Correlation between plasma levels of D-dimer and IL-1, IL-6, and TNF-α in patients with rheumatoid arthritis

Objective: The aim of this study was to investigate changes in levels of plasma D-dimer (D-D) in rheumatoid arthritis (RA) patients and analyze its relationship with inflammatory factors interleukin-1 (IL-1), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-alpha). Methods: Plasma levels of D-D, in 138 RA patients and 100 healthy controls, were determined and its correlation with age, rheumatoid factor (RF), erythrocyte sedimentation rate (ESR), IL-1, IL-6, and TNF-alpha were evaluated. RA patients in the observation group were divided into 3 subgroups based on RA disease activity score 28 (DAS28). There were 52 cases in group A (DAS28>5.1), 42 cases in group B (3.2<DAS28 <= 5.1), and 44 cases in group C (1.6<DAS28 <= 3.2). Results: Plasma D-D levels in the RA group were significantly higher than those of healthy control groups (P<0.01). In addition, plasma levels of D-D in groups A and B were significantly higher compared to those in group C (both P<0,01). Moreover, in all RA patients, D-D levels had a significantly positive correlation with age, ESR, RF, C-reactive protein, IL-1, IL-6, and TNF-alpha (all P<0.01). Conclusion: D-D can be used as a nonspecific inflammatory response index for clinical diagnosis of RA and as a guide for clinical treatment of this disease.