Neurofilament light chain and MRI volume parameters as markers of neurodegeneration in multiple sclerosis.

BACKGROUND: Neurofilament light chain (NfL) is considered a major marker of neurodegeneration and disease activity. Higher levels of NfL are associated with worse clinical outcomes and increased brain atrophy. In treated patients with Relapsing-Remitting Multiple Sclerosis (RRMS), we aimed to determine the level of NfL, an association between NfL and demographic, clinical and magnetic resonance imaging (MRI) characteristics as well as brain volume parameters. We wanted to confirm that level of NfL is clinically useful as biomarker of neurodegeneration and disease activity. METHODS: 56 treated RRMS patients were enrolled. Plasmatic levels of NfL (pNfL) were measured by SIMOA® technique. Clinical severity of MS was expressed by Expanded Disability Status Scale (EDSS), and volumetric analysis of MRI data was performed using Icobrain software. RESULTS: The mean pNfL level was significantly higher in MS patients than in healthy controls (14.73 ± 6.38 versus 6.67 ± 3.9, p<0.001). In patients, we did not find association between pNfL and MRI activity, number of new T2 lesions, and number of enhancing lesions. Levels of pNfL correlated significantly with atrophy of whole brain volume (Wbv), atrophy of grey matter volume (Gmv), and negatively with Wbv. We found significantly positive correlation between pNfL levels and EDSS. CONCLUSION: Study shows association of pNfL with Wbv, presence of brain atrophy and EDSS, and strong correlation of EDSS with multiple MRI volume parameters. We did not confirm association pNfL with disease activity. Our data suggest that pNfL and MRI volume parameters could be considered as biomarkers of neurodegeneration in MS.

Oxidative stress in patients with newly diagnosed multiple sclerosis: any association with subclinical atherosclerosis?

OBJECTIVES: Multiple sclerosis (MS) is a chronic inflammatory autoimmune and neurodegenerative disease of the central nervous system (CNS) typically affecting young adults. Although the pathogenesis of MS is not fully understood, there is evidence to suggest that inflammation-induced oxidative stress can play a role in demyelination and axonal damage. Oxidative stress also participates in the pathogenesis of endothelial dysfunction and atherogenesis. Data from large epidemiological studies showed a higher risk of vascular events in MS patients. The aim of our study was to analyse the presence of oxidative stress and its association with the parameters of subclinical atherosclerosis in the early stages of MS. MATERIAL AND METHODS: We compared 13 newly diagnosed MS patients with a group of 13 healthy age- and BMI-matched controls. Blood samples were measured for total antioxidant activity using TEAC assay. Endothelial function, expressed as reperfusion hyperaemia index (RHI) and arterial stiffness, expressed as augmentation index standardized to a pulse of 75/min (AI@75) were assessed using peripheral arterial tonometry. RESULTS: MS patients had significantly lower TEAC compared to controls [0.8 (0.4-2.4) vs. 1.2 (0.6-3.8) mmol/l; p=0.004]. The frequency of increased arterial stiffness (61.6% vs. 30.8%) and endothelial dysfunction (46.2% vs. 38.5%) was comparable in MS patients and in controls. There was no significant association between TEAC, increased arterial stiffness or endothelial dysfunction in patients and controls. CONCLUSION: Our study showed decreased antioxidant capacity in newly diagnosed MS patients compared to controls. We failed to find association of subclinical atherosclerosis with oxidative stress in newly diagnosed MS.