title: Serum IFN neutralizing antibodies and neopterin levels in a cross-section of MS patients.
abstract: OBJECTIVE
  To determine levels of serum interferon beta (IFNbeta) neutralizing antibody (NAb) and neopterin-an IFN biologic response marker-in patients with MS treated with Betaseron or Avonex.
  
  
  BACKGROUND
  Controversy exists over the relative immunogenicity of IFNbeta-1a and IFNbeta-1b and the reasons for any such difference. To determine the role of patient profile and test methodology in IFNbeta, NAb levels need to be measured blindly and simultaneously in a predefined closely matched MS patient cohort.
  
  
  METHODS
  Serum NAb and neopterin levels were measured in closely matched patients on Avonex (n = 98) or Betaseron (n = 64). NAb were determined by Athena Diagnostics and serum neopterin levels by Covance Laboratories using a competitive binding radioimmunoassay.
  
  
  RESULTS
  More patients taking Betaseron (22%) than Avonex (7%) had elevated titers of NAb (p = 0.008). Mean serum neopterin levels were lower in patients with high as compared to low NAb titers (p = 0.0002). No difference in mean neopterin levels was found comparing the total Betaseron group to the Avonex group; however, in the subset of patients with low NAb titers, mean neopterin levels were higher in the Betaseron than in the Avonex group (p = 0.027). A random cross-sectional sampling of patients on Avonex showed a decrease in neopterin levels over time between weekly doses.
  
  
  CONCLUSIONS
  NAb are more commonly found with Betaseron than Avonex. More studies are needed to determine the correlation among serum neopterin levels, other biologic response markers, NAb, and disease activity in patients with MS being treated with IFNbeta.
authors.affiliation: New Jersey Medical School, University of Medicine and Dentistry of New Jersey, Newark 07107-3001, USA. cooksd@umdnj.edu
authors.forename: S D
authors.initials: SD
authors.lastname: Cook
authors.forename: J R
authors.initials: JR
authors.lastname: Quinless
authors.forename: A
authors.initials: A
authors.lastname: Jotkowitz
authors.forename: P
authors.initials: P
authors.lastname: Beaton
mesh_terms: D000328:Adult; D000906:Antibodies / Q000097:blood*; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D000068556:Interferon beta-1a; D000068576:Interferon beta-1b; D016899:Interferon-beta / Q000276:immunology* / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000188:drug therapy / Q000276:immunology*; D019798:Neopterin / Q000097:blood*; D009500:Neutralization Tests
chemical_list: D000906:Antibodies; D000068576:Interferon beta-1b; D019798:Neopterin; D016899:Interferon-beta; D000068556:Interferon beta-1a