CD4+CD25+ regulatory T cells (TREG) in systemic lupus erythematosus (SLE) patients: the possible influence of treatment with corticosteroids.

Systemic Lupus Erythematosus (SLE) is a chronic, systemic autoimmune disease characterized by loss of tolerance to self-antigens. Regulatory T cells (T(REG)) are those CD4+ T cells that constitutively express high levels of CD25 and exhibit powerful suppressive properties. The aim of this work was to quantify CD4+CD25+ (T(REG)) cells and the Mean Fluorescence Index (MFI) of T(REG) in the peripheral blood of patients with SLE and to correlate these findings with their disease activity scores and drug therapy. This study included 24 SLE patients with various disease activity scores (SLEDAI) and 24 healthy age and sex matched controls. Flow cytometry was used to examine the frequency of CD4+CD25+ T cells and the MFI of CD4+CD25+(high) T cells (T(REG)). CD4+CD25+ T cells % and MFI of CD4+CD25+(high) T cells were higher in SLE patients than controls (p value=0.62 and=0.037 respectively) and both CD4+CD25+ T cell % and the MFI of CD4+CD25+(high) T cells showed highly significant correlation with SLEDAI scores (both with a p value<0.001) and were higher in patients taking glucocorticoids than those not on glucocorticoids (p= 0.023, 0.048 respectively). We conclude that the increase in T(REG) cells in our patients may be due to corticosteroid treatment.