Aim: The aim of this study was to evaluate the relationship between Interleukin-6 (IL-6)
serum level and the severity and activity of Rheumatoid Arthritis (RA).
Methods: In this cross-sectional study, 120 RA patients referred to the rheumatology clinic, the patients
were diagnosed by rheumatologists according to ACR / EULAR 2010 criteria. Based on
DAS28 score the patients were divided into 4 groups: Remission, Mild, Moderate and Severe. Each
group contained 30 patients. Serum levels of Erythrocyte Sedimentation Rate (ESR), C-Reactive
Protein (CRP), anti-Cyclic Citrullinated Peptide (anti-CCP) and Rheumatoid Factor (RF) and serum
levels of IL-6, were measured. The relationship between these factors was measured and compared
to the relationship between IL-6 and these factors, and the activity of the disease was evaluated
based on DAS-28.
Results: This study showed that the serum level of IL-6 has a significant relationship with RA activity
according to DAS-28 (P value <0.001). There is also a significant relationship between the
ESR level, the number of painful joints, and the number of swollen joints, and the severity of the
disease based on VAS.
Conclusion: Generally the findings of this study indicate that serum level of IL-6 plays an important
role in the severity and activity of RA disease and can be considered as a determining factor in
evaluating the severity of RA in RA patients and it is a good guide for a step up or down of treatment.