TNF and rheumatoid arthritis: In patients with rheumatoid arthritis, serum S100A8/A9 and IL-33 levels were reduced after infliximab or anti-TNF-α treatment, respectively (10, 28); and in Juvenile Idiopathic Arthritis patients, serum concentrations of S100A8/S100A9 decreased significantly after intraarticular triamcinolone therapy (29); serum HMGB1 levels were decreased after the treatment with statins or prednisolone in patients with granulomatous polyangiitis (30).