title: Effects of interferon β-1a and interferon β-1b monotherapies on selected serum cytokines and nitrite levels in patients with relapsing-remitting multiple sclerosis: a 3-year longitudinal study.
abstract: OBJECTIVE
  Interferon (IFN)β treatment is a mainstay of relapsing-remitting multiple sclerosis (RRMS) immunotherapy. Its efficacy is supposedly a consequence of impaired trafficking of inflammatory cells into the central nervous system and modification of the proinflammatory/antiinflammatory cytokine balance. However, the effects of long-term monotherapy using various IFNβ preparations on cytokine profiles and the relevance of these effects for the therapy outcome have not yet been elucidated.
  
  
  METHODS
  Changes were compared in serum levels of TNFα, IFNγ, interleukin (IL)-6, IL-10 and nitrite between RRMS patients given 3-year treatment with intramuscular IFNβ-1a (30 μg once a week) or subcutaneous IFNβ-1b (250 μg every other day). Only the data from patients who completed the 3-year study (n = 20 and n = 18, respectively) were analyzed.
  
  
  RESULTS
  Three-year IFNβ-1a or IFNβ-1b monotherapy reduced serum nitrite levels by 77 and 71%, respectively, lowered multiple sclerosis relapse annual rate by 70 and 71%, respectively, and significantly and similarly lowered Expanded Disability Status Scale scores in both study groups (by 0.9 on average). The two monotherapies showed little if any effect on cytokine levels and cytokine level ratios after the first year, but exerted diverging effects on these indices later on; the only exception was the IFNγ/IL-6 ratio that showed a monotonous rise in both study groups over the entire study period.
  
  
  CONCLUSIONS
  During long-term IFNβ monotherapy, the levels of the studied cytokines show no relevance to the course of RRMS and neurological status of patients, whereas there seems to be a link between these clinical indices and the activity of nitric oxide-mediated pathways.
authors.affiliation: Department of Neurology, Military Institute of Medicine, Warsaw, Poland.
authors.forename: Adam
authors.initials: A
authors.lastname: Stępień
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Chalimoniuk
authors.forename: Natalia
authors.initials: N
authors.lastname: Lubina-Dąbrowska
authors.forename: Stanisław J
authors.initials: SJ
authors.lastname: Chrapusta
authors.forename: Henrik
authors.initials: H
authors.lastname: Galbo
authors.forename: Józef
authors.initials: J
authors.lastname: Langfort
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D016207:Cytokines / Q000097:blood*; D005260:Female; D006801:Humans; D007273:Injections, Intramuscular; D007279:Injections, Subcutaneous; D000068556:Interferon beta-1a; D000068576:Interferon beta-1b; D016899:Interferon-beta / Q000008:administration & dosage*; D008137:Longitudinal Studies; D008297:Male; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000097:blood* / Q000188:drug therapy*; D009573:Nitrites / Q000097:blood*; D016896:Treatment Outcome
chemical_list: D015415:Biomarkers; D016207:Cytokines; D009573:Nitrites; D000068576:Interferon beta-1b; D016899:Interferon-beta; D000068556:Interferon beta-1a