Circulating lymphocyte subpopulations in patients with systemic lupus erythematosus and their correlation with disease activity.

Abstract

The aim of the present study was to evaluate the overall alterations of peripheral blood lymphocyte subsets in patients with systemic lupus erythematosus (SLE). A total of 120 patients diagnosed with SLE and 64 health donors were enrolled. The lymphocyte subsets were detected using flow cytometry. Then the changes of lymphocyte subsets in patients and their correlation with disease activity were investigated. Compared with healthy controls, the counts of lymphocytes, T cells, B cells and NK cells in SLE patients were significantly decreased. Further analysis of T cells subpopulations revealed that the decrease in T cells counts in SLE patients was mainly attributed to a sharp decrease in CD4 + T cells counts. Meanwhile, there was a positive correlation between CD4 + T cells counts and serum complement 3 levels, and patients with lower CD4 + T cells counts had higher SLEDAI score. The counts of CD8 + T cells were comparable between SLE patients and controls, while the proportion of CD8 + T cells and cytotoxic T cells (CD8 + CD28 +) was prominently higher in SLE patients. Besides, the expression of HLA-DR on the surface of T and NK cells was significantly upregulated in SLE patients. Circulating lymphocyte subsets of SLE patients were seriously dysregulated, characterized by a decrease in CD4 + T cells and NK cells, as well as an increase in the proportion of activated T and NK cells. Reduction in CD4 + T cells in SLE patients was highly consistent with disease activity, indicating the crucial role of CD4 + T cells in the onset and progression of SLE.