Quantification of regulatory T cells in patients with systemic lupus erythematosus

CD4(+) T cells that constitutively express CD25 exhibit powerful suppressive properties. Such cells have been denominated regulatory T cells (T-R). Alterations in TR cells are known to cause organ-specific autoimmune disease in animal models. The aim of this work was to quantify CD4(+)CD25(+) T cells in patients with systemic lupus erythematosus (SLE). Thirty untreated patients (ten with active disease) and ten healthy volunteers were studied. Flow cytometry was used to quantify cell populations. CD4(+)CD69(+), CD4(+)CD25(+) and CD4(+)CD25(bright) cells were considered. Peripheral blood mononuclear cell cultures were performed and supernatants collected for IL-10 and 12 measurement. CD4(+)CD25(+) cells were significantly decreased in patients with active disease when compared to control subjects and patients without disease activity (P<0.001). CD4(+)CD69(+) cells were increased in patients with active disease when compared to controls (P=0.041). Accordingly, CD4(+)CD25bright cells were decreased in patients with active disease compared to healthy subjects (P<0.001). IL-12 production was hampered in cells from patients during periods of active disease when compared to healthy controls and patients during remission (P<0.001). We observed a correlation between decreased T-R number and reduced IL-12 mononuclear cell production (r=0.362, P=0.05). This work demonstrates that CD4(+)CD25(+) T cells are decreased in patients with clinically active SLE. (C) 2003 Published by Elsevier Ltd.