title: Serum levels of IL-17A in patients with relapsing-remitting multiple sclerosis treated with interferon-β.
abstract: BACKGROUND
  Interleukin-17 (IL-17), which is secreted by Th17 cells, is a proinflammatory cytokine that is implicated in the pathogenesis of multiple sclerosis (MS) and plays a role in nonresponse of MS patients to interferon-β (IFN-β) therapy.
  
  
  OBJECTIVE
  The purpose of this study was to establish a correlation between nonresponders (NR) and IL-17A serum titers and binding antibodies (BAbs) to IFN-β, as well as to find a correlation between IL-17A serum levels and other features of MS patients.
  
  
  METHODS
  Our prospective study included 72 inactive relapsing-remitting multiple sclerosis (RRMS) patients that had been treated for at least 18 months with IFN-β and 15 healthy subjects. We determined the serum levels of IL-17A and of BAbs. IL-17A levels were considered elevated (IL-17A+) if the recorded value was greater than 1.6 pg/ml.
  
  
  RESULTS
  Twenty-seven patients (37.5%) were NR and had a significantly higher serum IL-17A level compared to the responders group. Nineteen patients (26.4%) were IL-17A+ and had had a significantly higher number of relapses in the previous year and a higher Expanded Disability Status Score. The majority of IL-17A+ patients were NR and had a shorter MS duration.
  
  
  CONCLUSIONS
  RRMS patients with high serum IL-17A levels do not respond well to IFN-β therapy and have shorter MS duration compared to patients with low IL-17A levels. This response is not influenced by the presence of BAbs.
authors.affiliation: First Neurological Clinic, University Emergency County Hospital, Târgu Mureş, România. iipascu@redatronic.ro
authors.forename: Rodica
authors.initials: R
authors.lastname: Bălaşa
authors.forename: Zoltan
authors.initials: Z
authors.lastname: Bajko
authors.forename: Adina
authors.initials: A
authors.lastname: Huţanu
mesh_terms: D000328:Adult; D004351:Drug Resistance; D005260:Female; D006801:Humans; D007155:Immunologic Factors / Q000627:therapeutic use*; D016899:Interferon-beta / Q000627:therapeutic use*; D020381:Interleukin-17 / Q000097:blood*; D008297:Male; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000097:blood* / Q000188:drug therapy
chemical_list: C508717:IL17A protein, human; D007155:Immunologic Factors; D020381:Interleukin-17; D016899:Interferon-beta