This double staining has never been associated with MS, but a reduction in the number of CD19/CD200 B lymphocytes has recently been described in the acute phase of severe alopecia areata, a hair follicle-specific Th1 cell-mediated autoimmune disease (Gilhar and Kalish, 2006; Ma et al., 2017). Here, CD19 is linked to myeloid sarcoma.