To investigate the relationship between leucine-rich-alpha-2 glycoprotein 1 (LRG1) and activity of rheumatoid arthritis (RA).

A total of 129 RA patients treated at Zhangjiagang Hospital Affiliated to Soochow University from January 2020 to June 2021 were divided into a mild group, a moderate group, and a severe group according to 28-joint disease activity score (DAS28). There were 39 males and 90 females with a mean age of (59.83＜8.74) years. Sixty healthy subjects were selected as a control group, and there were 19 males and 41 females with an average age of (59.51＜9.09) years. General data (gender, age, and body mass index) and laboratory indexes (LRG1, transforming growth factor (TGF)-β1, and interleukin (IL)-6) were compared among the groups. Spearman correlation analysis was used to analyze the correlation between LRG1 and DAS28 score, TGF-β1, and IL-6.

There was no significant difference in gender, age, or body mass index among the groups (P＞0.05 for all). The levels of LRG1 in the mild, moderate, and severe RA groups were all significantly higher than that in the control group (P＜0.05 for all). The level of LRG1 increased significantly with the increase of RA activity (P＜0.05). Spearman correlation analysis showed that LRG1 was positively correlated with DAS28 score (r=0.930, P＜0.05). The levels of TGF-β1 and IL-6 in the mild, moderate, and severe groups were significantly lower than those in the control group (P＜0.05 for all). With the elevation of RA activity, the level of TGF-β1 decreased significantly and IL-6 increased significantly (P＜0.05 for both). Spearman correlation analysis showed that the expression of LRG1 was negatively correlated with TGF-β1 (r=-0.785, P＜0.05) but positively correlated with IL-6 (r=0.816, P＜0.05).

LRG1 is positively correlated with the activity of RA, and it can be used as an indicator of RA activity.