Abstract: Objective: To investigate the serum levels changes of leucine rich-α-2-glycoprotein 1(LRG1),soluble CD134(sCD134),and tumor necrosis factor-α(TNF-α) in patients with rheumatoid arthritis(RA),and their correlation with disease activity. Methods: A total of 120 patients with RA were selected as RA group,and divided into the remission group(30 cases),low-moderate activity group(61 cases) and high activity group(29 cases) according to the disease activity score 28(DAS28).In addition,65 non-RA patients at the same time were selected as the non-RA group,and 40 healthy physical examinees were selected as healthy control group.The serum levels of LRG1,sCD134 and TNF-α were detected by enzyme-linked immunosorbent assay(ELISA),and the clinical data between healthy control group and RA group were compared.The correlations of serum levels of LRG1,sCD134 and TNF-α in RA patients were analyzed by Pearson method.Spearman correlation analysis was used to analyze the correlation between the serum levels of LRG1,sCD134 and TNF-α and DAS28 score. Results: The serum levels of LRG1,sCD134 and TNF-α in the RA group and non-RA group were higher than those in healthy control group,and the serum levels of LRG1,sCD134 and TNF-α in the RA group were higher than those in non-RA group(P<0.05).There was no statistical significance in the gender composition,age,body mass index,systolic and diastolic blood pressure between healthy control group and RA group(P>0.05).The serum levels of LRG1,sCD134,TNF-α and DAS28 score in the high activity group and low-moderate activity group were higher than those in remission group,and the serum levels of LRG1,sCD134,TNF-α and DAS28 score in the high activity group were higher than those in low-moderate activity group(P<0.05).The results of Pearson correlation analysis showed that the serum LRG1 levels were significantly positively correlated with sCD134 and TNF-α levels,and the serum sCD134 levels were significantly positively correlated with TNF-α levels in RA patients(r=0.495,0.487,0.746,P<0.01).The results of Spearman correlation analysis showed that the serum levels of LRG1,sCD134 and TNF-α were positively correlated with DAS28 score(disease activity) in RA patients(r=0.528,0.807,0.813,P<0.01). Conclusions: The serum levels of LRG1,sCD134 and TNF-α in RA patients are closely related to the disease activity.Detecting the serum LRG1,sCD134,TNF-α levels of patients has certain reference value for evaluating the degree of disease activity and selecting treatment plan.