CD8CD11a(high) cells decreased in multiple sclerosis but not in neuromyelitis Optica.

In order to clarify the immunological characteristics of multiple sclerosis (MS) and neuromyelitis optica (NMO), we analyzed CD3, CD4, CD8, CD20, CD4(+)CD25(+), CD4(+)CD29(+), and CD8(+)CD11a(high) cells in peripheral blood from patients with MS (16 stable, 6 active) and NMO (15 stable, 7 active), as well as 9 with NMO spectrum, 6 with clinically isolated syndrome (CIS), and 13 with other neurological diseases using flow cytometry. Significant decreases in the numbers of CD8(+) CD11a(high) cells were observed in stable and active MS and CIS. Our findings indicate that CD8(+)CD11a(high) cells play different roles in MS and NMO, and their presence may be related to the pathogenesis of MS from the early stage.