Quantification of regulatory T cells in patients with systemic lupus erythematosus

Abstract

CD4 +T cells that constitutively express CD25 exhibit powerful suppressive properties. Such cells have been denominated regulatory T cells (T R). Alterations in T Rcells 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 brightcells 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 +CD25 brightcells 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 Rnumber 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.