Ahmed, Ammar A.Jewad, Abdulkareem M.2026-02-122026-02-122025-12European Journal of Clinical and Experimental Medicine T. 23, z. 4 (2025), s. 962–9682544-1361https://repozytorium.ur.edu.pl/handle/item/12200The Ethics Committee approved the protocol on 17/12/2023, No 860, and the study was conducted in accordance with the Declaration of Helsinki.Introduction and aim. Rheumatoid arthritis (RA) is a chronic disease characterized by synovial inflammation and joint destruction. This study evaluated the novel biomarkers vitamin D binding protein (VDBP), retinol-binding protein 4 (RBP4), N-terminal pro-B-type natriuretic peptide (NT-proBNP), and endothelin-1 (ET-1) for RA diagnosis. To our knowledge, this is the first study to simultaneously assess these biomarkers across different treatment stages in RA, linking systemic inflammation with subclinical cardiovascular involvement. Material and methods. A case-control study enrolled 61 RA patients [G1 (newly diagnosed, untreated, n=10)], G2 [3 months csDMARDs, n=22], G3 [≥6 months biologic+csDMARDs, n =29]), 27 age/sex-matched healthy controls. The serum levels of VDBP, RBP-4, CRP, NT-proBNP, and ET-1 measured using enzyme-linked immunosorbent assay. Results. All evaluated biomarkers were significantly elevated in RA patients compared to controls (p<0.0001): RBP-4 (49.172±21.935 vs. 14.006±3.988 ng/mL), VDBP (12.091±3.334 vs. 2.882±1.136 ng/mL), NT-proBNP (1341.787±626.068 vs. 11.452±3.260 pg/mL), ET-1 (14.246±4.031 vs. 3.932±1.422 pg/mL). Subgroup analysis revealed a significantly higher VDBP in newly diagnosed untreated patients (G1:14.455±4.126 ng/mL) than in treated groups (G2:11.379±2.632; G3:11.816±3.269 ng/mL; p<0.05). NT-proBNP peaked in G1 (1789.2±710.81 pg/mL), decreased in csDMARD-treated (G2: 1154.0±537.58 pg/mL), biologic-treated (G3: 1329.96±601.18 pg/mL) group. Conclusion. VDBP, RBP-4, CRP are effective diagnostic biomarkers of RA. Significant elevations in NT-proBNP and ET-1 levels associated with cardiac complications, correlated with disease activity, and improved with therapy.engAttribution-NonCommercial-NoDerivatives 4.0 Internationalhttp://creativecommons.org/licenses/by-nc-nd/4.0/endothelin 1N-terminal pro-brain natriuretic peptide retinol–binding protein-4vitamin D binding proteinarticle10.15584/ejcem.2025.4.19