Association of interleukin-6 and its -174G/C promoter polymorphism with clinical and laboratory characteristics of non hepatitis C virus rheumatoid arthritis patients

Serum IL-6 levels and -174G/C promoter polymorphism were higher in RA patients than in healthy controls. The positive correlation of IL-6 level with the DAS28 and duration of morning stiffness may confirm its' increased involvement in the pathogenesis of RA and may point to the need for considering of anti-IL-6 agents in their management plan. The negative correlation of IL-6 level with the hemoglobin level may confirm IL-6 play a significant role in anemia of RA.