CD40LG and myeloid sarcoma: Thus, the objectives of this study were (1) to evaluate the in vivo antiviral activity of teriflunomide in MS patients through the evaluation of the variation of IgG antibody titers against EBNA-1 and VCA of EBV and IgG and IgM against HHV-6 between the baseline visit (before treatment initiation) and after 6 months of treatment with teriflunomide (2), to associate the variation of these titers with the clinical and radiological response after 24 months of treatment with teriflunomide, and (3) to search for early response biomarkers to teriflunomide.