Figure 2

Effect of Rituximab therapy on the levels of peripheral blood regulatory T cells. In 17 systemic lupus erythematosus patients that received Rituximab (0.5 to 1.0 g at days 0 and 15), the levels of (a) CD4+CD25^bright and (c) CD4+CTLA-4+ cells, and CD4+ lymphocytes synthesizing (b) TGF-β+ or (d) IL-10 was assessed in peripheral blood by flow cytometry before (day 0), and at days 30 and 90 of Rituximab therapy, as described in Materials and methods. The inset in (a) shows how the expression of CD25 by activated CD8+ cells (left histogram) was employed to define CD4+CD25^bright cells (right histogram). The arithmetic mean is indicated with a horizontal line, and the standard deviation with a vertical line. In all cases, the percentage of positive cells is referred to the gate of lymphocytes, defined by side and forward scatter characteristics.