Frequency and Significance of CD4~+CD25~+T Cell Subpopulations in the Peripheral Blood of Patients with Systemic Lupus Erythematosus

Objective:To investigate the frequency and ratio of CD4+CD25+T cell subpopulations in the peripheral blood of patients with systemic lupus erythematosus(SLE).Methods:The peripheral blood mononuclear cells(PBMC) from 35 patients including 20 active SLE and 18 healthy controls were counted and stained for CD3,CD4 and CD25.Cells were examined by flow cytometry.Disease activity was assessed by systemic lupus erythematosus activity index(SLEDAI).Results:The frequency of total CD4+CD25+T cells,CD4+CD25highT cells and CD4+CD25 intT cells was not significantly different in SLE patients compared with that of healthy controls,and was not correlated to SLEDAI scores.But the index of CD4 +CD25high T:CD4+CD25intT ratio was significantly decreased in active SLE patients compared with that of inactive SLE and control groups,and the ratio was correlated to SLEDAI scores.Conclusion:This study demonstrates that CD4+CD25high T:CD4+CD25intT ratio is decreased in the peripheral blood of active SLE patients.It appears that unbalance between CD4 +CD25high regulatory and CD4+CD25int T effector cells plays an important role in the pathogenesis of active SLE.