CD8A and myeloid sarcoma: To investigate whether MS patients are also hallmarked by an accumulation of high-level EBNA- and CNS-derived peptide-specific B cell and T cell responses, we then collected PBMCs of n = 20 MS patients and n = 80 healthy controls and quantified all EBNA- and CNS-specific CD19+ B cell, CD4+ T cell, and CD8+ T cell levels by flow cytometry.