Autoimmune diseases such as rheumatoid arthritis (RA) are the consequence of a persistent imbalance between pro- and anti-inflammatory immune mechanisms, leading to chronic inflammation. The objective of this study was to determine whether the high sensitive C-reactive protein (hs-CRP) and cytokines are elevated in RA patients and to investigate the relationship between these markers and disease activity in RA, measured by disease activity score 28 (DAS28).
We studied 110 RA patients according to American College of Rheumatology revised criteria for RA, and 55 controls matched by age and sex. Serum levels of hs-CRP and cytokines interleukin (IL)-6, IL-10 and tumour necrosis factor-α (TNF-α) were estimated and correlated with the DAS28. Serum hs-CRP was assayed immunoturbidimetrically and cytokines were analysed by commercially available ELISA kit.
We found that RA patients had significantly higher levels of serum hs-CRP (p<0.001), IL-6 (p<0.001), TNF-α (p<0.001), and IL-10 (p<0.01) as compared to healthy controls. hs-CRP, IL-6 and TNF-α correlated positively (p<0.001) and IL-10 correlated negatively (p<0.01) with DAS28.
These results demonstrate that RA patients have high levels of inflammatory markers, and these levels are correlated with the DAS28. These findings suggest a possible role of these markers in the pathogenesis of RA. Moreover, these biomarkers can be used as markers of disease activity in the diagnosis and treatment of RA.