RESUMO
Background: There is clear evidence that CD4+CD25[hl] naturally-occurring regulatory T cells [nTregs] are important component of the immune system in controlling tiutoimmunity. These cells exhibit powerful suppressive properties. Objectives: This study was conducted to determine [i] the percentage of CD4CD25[hl] nTregs in pediatric patients with systemic lupus erythematosus [SLE] before and after corticosieroid treatment, and [ii] the correlation between the percentage of nTregs and SLE disease activity index [SLEDAI]. Subjects and Methods: Thirty children with new-onset SLE were enrolled in this study. Patients were divided into 2 groups according to their disease activity. Further 24 children were included as a control group. Flow cytometric analysis was used for evaluation of the percentage of CD4+CD25[hl] nTregs in the peripheral blood of SLE patients, and control subjects
Results: A significant lower percentage ofCD4+CD25[hl] nTreg was detected in children with active SLE compared to those with inactive disease [0.59 +/- 0.27% versus 1.28 +/- 0.35%; p = 0.0001], and control subjects [0.59 +/- 0.27% versus 2.29 +/- 0.39%; p'= 0.0001]. A significant increase in the percentage of CD4+CD25[hl] nTregs was detected after corticosteroid therapy [p = 0.0001], but with no significant difference between patients with active and inactive disease [p >0.05]. Intriguingly, the percentage of nTregs was inversely correlated with SLEDAI [T = -0.6, p 0.001]. Conclusion: These results suggest that the quantitative defect of nTregs in pediatric patients with SLE may play a role in the patho genesis of this autoimmune disorder?