title: [Clinical study of etanercept for treating ankylosing spondylitis].
abstract: OBJECTIVE
  To evaluate the efficacy and safety of etanercept, a tumor necrosis factor (TNF)-alpha inhibitor, in the treatment of ankylosing spondylitis (AS), and investigate its effect on serum levels of matrix metalloproteinase-3 (MMP-3).
  
  
  METHODS
  Forty-eight patients with AS received etanercept 25 mg twice a week for a treatment course of 12 weeks. The patients' symptoms, signs, Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Bath Ankylosing Spondylitis Functional Index (BASFI), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) levels and side effects were observed before and after the treatment. The serum levels of MMP-3 was determined using enzyme-linked immunosorbent assay (ELISA).
  
  
  RESULTS
  All the patients completed the treatment. The degree of spinal pain and pain at night, the duration of morning stiffness, the finger-to-floor distance, BASDAI and BASFI were significantly improved after the treatment (P<0.05). Etanercept treatment resulted in a significant reduction in serum MMP-3 level in the AS patients to 31.22-/+10.26 ng/ml as compared with the level before treatment (46.17-/+25.74 ng/ml, P<0.05). The reduction of serum MMP-3 was positively correlated to decrement of ESR and CRP (r=0.397 and 0.474, respectively, P<0.05). The most common adverse events of etanercept included injection site reaction and upper respiratory infection.
  
  
  CONCLUSIONS
  Etanercept treatment has obvious therapeutic effects on AS without serious adverse effects. MMP-3 may be a potentially useful indicator to assess the effect of anti-TNF-alpha treatment in AS patients.
authors.affiliation: Department of Rheumatology and Clinical Immunology, First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China. lliuq@mail.sysu.edu.cn
authors.forename: Liu-qin
authors.initials: LQ
authors.lastname: Liang
authors.forename: Zhong-ping
authors.initials: ZP
authors.lastname: Zhan
authors.forename: Yu-jin
authors.initials: YJ
authors.lastname: Ye
authors.forename: Di
authors.initials: D
authors.lastname: Fu
authors.forename: Han-shi
authors.initials: HS
authors.lastname: Xu
authors.forename: Xiu-yan
authors.initials: XY
authors.lastname: Yang