Multiple sclerosis (MS) is a chronic inflammatory and neurodegenerative disease. Quantifying neuronal damage is a critical step for patient care. Neurofilament light chain (sNfL) and glial fibrillary acidic protein (sGFAP) are the most promising serum biomarkers reflecting neuronal damage and astroglial activation, respectively. This study analyzed sNfL and sGFAP in 177 MS patients and 71 healthy controls (HCs) using SIMOA technology, classifying patients as responders (Rs) or non-responders (NRs) based on “No Evidence of Disease Activity 3” (NEDA-3) status during two years of treatment. Longitudinal analyses were performed for Dimethyl fumarate (DMF) and Ocrelizumab (OCRE) treatment. Biomarker–age correlation analysis in HCs confirmed correlation between both NfL and GFAP, with age and cut-off values specific for age decades being calculated. Both biomarkers were higher in MS patients compared to HCs. sNfL showed a significant increase in NR patients overall. In contrast, sGFAP was elevated in the low-to-moderate-efficacy treatment agents (LETAs) NR group and also in the DMF NR subgroup, suggesting that it monitors persistent astrogliosis. Longitudinal analysis showed that both biomarkers decreased during DMF treatment after one year. During OCRE treatment, sNfL rapidly reduced to HC levels within one year, while sGFAP decreased only after two years. This highlights that OCRE acts differently on the pathological processes linked to the two biomarkers.

Epstein–Barr virus (EBV) is causally associated with various malignancies and autoimmune diseases. It establishes a lifelong latent infection in host B-lymphocytes, and can strategically manipulate host cell metabolism and cell-to-cell communication via extracellular particles (EPs). While EBV-induced changes in fatty acid and mevalonate pathways are documented, the role of the sphingolipid network in this process remains poorly understood. In this study, we characterized both the EP and the cellular sphingolipid signatures of three EBV-infected (EBV+) lymphoblastoid cell lines compared to three EBV-negative (EBV−) counterparts. Lipidomic analysis revealed a profound metabolic redirection in EBV+ cells, characterized by reduced ceramide and sphingomyelin levels, and a significant upregulation of glycosphingolipids (GSLs), particularly hexosylceramide and globotrialosylceramide. Furthermore, EBV+ cells released larger, more heterogeneous EPs that are significantly enriched in GSLs and in the viral non-coding RNA EBER1. Our findings suggest that EBV-induced reshaping of sphingolipid metabolism correlates with altered physical properties of the secretome, potentially contributing to viral pathogenesis and microenvironmental manipulation.