Recovery of CD4⁺CD25^bright T-cell frequency after ASCT. The relative number of CD4⁺CD25^bright T cells in 25 healthy controls, 8 systemic JIA patients on conventional therapy (syst-co), and 12 children who received ASCT for refractory JIA was measured by FACS staining. The patient represented by open triangles suffered a complete relapse 6 months after ASCT. Since it has been shown that the regulatory CD4⁺ T cells preferentially reside within the CD4⁺CD25^bright population, only the CD4⁺CD25^bright T cells and not the CD4⁺CD25 total T cells were analyzed. ^*P < .05; ^**P = .06. The dotplots show a representative example of the increase in CD4⁺CD25^bright T cells after ASCT (A). Mean and SEM of the absolute CD4⁺ T-cell counts per microliter in 12 children before and after ASCT for refractory JIA. For comparison, mean CD4⁺ T-cell count in healthy children of the same age: 1.0 × 10⁹/L (1000/μL); range, 0.3-2.0 × 10⁹/L (300-2000/μL) (B).¹