CD8A and myeloid sarcoma: Our specific aims were to determine: (1) whether the frequency of T cells specific for EBV infected B cells is increased or decreased in patients with MS; (2) whether EBV infected B cells of patients with MS can be killed by cytotoxic CD8+ T cells from HLA matched healthy subjects; (3) whether EBV specific CD8+ T cells generated in vitro from patients with MS can kill EBV infected B cells; and (4) whether there is a correlation between T cell and antibody immunity to EBV.