Cell adhesion molecules and plasminogen activator inhibitor type-1 (PAI-1) in patients with rheumatoid arthritis: influence of metabolic syndrome.

Rheumatoid arthritis (RA) is a chronic inflammatory and systemic disease characterized by endothelial activation. The main objective of this study was to verify the profile of cell adhesion molecules (CAM) in RA patients, and the influence of metabolic syndrome (MetS) and drugs used in the treatment of RA in this profile. A second objective was to propose models of prediction of activity in RA using these biomarkers. A total of 115 healthy individuals and 144 RA patients were enrolled. Disease activity was determined by DAS28 (disease activity score 28) based on erythrocyte sedimentation rate (DAS28-ESR) or C-reactive protein (DAS28-CRP). Serum CAM and plasminogen activator inhibitor type-1 (PAI-1), anthropometric and immunological parameters were measured. Vascular cell adhesion molecule-1 (VCAM-1) was significantly decreased, and PAI-1 was significantly higher in RA patients as compared to controls. Binary logistic regression analysis showed that VCAM-1, CRP, and tumor necrosis factor-α (TNF-α) predicted RA with a sensitivity of 95.9% and a specificity of 89.5%. 42.9% of the variance in DAS28-ESR and 49.2% of the variance in DAS28-CRP are explained by increased PAI-1, TNF-α, body mass index (BMI) and decreased platelet endothelial cell adhesion molecule 1 (PECAM-1). Our data show that lower levels of VCAM-1 are associated with RA independently of MetS, while increased PAI-1 levels were associated with both RA and MetS and increased selectins (E-selectin and P-selectin) were exclusively associated with MetS and not with RA. A model to predict disease activity based on PECAM-1, PAI-1, TNF-α, age and BMI is proposed.

Metabolic syndrome and the decreased levels of uric acid by leflunomide favor redox imbalance in patients with rheumatoid arthritis.

Oxidative stress plays a role in the pathophysiology of rheumatoid arthritis (RA). The aim of the present study was to verify the influence of metabolic syndrome (MetS) and disease-modifying antirheumatic drugs on nitrosative and oxidative biomarkers in patients with RA. A total of 177 patients with RA and 150 healthy volunteers participated in this study, which measured lipid hydroperoxides, advanced oxidation protein products (AOPP), nitric oxide metabolites (NOx), carbonyl protein, total radical-trapping antioxidant parameter (TRAP), uric acid (UA), and C-reactive protein (CRP). NOx and the NOx/TRAP ratio were significantly increased in RA, while no significant differences in lipid hydroperoxides, AOPP, UA, and TRAP levels were found between both groups. Treatment with leflunomide was associated with increased levels of carbonyl protein, and lowered levels in TRAP and UA, while the NOx/TRAP ratio further increased. NOx and the NOx/TRAP ratio were significantly higher in women than in men, while TRAP and UA were significantly lower in women. MetS was accompanied by increased AOPP and UA levels. RA was best predicted by increased NOx/TRAP ratio, CRP, and BMI. In conclusion, our data demonstrated that NOx and NOx/TRAP are strongly associated with RA physiopathology. Our findings suggest that inhibition of iNOS may become an interesting therapeutic approach for the treatment of RA. In addition, the presence of MetS and a decrease in levels of UA by leflunomide favor redox imbalance in RA patients. More studies are needed to evaluate the impact of antioxidant capacity reduction on RA progression.