Expression and significance of Th17 and Treg cells in peripheral blood of patients with systemic lupus erythematosus

Abstract

To explore the expression and significance of Th17 and Treg cells in peripheral blood of patients with systemic lupus erythematosus (SLE). Thirty active SLE patients (including 17 SLE patients with lupus nephritis), 20 inactive SLE patients and 20 healthy controls were enrolled. The expressions of Th17 cells and CD4+CD25+Foxp3+Treg cells in peripheral blood mononuclear cells (PBMC) were evaluated by flow cytometry. The correlations between the expression of Th17 cells, CD4+CD25+Foxp3+Treg cells and disease activity (SLEDAI), as well as the ratios of Th17 cells and Treg cells (Th17/Treg) in SLE patients and healthy controls were analyzed respectively. The expression of Th17 cells in PBMC of SLE patients was higher than that in healthy controls [(1.39 ± 0.60)% vs (0.80 ± 0.33)%, P < 0.01] while the expression of CD4+CD25+Foxp3+Treg cells decreased in SLE patients [(3.09 ± 1.54)% vs (6.04 ± 1.49)%, P < 0.01]. The increased expression of Th17 cells and reduced CD4+CD25+Foxp3+Treg cells in PBMC were positively correlated with SLEDAI and negatively correlated with complements C3 and C4. There were increased expression of Th17 cells and reduced CD4+CD25+Foxp3+Treg cells in PBMC of lupus nephritis versus SLE patients without nephritis. There is an abnormal elevation of Th17 cells and decrease of CD4+CD25+Foxp3+Treg cells in PBMC of SLE patients. The imbalance between Th17 and Treg cells may play a critical role in the pathogenesis of SLE.