Our finding of an increase in the frequencyof CD8+ T cells binding the GLC-Dextramer derived from the lyticprotein BMLF1 during attacks confirms the results of Angelini etal.27 who found an increasedfrequency of CD8+ T cells binding HLA-class I pentamers of EBV lyticpeptides during the active phase of MS; however, by also examining cytokineproduction by these lytic-specific T cells we were able to show that their functionactually decreased during attacks whereas latent-specific T cells increased in bothnumber and polyfunctionality. This evidence concerns the gene CD8A and myeloid sarcoma.