Abstract： Objective To investigate the serum levels of Caspase-1(Caspase-1),Dickkopf-1(DKK-1)and interleukin-2 receptor α(IL-2Rα)in patients with systemic lupus erythematosus(SLE),and to analyze their correlation with the severity of the disease and their evaluation value in renal function impairment.Methods A total of 114 SLE patients were selected as the study group,and 38 healthy volunteers were selected as the control group.The levels of serum Caspase-1,DKK-1 and IL-2Rα were compared between the two groups and the study group with different disease course.The correlation between serum Caspase-1,DKK-1,IL-2Rα and clinical indicators(white blood cell count,hemoglobin,lymphocyte count,platelets,ery-throcyte sedimentation rate,serum creatinine,24 h urinary protein,anti-double DNA antibody(dsDNA),complement C3,com-plement C4)and disease degree was analyzed.According to the degree of renal impairment,the study group was divided into 58 cases with normal renal function,31 cases with mild abnormal renal function,and 25 cases with moderate and severe ab-normal renal function.The levels of serum Caspase-1,DKK-1 and IL-2Rα were compared,and the evaluation value of their on the degree of renal function impairment was analyzed.Results The levels of serum Caspase-1 in the study group were lower than those in the control group,and the levels of serum DKK-1 and IL-2Rα were higher than those in the control group(P<0.05).With the severity of disease and renal function,the serum Caspase-1 level was decreased,and the serum DKK-1 and IL-2Rα levels were increased(P<0.05).Serum Caspase-1 was positively correlated with white blood cell count,lymphocyte count,complement C3 and complement C4,but negatively correlated with erythrocyte sedimentation rate,anti-DSD-NA antibody and disease degree(P<0.05).Serum DKK-1 and IL-2Rα were negatively correlated with white blood cell count,lymphocyte count,complement C3 and complement C4,but positively correlated with erythrocyte sedimentation rate,anti-DSD-NA antibody and disease degree(P<0.05).The AUC of serum Caspase-1,DKK-1 and IL-2Rα combined in the assessment of renal lesion was higher than that of single index assessment(P<0.05).Conclusion Serum Caspase-1 levels are decreased and serum DKK-1 and IL-2Rα levels are increased in SLE patients,which are closely related to the severity of the disease.Combined detection of caspase-1 and IL-2rα levels has certain value in evaluating the degree of renal function impairment.