Association of Serum Copeptin Levels with Inflammatory Status and Disease Activity in Patients with Rheumatoid Arthritis

الملخص

Rheumatoid arthritis (RA) is a chronic autoimmune inflammatory condition characterized by persistent synovial inflammation and progressive joint damage. Copeptin, a stable biomarker of arginine vasopressin secretion, has recently been implicated in several inflammatory disorders. This study aimed to evaluate serum copeptin levels in patients with RA and to investigate their association with inflammatory markers and disease activity. A case-control study was conducted on 90 participants, including 45 patients diagnosed with RA and 45 age- and sex-matched healthy controls. Serum copeptin levels were measured using the enzyme-linked immunosorbent assay (ELISA) technique, while erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and Disease Activity Score-28 (DAS28) were assessed in RA patients. The findings demonstrated significantly elevated serum copeptin levels in RA patients compared with controls (7.94 ± 2.63 vs. 4.38 ± 1.51 ng/mL; P < 0.001). In addition, serum copeptin showed significant positive correlations with ESR (r = 0.44, P = 0.004), CRP (r = 0.51, P = 0.001), and DAS28 score (r = 0.56, P < 0.001). Multiple stepwise linear regression analysis further revealed that DAS28 score and CRP were independent predictors of serum copeptin levels. These findings suggest that serum copeptin is elevated in RA patients and may reflect inflammatory activity and disease severity.