Role of Pro- and Anti-Inflammatory Cytokines in Rheumatoid Arthritis: Correlation with Disease Activity.

Abstract

Background: Rheumatoid arthritis (RA) is a chronic and debilitating autoimmune disease characterized by chronic inflammation with subsequent cartilage and bone destruction. Cytokines are  key mediators of inflammation and can be found in abundance both in the joint and blood of patients. This study was designed to evaluate the role of pro- and anti-inflammatory cytokines in pathogenesis of RA, as well as study the correlation among these cytokines.
Patients and methods: Forty patients with RA and thirty age-matched healthy controls were included in this study. Serum cytokines were measured by enzyme-linked immunosorbent assay.
Results: The serum levels of pro-inflammatory cytokines (IL-1α, IL-2, IL-6, IL-8, IL-12 and TNF-α) were significantly higher in RA patients than in healthy controls (p<0.01, p<0.05). Moreover, these levels were significantly increased in active RA patients than in inactive RA (p<0.01, p<0.05). On the other hand, the serum levels of IFN-γ and anti-inflammatory cytokines (IL-4, IL-10) showed no significant differences between RA patients and healthy controls and neither between active RA patients and inactive RA (p>0.05). Interestingly strong positive correlation was found among each of (IL-1α, IL-2, IL-6, IL-8, IL-12 and TNF-α), p<0.05.While strong negative correlation was noticed between IL-6 and (IL4 and IL-0) and also between TNF-α and (IL4 and IL-0), p<0.05.
Conclusion: The current study suggests that serum levels of pro-inflammatory cytokines (IL-1α, IL-2, IL-6, IL-8, IL-12 and TNF-α) may play an important role in RA and may be used as a marker of disease activity. Moreover imbalance between pro- and anti-inflammatory cytokines may yield effective therapeutic targets in this inflammatory disease.