Objective To investigate the expression and clinical significance of microRNA(miR)-146a and miR-181a in urine exosome of patients with systemic lupus erythematosus(SLE).Methods A total of 40 pa-tients diagnosed with SLE at West China Hospital,Sichuan University from January 2023 to October 2023 were selected as the SLE group,and another 20 healthy individuals who underwent physical examinations dur-ing the same period were selected as the control group.According to SLE disease activity index(SLEDAI),SLE patients were divided into low activity group(19 cases,SLEDAI≤9 scores)and high activity group(21 cases,SLEDAI>9 scores).Real-time PCR was used to detect the expression of miR-146a and miR-181a in u-rine exosome,enzyme-linked immunosorbent assay(ELISA)was used to detect serum interleukin(IL)-1β,IL-6,tumor necrosis factor(TNF)-α,complement C3,IgG and anti-cardiolipin antibody(ACA)levels,and re-ceiver operating characteristics(ROC)curve was used to analyze the diagnostic value of miR-146a and miR-181a expression in urine exosome for SLE and SLE accompanied renal injury.Results The relative expression level of miR-146a and miR-181a in urine exosome in the SLE group was significantly higher than in the control group(P<0.05),and the relative expression level of miR-146a and miR-181a in urine exosome in the high ac-tivity group was significantly higher than in the low activity group(P<0.05).The relative expression level of miR-146a and miR-181a in urine exosome in SLE with renal injury was higher than in SLE without renal inju-ry(P<0.05).The serum levels of IL-1β,IL-6,TNF-α,IgG and ACA in the high activity group were signifi-cantly higher than those in the low activity group,and the serum C3 level in the high activity group was signif-icantly lower than that in the low activity group(P<0.05).miR-146a in urine exosome of SLE patients were significantly positively correlated with serum IL-1β,IL-6,TNF-α,IgG and ACA levels(r=0.443,0.493,0.410,0.381,0.340,P<0.05),and negatively correlated with serum C3 levels(r=-0.340,P<0.05).miR-181a in urine exosome of SLE patients were significantly positively correlated with serum IL-1β,IL-6,TNF-α,IgG and ACA levels(r=0.342,0.470,0.373,0.371,0.334,P<0.05),and negatively correlated with serum C3 levels(r=-0.368,P<0.05).The area under the curve of miR-146a and miR-181a in urine exosome for diagnosing SLE were 0.907 and 0.897,and the area under the curve of miR-146a and miR-181a in urine exo-some for diagnosing SLE complicated with kidney damage were 0.859 and 0.815.Conclusion The expression levels of miR-146a and miR-181a in urine exosome have a good evaluation value for the disease activity of SLE,and have a potential application value for the prediction and diagnosis of SLE.