CXCL9 and its Receptor CXCR3, an Important Link Between Inflammation and Cardiovascular Risks in RA Patients

Cardiovascular disease (CVD) is the most common cause of mortality in rheumatoid arthritis (RA), and Inflammation has a decisive role in its pathogenesis. CXCL9 contributes to multi aspects of inflammatory reactions associated with the pathogenesis of CVD. In the current study, we evaluated the association of plasma CXCL9 and CXCR3 gene expression with Cardiovascular risk factors in RA patients for the first time. Thirty newly diagnosed, 30 on-treatment RA patients, and 30 healthy subjects were recruited in this study. The plasma concentration of CXCL9 and CXCR3 gene expression were measured using ELISA and Real-Time PCR, respectively. The CVD risk was evaluated using Framingham Risk Score (FRS) and Systematic Coronary Risk Evaluation (SCORE). The plasma levels of CXCL9 were significantly higher in the newly diagnosed and on-treatment RA patients compared to the control group (P < 0.0001 and P < 0.001, respectively). Also, The CXCR3 gene expression was strongly elevated in newly diagnosed and on-treatment patients (P < 0.001 and P < 0.01, respectively). The CXCL9 and CXCR3 were significantly associated with RA disease activity (P = 0.0005, r = 0.436; P = 0.0002, r = 0.463, respectively). The FRS was remarkably higher in newly diagnosed and on-treatment patients (P = 0.014 and P = 0.035, respectively). The CXCR3 gene expression significantly correlated with age, systolic blood pressure, FRS, and SCORE (P = 0.020, r = 0.298; P = 0.006, r = 0.346; P = 0.006, r = 0.349; P = 0.007, r = 0.341, respectively). The CXCL9 plasma concentration had a significant negative correlation with plasma HDL and LDL levels (P = 0.033, r = -0.275; P = 0.021, r = -0.296, respectively). CXCL9 and CXCR3 correlates with different variables of CVD in RA.