Figure 4.

The relationships between disease activity and the frequencies or relative ratios of regulatory T-cell (Treg) subsets and effector T cells (Teffs) in patients with systemic lupus erythematosus (SLE). (a) The ratios of different Treg subsets versus Teffs were negatively correlated with the titre of anti-double-stranded DNA immunoglobulin G (anti-dsDNA IgG) in patients with inactive SLE (n = 18). (b) The results are shown as the percentage of CD25^high Tregs, CD25^low Tregs, CD25⁻ Tregs and Teffs in healthy controls (n = 36); SLE patients exhibiting normal complement levels (Non-low C’) (n = 18); and SLE patients exhibiting low complement levels (Low C’) (n = 69). Lines within the vertical points mark the mean for each group. A P-value of<0·05 was considered as significant following analysis of the results using the Mann–Whitney U-test. *P <0·05 compared with normal subjects; δP <0·05 compared to SLE subjects with normal complement levels. See Fig. 1 for other definitions.