Our finding of an elevated anti-EBNA1 IgG titre in patients with MS is consistent with previous reports.25–27 We also observed an inverse correlation between the anti-EBNA1 IgG titre and the anti-LCL T cell frequency, suggesting that the elevated anti-EBNA1 IgG titre might be a consequence of decreased CD8+ T cell immunity to EBV. Here, CD8A is linked to myeloid sarcoma.