| 1. |
- Delcoigne, Bénédicte, et al.
(författare)
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Blood neurofilament light levels segregate treatment effects in multiple sclerosis
- 2020
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Ingår i: Neurology. - 1526-632X. ; 94
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Tidskriftsartikel (refereegranskat)abstract
- Copyright © 2020 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology. OBJECTIVE: To determine factors (including the role of specific disease modulatory treatments [DMTs]) associated with (1) baseline, (2) on-treatment, and (3) change (from treatment start to on-treatment assessment) in plasma neurofilament light chain (pNfL) concentrations in relapsing-remitting multiple sclerosis (RRMS). METHODS: Data including blood samples analyses and long-term clinical follow-up information for 1,261 Swedish patients with RRMS starting novel DMTs were analyzed using linear regressions to model pNfL and changes in pNfL concentrations as a function of clinical variables and DMTs (alemtuzumab, dimethyl fumarate, fingolimod, natalizumab, rituximab, and teriflunomide). RESULTS: The baseline pNfL concentration was positively associated with relapse rate, Expanded Disability Status Scale score, Age-Related MS Severity Score, and MS Impact Score (MSIS-29), and negatively associated with Symbol Digit Modalities Test performance and the number of previously used DMTs. All analyses, which used inverse propensity score weighting to correct for differences in baseline factors at DMT start, highlighted that both the reduction in pNfL concentration from baseline to on-treatment measurement and the on-treatment pNfL level differed across DMTs. Patients starting alemtuzumab displayed the highest reduction in pNfL concentration and lowest on-treatment pNfL concentrations, while those starting teriflunomide had the smallest decrease and highest on-treatment levels, but also starting from lower values. Both on-treatment pNfL and decrease in pNfL concentrations were highly dependent on baseline concentrations. CONCLUSION: Choice of DMT in RRMS is significantly associated with degree of reduction in pNfL, which supports a role for pNfL as a drug response marker.
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| 2. |
- Petzold, Axel, et al.
(författare)
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Neurofilament ELISA validation
- 2010
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Ingår i: JOURNAL OF IMMUNOLOGICAL METHODS. - 0022-1759. ; 352:1-2, s. 23-31
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Tidskriftsartikel (refereegranskat)
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| 3. |
- Petzold, Axel, et al.
(författare)
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Neurofilament ELISA validation
- 2010
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Ingår i: JIM - Journal of Immunological Methods. - : Elsevier BV. - 0022-1759 .- 1872-7905. ; 352:1-2, s. 23-31
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Neurofilament proteins (Nf) are highly specific biomarkers for neuronal death and axonal degeneration. As these markers become more widely used, an inter-laboratory validation study is required to identify assay criteria for high quality performance. METHODS: The UmanDiagnostics NF-light (R)enzyme-linked immunoabsorbent assays (ELISA) for the neurofilament light chain (NfL, 68kDa) was used to test the intra-assay and inter-laboratory coefficient of variation (CV) between 35 laboratories worldwide on 15 cerebrospinal fluid (CSF) samples. Critical factors, such as sample transport and storage, analytical delays, reaction temperature and time, the laboratories' accuracy and preparation of standards were documented and used for the statistical analyses. RESULTS: The intra-laboratory CV averaged 3.3% and the inter-laboratory CV 59%. The results from the test laboratories correlated with those from the reference laboratory (R=0.60, p<0.0001). Correcting for critical factors improved the strength of the correlation. Differences in the accuracy of standard preparation were identified as the most critical factor. Correcting for the error introduced by variation in the protein standards improved the correlation to R=0.98, p<0.0001 with an averaged inter-laboratory CV of 14%. The corrected overall inter-rater agreement was subtantial (0.6) according to Fleiss' multi-rater kappa and Gwet's AC1 statistics. CONCLUSION: This multi-center validation study identified the lack of preparation of accurate and consistent protein standards as the main reason for a poor inter-laboratory CV. This issue is also relevant to other protein biomarkers based on this type of assay and will need to be solved in order to achieve an acceptable level of analytical accuracy. The raw data of this study is available online.
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| 4. |
- Warnke, Clemens, et al.
(författare)
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Cerebrospinal Fluid JC Virus Antibody Index for Diagnosis of Natalizumab-Associated Progressive Multifocal Leukoencephalopathy
- 2014
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Ingår i: Annals of Neurology. - : Wiley. - 0364-5134 .- 1531-8249. ; 76:6, s. 792-801
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Progressive multifocal leukoencephalopathy (PML), caused by JC virus (JCV), can occur in patients receiving natalizumab for multiple sclerosis (MS). JCV detection by quantitative polymerase chain reaction (qPCR) in cerebrospinal fluid (CSF), or brain biopsy, is required for probable or definite diagnosis of PML. However, in some patients only low levels of JCV DNA (<100 copies/ml) are present in CSF, making the diagnosis challenging. Our objective was to assess the complementary value of a CSF JCV antibody index (AI(JCV)) in the diagnosis of natalizumab-associated PML.Methods: AI(JCV) was assessed in 37 cases of natalizumab-associated PML and 89 MS-patients treated with natalizumab without PML. Sera and CSF were tested in a capture enzyme-linked immunosorbent assay, using JCV-VP1 fused to glutathione S-transferase as antigen. Albumin levels and total immunoglobulin G concentration were determined by immunonephelometry, and the AI(JCV) was calculated as published.Results:Twenty-six of 37 (70%) patients with natalizumab-associated PML exhibited an AI(JCV) > 1.5, whereas this was seen in none of the controls (p < 0.0001). At time of the first positive qPCR for JCV DNA, 11 of 20 (55%) patients with natalizumab-associated PML had an AI(JCV) > 1.5. JCV DNA levels of <100 copies/ml were seen in 14 (70%) of these 20 patients, of whom 8 (57%) demonstrated an AI(JCV) > 1.5.Interpretation: Determination of the AI(JCV) could be an added tool in the diagnostic workup for PML and should be included in the case definition of natalizumab-associated PML. Ann Neurol 2014;76:792-801
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| 5. |
- Warnke, Clemens, et al.
(författare)
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Natalizumab exerts a suppressive effect on surrogates of B cell function in blood and CSF
- 2015
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Ingår i: Multiple Sclerosis Journal. - : Sage Publications. - 1352-4585 .- 1477-0970. ; 21:8, s. 1036-1044
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Tidskriftsartikel (refereegranskat)abstract
- Background: Natalizumab for multiple sclerosis (MS) increases the risk of progressive multifocal leukoencephalopathy (PML). Objective: We aimed to assess the effect of natalizumab on cellular composition and functional B cell parameters including patients with natalizumab-associated PML (n=37). Methods: Cellular composition by flow cytometry, levels of immunoglobulin (Ig)G/IgM by immunonephelometry, and oligoclonal bands by isoelectric focusing were studied in blood and cerebrospinal fluid. Results: In MS patients treated with natalizumab without PML (n=59) the proportion of CD19+ B cells was higher in blood, but lower in cerebrospinal fluid compared with MS patients not treated with natalizumab (n=17). The CD4/CD8-ratio in cerebrospinal fluid was lower, and IgG and IgM levels as well as the IgG index dropped in longitudinal samples during natalizumab therapy. Oligoclonal bands persisted, but the total amount of the intrathecally produced IgG fraction, and the polyclonal intrathecal IgG reactivity to measles, rubella, and zoster declined. At the time of diagnosis of PML patients with natalizumab-associated PML had low total IgG levels in blood and cerebrospinal fluid. Conclusions: Natalizumab impacts B and T cell distribution and exerts an inhibitory effect on surrogates of B cell function in periphery and in cerebrospinal fluid, potentially contributing to the increased risk of developing PML.
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