The frequency of IL-17+ CD4+ T cells correlates with disease activity. (a-c) Relation between SLEDAI score and the frequency (%) of (a) CD4+IL-17+ T cells, (b) CD4+IL-17+IFN-γ+ T cells and (d) CD4+IFN-γ+ T cells in patients with SLE (n = 25). (d) Dot plots showing the frequency of CD4+ T cells producing IL-17 and/or IFN-γ in a patients with SLE at the times of high and low disease activities (SLEDAI score, 16 and 6, respectively). Representative data from two patients with SLE. (e) The frequency of CD4+IL-17+ T cells in patients with (+, n = 11) and without (-, n = 14) lupus nephritis. Numbers in dot plots indicate the frequency of cells for each quadrant. Bars show the means.