title: Cytokine correlates of clinical response patterns to infliximab treatment of ankylosing spondylitis.
abstract: OBJECTIVE
  To identify clinical and immunological markers of response to treatment with infliximab in ankylosing spondylitis (AS).
  
  
  METHODS
  Baseline and sequential cytokine levels (IL1, TNFalpha, IFNgamma, TGFbeta and IL10) were examined after 52 weeks of infliximab treatment 5 mg/kg in 22 patients.
  
  
  RESULTS
  At week 52, 18 patients were responders and four non-responders according to ASAS group criteria. Clinical measures of disease activity between the two groups at baseline were similar, apart from a trend towards longer disease duration in non-responders (p = 0.08). Baseline CRP and TNFalpha levels were higher in responders than non-responders (p<0.01 and p<0.006, respectively). The two groups had similar baseline cytokine levels, apart from TNFalpha. Baseline CRP levels did not correlate significantly with baseline cytokine levels in responders, but a strong correlation was noted between baseline CRP and IL1, IFNgamma, and IL10 in non-responders. Apart from an early rise in TGFbeta and a decrease in IL10 in responders after the first infusion, sequential cytokine analysis for the first six months of treatment was not related to clinical disease activity measures.
  
  
  CONCLUSIONS
  Although sequential cytokine analysis does not appear to be informative, baseline CRP and TNFalpha levels are useful markers of clinical response patterns in patients with AS treated with infliximab.
authors.affiliation: Department of Medicine and Division of Rheumatology, University of Toronto, Toronto, Ontario, Canada.
authors.forename: M A
authors.initials: MA
authors.lastname: Stone
authors.forename: U
authors.initials: U
authors.lastname: Payne
authors.forename: C
authors.initials: C
authors.lastname: Pacheco-Tena
authors.forename: R D
authors.initials: RD
authors.lastname: Inman
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D018501:Antirheumatic Agents / Q000627:therapeutic use*; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000378:metabolism; D016207:Cytokines / Q000097:blood*; D016903:Drug Monitoring / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D000069285:Infliximab; D008297:Male; D008875:Middle Aged; D018579:Patient Selection; D011379:Prognosis; D013167:Spondylitis, Ankylosing / Q000097:blood / Q000188:drug therapy* / Q000276:immunology; D016896:Treatment Outcome; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D000911:Antibodies, Monoclonal; D018501:Antirheumatic Agents; D015415:Biomarkers; D016207:Cytokines; D014409:Tumor Necrosis Factor-alpha; D002097:C-Reactive Protein; D000069285:Infliximab