL), phosphorylated neurofilament heavy chain (pNfH), tau protein (tau), ubiquitin C‐terminal hydrolase L1 (UCHL‐1), glial fibrillary acidic protein (GFAP), calcium‐binding protein B (S100B), soluble triggering receptor expressed on myeloid cells 2 (sTREM‐2), and chitinase‐3‐like protein 1 (YKL‐40). The cohort comprised participants with Parkinson's disease (PD, n = 151), multiple system atrophy (MSA, n = 17), dementia with Lewy bodies (DLB, n = 45), tau protein‐related neurodegenerative disorders (n = 80, comprising patients with progressive supranuclear palsy (PSP, n = 38), corticobasal syndrome (CBS, n = 16), Alzheimer's disease (AD, n = 11), and frontotemporal degeneration/amyotrophic lateral sclerosis (FTD/ALS, n = 15), as well as healthy controls (HC, n = 20). Receiver operating curves (ROC) with area under the curves (AUC) are given for each marker. Results: CSF total aSyn was decreased. NfL, pNfH, UCHL‐1, GFAP, S100B, and sTREM‐2 were increased in patients with neurodegenerative disease versus HC (P < 0.05). As expected, some of the markers were highest in AD (i.e., UCHL‐1, GFAP, S100B, sTREM‐2, YKL‐40). Within ASRD, CSF NfL levels were higher in MSA than PD and DLB (P < 0.05). Comparing PD to HC, interesting serum markers were S100B (AUC: 0.86), sTREM2 (AUC: 0.87), and NfL (AUC: 0.78). CSF S100B and serum GFAP were highest in DLB. Conclusions: Levels of most marker candidates tested in serum and CSF significantly differed between disease groups and HC. In the stratification of PD versus other tau‐ or aSyn‐related conditions, CSF NfL levels best discriminated PD and MSA. CSF S100B and serum GFAP best discriminated PD and DLB. © 2021 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson Movement Disorder Society. [ABSTRACT FROM AUTHOR]

Background: The objective of this study was to assess neurofilament light chain as a Parkinson's disease biomarker. Methods: We quantified neurofilament light chain in 2 independent cohorts: (1) longitudinal cerebrospinal fluid samples from the longitudinal de novo Parkinson's disease cohort and (2) a large longitudinal cohort with serum samples from Parkinson's disease, other cognate/neurodegenerative disorders, healthy controls, prodromal conditions, and mutation carriers. Results: In the Parkinson's Progression Marker Initiative cohort, mean baseline serum neurofilament light chain was higher in Parkinson's disease patients (13 ± 7.2 pg/mL) than in controls (12 ± 6.7 pg/mL), P = 0.0336. Serum neurofilament light chain increased longitudinally in Parkinson's disease patients versus controls (P < 0.01). Motor scores were positively associated with neurofilament light chain, whereas some cognitive scores showed a negative association. Conclusions: Neurofilament light chain in serum samples is increased in Parkinson's disease patients versus healthy controls, increases over time and with age, and correlates with clinical measures of Parkinson's disease severity. Although the specificity of neurofilament light chain for Parkinson's disease is low, it is the first blood‐based biomarker candidate that could support disease stratification of Parkinson's disease versus other cognate/neurodegenerative disorders, track clinical progression, and possibly assess responsiveness to neuroprotective treatments. However, use of neurofilament light chain as a biomarker of response to neuroprotective interventions remains to be assessed. © 2020 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society. [ABSTRACT FROM AUTHOR]

α‐Synuclein is the major component of Lewy bodies and a candidate biomarker for neurodegenerative diseases in which Lewy bodies are common, including Parkinson's disease and dementia with Lewy bodies. A large body of literature suggests that these disorders are characterized by reduced concentrations of α‐synuclein in cerebrospinal fluid (CSF), with overlapping concentrations compared to healthy controls and variability across studies. Several reasons can account for this variability, including technical ones, such as inter‐assay and inter‐laboratory variation (reproducibility). We compared four immunochemical methods for the quantification of α‐synuclein concentration in 50 unique CSF samples. All methods were designed to capture most of the existing α‐synuclein forms in CSF ('total' α‐synuclein). Each of the four methods showed high analytical precision, excellent correlation between laboratories (R2 0.83–0.99), and good correlation with each other (R2 0.64–0.93), although the slopes of the regression lines were different between the four immunoassays. The use of common reference CSF samples decreased the differences in α‐synuclein concentration between detection methods and technologies. Pilot data on an immunoprecipitation mass spectrometry (IP‐MS) method is also presented. Our results suggest that the four immunochemical methods and the IP‐MS method measure similar forms of α‐synuclein and that a common reference material would allow harmonization of results between immunoassays. α‐Synuclein is a synaptic protein that forms intracellular Lewy body inclusions in Parkinson's disease and other so called synuclein aggregation disorders. There are several methods to measure α‐synuclein concentration in human cerebrospinal fluid, where it is a candidate diagnostic and prognostic biomarker. In the current paper, we compared the analytical characteristics of four immunochemical (MSD, BioLegnd, Adx, and Roche) and one mass spectrometry‐based method. Variance component analysis partitions the total variance associated with 49 sample measured by site, kit lot, and replicate. The results show that the different methods measure similar forms of α‐synuclein and that a common reference material would allow for assay harmonization, which will be important in studies evaluating drugs that target α‐synuclein pathology specifically. [ABSTRACT FROM AUTHOR]

Introduction Accurate diagnosis of prion diseases and discrimination from alternative dementias gain importance in the clinical routine, but partial overlap in cerebrospinal fluid (CSF) biomarkers impedes absolute discrimination in the differential diagnostic context. Methods We established the clinical parameters for prion disease diagnosis for the quantification of CSF α-synuclein in patients with sporadic ( n = 234) and genetic ( n = 56) prion diseases, in cases with cognitive impairment/dementia or neurodegenerative disease ( n = 278), and in the neurologic control group ( n = 111). Results An optimal cutoff value of 680 pg/mL α-synuclein results in 94% sensitivity and 96% specificity when diagnosing sporadic Creutzfeldt-Jakob disease (CJD). Genetic CJD cases showed increased CSF α-synuclein values. No increased α-synuclein levels were detected in non-CJD cases with rapid progression course. Discussion Detection of α-synuclein in the CSF of patients with suspected CJD is a valuable diagnostic test reaching almost full discrimination from non-prion disease cases. These data highlight the utility of CSF α-synuclein quantification in front of classical CSF biomarkers in clinical routine. [ABSTRACT FROM AUTHOR]

Background: Synthesis of clonal IgG is a consistent feature of patients with multiple sclerosis (MS). Whether oligoclonal bands (OCBs) represent unspecific disease bystanders or active components in MS pathology is an open question. The aim of this study was to develop a method to quantify and compare the reactivity of cerebrospinal fluid (CSF) antibodies from patients with and without MS. Methods: We collected CSF from 262 patients from two different cohorts, which included 148 patients with MS and 114 with other neurological diseases (OND). We established a highly sensitive electrochemiluminescence (ECL)-based assay to measure CSF antibody reactivity against purified myelin particles and biotin anchored liposomes. The diagnostic value of the ECL score against myelin particles was assessed with receiver operating characteristic curves. Results: CSF from patients with MS have higher reactivity toward purified myelin particles as compared to those with OND with OCBs. Using liposomes with defined lipid compositions and myelin particles from ceramide synthase 2 (CerS2) knockout mice, we find that some of the CSF antibody reactivity is directed against cerebrosides. Conclusion: The ECL-based assay system expands the currently available toolbox for the detection of autoantibodies in MS and related diseases. [ABSTRACT FROM AUTHOR]

Aims Natalizumab is a humanized monoclonal antibody specific for CD49d receptors of integrins. It inhibits the entry of inflammatory cells into the central nervous system and is approved for the treatment of relapsing-remitting multiple sclerosis ( MS). Several lines of evidence indicate an involvement of B cells and plasma cells in MS pathogenesis. However, treatment with the natalizumab analogon PS/2 immunoglobulin G ( IgG) has so far only been investigated in T cell-mediated animal models of MS. Due to the importance of B lineage cells in the pathogenesis of MS, the objective of the present study has thus been to analyse the effects of PS/2 IgG in a mouse model of MS with T and B cell cooperation ( OSE mice). Methods OSE mice were treated with the natalizumab analogon PS/2 IgG either at disease onset or after peak of disease. Treatment was also performed with PS/2 F(ab′)2 fragments. Results PS/2 IgG treatment improved the clinical outcome and decreased spinal cord demyelination and immune cell infiltration if given early in the disease course. Treatment increased blood leukocytes and resulted in a partial internalization of CD49d in T and B cells. The therapeutic effects of PS/2 IgG injections were independent of the Fc fragment as F(ab′)2 injections were equally beneficial. In contrast, PS/2 IgG was not effective when given late in the disease course. Conclusions Results indicate that natalizumab may also be beneficial in MS with B cell-driven immunopathogenesis. [ABSTRACT FROM AUTHOR]

Tumor necrosis factor (TNF)-α is a potent proinflammatory cytokine that is able to induce tissue destruction and bone resorption. A G-to-A polymorphism at the -308 position of the TNF-α promoter region was suggested to influence TNF-α production. We had previously shown that monocytes of patients with localized early-onset periodontitis (EOP) secrete high levels of TNF-α compared to matched controls. The aim of the present study was to investigate the possible link between the -308 polymorphism in the TN F-α gene and EOP. Genomic DNA was extracted from the blood of 64 individuals from 11 nuclear families with EOP. The TNF-α polymorphism at -308 was assessed using allele-specific polymerase chain reaction. 77% of the tested adolescents were found to have the G/G genotype, and 23% had the G/G genotype. in the diseased subjects. 81% were with G/G genotype and 19% with G/G genotype. The healthy children had 74% G/G genotype, while 26% had G/G genotype. The differences between the disease group and the healthy group were not statistically significant, in summary, the present results could not demonstrate any link between EOP and genetic polymorphism in the -308 position of the TNF-α promoter. [ABSTRACT FROM AUTHOR]