The relationship of LRG1 level and disease activity indexs in rathotid arthritis

Aims: Aim of this study is to determine the relation between Leucine-rich alpha-2-glycoprotein 1 (LRG1) a new biomarker in Romatoid Artrit (RA) and disease activity index. Materials and Methods: The sample of the study consisted of 140 rheumatoid arthritis patients followed in Hatay Mustafa Kemal University Hospital Rheumatology outpatient clinic, 35 of whom achieved remission, 35 with low disease activity, 35 with moderate disease activity, and 35 with high disease activity, and 35 healthy controls. Socio-demographic data of all patients and healthy individuals included in the study were recorded. Tender/swelling joints of the patients included in the study were determined, Disease Activity Score 28 (DAS28), Clinical Disease Activity Index (CDAI), Simplified Disease Activity Index (SDAI) and Routine Assessment of Patient Index Data 3 (RAPID3) were calculated. LRG1, TGFβ, IL-6 and TNF-α levels were measured in the serum of all patients and healthy individuals included in the study. Results: In our study, LRG1, TNF-α, IL-6, and TGF‐β1 levels of the RA patient group were found to be higher than the control group. The median LRG1 value of the patients was 226.03 (100.15-805.95), and the median LRG1 value of the individuals in the control group was 117.19 (74.73-156.61) (p<0.001). The median TGF-β1 value of the patients was 257.07 (185.05-990.80) and the median TGF-β1 value of the individuals in the control group was 214.60 (163.78-359.07) (p<0.001). The median TNF-α value of the patients was 134.26 (90.33-713.80), and the median TNF-α value of the individuals in the control group was 118.18 (89.90-146.10) (p<0.001). The median IL-6 value of the patients was 134.26 (90.33-713.80), and the median IL-6 value of the individuals in the control group was 118.18 (89.90-146.10) (p=0.002). LRG1 levels were found to be significantly higher in the group with high disease activity compared to the other groups (p<0,001). A moderate positive correlation was detected between LRG1 and TNF-α and IL-6. A strong positive correlation was detected between LRG1 levels and DAS28, CDAI, SDAI and RAPID3 scores. A moderate positive correlation was found between TNF-α and IL-6 levels and DAS28, CDAI, SDAI and RAPID3 scores. As a result of the ROC analysis, it was determined that the serum LRG1 level had a successful performance in the follow-up of RA disease (p<0,001). Conclusion: It suggests that LRG1 reflects the burden of systemic inflammation in RA and may play a role in the inflammatory process. LRG1 may be a useful marker of disease activity in patients with RA. Key words: LRG1, rheumatoid arthritis, disease activity, TGFβ, IL-6, TNF-α