title: Baseline predictors of response to TNF-α blocking therapy in ankylosing spondylitis.
abstract: OBJECTIVE
  Identifying the characteristics of patients with ankylosing spondylitis (AS) before start of treatment which are able to predict a beneficial response to tumor necrosis factor-alpha (TNF-α) blocking therapy is relevant, especially in view of the high costs and potential side-effects of these agents. This review provides an overview of clinical trials and observational studies investigating baseline predictors of response after 3-6 months of TNF-α blocking therapy and baseline predictors of long-term anti-TNF-α treatment continuation in AS.
  
  
  RESULTS
  In multiple studies, increased acute phase reactants, higher disease activity, higher functional status, younger age, and HLA-B27 positivity were identified as independent baseline predictors of achieving clinical response to TNF-α blocking therapy. Increased acute phase reactants, presence of peripheral arthritis, and male sex were repeatedly identified as independent baseline predictors of anti-TNF-α treatment continuation.
  
  
  CONCLUSIONS
  Several studies using multivariate analyses identified comparable baseline predictors of response and/or continuation of TNF-α blocking therapy. The single predictors identified have, at best, moderate capacity to predict treatment response in the individual patient. The development of a prediction model may lead to a more robust instrument to support physicians in decision making on TNF-α blocking therapy in AS in daily clinical practice.
authors.affiliation: Department of Rheumatology and Clinical Immunology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands. s.arends@umcg.nl
authors.forename: Suzanne
authors.initials: S
authors.lastname: Arends
authors.forename: Eveline
authors.initials: E
authors.lastname: van der Veer
authors.forename: Cees G M
authors.initials: CG
authors.lastname: Kallenberg
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Brouwer
authors.forename: Anneke
authors.initials: A
authors.lastname: Spoorenberg
mesh_terms: D018501:Antirheumatic Agents / Q000494:pharmacology / Q000627:therapeutic use*; D015415:Biomarkers / Q000097:blood; D005260:Female; D006801:Humans; D008297:Male; D011379:Prognosis; D012720:Severity of Illness Index; D012737:Sex Factors; D013167:Spondylitis, Ankylosing / Q000175:diagnosis / Q000188:drug therapy*; D016896:Treatment Outcome; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors*
chemical_list: D018501:Antirheumatic Agents; D015415:Biomarkers; D014409:Tumor Necrosis Factor-alpha