Search

Background: Neurofilament light chains (NfL) are cytoskeletal biomarkers of axonal damage, about 40-fold higher in cerebrospinal fluid (CSF) compared to serum, and requiring ultrasensitive techniques to be measured in this latter fluid., Objectives: To compare CSF and serum NfL levels in multiple sclerosis (MS) patients using different platforms., Methods: 60 newly diagnosed relapsing-remitting MS patients (38 females; median age: 36.5 years, range: 15-60) were enrolled before steroid or disease-modifying treatments. CSF and serum NfL were measured with: the commercial Ella™ microfluidic platform (Bio-Techne), the Lumipulse™ Chemiluminescent Enzyme ImmunoAssay (Fujirebio), and the SIMOA™ on the SR-X instrument using NF-light assays (Quanterix)., Results: CSF and serum NfL absolute levels strongly correlated between assays, although being more elevated with Ella™. Passing-Bablok regression showed high agreement in measuring CSF NfL between assays (with greater proportional difference using Ella™), and very high agreement for serum comparing SIMOA™ and Lumipulse™. Similarly, the Bland-Altman comparison evidenced lower biases for Lumipulse™ for both fluids., Conclusions: CSF and serum NfL in naïve MS patients are reliably measured with all assays. Although not interchangeable, SIMOA™ and Lumipulse™ showed high agreement for serum and CSF values., Competing Interests: Declaration of competing interest Conflicts of interest/Competing interests: none for all authors for this work; Ethics approval: local Ethical Committee approvals (Comitato Etico Interaziendale AOU "Maggiore della Carità" di Novara, ASL BI, ASL NO, ASL VCO): CE 060/2022 and 260/2022). Consent to participate/consent for publication: written consent obtained from all participants; Availability of data and material: data available on request., (Copyright © 2023. Published by Elsevier B.V.)

Background: The earliest detection of progressive multifocal leukoencephalopathy (PML) is crucial in Natalizumab (NTZ)-treated Multiple Sclerosis (MS) patients. This study aims to assess serum Neurofilaments (sNFL) ability to early detect PML in longitudinal patients' follow-up., Methods: NFL were retrospectively measured in four PML cases occurred at the Regional Referring Center for MS (CRESM, Italy), in samples collected since one year before PML diagnosis, at PML diagnosis, during PML and in post-PML follow-up. sNFL levels were interpreted according to previously defined reference values. Clinical examination and EDSS were performed at each NTZ infusion. Routinary MRI was undertaken every six months; after PML diagnosis, MRI was performed according to clinical evaluation. sNFL were also measured in 45 NTZ-treated patients experiencing NEDA-3 status for at least 12 months., Results: Patients showed different PML onsets and manifestations: in 3 patients routinary brain MRI revealed radiological signs of PML preceding different clinical manifestations, while in one patient brain MRI was performed after the clinical onset. PML diagnosis was defined at the time of the first detection of JCV DNA in cerebrospinal fluid. The following different PML phases were considered: 1. Basal (up to 4 months before PML diagnosis): sNFL values were in the normal range in all patients' samples, except for one (median 9.1 pg/ml, range 6.2-15.1 pg/ml) 2. Pre-PML (within 3 months before PML diagnosis): sNFL were elevated in all available samples (median 19.50 pg/ml, range 15.50-33.80 pg/ml). 3. PML diagnosis: sNFL were elevated in all patients (median 59.20 pg/ml, range 11.1-101.50 pg/ml). 4. PML/IRIS: during this phase, sNFL levels reached their peak (median 96.35 pg/ml, range 20.5-272.9) in all patients. 5. Post-PML (recovery phase, starting from the first MRI without enhancement, up to the end of follow-up): sNFL levels showed a decrease (median 12.80 pg/ml, range 9.30-30.60); however, based on reference values, sNFL were still elevated in 2 out of 4 patients at the end of their follow-up (622 and 887 days after PML diagnosis). sNFL were always elevated when MRI scan suggested a suspicious of PML. In NEDA-3 patients, sNFL levels were in the normal range in all patients' samples (median 4.7 pg/ml, range 1.4-8.6 pg/ml)., Conclusion: Elevated sNFL were observed not only at PML diagnosis, but also in pre-PML phase. At PML recovery, sNFL weren't normalized in all patients' samples, suggesting ongoing neuronal degeneration. sNFL represent a reliable biomarker and should be introduced in clinical practice as an additional/alternative parameter to MRI to early detect and monitor PML., Competing Interests: Declaration of Competing Interest Valentino Paola received speaker honoraria from Roche, research support from Merck and grant support from Quanterix. Malucchi Simona received speaker honoraria from Biogen and Roche. Bava Cecilia Irene: nothing to discose Martire Serena: nothing to discose Capobianco Marco served on the scientific advisory board of Biogen, Sanofi Genzyme, Novartis, Roche, Becton-Dickinson, Alexion and Horizon and received speaker honoraria from Almirall, Biogen, Novartis, Sanofi Genzyme. Malentacchi Maria: nothing to discose Sperli Francesca: nothing to discose Oggero Alessandra: nothing to discose Di Sapio Alessia received personal compensation for speaking and consulting by Biogen, Novartis, Roche, Sanofi and Alexion and has been reimbursed by Merck, Biogen, Genzyme and Roche for attending several conferences. Bertolotto Antonio served on the scientific advisory board of Almirall, Bayer, Biogen, and Genzyme; received speaker honoraria from Biogen, Novartis and Sanofi and grant support from Almiral, Biogen, Associazione San Luigi Gonzaga ONLUS, Fondazione per la Ricerca Biomedica ONLUS, Mylan, Novartis and the Italian Multiple sclerosis Society., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Introduction: Extended interval dosing (EID) of Natalizumab (NAT) has been proposed to reduce progressive multifocal leukoencephalopathy (PML) risk associated with standard interval dosing (SID) in people with multiple sclerosis (MS). Previous studies have suggested that NAT effectiveness is maintained in the great majority of patients who switch from SID to EID; monitoring of disease activity is currently based exclusively on clinical and MRI parameters. Frequent MRI are expensive and not always applicable, underlining the need for biological markers able to detect central nervous system lesions. Serum Neurofilament-light chain (sNFL) currently represents the most promising biomarker of disease activity, prognosis and treatment response in MS, and their clinical suitability is increasingly evident. The objective of the present study is to assess the applicability of sNFL as additional/alternative measure of treatment efficacy during EID regimen., Methods: We measured sNFL by Simoa technology in longitudinal samples from 63 Relapsing Remitting (RR) MS patients switched from SID to EID., Inclusion Criteria: diagnosis of RRMS, age 18-60 years; NAT SID for at least 12 months; NEDA-3 (no evidence of disease activity) for at least 12 months; availability of at least 2 serum samples collected 6 months apart. Patients' follow-up time during EID was at least 12 months and 2 blood samples were collected after at least 6 and 12 months. Clinical examination was performed before each infusion, while MRI 6 and 12 months after NAT initiation and according to PML risk during the whole study., Results: No patients showed clinical or MRI activity during the whole follow-up. sNFL levels measured during SID and EID were comparable, without significant difference between groups. The effect of EID on NFL levels did not show significant effects (LMM, p> 0.05) and sNFL levels did not vary with time during SID or EID protocols (LMM, p> 0.05). Intra-individual sNFL levels demonstrated overall stability during SID and EID (median CV=11% between SID and EID samples). According to our previously published reference values, sNFL levels were in the normal range in all samples, both during SID and EID., Conclusions: Our results suggest that sNFL quantification can be used as an alternative/additional approach to MRI in managing individual patients. The present work provides a new clinical application of sNFL to monitor NAT efficacy., Competing Interests: Declaration of Competing Interest Valentino Paola received speaker honoraria from Biogen, Novartis and Roche, research support from Merck and grant support from Quanterix. Malucchi Simona received speaker honoraria from Biogen. Martire Serena received speaker honoraria from Biogen and Novartis and served on the advisory boards of Biogen and Novartis Bava Cecilia Irene: nothing to discose Capobianco Marco served on the scientific advisory board of Biogen, Sanofi Genzyme, Novartis, and Bayer Schering and received speaker honoraria from Almirall, Biogen, Novartis, Sanofi Genzyme, and Teva. Bertolotto Antonio served on the scientific advisory board of Almirall, Bayer, Biogen, and Genzyme; received speaker honoraria from Biogen, Novartis and Sanofi and grant support from Almiral, Biogen, Associazione San Luigi Gonzaga ONLUS, Fondazione per la Ricerca Biomedica ONLUS, Mylan, Novartis and the Italian Multiple sclerosis Society., (Copyright © 2022. Published by Elsevier B.V.)

Background: Serum Neurofilament Light (sNFL) is the most promising marker for patient's monitoring in Multiple Sclerosis (MS). However, operating reference values for use in clinical practice are still lacking. Here, we defined sNFL reference cut-off values in a cohort of healthy controls (HC) and assessed their performance in Multiple Sclerosis (MS) patients, as well as the intra-individual sNFL variability., Methods: We measured sNFL by single molecule array (Simoa) assay in 79 HC assessing their correlation with age. Changes of sNFL levels were evaluated during a short-term follow-up (median 67 days between consecutive samples) in a subgroup of 27 participants. sNFL were tested in 23 untreated MS patients, at both diagnostic time and start of therapy (median 80 days after), considering disease activity., Results: Findings confirmed a correlation between sNFL levels and age in HC, thus cut-off values specific for age decades were calculated. sNFL did not vary significantly with time during short-term follow-up (median CV 13%). sNFL levels in MS patients were higher and demonstrated a higher variability between diagnostic time and treatment start (median CV 39%). According to cut-off values, "pathologic" sNFL levels were found in 57% of MS patients at diagnostic time, and in 30% of samples at treatment start. In particular, "pathologic" sNFL levels were found in 80% of samples (16/20) obtained during a phase of disease activity, while a total of 85% of samples (22/26) associated with inactive disease showed sNFL in the normal range., Conclusion: This study demonstrates an overall intra-individual stability of sNFL values in the short-term in HC and suggests age-dependent reference cut-off values that could be beneficial for sNFL implementation in clinical practice., (Copyright © 2021 Elsevier B.V. All rights reserved.)