Plasma IL-17A Is Increased in New-Onset SLE Patients and Associated with Disease Activity

To investigate the role of interleukin-17A (IL-17A) and Th17 cell in the pathogenesis of systemic lupus erythematosus (SLE), we studied the plasma IL-17A and the expression of Th17 cell transcription factor ROR gamma t in Chinese new-onset SLE patients. Sixty SLE patients aged between 18 and 40 years and 56 age-matched healthy volunteers were involved in the study. Enzyme-linked immunosorbent assay was used to measure plasma IL-17A level, and rea1-time fluorescent quantitative polymerase chain reaction was used to measure ROR gamma t mRNA. The results showed that both IL-17A level and ROR gamma t mRNA in SLE patients were higher than that of controls. Correlation analysis indicated that plasma IL-17A level was positively correlated with Systemic Lupus Erythematosus Disease Activity Index, not with ROR gamma t mRNA. We concluded that IL-17A might play a role in the pathogenesis of SLE and associated with disease activity. ROR gamma t-determined Th17 cell might be involved with increased IL-17A in SLE but not exclusively the unique source.