title: Blood and synovial fluid cytokine signatures in patients with juvenile idiopathic arthritis: a cross-sectional study.
abstract: BACKGROUND
  Juvenile idiopathic arthritis (JIA) consists of a heterogeneous group of disorders with, for the most part, an unknown immunopathogenesis. Although onset and disease course differ, the subtypes of JIA share the occurrence of chronic inflammation of the joints, with infiltrations of immunocompetent cells that secrete inflammatory mediators.
  
  
  OBJECTIVE
  To identify a panel of cytokines specifically related to the inflammatory process in JIA.
  
  
  METHODS
  Using a new technology, the multiplex immunoassay, 30 cytokines were measured in plasma of 65 patients with JIA, of which 34 were paired with synovial fluid. These data were compared with plasma of 20 healthy controls and 9 patients with type I diabetes, a chronic inflammatory disease.
  
  
  RESULTS
  Patients with JIA had, irrespective of their subclassification, significantly higher levels of tumour necrosis factor alpha, macrophage inhibitory factor (MIF), CCL2, CCL3, CCL11, CCL22 and CXCL9 in plasma than controls. In paired plasma and synovial fluid samples of patients with JIA, significantly higher levels of interleukin (IL)6, IL15, CCL2, CCL3, CXCL8, CXCL9 and CXCL10 were present in synovial fluid. Cluster analysis in all patients with JIA revealed a predominant pro-inflammatory cytokine cluster during active disease and a regulatory/anti-inflammatory-related cytokine cluster during remission. Whether a discrimination profile of various cytokines could help in the determination of disease classification was tested.
  
  
  CONCLUSIONS
  It is suggested that several cytokines (IL18, MIF, CCL2, CCL3, CCL11, CXCL9 and CXCL10) may correspond to the activation status during inflammation in JIA and could be instrumental in monitoring disease activity and outcomes of (new) immunotherapies.
authors.affiliation: Department of Pediatric Immunology, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Wilco
authors.initials: W
authors.lastname: de Jager
authors.forename: Esther P A H
authors.initials: EP
authors.lastname: Hoppenreijs
authors.forename: Nico M
authors.initials: NM
authors.lastname: Wulffraat
authors.forename: Lucy R
authors.initials: LR
authors.lastname: Wedderburn
authors.forename: Wietse
authors.initials: W
authors.lastname: Kuis
authors.forename: Berent J
authors.initials: BJ
authors.lastname: Prakken
mesh_terms: D000293:Adolescent; D001171:Arthritis, Juvenile / Q000097:blood / Q000276:immunology*; D018925:Chemokines / Q000032:analysis / Q000097:blood; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D016207:Cytokines / Q000032:analysis* / Q000097:blood; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000276:immunology; D016002:Discriminant Analysis; D005260:Female; D006801:Humans; D007118:Immunoassay / Q000379:methods; D007378:Interleukins / Q000032:analysis / Q000097:blood; D008263:Macrophage Migration-Inhibitory Factors / Q000032:analysis / Q000097:blood; D008297:Male; D013582:Synovial Fluid / Q000276:immunology*; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis / Q000097:blood
chemical_list: D018925:Chemokines; D016207:Cytokines; D007378:Interleukins; D008263:Macrophage Migration-Inhibitory Factors; D014409:Tumor Necrosis Factor-alpha