Abstract:

Objective To estimate the relationship between T helper 17 （Th17） cell-mediated inflammatory damage and systemic lupus erythematosus （SLE）. Methods Serum interleukin （IL）-17A levels were measured by enzyme-linked immunosorbent assay （ELISA） in 102 patients with SLE and 68 normal human controls. Real time-quantitative PCR was used to quantify the expression levels of RORγt mRNA in peripheral blood mononuclear cells （PBMCs） from 27 patients with SLE and 13 normal human controls. Linear regression analysis and Spearman correlation analysis were conducted to assess the relationship of serum IL-17A levels with RORγt mRNA expression, SLE disease activity index （SLEDAI）, and the concurrence of renal damage. Results There was a significant increase in serum IL-17A levels and RORγt mRNA expression in patients with SLE compared with the normal controls ［14.75 （5.12 － 69.76） vs. 5.77 （2.22 － 9.60） ng/L, P ＜ 0.01; 1（0.40 － 2.62） vs. 0.19 （0.15 － 0.75）, P ＜ 0.01］. The serum levels of IL-17A in patients with SLE were positively correlated with the levels of serum C-reactive protein, plasma creatinine and prevalence of urinary cast （r = 0.33, P ＜ 0.01; r = 0.26, P ＜ 0.05; r = 0.27, P ＜ 0.05）, but unrelated to SLEDAI （P > 0.05）. The mRNA expression level of RORγt was positively correlated with serum IL-17A levels （r = 0.47, P ＜ 0.01）, but negatively correlated with serum C3 levels in patients with SLE（r = －0.46, P ＜ 0.05）. There was no significant difference in the levels of serum IL-17A or RORγt mRNA expression between patients with highly and lowly active SLE or between patients with and without renal damage（all P ＞ 0.05）. Conclusions Th17 cell-mediated inflammatory damage may be involved in the pathogenesis of SLE, and associated with renal damage, but is unlikely the only factor affecting the activity of SLE or predominant factor in the pathogenesis of SLE and concurrent renal damage.

Key words: lupus erythematosus, systemic