Abstract: Objective: To compare the clinical efficacy and safety between etanercept and infliximab in the treatment of adolescent ankylosing spondylitis (AS),and to provide reference for guiding clinical medication. Methods: Sixty male adolescents with AS from our Hospital were used as the subjects and randomly divided into etanercept group and infliximab group (n=30).All patients in the 24 weeks before treatment and during the treatment were not taken the disease-modifying anti-rheumatic drugs (DMARDS).The pillow-wall distance,finger-ground distance,Sch ber test,AS activity index (BASDIA),AS functional Index (BASFI),C-reactive protein (CRP) levels,erythrocyte sedimentation rate (ESR),MRI performance and other indicators of the patients in two groups were measured and evaluated 12 and 24 weeks after treatment,and statistical analysis was performed to assess the clinical efficacies of the two drugs and the adverse effects were recorded. Results: Etanercept and infliximab had good effects on the AS 24 weeks after treatment,and the pain of low back and lumbosacral of the patients in two groups were significantly reduced or disappeared,and the total clinical efficacies in two groups were 96% and 93%, respectively (P>0.05).There were significant improvements in the indexes of morning stiffness,finger-ground distance,pillow-wall distance,Sch ber test,BASDAI scores,BASFI scores,ESR and CRP levels of the patients in two groups 12 and 24 weeks after treatment compared with before treatment(P<0.05).During treatment,1 case of erythema was found in etanercept group;2 cases of moderate infection,2 cases of digestive system reaction, and 1 case of pruritus were found in infliximab group;the differences in the incidence rates of adverse effects between two groups were statistically significant (P<0.05). Conclusion: Etanercept and infliximab have good therapeutic effects in the adolescent patients with AS.They can improve the joint symptoms of hip joint involved in AS;the short-term efficacies of the patients in two groups have no significant difference,but the incidence rate of adverse effects of etanercept is slightly less than that of infliximab.

Key words: adolescent, etanercept, ankylosing spondylitis, tumor necrosis factor, infliximab