title: Frequency of Th17 CD4+ T cells in early rheumatoid arthritis: a marker of anti-CCP seropositivity.
abstract: OBJECTIVE
  To examine the frequency and phenotype of Th17 cells in the peripheral blood of early RA (eRA) patients.
  
  
  METHODS
  CD4+ T cells were isolated from the peripheral blood of 33 eRA patients, 20 established RA patients and 53 healthy controls (HC), and from the synovial fluid of 20 established RA patients (RASF), by ficoll-hypaque gradient and magnetical negative selection. After polyclonal stimulation, the frequency of Th17 and Th1 cells was determined by flow cytometry and concentrations of IL-17, IFN-γ, TNF-α and IL-10 were measured by ELISA in cell-free supernatants.
  
  
  RESULTS
  When all of our eRA patients were analyzed together, a significantly lower percentage of circulating Th17 cells and a lower CD4-derived IL-17 secretion were observed in comparison with HC. However, after stratifying by anti-CCP antibody status, circulating Th17 cells were decreased in anti-CCP(+) but not in anti-CCP(-)-eRA. All Th17 cells were CD45RO+CD45RA- and CCR6+. Dual Th17/Th1 cells were also exclusively decreased in anti-CCP(+)-eRA. Circulating Th17 and Th17/Th1 cells were negatively correlated with anti-CCP titres. When anti-CCP(+)-eRA patients were retested one year after initiating treatment with oral methotrexate, their circulating Th17 frequency was no longer different from HC. Of note, the percentage of circulating Th1 cells and the secretion of CD4-derived IFN-γ, TNF-α and IL-10 were not different between eRA patients and HC. In established RA patients, circulating Th17 and T17/Th1 cell frequencies were comparable to HC. In RASF, both Th17 and Th1 cells were increased when compared with blood of eRA patients, established RA patients and HC.
  
  
  CONCLUSIONS
  Decreased circulating Th17 levels in eRA seem to be a marker of anti-CCP seropositivity, and return to levels observed in healthy controls after treatment with methotrexate.
authors.affiliation: Department of Rheumatology, Hospital Universitario La Paz-IdiPaz, Madrid, Spain.
authors.forename: Irene
authors.initials: I
authors.lastname: Arroyo-Villa
authors.forename: María-Belén
authors.initials: MB
authors.lastname: Bautista-Caro
authors.forename: Alejandro
authors.initials: A
authors.lastname: Balsa
authors.forename: Pilar
authors.initials: P
authors.lastname: Aguado-Acín
authors.forename: Laura
authors.initials: L
authors.lastname: Nuño
authors.forename: María-Gema
authors.initials: MG
authors.lastname: Bonilla-Hernán
authors.forename: Amaya
authors.initials: A
authors.lastname: Puig-Kröger
authors.forename: Emilio
authors.initials: E
authors.lastname: Martín-Mola
authors.forename: María-Eugenia
authors.initials: ME
authors.lastname: Miranda-Carús
mesh_terms: D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000097:blood* / Q000276:immunology / Q000473:pathology; D001323:Autoantibodies / Q000097:blood* / Q000276:immunology; D015415:Biomarkers / Q000097:blood; D018791:CD4 Lymphocyte Count; D016207:Cytokines / Q000097:blood* / Q000276:immunology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D013582:Synovial Fluid / Q000276:immunology / Q000378:metabolism*; D018417:Th1 Cells / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D058504:Th17 Cells / Q000276:immunology / Q000378:metabolism* / Q000473:pathology
chemical_list: D001323:Autoantibodies; D015415:Biomarkers; D016207:Cytokines