title: Th1 and Th17 cell subpopulations are enriched in the peripheral blood of patients with systemic juvenile idiopathic arthritis.
abstract: OBJECTIVE
  The role of the adaptive immune system has not been explored in detail compared with the innate immune system in systemic JIA (sJIA) pathogenesis. The aim of this study was to examine the phenotype of circulating peripheral blood CD4(+) T-cell subpopulations in a cross-sectional study of sJIA patients during disease remission on medication and during acute flare of the disease.
  
  
  METHODS
  Flow cytometry was used to examine the phenotype and cytokine production of IFNγ-, IL-4- and IL-17-producing CD4(+) T cells in the peripheral blood of 10 sJIA patients with active disease, 9 sJIA with inactive disease, 14 JIA patients with oligoarticular onset, 10 adult control subjects and 10 age-matched control subjects. In parallel, we examined the proportion of FoxP3(+) Tregs.
  
  
  RESULTS
  IFNγ- and IL-17-producing CD4(+) T cells and IL-17-producing CD3(+)CD4(-) T cells were present at higher proportions in the peripheral blood of sJIA patients, irrespective of their disease status. Our data also confirm the known increase of the proportions of IFNγ-producing Th1 cells with increasing age and suggest an increase with age in the IL-17-producing CD4(+) T-cell population.
  
  
  CONCLUSIONS
  This study is the first to describe significantly higher proportions of Th1 and Th17 T helper cell subsets in the peripheral blood of sJIA patients. These proinflammatory cells may play a pathogenic role in sJIA. Our data also emphasize the importance of using paediatric age-matched control subjects when evaluating the T-cell cytokine profile in JIA.
authors: Department of Immunology and Molecular Pathology, University College London, 5 University Street, London WC1E 6JF, UK.
authors: Ebun
authors: E
authors: Omoyinmi
authors: Raja
authors: R
authors: Hamaoui
authors: Anne
authors: A
authors: Pesenacker
authors: Kiran
authors: K
authors: Nistala
authors: Halima
authors: H
authors: Moncrieffe
authors: Simona
authors: S
authors: Ursu
authors: Lucy R
authors: LR
authors: Wedderburn
authors: Patricia
authors: P
authors: Woo
mesh_terms: D000293:Adolescent; D001171:Arthritis, Juvenile / Q000097:blood / Q000276:immunology* / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D016207:Cytokines / Q000096:biosynthesis; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D016130:Immunophenotyping; D018655:Lymphocyte Count; D008297:Male; D018417:Th1 Cells / Q000276:immunology / Q000473:pathology*; D058504:Th17 Cells / Q000276:immunology / Q000473:pathology*
chemical_list: D016207:Cytokines