Objective: To analyze peripheral blood interleukin 6(IL-6)methylation status and its clinical significance in patients with systemic lupus erythematosus(SLE).Material and Method: Blood samples from 41 adult patients with SLE,and 20 healthy controlswere collected.The methylation status of IL-6 was determined by methylation specific polymerasechain reaction(MSP).The IL-6 expression was detected by real-time PCR.Correlations between IL-6methylation status and clinical features or laboratory findings in patients with SLE were investigated.Results: The methylation status and expression of IL-6 in peripheral blood could reflect the levelin peripheral blood mononucleated cells(PBMCs)of SLE.Significantly positive correlation was foundbetween IL-6 hypomethylation and renal disorder.Interleukin 6 hypomethylation was found negatively correlated with serum C3.Conclusions: The detection of IL-6 methylation status in peripheral blood could reflect the status in PBMC with SLE.Interleukin 6 may play a role in renal disorder with SLE patients.Interleukin 6 could be considered as a new biomarker for predicting SLE flare.