Changes of frequency and expression level of CD161 in CD8+ T cells and natural killer T cells in peripheral blood of patients with systemic lupus erythematosus

Immunologic abnormalities of natural killer (NK) cells and T cells play a role in the pathogenesis of systemic lupus erythematosus (SLE). CD161 is expressed on most of the NK cells and on some T cells. The quantities of CD161‐expressing cells and expression levels of CD161 were analyzed in T cells and NK cells from patients with SLE compared with normal controls. The expression of CD161 on NK cells, NKT cells, CD4+ T cells, and CD8+ T cells in peripheral blood from patients with inactive SLE and active SLE, and from the normal controls group were determined using flow cytometry. The frequency and expression level of CD161 in the lymphocyte subsets and its relationship with the quantity of regulatory T cells, anti‐double stranded DNA antibody, and the titer of antinuclear antibody were evaluated. Both the percentages of the CD161+ subpopulation and the mean fluorescence intensities (MFIs) of CD161 in CD8+ T cells and NKT cells decreased significantly in SLE patients compared with normal controls (P