Cytokine Signatures Induced by Epstein-Barr Virus Antigens in Multiple Sclerosis: Elucidating the Role of B-Cell and T-Cell Hyperactivation in Disease Relapse

Objectives: To investigate the profile of Th1- and Th2-type cytokines in response to Epstein–Barr virus (EBV) antigens and to correlate this immune signature with clinical relapses in Multiple Sclerosis (MS). Specifically, we aimed to evaluate the cellular and humoral immune response following stimulation with a pool of lytic and latent EBV proteins. Methods: We employed ELISpot and ELISA to quantify Interferon-gamma (IFN-γ), Interleukin-18 (IL-18), Interleukin-10 (IL-10), and the B-cell activation marker soluble CD23 (sCD23). Measurements were performed on peripheral blood mononuclear cells (PBMCs) from MS patients and controls following stimulation with EBV peptide antigens. Results: MS patients exhibited significantly higher levels of all tested cytokines compared to controls. A statistically significant positive correlation was noted between IL-10 and sCD23 levels (p < 0.03), with significant correlations also found between IL-10 and IFN-γ (r = −0.56) and between IFN-γ and IL-18 (p < 0.02), a finding that warrants cautious interpretation. Crucially, both IL-10 and sCD23 levels strongly correlated with the Expanded Disability Status Scale (EDSS) score (p = 0.0003 and p = 0.0001, respectively). Conclusions: Our findings suggest a chronic, dysregulated immune response to EBV antigens in MS patients, characterized by the co-activation of inflammatory Th1 pathways and robust B-cell activation. These results support a pathogenetic model where the EBV-specific immune response, perpetuated by infected B-cells, may directly contribute to the immunopathological processes driving central nervous system (CNS) damage and clinical relapses.