PF4 and rheumatoid arthritis: To address this question, we aimed to evaluate the impact of RA on vascular injury by measuring circulating biomarkers associated with endothelial damage, such as E-selectin, intercellular adhesion molecule-1 (ICAM-1), and platelet activation, including platelet factor 4 (PF4), P-selectin, and CD40 ligand (CD40L), while tracking their changes throughout the procedure.