IL6 and arthritic joint disease: The severity of arthritis was evaluated by changes in paw oedema, body weight, arthritic index, radiological scores, histological assessment of synovial joints, erythrocyte sedimentation rate, haematocrit, haemoglobin, serum rheumatoid factor, serum C-reactive protein and serum levels of the pro-inflammatory cytokines IL-1β, IL-6, TNF-α, IL-18, IFN-γ, GM-CSF, and anti-inflammatory cytokines IL-4, IL-10, IL-13.