Department of Immunology and Rheumatism Affiliated Hospital of Yan''an University Yanan Shaanxi 716000 China;
Four wards of Department of Neurology Dongguan Branch Hospital Affiliated to Yan''an University Yanan Shaanxi 716000 China;
Tocilizumab; Leflunomide; Rheumatoid arthritis; Clinical efficacy; Adverse reactions;